Basically, you print too hot (and fast) without enough cooling. The deformed small pin in your image is a perfect example of depositing new layers onto too hot (not cooled down enough) prior layers.

You can easily solve this by printing two identical parts spaced apart from each other. This allows the layers to cool before the next is deposited.

From mastering Ultimaker Cura:

  When printing a series of small parts, print them all together. The
  travel time between the parts is often enough time for the layers to
  cool without changing your settings.

If you do want this to print as a single piece, you need to:

tune down hotend temperature (use the minimum temperature that gives good print results, printing a temperature tower will help to determine this),
increase minimal layer time (may not always work as speed will not be lowered under the minimum printing speed) and
increase part cooling fan percentage (or print a better fan duct that allows for more cooling air to reach the print; many fan ducts are too convergent, the pressure increase is then too big for the fan to effectively push air through it).


for sure the answer could be dissertation or even a book because there is no simple way to address "all" issues - it's just to wide area

but as the simple troubleshooting i would list it this way

is your printer alive so is it

working at all (check power, cables)
communicate with the world (check app, drivers, cables)
moving HE and heating HB (check jams, end-points, belts, screws)
is it extruding (check heating, temperature, HE jams, filament path)

if all above is "yes" then

is your printer making printouts and are those printouts

starts and continues (check heating HB, HB adhesion, leveling, cooling)
finished at all (check all above again, stepsticks temerature)
keeping the shape (check screws and nuts, couplings, stiffness, stability, temperatures)

if all above is "yes" then in general you are half way ;)

common issues - printout is

bent or skewed (check geometry, stiffnes, leveling, belts, vibrations, stepsticks temerature)
wrapped or overextruded (check temperature, extruding, printout angles)
underextruded (check filament flow, filament path, stepsticks temerature)
stringy (check temperatures, app settings)

that is the main path i think. all above is more or less applicable to all DIY printers and all prusa clones and all clones of clones ;)

it can go wrong and fork in all possible moments as there is so many aspects to screw...


Would a really short melt-zone be beneficial

There is a trade-off between the length of the melt zone and the speed at which you can print. The filament itself is somewhat of an insulator, so as the outside of the filament is heated up by being in contact with the melt zone, the inside stays cold. Therefore, the filament needs a certain amount of time inside the melt zone for the inside to fully melt. If you have a shorter melt zone, you need to print more slowly to give the filament enough time to melt. This is precisely the reason why the E3D volcano exists. It has a longer melt zone, so you can print more quickly.

You can partially compensate for a shorter melt zone by heating the nozzle up more, but there is an upper limit to how hot you can go (you don't want the outside of the filament to burn before the inside is melted).


Does color changing PLA require a hardened nozzle?

The color changing material used in the filament is most likely a Leuco dye.  There are several types and some can be abrasive (just like the glow in the dark dyes); but, they aren't like putting sand through your nozzle.  Since brass is really soft, even something like the dyes can cause it to wear; but, it will take a while.

The safest bet is to use a hardened nozzle; but, if you are just doing a small print then it probably won't be too hard on the brass nozzle either.  I have heard of people printing an entire spool of glow-in-the-dark PLA with a brass nozzle then examining the nozzle and not noticing any wear.

Also, some people like the better thermal characteristics of the brass over the steel; so, they just stick with the brass nozzle for everything and replace it when needed.


How can I get a 3D model from a bunch of 2D photos?

YES, it is possible to make a model from several shots, if you know the angle of rotation between the pictures.
most CAD programs allow to insert a picture, for example as backdrop or to trace it. We are interested in the later use:
We insert the picture, trace it in the picture's layer, then insert the next picture, rotated around the axis of rotation of the picture, and trace that. This we repeat again and again. The resulting cloud of outlines approximates the photographed body to a good degree.
There is a big caveat though: all photos must be in the same scale and distance, the rotation of the object has to be around one axis of the item itself (no wobble) and the rotation between the pictures has to be known quite exact. This principle is pretty much used by raster scanning by the way.
With a very hard contrast between the crystal and the backdrop, software might be able to automate the tracing process (for example use a white background and a black crystal and make sure no reflection hits the camera).
Example using Fusion360
Let's assume I have a perfect crystal like this octahedron with two cut tips

To model this, we need at least a photo of the XZ and YZ shape (that is, 90° rotation to each other), which look like this:

But that shape would also match a double-cone! So we'll need some intermediary photos, in this case, the 45° shot that lies on the plane of (XY-diagonal)Z Plane

As you see, the more outlines you have, the more detailed the pseudo-body becomes - it is just a gathering of vertices and lines yet though! But, we can take 3 points and create a construction area on these, then draw the face to merge all points on these faces...

Now, we turn these construction faces into modeling faces, then create a too large object and cut out the whole thing out...

The whole workflow looked like this for 4 pictures (0°, 45°, 90°, 135°)

The actual f3D design file is here.


How to specify rotation origin in openscad

rotate() always rotates around the origin of the object following it.
What you can do is to move your cylinder away from the origin, like this:

rotate(a=[90,0,0]) {
  translate([0,10,0]) cylinder(h=10,r1=10,r2=10);
}


Bigtreetech upload stalled after uncommented REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER

There is a temporary solution which I have found here, on the reprap forums, Re: Upload to the board failed after LCD enabled:

  An official fix has been posted. Grab the new ultralcd.cpp from [github.com]

Apparently the sources contained a bug which was fixed later, a new version download fixed the problem.


How can I become a certified Fusion 360 user?

Start with registering at their website and go from there.  There is a PDF of a list of things you have to have mastery in:

  SKETCHING

  Sketch Creation
  Create Dimensions
  Constraint selection and creation
  Edit a sketch
  Project Edges
  Edit a Sketch

  DRAWING

  Creating a Drawing View, Base, Projected, Section, Detail
  Add Annotations
  Editing a Created View
  Edit Border and Titleblock

  SCULPT

  Create a Form
  Edit a Form
  Thicken a Form

  DIRECT MODELING

  Feature Deletion
  Press & Pull Tool

  ASSEMBLY MODELING

  Create and Manage Top Level Assembly and Subassemblies
  Create a Component From a Body
  Align and Assembly Joints
  Interference
  Rigid Groups
  Motion Studies

  ADVANCED MODELING

  Sweep and Loft
  Boundary Fill
  Split and Combine bodies

  PART MODELING

  Create extrude features
  Apply Fillets and Chamfers
  Create complex hole features
  Create revolve features
  Create a pattern of features
  Create a shell feature
  Create Construction Planes and Axes
  Inspect command; measure, and section analysis


240°C, lots of cooling.

See Material Specification Print Sheet - Taulmann 618 Nylon.


You may need to secure the pneumatic coupling in the closed position with a small plastic clip (which should be supplied with the hot end).

You can print your own, providing that your printer will work for long enough (a paper clip might do the trick):

Thingiverse: Bowden Tube Clip v3

Addendum:

Some pneumatic couplers are sprung, so that you have to depress the coupling ring in order to release the tubing. In this case, no clip is usually required. Other pneumatic couplers (such as the one on an E3D V6) are unsprung. This makes it easier to secure and release the tube using the supplied clip. The disadvantage is that you may lose the clip. Sprung couplers sometimes lose their springiness, in which case a clip can be used to secure them in the closed position

It's "swings and roundabouts", really. You can to choose between the awkwardness of sprung couplers, or the risk of losing a clip. Either way, print some spare clips. You may need them one day.


Rather than stiffer springs, can I preserve my fine-tuned bed height using Nyloc nuts?

It's because the bed heats up. Since the bed can heat up to the point that locktite or nylon can soften, using those products to keep the screws from turning will have exactly the opposite effect.


What causes the print heat to 'catch' on the part?

I think that you should first verify that you have the latest firmware and a newer version of MakerWare. I experienced similar issues around that version of MakerWare and remember a lot of print errors came with it.

I believe the MakerBot Dual firmware is somewhere around 7.? and is no longer in development.

MakerWare is also no longer in development as a standalone application and seems to have been ported over to the MakerBot Desktop. However I've personally found v2.4.1 to be substantially more stable than v2.2.

I have not tested it, but supposedly the new MakerBot Desktop (v3.10) is compatible with the Replicator Dual "Original". I had tried an earlier version of MakerBot Desktop and reverted back to MakerWare 2.4 because I ran into issues with connectivity. However, I'm not certain it was an issue with software so much as the exploding voltage regulator...

It might be best to give the new software a shot and/or try v2.4 of MakerWare, if you can find it.

Here's the link to the latest MakerBot Desktop

Here's the release notes for MakerWare/MakerBot Desktop v1.0-latest (v3.10+)


The next logical step is to swap the working board with the one that powers the misbehaving motor. If this fixes the motor but makes the other one stop working, it hints that the stepper driver board might be broken. If it does not fix the motor but the right motor works again, while the left is not, then the motors or the board controlling the stepper drivers might be broken.

As changing the driver boards did (as OP said) swap the problem from the left to the right extruder, it is extremely likely that the board that was originally left is defective in some way.

Getting a replacement part might be in order, and until then, running with a single extruder.


Marlin menu navigation slow while printing

A Delta printer requires constant complex calculations to produce straight lines while printing.  The firmware, therefore, spends most of its time figuring out the step and timing sequence, and only the little remaining time between interrupts and these calculations is given to the user interface.

Marlin doesn't document any configuration parameters that would improve the user interface responsiveness, and in any case such improvement must necessarily come at the cost of printing speed and/or accuracy.  The processor is being used to its maximum capacity.  The only thing you might be able to do is dig into the firmware and try to change it yourself, as this is not a clear option within Marlin.

If working with the user interface while printing is important to you, your next step should probably be to change to a faster 32 bit processor. There are a few firmwares available for ARM and other architectures which may resolve your situation.


[The question ask asked is vague, but since you are new it is understandable.]

If you want to build a precision prototype then you have to decide on the level of precision that is necessary. There are different types of 3D printers and services available which give various levels of precision and functionality.

Fused Filament Fabrication/Fused Deposition Modeling - This is typically a means of producing functional prototypes using plastic filament. In terms of precision it is currently the lest precise, but the most cost effective.

Binder Jetting - This is basically crazy glue with food coloring which is inkjet printed onto a white powder layer by layer (vast oversimplification). Useful for producing prototypes with colours for product mockups but not for functional parts. This is mid the mid point in terms of price and precision.

Stereo Lithography / Photo polymerization  - Lasers cause a liquid resin to harden and stick to each other. Also notable for being the first form of 3D printing, this is the highest precision that is easily attainable. The cost varies based on the provider but it is usually the most expensive option.

Depending on your needs you may find that it is cheaper to develop a single prototype part (just one part not an entire machine) by sending out to a contract manufacturer as opposed to purchasing a 3D printer.

Here are some examples of what to do when:

If you want to develop a diamond engagement ring for a customer: Send out to a contract manufacturer, for Stereo Lithography
If you broke part of the cupboard and its easy to design a new one: Consider purchasing a sub $400 USD FFF machine and learn to use it.
If you are developing a new line of designer sneaker: Send out to a contract manufacturer for Binder Jetting.
If you are doing miniature figurines for a stop motion animation television series: Invest in a Binder Jet machine and learn how to use it.

In my experience, people don't buy a 3D printer until they have held a 3D printed part in their hand or have seen the machinery in person. If you are new, start with a contract manufacturer and when you start spending so much on them that it is equaling the cost of owning a machine, then invest in your own system.


How does this multiple-curve-beam flexural pivot work?

The picture looks as if there is a printed back surface to which the central part is attached.  This can not be the case, since otherwise the curved members would not be able to flex.  Everything inside the outer ring must be detached from the back shell.
Like all couplers, especially flexible couplers, there is a limit to the amount of torque the coupler can transmit.  Within the elastic limits of the material this looks like a good design, and a good match for 3D printing.  The forces are along the layers, not across the layers.
This looks like a good design for a rotary coupler.  I'm resisting calling it a "shaft" coupler since neither side is equipped with any connection to a shaft.  One could modify the design to have a larger central hub with a shaft hole (and set screw(s)).  As it is, there is an implied method to hold the outer ring, and a fairly explicit three-pin adapter to drop into the open slots in the arms which connect to the center.
I would use ABS rather than PLA, although it depends on the stiffness you require and ability to sustein abuse.  PLA is stiller than ABS, while ABS, within the elastic limits, is more compliant.  I am not confident that either of these plastics would stand up to thousands of millions of flexures.
I would prefer to print this of TPU or Nylon.  Both of these are tougher than ABS and PLA.  They withstand greater flex with fewer problems with micro cracks and degradation.  I have printed another shaft coupler of TPU, and it was both compliant and still.
It isn't possible to really nail down a material without knowing the application.
As to your question about one example being a transform of the other, I don't thing they are.  The A and B drawings are similar in function, but are not stressed and unstressed versions of the same part.  Either will work as a coupler.


The travel speed of 160 mm/s is a big red flag. PETG is not tolerant of a hot nozzle moving over it at high speeds, especially unretracted (combing). The nozzle will drag material in a stuttering pattern, every so often, marring the surface and pulling what it dug up into strings.

Lower the travel speed to the same as the print speed, and then experiment with whether you can increase it without problems. I would not try going over 80 mm/s and probably not even over 60.

For what it's worth, this sounds like softened/molten PETG is a non-newtonian fluid, where at low stress (slow moving nozzle pushing/pulling) it deforms gracefully, but at high stress (fast moving nozzle) it strongly resists deformation and has a discontinuous breaking point. A quick Googling turned up this article, Thermal, Rheological and Mechanical Properties of PETG/rPETG Blends, which might explain what's happening.


How to interpret Trinamic driver continuous debug reporting?

In the Marlin source code I found the function responsible for the report logs: report_polled_driver_data in Marlin/src/feature/tmc_util.cpp.

The values indicated appear to be:

<Axis>:<PWM scale>/<Current scale>/<StallGuard>|<Flags>|<OTPW count>

Where possible flags are as follows (where “debug” indicates that they only appear if TMC_DEBUG is enabled):

E: Error
O: Over-temperature
W: over-temperature pre-Warning
G: stallGuard (debug)
T: stealthChop (debug)
I: standstIll (debug)
F: otpw Flag


Why the Ender 5 Pro can't remember the axis position or cant move back to home anymore?

Once you pull the plug or disable power to the stepper motors, the printer forgets its location. That is perfectly normal and exactly how it is supposed to work.
The printer knows where the printer volume is once you have "homed" the printer. Homing is done prior to printing with G-code G28 which should be present in your start G-code script of your slicer. Once homed, the offsets from the endstops determine where the origin of the printer is and the maximum dimensions determine the build volume.
After you switched on the printer, the printer doesn't know where the origin is and movement is limited. E.g. when the following constant is defined: #define NO_MOTION_BEFORE_HOMING no movement at all is possible before the printer is homed, this can help prevent destroying the printer.


Having trouble getting first layer support to stick

There are many things you'll need to check and/or confirm to ensure that you will have a good bond to the bed. The first is to confirm that you are using a genuine Prusa printer as it appears in the photo. Having built one recently makes it easier for me to guess that is the case.

Have you performed the bed calibration sequence? The manual provides a series of steps which results in a zig-zag pattern of filament being placed on the bed, while the z-height is adjusted from the panel. You want to have a filament trace that is only slightly squished onto the bed, not flattened so much that it's cutting into the PEI and not so high that it's nearly cylindrical.

The bed must be of the correct temperature for the filament selected. If in doubt, raise it five to ten degrees C. I recently assisted with the aforementioned printer that had a peeling problem and the bed temperature had to be raised to 70°C from the "standard" 55°C generated by Slic3r.

It is critical that the bed be clean as well. Denatured alcohol is recommended, with application of a clean cloth.

Your photo is somewhat out of focus, making it difficult to determine if the brim is being created at an excessively high z-level, which will cause peeling. The main body of the print, also out of focus appears to be heavily flattened, but that could be an artifact of the photo.

The reflections on the bed appear to indicate that some gouges in the surface exist. If your PEI is damaged, you will have the problem you described. I've seen videos in which the bed is not quite as gouged and was refreshed with very light sandpaper or very light steel wool or both. Of course, after using such material, clean the surface thoroughly.

I understand the PEI that is applied by the manufacturer is quite thin and can be further damaged if too much pressure is applied while refreshing. It is far better to apply too little pressure if you plan to perform this task.

Consider to read through the manual and address all of the calibration aspects of the printer to establish a base point for the problem you are experiencing.


What is this weird support line doing in this print?

I do not know the Qidi slicer, but if you look closely, you will see this line is thinner than the normal support infill lines. You could try to visualize the G-code in a viewer, usually this can be done in the slicer itself, but online viewers are available. The viewer will not only show the printed lines, but also show moves by the print head (usually in a different color). You can check whether this extra line is actually printed or a move. If it is a move, this extra line is caused by your hotend which is leaking when it moves. You need to properly tune the hotend with respect to the retraction settings and temperature. There are numerous retraction test print objects to find on the internet.

Depending on your slicer settings, some slicers are able to define where each layer starts printing (e.g. random, or start at sharp corner). The fact you see a support structure "printed the full height of the object" tells you that each layer starts at the same position. It is not uncommon in uniform simple parts where each layer starts at the same position (X/Y) as this is instructed by the slicer setting. In Ultimaker Cura such an option is called Z Seam Alignment.

Bottom line, all slicers will do this when your printer is improperly tuned (incorrect settings for e.g. print temperature, retraction, coasting, travel speed). It is up to you to find the correct settings, test print objects help you with that.


As the rubber stamp needs to be soft in one axis for the whole area, you could use an infill that causes the same softness in all directions, but is sliced as such that the stamp experiences the same softness. Alternatively you can use the specific infill types for flexibility, but beware of the orientation:

Concentric
Cross
Cross 3D

First, to get the same softness in each direction you need to use an infill pattern that has similar/uniform properties (isotropic) in all dimensions.

It is suggested to look into the infill type called "gyroid" (see question What are the advantages of gyroid infill?).

This type of infill is described as:

  Gyroid infill is one of the strongest infill types for a given weight, has isotropic properties, and prints relatively fast with reduced material use and a fully connected part interior.

Second, since the stamp has relief, slicing the part may cause different infill height. You could look into Different infill in the same part to e.g. get a solid infill for under the relief to get a uniform infill for the "cushion".


Safely Hooking a Switch up to an OEM Power Supply?

At 250V a rating for 10A means 2500 Watts, which is fairly enough to use with a typical 3D printer. Make sure that the wire you use to connect the switch to the power supply can also take the current you need. Easiest way to get a cable that is safe to use is salvaging a mains cable from other devices. I would not use wires that were made for low power use and with unsolid connections.

*edit: I'm still not sure which cable you intended to use from this tower PC. If it is a mains cable like this
https://www.google.com/search?q=mains+power+cable&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjL6Y23l9zLAhUCrRoKHXvsArsQ_AUIBygB&biw=1421&bih=922
you should be on the safe side.


From the images you can see that the filament is not squished to the bed, e.g. the extruded skirt looks as if a round rod lies on the bed. The bottom picture shows that the skirt is even dragged (top left); this indicates that the initial bed to nozzle distance is too large. Please decrease the distance or look into your slicer if there is a height offset active.


If you enabled Z_SAFE_HOMING, then automatically the printer homes Z at the middle of the build plate, if the bed size dimensions are correctly defined (in your case X_BED_SIZE and X_BED_SIZE should be defined as 300).
In Configuration.h you can find:
#define Z_SAFE_HOMING

#if ENABLED(Z_SAFE_HOMING)
  #define Z_SAFE_HOMING_X_POINT ((X_BED_SIZE) / 2)    // X point for Z homing when homing all axes (G28).
  #define Z_SAFE_HOMING_Y_POINT ((Y_BED_SIZE) / 2)    // Y point for Z homing when homing all axes (G28).
#endif

If Z_SAFE_HOMING was enabled, and the bed properly dimensioned, it could be that the steps/mm are incorrectly defined.
Note that if a probe is used, the offset of the probe to the nozzle center is taken into account, this implies that the probe is moved to the center, not the nozzle. The code responsible for this is found in G28.cpp:
/**
 * Move the Z probe (or just the nozzle) to the safe homing point
 * (Z is already at the right height)
 */
destination.set(safe_homing_xy, current_position.z);

TERN_(HOMING_Z_WITH_PROBE, destination -= probe.offset_xy);

I.e. the ternary operation (TERN_) determines the addition of the probe offset.


SketchUp has a problem with generating the normals of an STL in the right way. As you see in the slicer, the model claims, that the "tops" are overhangs, which means that the whole model is "inside out" with the normals.
To fix that, you'd need to open the file in a program that can fix that by recalculating the normals. I suggest blender:

Open Blender
Delete the cube by clicking on it and pressing the delete button
Import the STL via Drag & Drop or the menu
Change to edit mode in the top left corner
A to select everything
Ctrl + N to recalculate normals
N then under Mesh Display > Normals hook Faces

Now, your model should look like a hedgehog, each face having a blue line poking out.
It also should show if there are any faces remaining, which can be selected and deleted manually by clicking it, so that only it is highlighted, and then pressing delete


Bottom Layer Compression (over extrusion) - Can't get rid of it

The first thing that comes to mind is that, even though you have levelled the bed, the print nozzle may be too close causing too much "squish" on the first layer. Squish isn't bad as it promotes adhesion, but in your case, as you are looking for finer tolerances on the holes, it may be a problem. I use a feeler gauge and aim for 0.15 mm gap when printing at 0.2 mm layer height.

Next thing to consider is ensuring you have calibrated your flow rate/extrusion multiplier. See here for detailed procedure

Assuming flow rate is calibrated I can think of some settings in Cura that could affect your print.

Initial Layer Flow
Flow Rate Compensation Factor
Combing Mode / Avoid Printed Parts

Initial Layer Flow enable the use of a higher/lower flow rate in you first layer. Typically I set this to a value larger that my flow rate, 120 %, as I want good adhesion and am less worried about the elephant's foot effect. However, you could reduce it to less than your flow rate although that may compromise adhesion unless you use a brim.

Flow Rate Compensation Factor For most circumstances this should be 100 % which indicates that your flow rate should be used as set and not compensated for. I would check that this value has not been altered cause over-extrusion.

Lastly, there are two travel settings. Combing Mode and Avoid Printed Parts work in combination to reducing the impact of travels in the finished print. I would ensure you have combing turned on (e.g. Not in Skin) and that you have enabled Avoid Printed Parts. More details on these settings can be found here


From the Benchys, it is apparent that the temperature is quite high or that there is not enough part cooling flow. This can be seen from the sagging of unsupported overhanging structures. Considering the bow of the Benchy is quite fine, the most probable cause is the temperature, usually with too less part cooling flow, the bow shows defects.
Please note that a Benchy is a gimmick that does show defects, but it isn't a calibration object, there are many other different test prints available.


CR-6 SE glass build plate - no lifting possible

I have had similar issues, and I have learned three tricks:

Some slicers (i.e. Cura) let you specify the height of your first layer, and I have found that slowly incrementing up from 0.16 mm by 0.2 mm to find the sweet spot of adhesion without warping. Every brand/type is different. But, usually, for me, fall between 0.18-0.22 mm.

Blue painters tape. If you don't need the glass flat finish of printing directly to glass, I always use blue tape. It makes for great adhesion, and also easy removal of super stuck prints, and you can just peel it off the build plate. With blue tape, I tend to add 2-3 °C to the bed temp.

Glue sticks (instead of hairspray). But, Elmer's glue sticks that go on purple and dry clear. When you use these, if a print is stuck, you just need to spritz some water around the print. The print and the glue will wick the water under the print, and reconstitute the glue. Once the glue is tacky again, the print will pop right off. The only downside is a slight texture to the print and not glossy glass flat.

The reason I like the colored glue, as it reconstitutes it activates the cobalt chloride and turns purple again. This is great for knowing when it is good to start printing again. And also tends to become less of a sticky mess than hairspray.


In the configuration.h file of Marlin 2.0.x you can define which stepper driver type is used to drive the stepper in the Stepper Drivers section.

You can choose to use the following constants from the array to configure the correct driver:

['A4988', 'A5984', 'DRV8825', 'LV8729', 'L6470', 'TB6560', 'TB6600', 'TMC2100', 'TMC2130', 'TMC2130_STANDALONE', 'TMC2208', 'TMC2208_STANDALONE', 'TMC26X', 'TMC26X_STANDALONE', 'TMC2660', 'TMC2660_STANDALONE', 'TMC5130', 'TMC5130_STANDALONE']

And update the section that links the steppers to the stepper driver by updating the following section of the configuration.h file.

//#define X_DRIVER_TYPE  A4988
//#define Y_DRIVER_TYPE  A4988
//#define Z_DRIVER_TYPE  A4988
//...
//#define E0_DRIVER_TYPE A4988
//...

by removing the // in front of the driver specification and update the constant of the correct stepper driver:

#define X_DRIVER_TYPE  DRV8825
#define Y_DRIVER_TYPE  DRV8825
#define Z_DRIVER_TYPE  DRV8825
//...
#define E0_DRIVER_TYPE DRV8825
//...

This results in the use of specific timings for the specific drivers. To be honest I have never set these constants when I used DRV8825 stepper drivers on my RUMBA board and my motors are operating smooth without these settings.

What you do need to look out for is when you replace stepper drivers is whether the micro stepping jumper settings on the board are correct for your stepper driver! I needed to set the jumper switches in a certain position to enable the 1/32 micro stepping functionality for the DRV8825 drivers. Knowing that the maximum micro step for the A4988 is 1/16, you also need to look out for the steps/mm; with more micro steps, you need twice as many steps per mm when you go from 1/16 to 1/32; e.g.:

#define DEFAULT_AXIS_STEPS_PER_UNIT   { 80, 80, 4000, 500 }

would need to be changed to:

#define DEFAULT_AXIS_STEPS_PER_UNIT   { 160, 160, 8000, 1000 }

Also, did you tune the new stepper drivers correctly? When you receive the stepper drivers, they are usually not tuned and the position of the potentiometer on the driver board is undefined! You need to calculate the correct $ V_{ref} $ for your stepper driver in use for the specific stepper you have (max current that the stepper can handle). For DRV8825 stepper drivers, the maximum current is defined as:

$$ A_{max} = V_{ref} \times 2 $$

For example, if you have a stepper motor rated for 1.4 A, you limit the current to 1.4 A by setting the reference voltage ($ V_{ref} $) to 0.7 V. More details are found here.


How to accurately print a thin piece with a hole pattern

Use the smallest nozzle possible to get better rounded edges on holes.
Slow down the print speed to increase accuracy and prevent errors.
Print it face down against the bed if possible to reduce support requirements for overhangs and increase hole quality.
Clean the bed well, increase bed temperature, stick glue, enable brim, or add 'mouse ears' to prevent warping.
Make sure the bed is levelled properly to prevent warping and increase finish surface quality.
Use a 'stringing tester' to find the best temperature to print at so that you can prevent stringing between holes.
Enable z-hop retraction to prevent stringing and errors.
You can bore through the holes with a drill to clean them flush.


Can a model change size when using a different filament type?

No, choosing a different filament type will not result in a different size (unless you use PLA that foams on extrusion, it increases size but then again all other dimensions would not fit either as it expands uniformly). The overall dimensions are defined by the coordinates in the G-code file which is based on the geometry of the model. If the printed model has dimensions that differ in the region of centimeters (like shown in your images) a different filament type will not change the size. Differences in the order of fractions of a millimeter are possible.

Probably the size has accidentally changed while loading the model in one of the tools prior to slicing to G-code.

Sidenote; there are techniques to anneal PLA after printing, you will then observe changes in the size of the part you printed, but I don't think you have annealed the print. From the link above:

  On average, you’ll see PLA shrinkage of about 5% and growth of about 2% along the relevant axes. If this shrinkage and growth is going to be a problem, you can compensate for it beforehand during the design and printing processes.


My Monoprice Select Mini v2 isn't pushing out filament and it isn't the nozzle

The push to release connection on the top of the heat sink may be secured with thread lock adhesive, but you should not have to remove it. Push the blue ring downward while pulling upward on the bowden tubing. It may be necessary to work it up and down while you push down on the blue locking fitting. I have to use a pair of pliers to hold the blue ring down while wiggling the bowden tube up and down, as it is rather tiny.
Once you have the tubing removed, check for high friction in the now-released bowden tube. Push filament from the extruder drive mechanism and observe how easily it passes through the tube to the open end. If you do not experience clogging, the problem resides in the heat sink/heat break/heater block area.
It's not uncommon for the nozzle to have an excessive gap between the heat break and the nozzle. This will allow for cooled filament to jam, preventing normal feeding.
From the Prusa support site:

Notice that the collet is visible in the photo and appears to hold a longer section of PTFE tubing. It should enter your heat sink until it bottoms against the recess cut into the metal. If it does not, you have the possibility (slim) of jamming in that locations.
Notice also that the nozzle is not flush against the heater block. The heatbreak is threaded into the block with the nozzle slightly lower than flush. This ensures a proper flow from the entry point to the nozzle. If it is not properly secured at either end, the heat break can bulge with filament that cools and creates the jam.


Scaling objects with constant wall thickness for 3D printing

Your question falls into two different categories, here at 3D Printing SE and there, at Blender SE.

I would consider that your objective would best be solved using some form of parametric modeling, an aspect that is rarely embraced by Blender. Even though the limitations of Blender make life interesting for you, there may be a couple of useful features within (and without) the program.

On Blender SE, a question of similar format exists, with a somewhat open-ended answer. A quick search using The Google, with the terms "Parametric Modeling with Blender" results in a number of different approaches. According to a quick perusal of the search results, some of the solutions involve free plug-ins or add-ons for Blender. More complexity rather than less, perhaps.

I'm familiar enough with the very simple basics of Blender to know I would not be able to make use of those answers. I'm also well aware that Blender's power extends beyond my own limitations with features supporting scripting, animation and so many other tools. Seeing the workflow diagrams/charts that make up some of the advanced portion of the program leads me to believe that one can accomplish your objective, but one must be a certified wizard with the program.

As an alternative, one could engage any one of the many parametric modeling programs available. I'm a fan of OpenSCAD, although the text/scripting interface can be daunting for some. If you've become skilled in Blender, a non-GUI format isn't necessarily the best route, although the GUI options are no less confusing, in my opinion.


From the comments/answers to your main question, the likely culprit is the hobbed wheel not catching the filament firmly enough.

The hobbed wheel I am referring to is the yellowish one at the centre of the picture.  The problem could be due to:

the wheel being of poor quality, with blunt teeth
the wheel being of the wrong diameter (too small)
the spring squeezing the wheel against the filament being too weak
[judging from the picture, I don't own the A8] it could even be that the nut on the lever that is pushed by the spring (top right of the picture) is too far down on the threaded rod, and prevents the lever to move far enough to push effectively.


It appears (now confirmed in your question) that you are using a Chimera 2-in-2-out hotend like depicted below:

Chimera hotends generally use all-metal heat breaks (not confirmed yet) which are harder to operate than "normal" PTFE lined hotends. A common problem that happens is that heat creeps up causing problems as a result of too slow printing or too high retraction length settings. Basically your problem is clogging related to all-metal heat break printing. This is recently asked in this question: "Apparently systematic nozzle clogging". Please read the answers to that question as they describe very well what happens and what to do.

Quoting from this article explains that it is a heating/cooling issue:

  Jams and clogs are often from a combination of excessive heat and
  non-optimal material flow.  This effect is worsened by poorly cooled
  all-metal hot ends, high torque extruder gears, small nozzles/layers,
  slow printing speeds, too thin first layer, and excessive retraction.

Please do read this article and the solutions they mention to get yourself acquainted with the problem and its solutions.

In your case this could well be a cooling issue in combination with a too high print temperature and a possibly too high retraction length setting (depends on the length of the Bowden tube). The fan you mounted in the front (onto the cooling ribs, so the rightt fan in your image) is too large for this hotend. You attached the fan to the left top mounting hole so that it exceeds the right and bottom area of your cooling ribs. Furthermore, this larger fan has a larger center (hub) to house the bigger engine so that you end up with a lower cooling flow for at least the right extruder as most of the cooling ribs area is blocked by the fan hub. Please fit a fan that fits this hotend. Printing a fan adaptors may not work as well, these fans have a very low static pressure difference, so a convergent duct may not work as well as you might think. Considering your temperature you are printing PLA; PLA could usually be printed well in the 185 - 195 °C temperature range (depending on the PLA), 210 °C seems a bit on the high side.

Another solution could be replacing the heat breaks for lined heat breaks:

As an aside, to explain a suggestion, in Himanshu's comment to coat your filament with some oils:

  Apply some oil on PLA filament with cotton.

Oil does lower friction in an all-metal hotend, but please beware that this needs to be vegetable oil. The reasoning behind this is that the oil hardens inside the throat to create a smooth coating on the inside, not lube the inside of the throat. This thread has some interesting material on that.

However, general consensus is not to do that:

  Micro-Swiss use slippery platings and such, they don't need it. I've
  also used B3 Picos and E3D v5, v6, Volcano and Chimera and even that
  one garbage QUBD mk7 knockoff. Never needed oil.

or

  Seasoning hotends is a myth that refuses to die. Just don't do it, it
  does more harm than good.


Ender 3 first print some area is smooth but some is rough?

It is most likely caused by inadequate part-cooling due to poor air-flow. Fit a [better] part cooling fan. There are plenty of designs on Thingiverse.

You may also be able to resolve the issue by adjusting the printing temperature, but the easiest solution is to install a good part-cooling fan.


First of all, make sure that you have correctly identified the X and Y axes, and that the stepper motors (and end-stop switches) are connected to the correct ports. The hot end moves on the X-axis, and the bed moves on the Y-axis. If you connect the X and Y motors the wrong way round, you will get reversed text.
If the X and Y motors are connected to the correct ports, you may need to invert the motor directions in firmware. There are #define statements to allow you to do this.


What is the purpose behind a glass nozzle?

Ceramic I can understand - very strong, great thermal range capability.  Glass not so much - you'd need some seriously careful annealing at least.
 In either case the material is much harder than brass, or even steel, so you could presumably use tougher tools to unclog, etc. as needed.  If you're using materials loaded with wood or metallic particles, the glass/ceramic tip will be less likely to degrade than brass.

BTW, glass being a thermal insulator means it may take longer to heat up, but the energy required is probably less . The specific heat of glass is on the order of .84 J/gm-K . Compare with brass at  0.38 , but keep in mind the rate at which brass will shed heat into the air vs. glass.  In either case the energy is tiny compared with the thermal mass of the hotend assembly.


Why do some models appear broken in slicing software?

My understanding is that this occurs when the object is not a true solid. Since an STL holds the triangulation of each face and spline, the slicing engine is not "smart" enough to determine if there is a gap in the model and therefore if it should be filled in and how. When the slicer encounters a gap, it will either treat the endpoint as the end of the feature or navigate to the next point on the layer, resulting in either gaps in the print or extra inclusions that don't make sense.
I've noticed that my models will fail as a true solid when I use complex solid tools such as Union, Subtract, and Trim. A lot of times there will be a rounding error in how these tools interact with the solid model that will result in a small (sometimes not very small) gap in the outer shell of the solid model. When exported to an STL, the gap is retained.
@kareem mentioned it in their answer, but Microsoft does provide online tool(s) for 3D Printing including a solid repair tool. Use Microsoft 3D Tools to upload your STL and try to automatically detect and fix issues with your file(s).


My print is warping: how can I ensure that it cools evenly?

Without more information we cannot address what is causing your edges to turn up. This can depend on the model being printed, the process, the material, the bed, and the method used to bond it to the bed.

As far as the initial question, a fan will most certainly ensure uneven cooling.

The middle of the print is, and will remain, the warmest.  If you want the print to cool evenly, you'll need an enclosure to block out drafts and air currents, and you'll need to bring the heated bed temperature and enclosure temperature down slowly over a long period of time.


Generally, a timing belt is a complicated device and many things depend on its internal construction and materials (it may be damaged when bound in wrong direction, or when cut, and when overtighten of course, etc.). There is also physics and math applicable, based on Mersenne's laws.
Some vendors provide calculators (online or as phone apps), which can calculate tension (force in Newtons or lbs) or the frequency (Hz). Therefore often the advice is to tension the belt until some (bass) sound is present - and professionals would tune belts with a sound tuner. There are also hints that belts should be possible to connect with fingers with slight or significant pressure (so not consistent). There is also visual guideline: when you slowly move the carriage with hand, the belt should remain straight. (Slowly, because belt is elastic and may behave different when moving carriage stronger and faster against friction of pulley.)
I would suggest to read this article on 3dprintingspot.com for many practical suggestions.


Major factors affecting extrusion:

Nozzle diameter
Extrusion ratio
Extrusion stepper calibration
Filament actual diameter
Extrusion width setting
Nozzle temperature

According to the photos, temperature is acceptable (may be a bit high, but it is not a problem in this case). Extrusion ratio is 1 and should not be changed in normal operation. Extrusion width is often set to auto but sometimes calibrating it gives better results in slic3r. If stepper is calibrated properly, then I would check for nozzle and filament diameters. For nozzle it should be enough to verify that 0.4 bit fits in and 0.5 doesn't. Filament can be measured by digital caliper. Difference between 1.75 and 1.73mm may have significant difference resulting in under-extrusion.


Calculating the estimated print time of an already sliced file

First of all, there are some nice open source analyzers written in JavaScript that you can use online, or read the source to, at https://www.gcodeanalyser.com/ and http://gcode.ws/. Their predictions don't fully match actual printer firmware, but they do a reasonably close job, and reading them would be informative.

Basically, the story behind acceleration and jerk is that you can't change the velocity (speed or direction) of the print head instantaneously. It takes time to speed up and slow down. Acceleration is the max rate at which the velocity of the print head can change. Jerk is something of a misnomer/hack, and is the max fake-instantaneous change in velocity allowed at the junction of two segments/curves. The point of jerk is to avoid choppy motion when moving along a curve made up of many segments by accelerating/decelerating at each tiny corner. Note that there are two sets of settings for both acceleration and jerk:

a maximum absolute value (3D vector length) that frequently changed as part of the gcode in order to use different acceleration profiles for print moves vs travel moves, walls vs infill, etc.
per-axis absolute values (standard 1D absolute value) for the limitations of the machine, that are usually set in the printer's settings or the start gcode profile for your printer and never changed.

Movement is constrained to always respect both sets of settings.

Printer firmware uses acceleration and jerk settings along with lookahead at upcoming motion commands to decide how to actually operate the motors. When it starts a motion, it has to accelerate up to the configured max velocity within the acceleration constraints. It also has to start slowing back down midway through unless it knows the next motion is going to continue in the exact same direction; how much it has to slow down depends on the difference in the vectors of motion. If the next motion is going to be in approximately the same direction, it may be able to avoid slowing down by using the jerk allowance to make an "instantaneous" change of velocity at the corner. Only if you have long (relative to speed) linear or approximately linear motions will you ever actually reach the requested speed.

So, to estimate print time, you need to model this. Keep track of print head velocity while processing/simulating the gcode, and for each motion command, compute velocity as a function of time using the acceleration limits (accelerating at the max rate they allow). You also need to figure out the final velocity you want to end the motion with in order to be able to start the next motion command, and a point to start decelerating if necessary to reach that.


How to clean up my build plate for a new build surface?

In my experience, we deal with 3M™ Adhesive Transfer Tape 468MP; high-temperature glue residue. To remove the leftover glue from my Aluminium build plate I found that it works best if I apply paint thinner.

I ran out of acetone for one refurbishment so I tried thinner and white (cleaning) spirit; the latter option did not work well. However, thinner worked very well. I got a bottle of "thinner" at the hardware store's house brand and found it to be more aggressive stuff than turpentine or acetone. I had tried those latter 2 but found that "thinner" works best.

Putting the thinner fluid on paper cloth directly to clean the glue did not work well. I applied the thinner directly onto the glue (splash it on), waited for a while to let it soak in to weaken the bonds after which you can remove it with a spatula and kitchen paper towel.

The exact contents of paint thinners are not always available but they contain various hydrocarbons.


How to log each G-code line read from the SD card to serial on marlin firmware

If you have the hardware at hand, you can use OctoPrint to collect the data you require. It's common for users to create an OctoPrint server on a Raspberry Pi, but it can be installed easily on a Windows or Linux machine as well. Once in place, logging is available for various types of information.
From the OctoPrint blog:
The logs are crucial instruments of analysis and debugging, so it's usually in your best interest to provide them when asking for help or reporting a bug, even if not explicitly prompted for them:

octoprint.log: OctoPrint's main application log file. Contains a
general log of everything that happens while OctoPrint is running.
Includes version information, installed plugins and a myriad of more
data points.
This must always be included when reporting a bug 47 to allow for
further analysis and reproduction. It is also a very good idea to
provide this when asking for help :wink:
serial.log: A log of all of the communication going on between
OctoPrint and your printer. Usually disabled for performance reasons,
enable it through Settings > Serial Connection.
Either that or at the very least the output in OctoPrint's Terminal
tab is crucial for analysis of any kind of communication issues or
misbehaviours observed with your printer, so it's important to include
it when discussing such issues.
plugin_pluginmanager_console.log: A log of the command line activity
of the plugin manager. Very important for analysis of such questions
like "Why can't I install plugin $xyz?", so if you have such a
problem, best include this.
plugin_softwareupdate_console.log: A log of the command line activity
of the software updater. Very important for analysis of such questions
like "Updating OctoPrint always fails, why?", so if you have such a
problem, best include this.

Third party plugins might also have special log files here. If a plugin author asks you to provide a special log created by their plugin for further analysis, this should be where you can find it.
The above selection is from the linked site, which also includes embedded links for more information regarding the log files. Note that serial.log is specifically referenced to collect data between OctoPrint and your printer, although it defaults to disabled on install.


How many times can you re-flash the Marlin firmware to a RAMPS 1.4 board before it degrades the ROM?

The EEPROM is not where the program itself is stored, what's relevant for your question is the flash. The flash in the ATmega2560 is rated for 10,000 cycles (i.e. you can reprogram it at least 10,000 times).


Solidworks: Coincident or interfering geometry when saving assembly to STL

Solidworks has means for detection and eradication of these errors. If there's unwanted intersection, then you can either separate the parts or merge them (by saving assembly as a part). If you work with SLDPRTs, then use mating options correctly, avoid manual mating, make sure that the design of your components actually allows them to mate without intersections and you'll have no problems. If you work with parts that are loaded from STLs though, then you'll probably have a lot of these errors when trying to align parts. Solidworks can't work smoothly with STL models, alas, you'll need some other tool, MeshLab or something.


Flashing a bootloader on Ender 3 without Arduino

What you need to is called a ICSP or ISP: in-circuit serial programmer or in-system programmer, which excludes the USB to TTL device you own.

I've never used an ESP8266 as ICSP but it seems there are some resources out there reporting it is possible.
If you want to go the easiest way probably you want to buy an Arduino and follow the tons of tutorials out there, if you are looking to save some money then you might get around buying an ICSP like the very well known USBASP (just Google for that).


How do I set up a 2 in 1 out extruder system in Marlin

You need to change the amount of extruders in the Configuration.h:
Set 2 extruders by defining:
// @section extruder

// This defines the number of extruders
// :[0, 1, 2, 3, 4, 5, 6, 7, 8]
#define EXTRUDERS 2

Define that you have a single nozzle:
// For Cyclops or any "multi-extruder" that shares a single nozzle.
#define SINGLENOZZLE

If you want to switch filament during a print, you need to write tool loading and unloading (tool changing) scripts for the slicer you use, also do print a filament prime/wipe tower that is large enough to purge the filament to prevent color mixing.
In case color mixing, you do not set the amount of extruders, instead you need to define that mixing is being used:
#define MIXING_EXTRUDER

furthermore, the amount of mixing stepper need to be defined:
#define MIXING_STEPPERS 2


I've not seen trapezoid lead screws with 5 mm lead, you can get 5 mm lead ball screws though.

On one printer I use 4 mm lead screws to get native 0.02 mm resolution (so 5 full steps for 0.1 mm, 10 for 0.2 mm, etc.). I also geared down 8 mm lead screws with a 2:1 ratio (e.g. to use a single Z-stepper driving a belt that drives 2 lead screws), works fine.


My first attempt at pausing a print and changing filaments resumed from the wrong position -- how do I troubleshoot?

You are out of luck:

Print gcode is written in relative coordinates. If you move the printhead manually, the printer does not know this, and will just follow its relative path from the new position - which is what commonly is called layer-shifting.

To try to mitigate this, there are ways, but they are a little tricky:

If your printer has a change filament option, then choose that - this saves the absolute position of the printhead before moving it to X0Y0, then usually extracts the filament and waits for the new filament to be inserted and the printer waits till given a resume-OK. Then it will move to the saves absolute position, and resume the code from the point it paused.
If your printer has a pause option that moves the printhead to X0Y0, this can be used, using a manual extraction. Resuming the print will be easy.
Some slicers support to call "Change filament at layer X", which will call a move to X0Y0 and pause, allowing manual change even if the normal pause behavior is not to move to X0Y0.

As you see: NO manual commands are given here! You can not move the printhead up/down/sideways without having a good chance of inducing a layer shift.

The Pause behavior can be adjusted in the firmware.


What happened around 2012~2013 in 3D printing field

A great story on the history of 3D printing is published by 3DSOURCED. It shows that the patents for FDM and SLA expired a few years earlier and the RepRap 3D printer self replicating project became very popular. Also, 3D printer manufacturers emerged and electronics, software and parts became available at a larger scale, so that it was more affordable for a hobbyist to dive in.


PLA Filament Not Softening During Load w/ FlashForge Creator Pro

After all of this trial and error it was a simple solution.

I did not snip off the end of the filament after unloading. The filament had been tapered after unloading because of the way it was extruded previously. I don't know exactly why (please feel free to add to this answer) but when I made a clean cut on the end of the filament and then fed it through, it extruded with no problem.


Why does slic3r get an error "302 moved temporarily" when uploading to OctoPrint?

Specific answer: use "octopi.local" rather than "octopi", since that will properly resolve to the correct Octopi IP Address.

More generally, investigating the network traffic on my network (AT&T Fiber Home) revealed these facts regarding the octopi server:

With a browser, the octopi can be accessed via either "octopi:80" or "octopi.local:80".
However, "octopi" actually talks to the network router, which sends a "302" message with the target name "octopi.local".
So, for the browser it seems either name is correct, but in actuality only "octopi.local" is the correct network name for the octopi system.

And these facts regarding the slic3r configuration:

slic3r does not process "302" messages, instead treating them as errors.  This is OK, since a properly configured network won't be generating these.
the slic3r connection test is incomplete.  It reports success because it receives an HTTP response, even though the response is a 302 rather than the version information that it is requesting.

So in this particular case, entering "octopi.local" instead of "octopi" corrected the error.  If you receive a 302 error, you will need to research and verify the exact IP address or host name for the target Octopi system.

A future version of slic3r should probably report an error on the "test" button if it doesn't (a) get a proper 200 return code and (b) return the proper version information as slic3r is requesting.


How to wire P.I.N.D.A. v2 to an SKR V1.3 board?

TL;DR
To answer your question how (by assuming you have a 4 pins PINDA v2 sensor) to connect the sensor to your board, you have 2 options:

Do not connect the white wire and treat the sensor as you would use a normal endstop switch (blue is ground, brown is +5 V, black is signal),
Connect the 4 wires (use a splitter cable to split out into a 3 and 1 pin connector, see image below), use the additional pin to read the thermistor value through a free analogue pin, this requires you to do a lot of code changes if you are using a different firmware than the original Prusa firmware.

The PINDA v2 auto bed leveling sensor has an additional wire, usually these bed leveling sensors only have 3 wires (power, ground and signal). The PINDA v2 probe has an additional wire that is connected to a thermistor. This thermistor reading is used by Prusa to compensate the trigger distance with temperature variation.

Wiring the fourth pin would require to reverse engineer the logic behind the temperature compensation if you aren't using the firmware of Prusa (e.g. when you are using Marlin firmware; this is not very simple!). Do note this is something engineered by Prusa printing engineers and implemented in their custom fork of Marlin firmware.
E.g. the compensation is calculated in Marlin_main.cpp by function temp_compensation_pinda_thermistor_offset. This function is called to return the offset based on the read temperature (actual calculation is done in temp_comp_interpolation(temperature_pinda)):

#ifdef PINDA_THERMISTOR
            offset_z = temp_compensation_pinda_thermistor_offset(current_temperature_pinda);
#endif //PINDA_THERMISTOR

It is perfectly fine to not connect the white wire, this is the signal needed to read out the thermistor value used for the temperature compensation. This will disable the compensation feature and will revert the sensor to a normal inductive sensor.


Bed temperature command going to 0 °C with no obvious reason when print is started

I tried, by instrumenting code, to know where/when the temp bed is modified.

I found that it is called in the gcode M81 when starting the print.

Wait M81? isn't it M80 to switch on the PSU?

What I did in fact was both wiring this up side down and mixing M80 with M81.

But what I didn't know is that M80 and M81 are not strictly opposite functions.

Indeed, M81 puts the PS_ON signal to PS_ASLEEP != PS_AWAKE but also disable all heaters.
I couldn't see it without serial trace because the extruder temp is set back after the M81, but not the bed temp.

Problem solved.

Hope this can help people in the future to spend less time than me on that simple mistake.

Note: What remains a mystery, though, is: why was it working before on previous prints and then, suddenly, broke?!!


Is it better use Nylon fillement for cold pull even if I have been using PLA?

Nylon holds better when pulled, PLA may snap.
Also it can grab particles around it, but it keeps low friction so the force you use to pull goes to detaching the dirt instead of rubbing against the walls.
By getting solid and by maintaining strength at higher temperatures, you can pull when it's hotter (with PLA you should pull at what? 40 °C?) and by being hotter can grab particles and remains of other filaments which are potentially softer. It's pulled at around 140-150 °C so that ABS and PLA at that temperature are very sticky and soft.
By holding easily higher temperatures (250-260 °C easily) you can also extrude it and it will melt any other filament in the nozzle.
Try doing some cold pulls with a light colour PLA to be able to see what it grabs. After a couple of pulls it should be clean. Then do nylon and check how much more stuff it will remove. If it's nothing, no need of using nylon. If it's dirty, it's the proof it can clean everything better than PLA.
A sample of nylon (50 g usually) will be sufficient for a long time so no need to get a full spool.


Try printing with the heated printbed off. Heat makes the pla stick more to buildtak


EvilTeach's answer is correct, ABS is a more reliable plastic for any kind of work which may get above what feels "hot to the touch."

Just to elaborate on the why: the property you're looking for in the thermoplastic (which will determine the continuous operating temperature) is glass transition temperature. This is the point at which the plastic begins to flow, and becomes deformable as EvilTeach described. PLA reaches this state at around 60 °C, whereas ABS is around 105 °C, just suiting your specifications. To go a bit further, polycarbonate offers a glass transition temperature of around 150 °C, and Ultem at 217 °C. So there's a thermoplastic for everyone, you just need to know what you're looking for!


It is not too rare to create a new machine in Ultimaker Cura to be set to 2.85 mm as this is the default. Also some bugs in the past did reset or assume this diameter unless you manually set it, and unless we know your exact version we can't confirm it is really this.
Underextrusion why?
The 0.55 mm more radius result in an underextrusion due to the pressed through volume, and since $V=A\times l$, we need to see the area to see how severe the underextrusion is for one given extruded length. $A_{1.75}=2.405\text{ mm²}$ and $A_{2.85}=6.379\text{ mm²}$ are rather obvious, so $\frac {\text{real extrusion diameter}} {\text{calculated extrusion diameter}}=\frac{A_{1.75}}{A_{2.85}}=37.7\ \%$, so only about 40 % of the needed filament is pressed through the nozzle as the slicer thinks it is almost twice the diameter. This matches well with the 130% still being very spotty, as that'd need a much higher factor to compensate for the underextrusion. A compensating extrusion multiplier would be $\frac 1 {0.377}=265.25\ \%$.
Fixing
To fix this, check under filament and set it to 1.75 mm so you force the correct diameter. Remember that filament diameter is not saved in the printer profile but in the material database.
You might need to restart Ultimaker Cura to activate these new settings.


If the equipment has to be removable, then there's no point in trying to make a one-piece object in the first place.  So it looks like you have two problems. The first is to decide what's the best way to split your container to facilitate both putting the equipment inside & removing it; the second is how to latch the two together.  I can't answer the first since you haven't shown us the equipment.

As to the second: there are a number of plans for spring-latching connectors (such as used with straps, backpack covers, etc) on thingiverse.com.  If you have no constraints on the exterior of your container, I would just merge the latching connectors into the container wall (e.g. with meshmixer) .


Anyone tried Varathane water-based Wood Stain on Hatchbox Wood PLA?

I ended up using Saman brand water-based wood stain, also from Rona hardware (a brand of Lowe's Canada). The selection of colours for Saman stains was greater than the Varathane stains.

I applied a single coat of colour #117 "Chamois" to the stem portion of the wand, and two coats of colour #120 "Dark Walnut" to the handle. I did not apply a varnish or sealer. The results seem acceptable, given that I Am Not A Carpenter, and this is my first go at printing and finishing wood PLA! Overall, I'm quite happy with the result. I left the PLA mostly unsanded to take advantage of the layers' wood-grain appearance.


Cura has several settings that can cause it to erroneously omit small top/bottom surface "skins". Look for preshrink ("Skin Removal Width"), expansion ("Skin Expand Distance"), and particularly the limits on when expansion takes place ("Maximum Skin Angle/Minimum Skin Width for Expansion").
Normally Cura shrinks then expands skins by the same amount, proportional to line width, to avoid generating skin (which is slow to print and harms layer adhesion when mixed with walls) in places where the walls will already cover it. But the recently added max-angle/min-width settings cause the expansion to be skipped in certain places, leaving just the shrinking, and thereby serious gaps in the surface. This feature is just misguided and should be disabled by setting the min width to 0.
If you still have problems after that, you can try lowering both the shrink and expand, possibly even all the way to 0, but this will harm print quality and shouldn't be necessary.


Ender 5 Plus - does not level, the Z axis goes down, always

I had the same problem with my Ender 5 Plus.
There is a small set screw at the top of the BLTouch you will need to tighten this in to adjust the location of the sensor pin. Keep screwing it more and more until you see it initialize reliably that is it should move out and back twice to initialize.
When the BLTouch initializes correctly then the leveling can be completed.


Ender 3 Pro distance between nozzle and bed too large

Your springs are WAY too much compressed. Turn them loose into the "UP" direction till you are almost at the bed and then level your bed.


The G92 command is used to set the start position (origin) of one of more axes (including the current extruder) to any arbitrary value. The command G92 E0 is often used to perform retraction and nozzle priming. For example, the following commands are often used in start-gcode sequences (prologues) to prime the current extruder by extruding a small amount of filament:

G92 E0     ; Reset the extruder's origin
G1 F200 E3 ; Extrude 3 millimetres of filament
G92 E0     ; Reset the extruder's origin

RepRap Wiki: G92: Set Position


TPU filament usage for dental application?

There are a Ton of issues with using this type of material. First off there is no way anything that comes out of your FDM printer will be sanitary enough to meet the requirements for medical applications. Your nozzle might even be contain Lead. Last you would need this printer to be cleaned to clean room standards. As well as stored and operated in one..

Second I have not heard of a flexible material that meets FDA requirements. (which is not the same as does not) You have to worry about even the additives they add for color. Or straight up contamination of the material.

I do want to mention that there are people who use SLA printers for dental items. I cannot say how SLA would meet food or medical grade requirements. My guess is a lack of regulation.

So a bad idea I would say...


How to print text upside down for minimal support when printing

welcome to 3DPrinting.

To make this easier to talk about, let me call the surface on which you want to print the letters the "tabletop".

Looking at your picture, let me guess that you would print the object with the tabletop down.  Then everything prints naturally, with no bridging and no overhangs.

You want to put text on the tabletop.  This could be done by using support material to lift the bed up to the text height, or, in the converse, by using support material to permit the entire object to be printed with the tabletop up.  I can't see enough detail in your drawing to know if the object is printable with the tabletop up without using support material, so I will assume that it is not.

In your drawing, the lettering is a different color from the table.  I'll assume that this is not your intention, and you want the entire object with the text to be printed with one material.

I have solved this in two ways in different cases.

In one case, I wanted extruded letters printed on a vertical surface.  I surrounded the letters with a 45 degree draft so that the overhang was printable.  This won't help you here unless the object is printable on the side.

In another case, I changed my design to have letters engraved rather than extruded.  That prints well against the bed, with no overhang issues, and only short bridging required.

Engraved letters are readable, like extruded letters, and can be printed against the bed.


Yes
I had a somewhat similar clog once, and I could fix it back up. However, it is a lot of work.
Hobbyist Way
Step 1: heat
As long as the heater cartridge is still ok, just fire up the printer, move up the print head by 50 mm and wait some two or three minutes till the goop is warmed enough at the core to melt. Set the hot end to 200 °C and no cooling fan.
Step 2: rough clean
Check the cables for your hot end and thermistor as long as the plastic has not yet softened up around them and especially surrounding the thermistor: When the glob is removed in one swoop, you might tear the lines! It's better to use a sculpting tool or exacto-blade on the softening plastic and make an opening that allows the glob to be pulled away safely with minimal pull on the cabling.
When the blob has softened enough, you can just pull at the outer of the blob to pull it down. Use a tool like pliers and pull off the worst that still sticks to the hotend. Pulling the blob free can take a while, so be patient and careful.
If you have a soldering iron, you can use that as a heated scraper from the outside and skip on heating from the inside. If you have no temperature control (as if your thermosensor is shot) outside heat is the only safe way.
Step 3: Cool down
After having made a rough clean up from the outside, let it cool down so you can dismantle it.
Step 4: dismantle and clean the hotend.
This is actually rather simple, and I will point to a question where I outlined that for a broken thermistor cartridge. You have a working thermosensor at least, so less problems on that front.
Shortcut
If you have a hot air gun for hot air soldering, you can be much faster! Skip step 1 to 3, dismantle the hotend and go straight to Step 4, dismantling it and cleaning it out of the machine with the hot air soldering tool as a heat source. Heat and scrape away, and get out the thermosensor and thermosensor as soon as possible to prevent destroying them.


Take a detailed model and make it suitable for 3D printing?

I would recommend "The Maker's Muse" youtube video channel.

In particular this video Fixing impossible STL's with Meshmixer 3.1.118 BETA might solve your problem.

Few other videos which might help:

How to make Engineering Assemblies 3D Printable using Meshmixer
Add smoothness to your meshes using remeshing! 3D 101
A Detailed look at Processes and Profiles in Simplify3D
Tidy up your prints with the Modifi3D
How to Print Bigger Things - 3D Printing 101


Welcome to the site!

In regards to quads, vs polygon. People will often reduce the overall detail to make it easier to print. But so long as after you export it to a STL and verify that your Manifold edges were done correctly and what you though was solid is solid, you should be good to go. As near as I can tell so long as you can export it to STL then it doesn't matter what meshing you use. That said I see Polygons more than anything.

Worst case you can run it through a STL repair program and it will make the required changes for you. Usually I used these tools to fix poorly rendered files.
My favorite is Nettfab. which is now part of microsoft.

You can verify if it will print by downloading slic3r, then "slicing" the file. After that you should be able to view a layer by later output.

Article talking about quads vs triangles from design

Shapeways article on preparing blender files for 3d printing


Thread pitch of Ender 3 bed leveling screws

I measured mine with a thread gauge and it says the pitch is 0.7 mm.
So, as the stock adjustment wheels have 14 bumps around their circumference, turning by one of those is an adjustment of exactly 0.05 mm (assuming no backlash).
I can't speak for anyone else's, but due to the availability of replacement height adjustment wheels which don't specify alternative thread pitches, I guess that's the only one in use. I encourage you to verify my finding before relying on it.


Delta bots always need all motors to step to maintain a straight level. Microstepping, is not magic, the incremental torque decreases per step so that you will be more likely to miss a few micro-steps. Furthermore, the signal that creates voltages for the micro-step positioning is usually not perfectly sinusoidal (pulse-width voltage modulation is used to achieve micro-stepping by controlling the current; the driver sends two voltage sine waves, 90 degrees out of phase to the motor windings), micro-stepping drives can only approximate a true sine wave. This means that some torque ripples, resonance, and noise remains and hence resulting in odd stepper behavior, like seen below from this ref. (after the half step the stepper jumps to the full step and maintains that value for a while):

This is seen as a Moiré pattern in your printed products. As an example, if the head is moved in Z direction by micro-step, you will almost certainly notice that the head doesn't move on every micro-step, but only every 3rd or 4th micro-step (as an example). When using higher resolution steppers like the 0.9° stepper motors, you will still miss micro-steps (e.g. the same, so also on every 3rd or 4th micro-step the head moves), but as the micro-step is half the size of that one of a 1.8° stepper motor, the accuracy as in precision and resolution is higher.

In that sense, if you change your stepper drivers for higher micro-stepping drivers (from 1/16 to 1/32 as you mention), it will not help you improve the resolution much because the incremental torque from one to another 1/32 micro-step is lower than for 1/16 micro-steps as can be seen in the figure below (taken from this ref.).

So, using 0.9° motors (and keeping 1/16 micro-stepping) improves positioning accuracy as described above, it will also reduce the noise, because the torque per unit angular error is nearly doubled. Also remember that if you are using 8-bit electronics (you hint to an ATMega board), then even 1/32 micro-stepping burdens the processor to achieve reasonable travel speeds. With 8-bit electronics, it is usually suggested to use 1/16 stepping.

Upgrading an existing printer from 1.8° to 0.9° stepper motors is probably not worth for the majority of users (note that the maximum allowable speed also reduces when using 0.9° stepper motors). Unless you are designing and building a new delta, or aren't on a tight budget you could opt for the additional costs of buying 0.9° stepper motors.

Note that updating to higher micro-stepping values not necessarily implies that the quality of your products also increase. See e.g. this reference.


Does the layer thickness have any effect of the strength of the 3D printed object?

3D Matter has published an excellent article on the subject. They find that thicker layers result in a stronger part, with 0.3mm layers giving a part that is around 24% stronger than the same part printed with 0.1mm layers.

One small issue with this study is that it did not look at the effects of temperature. Raising the temperature generally results in stronger parts because the layers will fuse better. It is possible that you could make a 0.1mm part just as strong as a 0.3mm part by raising the printing temperature.

Another consideration for inter-layer bonding is how much the next layer is "squished" onto the previous one. Using a wider extrusion width will improve strength.

The main issue with the strength of FDM parts is that they tend to break much easier along the layers, much like how wood is much stronger across the grain. You have to take this into account when making your design, and ensure that features that will be subjected to stress/strain are printed in the XY-plane.


You've covered a couple of concerns "outside the box," but the real tests will come when you pour some of the resin into the vat.

If you don't get a reaction with the release layer, score one for your side. The release layer is a silicone kind of compound, which typically is un-reactive to most substances, but that's not to say the thinner qualifies in that respect.

To be cautious, you could dab a bit on the corner of the vat, especially out of the usual scan area or off the build plate contact surface. If it sits without clouding the release layer, the next test would be a layer test.

You could even remove the build plate, pour the modified resin in the vat and run a model comprised of only one layer, perhaps two. You'd be able to carefully pull the cured resin off the release layer and make a preliminary determination.

If all is well by this point, it's time to create a model, yes?

I hope you'll report back on your results. My Pegasus is still in the box from Kickstarter days. I'm sure my resin is well beyond the "sell-by" date!


Try to,
First, remove the heat block from the extruder/heat sink. Heat the hot end to ~ 230 'C. Then try to unscrew the nozzle while holding the heat block with a wrench or plier. Be extra careful with the heat block and with the plier.


Retraction distance, print speed (I don't know about Combing mode or Comb Distance but I doubt that's the problem) have IMO nothing to do with this.

Neither would hotend temperature.

  It shouldn't be a problem with the Z-axis or the temperature control. It also only appears on large objects.

You have a very fine X/Y layer so albeit your affirmation, I must raise the idea that it might actually be exactly the temperature control of the heat bed (if you have one) and it definitely seems to be the z axis. How would this problem appear otherwise?

You say it affects only large objects, and also that it doesn't affect PLA, does it affect large PLA objects? Photos would be helpful :-) !

My hypothesis is that you have a heat-bed and that the heatbed is changing the z-height.

It does so when it changes temperature (because material contracts/expands according to temperature), and heatbeds change temperature all the time.

Usually you have the same temperature control method all the time, so small or big objects doesn't change the method, but what they change is the time they stay on the same level; small objects less, big objects much so the z-bulging will be seen if you spend 2 minutes on one layer, while it might be mitigated on a layer taking 20 seconds.

What's your heat bed temperature control software / how is it configured?

FYI I use Marlin and I get these problems when I don't (correctly) auto-tune the heat-bed pid or use bang-bang beat-bed heating.


The fact that the temperature reading stays steady while heating and changes once it stops heating makes me thing that you might have a short between your heater wires and sensor wires or somehow have them interconnected. Especially if it shows the same temperature when it's actually below 110°C and heating but shows correct when not heating. I would try to separate the heater wires from the sensor wires and make sure they are not touching, also check that the sensor wires are not touching the heating block.


Is there a problem with removing a polished rod from the Z-axis?

First a resounding no. Not a good idea. Are you saying it works now that you have removed the smooth rod?

That tells me for sure your issue was Binding. Which is a tricky problem to solve. Binding usually happens when your carriage is not level. Take a bubble leveler and verify.

Another time it happens is when your Acceleration / Jerk settings are too high. Try reducing the Acceleration for Z in the firmware.

Another possibility is your rod is Bent. Take the rod on a flat surface. Inspect it as you roll it around. Do the same with the other rod. If it bows and is not completely flat, then you will need to replace it.

Last is make sure your printers frame is put together. If it is causing the rod to bend as it is not aligned right then you should try to see if you can fix it and contact the seller.

Technically you can run without the second rod. Maybe. I do not advise. It is sort of like cutting off a leg because you have a cramp. It will hurt your overall quality and it is better to just resolve the issue.


Why won't my filament feed through the extruder anymore?

I figured out the issue. I think I was shoving it in the wrong hole.

I took apart my extruder component. There's a good video on it here.
But basically, you just have to loosen the two bottom screws on the side fan like this:

I checked everything out first. I cleaned the extruder head with the included pin. I also shoved the filament through the heated area and filament came out ok.

But then I discovered the filament could go in the wrong way sometimes through the extruder.

This is the correct way for the filament to go through. It should come out of that plastic hole.

But once in awhile, I accidentally pushed the filament through this way.

If the filament was bent and I pushed the lever too hard, it would often find its way down the wrong path.
So I played around with how much force I should be holding down the  lever and how hard I should be pushing the filament through.

I don't know if other 3D printer extruder feeders are designed this way, but seems error prone. Or maybe it's just me.


Yes, this should work.

According to this 4-pin fan specification, such fans use a 5V PWM signal.
You would have to make sure the PWM frequency on the pin you use satisfies that 21-28 kHz range specified in the document.

According to 3.3 and 3.4 in the document, you may not be able to turn the fan off completely when using the PWM input signal.


If you break up a large piece into multiple smaller pieces and properly glue them together, you basically add stiffeners (as a result of printing walls). This could lead to a more stiff model; this might have been confused by calling large prints more brittle opposed to constructed models.

If printing is conducted at similar conditions on large printers, there shouldn't be a reason why the model becomes more brittle unless the conditions aren't the same. But that would be true for printing at small printers too, e.g. if one print was printed in a draft.


Possible ways to print soft skin for human robot?

Oh that is a tricky tricky question!

First you will probably need a good scan of the robot. You will have the cad of the robot but chances are scanning will make life easier.

http://www.3ders.org/articles/20151201-kinect-easy-3d-printing-tool-with-release-of-3d-scan-app-for-windows.html

Also see Reprap for other options

http://reprap.org/wiki/3D_scanning

Following... it is not going to be that simple. If it was my project I would
Print a mold out of ABS. ABS reacts to acetone and you can vapor treat it.

http://www.logarithmic.net/pfh/blog/01366106156

That said you might burn your house down. Also it is inconsistent. But would give you a smooth finish.

Next you can do just normal mold printing and be okay with the ribbing. Then you pour your silicon material

Next you can well just print with silicon. The ninjaflex guys have a ton of different types of flexible materials and new ones coming out.

https://ninjatek.com/products/filaments/ninjaflex/

On that topic I will mention a local company that I have no direct affiliation with. I just see them at the hacker space. They make a extruder just for flexibles.

https://flexionextruder.com/

Other areas to look at. More for making metal but it may be of use.

http://www.instructables.com/id/From-3d-printed-part-to-metal-the-lost-plaabs-me/

Last is again the mold but you make the molds on a expensive form 1. Or you make the skin on the form1 as they can do flexibles. Small build area. Material is around 100 a ltr or more

http://formlabs.com/products/3d-printers/form-1-plus/

Good luck!

Also check out this facebook group (no affiliation)

https://www.facebook.com/groups/3DPrintProps/

If anyone has done this it is those guys. Oh Wait No I take that back Look into these fellows. They have a very active group. (google group) not to mention that they are also directly doing what you are.

http://inmoov.fr/

Just don't be like this guy and make it look like a movie star...
http://www.mirror.co.uk/news/weird-news/man-builds-scarlet-johansson-robot-7667715


Why is the printed object smaller than original model?

Are you using the stock firmware of your printer? Sounds like to me that you have 16 tooth pulleys and your firmware is set to 20 tooth i.e. 80 steps per mm

The calculation behind the steps per mm is $\frac{\text{Steps per Revolution} \times Microsteps}{Teeth \times Pitch}$. The reason for this is that one revolution of the pulley will move the belt the number of teeth times the pitch of the belt. Now take the total number of steps, Steps per Revolution times microsteps, and divide by the distance moved giving the steps per mm.

In $\underline{most}$ hobby 3D printers you have:

1.8 degrees steppers which equals $\frac{360}{1.8}=200$ steps per revolution , Less common is 0.9 degrees steppers $\frac{360}{0.9}=400$
GT2 is the most common belts now which have a pitch of 2mm
The two most common pulleys are 16 tooth and 20 tooth,
Depending on what stepper drivers and or configuration you have

A4988 $\to$ 16 microsteps
DRV8825 $\to$ 32 microsteps
Trinamic $\to$ 16-256 mircosteps

In your situation I believe you have a 1.8 degree stepper with 16 microsteps, a gt2 belt, and a 16 tooth pulley. Which means your XY steps per mm should be $\frac{200 \times 16}{16 \times 2} = 100$. While your firmware is expecting 20 tooth pulleys, yielding $\frac{200 \times 16}{20 \times 2} = 80$. This would result in your prints being $\frac{100-80}{100} = 20\%$ smaller, which explains your results with the circles.

Generalizing, the steppers, microsteps, and pitch don't matter. To go between 16 tooth pulleys to 20 tooth, multiply by $0.8=\frac{16}{20}$. From 20 tooth to 16 tooth, multiply by $1.25=\frac{20}{16}$.


How could I print a large sphere-like object?

A sphere can be put together quarters easily, but those need support in the center. However, there is a slightly different cut is more economic:

Cut a top and bottom "plate" off, print them separately, the lower one "upside down"
Cut the remaining piece into quarters

For more equal printing, maybe even cut them along the equator too and print the lower half "upside down"

This way, the support material can be reduced to a minimum - only the top and bottom will need any support, and it is easily accessible to smooth it away.

If the walls would be something like one millimeter thick, any good glue should work. If you want to reduce the visible seam, you might bevel the faces, so that the wall has a little gap on the inner wall. As most glues shrink as they harden, it will flatten into the "gap", evening out the internal face.


How to print at low temperatures (filament melting at about 70 °C)?

70 °C is a specialty filament. It is well below the MIN_TEMP defined in any sane firmware. In Marlin, you can't turn on the extruder in any way, while this is online.
You do need to define your firmware to allow such a print - either by dropping the value in the firmware or disabling Mintemp-protection and then flashing that firmware. That is quite invasive.
To temporarily disable the MIN_TEMP, you need to run the G-code M302 P1 or M302 S0 - M302 on its own does nothing. However, some firmware distributions might explicitly prevent these two commands of turning off the check.
In that case, you might use M302 S65 or similar to drop the MIN_TEMP.


Jerk causing vibration and Y layer shift... Bad stepper?

Your video doesn’t show a printer moving terribly fast, which makes it seem like it could be a problem with the motion or the electronics. Check the movement of the Y axis by hand, is it smooth? With the belt on, and the stepper motor attached, you’ll feel some resistance and little bumps, from the steps in the motor, but it should be pretty smooth, and especially it should be consistent across the range the bed can move. If you take the belt off, the motion should be like butter. Check the belt pulley isn’t slipping on the motor shaft. Check the idler on the other end of the belt spins freely.
The motor could be suspect, the driver could be suspect. Try running the printer so it sends the bed back and forth, and push against it with your hand a little as it moves. It should be pretty strong, and shouldn’t skip steps from some light pressure. If it does skip easily, it’s something with the motor or driver, or possibly the wiring to the motor (I had a failing connection on my extruder stepper that manifested as wimpy torque and skipped steps). You can beep the wire with a multimeter, and wiggle it around as you beep in case it is a loose/flaky connection. I’m not sure if the creality printers have trimpots for the motor drivers, but some drivers have a bias adjustment where you adjust a voltage with a multimeter, to decide how much current the motor gets. It’s not usually something that goes out of adjustment.
If it doesn’t skip steps easily from adding some resistance with your hand, then it might be an incorrect jerk setting on the printer, or the slicer travel speed is too fast, or, the hot end is hitting some plastic that is sticking up (an overhang curled up possibly), and skipping a step there maybe.


AnyCubic Support suggested I swap two of the motor drivers (X and Y) and after I did that, the problem disappeared.  I've had a half dozen good prints in a row now, no problems at all.

The drivers are inside the computer module - had to flip over the printer, take off the cover and pry out the top two modules and put them back in swapped.  Not difficult, but probably worth getting advice from AnyCubic before going ahead and doing it yourself unless you're comfortable with this sort of thing.


Is there any setting that could allow me to print this overhang without support?

First of all a minor correction: the feature you are trying to print is not a bridge (which is an unsupported length of filament between two parts of the print) but rather a overhang (which is an unsupported length of filament supported only at one end).

The reason why your overhang is impossible to print without support is that slicers create a shell first or - in other words - trace the perimeter of the layer you are printing.  This feature, combined with the fact that your overhang is perpendicular to the part it originates from, causes the printer to try to extrude into thin air the perimeter of your rail, like this (the yellow lines are the shell, the red ones the infill):

In the image above, also the infill is extruded into thin air, but this is actually something that you can change in most slicers (look for "infill pattern orientation" or something similar).

One option you have is to tweak the support parameters to make it unobtrusive and easy to remove, like for example this:

(The above was done in Cura, with infill pattern "lines", spaced 5mm apart and no support interface or other additional structures).

Since your parts won't be subject to a great deal of mechanical stress another solution could be to change their printing orientation.  In the following example, the overhangs do actually become bridges and as such should print without problems:

Just consider it will take considerably longer to print.


Homing is the process where the machine finds all the limits of the 3 axis (at the endstop switches), to have a common reference point for each axis. From the endstops, firmware defined values exist to give the printer head the offset to the home position, also known as origin (X=0, Y=0). If the origin position is in front of the plate, wrong offsets may be defined, but you can re-adjust the position.

If the stepper is driving the printer head away from the endstop on a particular axis on homing (in your case the X direction), there might be a few possible problems at hand:

The stepper cables are plugged in reversed
The wires in the stepper cable are switched
The stepper direction is reversed in firmware (this is not very probable for a kit or bought printer)
The stepper motor itself is build mirrored (not uncommon mistake for Y stepper motors on the Anet A8)

A quick fix would be to rotate the connector 180° of the cable going into the X stepper, if this works, you can disassemble the cable and properly arrange the stepper wires.


Issues with print Prusa i3 infill breaking and causing clogs

Try calibrating your Z again. It is hard to tell based on the picture, but it could be too close to the build plate, and thus is dragging while crossing the infill section, or it could be too far away and thus is not getting good layer adhesion.


It might be the case that the resin separated into layers in the tray. Try mixing the resin well in its container.

I have also heard it can help to filter the resin prior to mixing.


Rhino will let you create a custom lattice structure inside the solid object, this can in turn be used to create infill using grasshopper (an inbuilt scripting tool):

create a standard cell size and apply the lattice,
convert the whole thing to solid,
reimport into inventor


Does wood filament damage the printer nozzle?

If you haven't been to their site before, you should check out the forums on 3DHubs. There's a lot of how-to's. A quick Google search yields this link to a similar question.

The key thing to note is that in all technicalities, any material you run through the nozzle is going to cause some sort of wear on your nozzle. How quickly depends on the material or composition.

The answer to the question linked above relates it spot on to sandpaper. If you have sandpaper made out of metal (ie stainless pla), it will scratch your skin fairly easily. If you have sandpaper made out of tree bark (ie laywood pla), it probably won't scratch your skin as bad, but it'll still scratch. And just for poops and giggles, lets say you have sandpaper made out of pla; it'll take a while, but you could eventually make your skin raw if you rub the plastic against your arm long enough.

It is typically recommended to use one nozzle for each material type as to avoid cross-contamination of materials in your printing. With this idea in mind, if you are using many types of materials, you can also minimize failed prints due to clogging and other "damaged nozzle" type troubles.


What choices do we have on Clear resins for DLP?

Formlabs sells a completely clear resin that they've even made simple lenses from, but it's about $150 for a liter. I have no idea how well it would work with your DLP setup. Looks amazing in the pictures though.

MatterHackers sells PhotoCentric UV Firm Clear for $90 for a liter as well. It's not quite as easy finding pictures of this stuff, but from what it looks like, it's still pretty decent. Assuming you've got a UV DLP

Disclaimer, the PhotoCentric stuff says it's a UV resin (10nm to 400nm IIRC) and I have not the slightest clue what Formlabs designs their resin for, so YMMV.


The inductive sensors trigger to the metal plate under the glass bed. This implies that if you remove the slate of glass, the distance between the trigger point and the print bed is increased by the thickness of the glass slate. But, the trigger point is still exactly the same as if there were a slate of glass (as it triggers on the metal bed underneath). This extra distance need to be compensated for.

The method you are using is incorrect in determining the distance between the nozzle and bed with respect to the sensor trigger point. This answer on question: "Z Offset on autoleveling sensor setup" describes how you need to determine the distance between nozzle and bed from the trigger point. It includes a manual step to lower the nozzle a paper thickness above the build plate.

If you insist on using G-code (e.g. in your start G-code script), you can redefine the Z=0 level by adding a G-code G92. In case of a 3 mm glass plate, you should add after the homing (G28) and probing of the bed (G29) the following:

G1 Z0  ; This will move the nozzle to Z=0 as if there was a slate of glass,
         but in fact it is still 3 mm offset
G92 Z3 ; This redefines the old Z=0 (with glass) to be Z=3 mm


Can't get print to stick, no matter what I try

Your nozzle is clearly too far from the bed. The plastic should be squashed down slightly. Some firmwares have an option where you can adjust the height of the nozzle "live" during the first layer, in Marlin this is called "babystepping". This can be very useful because you can get the height correct without having to mess with the physical leveling of the bed.


Getting wrong measurements on my Kossel Linear Plus after installing SKR 1.3 with Marlin 2.0

So the problem was that the TMC2208 were wired for UART mode, yet Marlin was configured for standalone, which apparently makes them work, but with completely wrong step sizes. Changing it in the configuration completely eliminated the problem