The four main motor speed limits in a 3d printer are:

Firmware step generation frequency limits
Firmware motion planner effects
Loss of torque and precision due to motor coil inductance and back-EMF effects
Mid-band resonance

Step generation rate limits will depend on the firmware and controller board used. There is a significant range, particularly when 32bit firmwares and RTOS-based platforms like MachineKit are compared to 8bit firmwares running on Atmega AVRs. Some examples:

Marlin on a 16 MHz 8bit Atmega can only run the stepper interrupt at 10,000 hz without bogging down the processor and blocking other critical algorithms (like motion planning). It can fire step rates up to 40,000 hz by pulsing the step line two or four times per interrupt, which effectively drops the microstep level in software and runs the motors rougher/louder.
Repetier on the same Atmega can run the stepper interrupt at 12,000 hz, because it is optimized more for execution speed than Marlin.
Repetier on an 84 MHz 32bit ARM Cortex-M3 can run the stepper interrupt at 80,000 Hz.

These limits typically only affect actual stepper speed when relatively fine microstepping is used. Consider an example based on a very typical Marlin printer configuration. Microstepping of at least 1/4 is strongly recommended to avoid resonance issues, so let's start with 1/16 stepping. This allows quad-stepping to effectively output 1/4-steps. Starting with finer microstepping will drop our top speed, and coarser microstepping will be louder and may encounter resonance, so this is a good starting point. Then asssume a typical 32mm-per-rev pulley on a 1.8 degree (200 steps/rev) stepper motor. This system has a resolution of 200*16/32= 100 steps/mm. At 40,000 Hz total stepping rate (quad-stepping at 10,000 Hz) we can theoretically travel at 400 mm/s before hitting Marlin's hard cap. That's probably going to be a higher RPM than we want to run the motor anyway, so it's not a very impactful limit.

In comparison, if we started at 1/128 stepping (such as with the THB6128 driver chip) our top speed with 8bit Marlin would be 50 mm/s. That's quite slow.

Firmware motion planners can further limits motor speed by ramping up and down to traverse turns and corners. If the model geometry has lots of sharp turns, the target speeds commanded by the gcode are likely to never actually be reached. Only long, straight line paths will have enough ramping time to hit the speed target. You can see this yourself by printing a very small model at a variety of feedrates and timing the actual print duration: at a certain point, increases in the commanded speed will make no difference on actual print times.

Another constraint some firmwares enforce is requiring the ability to safely decelerate to a stop within the length of all the motion commands in the planner queue. This allows the printer to gracefully handle a sudden loss of input, such as as if the host computer stops transmitting USB commands, or if the SD card experiences a series of read errors. If the printer just abruptly stops from full speed when it runs out of commands, it is likely to lose position and ruin the print. Whereas if it can decelerate to a safe stopping speed, it may be able to resume after the command stream resumes.

In terms of actual motor behavior, the inductance and back-EMF introduce significant limits because they decrease motor torque at higher RPMs. This produces a torque/RPM curve that drops off at higher speeds:

http://www.geckodrive.com/support/step-motor-basics.html

Note in the picture that there is a flat "constant current" region on the left side at low speeds. This is the range where the chopping driver is limiting coil current. On the right side of the curve, current is not able to reach the target before it must be switched back off for the next step. That reduces field strength and thus torque.

There are two separate effects to consider here:

Motor coils are inductors, which means there is a first-order lag between applied voltage and coil current. A standard bipolar stepper motor with a microstepping driver must raise the coil current from zero to max or from max to zero every full step (eg every sixteen 1/16th microsteps). At high step rates, there is not enough time to fully charge the coil to its max current before the next step requires dropping the current back down. Without developing full coil current on each step, torque is lost.
Every motor is also a generator, and spinning the rotor generates back-EMF voltage within the motor coils. That voltage waveform gets overlaid on top of the drive voltage waveform with a phase shift dependent on the rotor position relative to the coil energization position. In simple terms, this voltage attempts to brake the motor: it always does whatever will slow the motor down. This means it opposes the applied drive voltage when the motor is applying forward torque, or assists the applied drive voltage when the motor is applying brake torque.

For a practical discussion of speed limits, we can simplify the situation by assuming back-EMF voltage opposes the drive voltage applied to the coils. This means there is less effective voltage raising/lowering coil current, and it takes longer for the current to change, and less coil current is developed than would be the case without back-emf. This further depresses the torque/RPM curve of the motor. And when the back-EMF voltage is around the same magnitude as the drive voltage, significant motor instability can result because of complex feedback effects between rotor position and effective coil voltage.

You can play with these effects using different motor configurations and speeds for a few popular 3D printer stepper drivers using my stepper driver simulator: https://github.com/rcarlyle/StepperSim

In closed-loop applications with position feedback and high-end drivers that can damp various instability modes, it may be ok to run the stepper all the way down the torque curve at very high RPMs. In more typical open-loop 3D printer applications, it's generally best to stick to the low-RPM part of the torque curve before inductance and back-EMF really take over the motor behavior. Losing too much torque can easily mean skipping steps and losing position, ruining the print.

Another important effect for steppers is mid-band resonance. This is not a normal mechanical resonance, but actually an electromechanical resonance effect. It's quite complicated, but the short explanation is that a stepper has an intrinsic 90-degree phase shift between position and torque, and when speeds rise to a point where coil inductance introduces an additional 90-degree phase shift between coil current and applied voltage, the electromechanical system has a highly-unstable 180-degree phase lag and thus creates a negative feedback loop. This can rapidly drop motor torque until the motor loses synchronicity with the driver's applied voltage and stalls.

Mid-band resonance only occurs when coil current is limited by inductance. It cannot occur in the constant-current drive range because there is not enough phase lag between applied voltage and coil current.

http://www.geckodrive.com/support/step-motor-basics.html

Unfortunately, measured torque curves available from manufacturers almost never show resonance zones, because the curves are produced by loading motors with friction-brakes that damp any kind of resonance effect from building. Whereas a 3D printer drivetrain load is almost entirely inertial (accelerating a mass) which is much more prone to resonance.

High-end drivers can automatically detect and damp mid-band resonance, but typical low-cost 3D printer drivers do not have this capability.

It is generally prudent to avoid entering an RPM range where mid-band resonance may occur. This is easily accomplished by sticking to the left side of the torque curve, in the constant-current operating region. This ensures high torque and good stability.

For a concrete example, consider the popular Kysan 1124090 stepper with a 24v power supply.

https://ultimachine.com/content/kysan-1124090-nema-17-stepper-motor

To maintain high torque and avoid mid-band resonance, we would want to keep the RPM to about 400 or less. For the same 32mm-per-rev pulley mentioned above, that would limit speeds to around 200-240 mm/s. Higher speeds are possible, but may encounter reliability issues.

This speed, of course, assumes a 24v PSU is used, to match the measured torque curve: a 12v PSU would have a significantly lower top speed before inductance starts to limit coil current, around half as fast. Higher supply voltage greatly increases the top effective speed for the motor.

Again, you can easily simulate this effect (using https://github.com/rcarlyle/StepperSim). This simulator output chart shows how inductance and back-EMF are keeping coil current from reaching the target:

For practical drivetrain design, a motor/driver simulator is really the best tool in the toolbox for finding the point where performance will start to degrade due to inability to hit current targets. It's simply too complex to apply simple equations or rules of thumb with any accuracy. These electrical effects and the firmware step generation limits are likely to be the two main restrictions on motor speed for most printers.

Of course, how fast you can melt plastic will tend to limit printing speeds significantly below the true motor speed limits, but that's a different discussion. For the moment, we can simply say that top motor speed tends to be unimportant for print moves in typical Cartesian printers. However, there are a few instances where they are likely to drive printer performance:

Linear Deltas, where carriages may need to run several times faster than the effector for certain move directions
Geared extruders with high reduction ratio (eg much over 5:1) for high retraction speeds
Short-pitch lead screws (or all-thread) that need high rotation speeds to achieve moderate linear speeds


Problem printing bigger models in the Ender 5

This sounds like a bed leveling issue.  As reported by others, I get much less warping with PETG than with ABS or even PLA, and deal with too much adhesion with PETG rather than too little.  With a Reprap x400, I printed a faceplate for the extruder to hold a electronic drop indicator.  This gives me much higher precision leveling. Of course, I remove the drop indicator after leveling.
If leveling isn't the issue, then you may be printing too fast.  The recommendations I've seen are to print PETG at 50 mm/s or less.  I print a a lower speed than that.


Are these the right types of electrical connectors for hooking my Switching Power Supply up to a wall outlet?

It is okay to just use bare wires in the type of screw connector found on your power supply. They're designed for it; they have a little plate under the screw that prevents the wires from being frayed by the screw.

If you want neater wire termination, you should use one of the spade type ones. Pick the smallest size that fits your wires.

PC power cords are generally fitted with an IEC C13 plug, and those are rated for 10A (meaning also the wires themselves will be able to carry at least that much current). This is fine for any home 3D printer which usually draws a fraction of that.


Nozzle jiggles when screwing into heating block

If the threads are damaged badly enough not to hold a nozzle rigidly, you should replace the heating block, but there might be hacks you could do to keep using it for a while until you're ready to replace. I've had luck replacing threads in completely unrelated applications with epoxy, and if you can get one that handles and transmits the heat well enough (maybe JB Weld? not sure) it might work here.

I don't think there's any indication you need to change to a different kind of heating block. That would only be indicated if there were lots of other people reporting the same problem you're having with your printer model or similar ones. It seems more likely that, if they're damaged, you just did it by over-tightening or over-vigorous cleaning with the brush.


Prusa Mk3 filament detection sensor, can you access the image data?

I am interested in finding out if it is possible to get access to the image data coming from that sensor? And I was interested in seeing if the image data could be used to measure the filament width?

No. The sensor is the PAT9125EL. The only output it provides is the movement in the X and Y directions. There is no way to get image data out of it.

  Could I add a rgb led and interpolate the filament color by comparing pixel intensity under different lighting conditions

No. The sensor uses laser light of a specific wavelength. It's likely not sensitive to any other wavelengths. On a positive note, there is an "average frame brightness" register that can be read from the chip, but I don't think it's likely to work with RGB LEDs.


How to wire 5 V proximity sensor Ender 3 V2?

That part seems dubious
Your part is labeled LJ18A3-8-Z/BX. That is a Z/BX type sensor of the LJ18A3-8 series - that first part dictates an M18 outer thread and thus dimensions and a triggering distance of 8mm. Z/BX indicates NPN NO, so a normally open sensor of the NPN type. However, that labeling indicates an inductive sensor with a required supply voltage of 6 to 36 V and a power draw of 10 mA between the supply and ground line and a digital output signal of 300 mA.
There is a variant in existence, that has a 5 V supply voltage, but its part number is different by 3 characters: LJ18A3-8-Z/BX-5V - the appended -5V is crucial to show it differs from the standard!
The Ender-3 Board
The Ender-3 board has a 24 V input from the power supply and runs its end-stops on 5 V logic. That would suffice to connect the output of a LJ18A3-8-Z/BX-5V sensor directly to a sensor pin.


Why are there so many print speed parameters in slicers?

There are multiple parameters because of the trade-off at print speeds.
Slow printing will have less ghosting and a better overall quality, but it takes way more time.
Fast printing will be fast (oh thank you, Captain Obvious), but you will get stronger ghostings and poorer line quality overall. Maybe some strange artifacts.
But you don't need a good print quality in areas that are not visible at all, but you do need it for the outer shell. Also, is the travel mostly just something that you want done as fast as possible but maybe not so fast that that the whole printer starts shaking?
So, you want to set different parameters for different parts.
Next reason: most slicers are used for a large variation of printers, and every printer is a litte bit different—even the same printer type with different addons (like a vanilla Anet A8 vs. a beefed up Anet A8). For the slicer to be able to be used by all these printers, it is necessary to be able to set multiple parameters.
To get deeper into your question about the different infill speeds: if you print a solid infill you will also need to give the printed material more time to cool down, because it is packed tightly and there is not much surface area for heat to get away. If you print these areas too fast you will end up with a part that is too warm and warps and deforms all the time while the next layers were printed on already, inserting even more heat into the part and isolating the warm parts from the outside. You can observe similar behavior when printing overhanging areas with thick walls: there the part will stay in a semi-solid state, and deforms all the time.
But how fast you have to go depends on the cooling system you have on your printer.


Auto Bed-Leveling with Inductive Proximity Sensors and Magnets

Good question. The magnets from the build plate will almost certainly interfere with your inductive sensor, the movement from the carriage will induce a current in the inductor as it approaches the magnet and may cause it to trigger. If you're looking for a mag build, I'd suggest looking at: http://www.3dprintermods.com/prestashop/index.php?id_product=9&controller=product

I'm just about to get into auto-leveling myself, with this particular build there are a few ways to get around the issue. If you plot your auto level to occur as far from the magnets as possible (x,y location wise), then you might be ok. Otherwise you might consider investigating optical and touch probes.


Mine is a shot in the dark, but the fact the overextrusion is so regular let me think it is due to something rotating going around in cycles.

The fact that the pattern changes with the flow parameter make me think the culprit is the stepper motor pushing the filament (as different flow means different number of rotations for the same lenght of printed wall).

A possibility could be an irregularity in the cobbed wheel biting it the filament: a longer tooth would push more filament into the hot end, for example.

Another cause could be a problem in the actual stepper motor, in which a failure in the coils causes it to move to steps instead of one, at some point.

There are possibly other suspects in firmware settings and stepper dirivers, but that's not the area of 3D printing I am most expert in.

Much more unlikely, it could be a defect in the filament, but that's easy to test: just swap it for another one!


To address the firmware problems, Download a fresh edition of Marlin 2.0.x and configure the Configuration.h and Configuration_adv.h yourself. Others' configurations are expecting fully stock parts, and will not be compatible with your system.
Your main problem seems to be in your Probe Z-Offset. To get good level, you need to calculate how far above the bed the nozzle is when the probe triggers. The BLTouch height screw is NOT for Z offset adjustment, and the Z-offset needs to be set with M851 in Marlin. See https://marlinfw.org/docs/gcode/M851.html for more detail on how to do this.
Additionally, the Z-MIN switch should not be connected when using the BLTouch, as it IS the new Z-MIN sensor.


Could anyone please provode me settings for Custom FFF for Zonestar Z6FB printer

After some pain, I figured out that if you are a poor Ubuntu/Linux user you should only use the AppImage version of Cura which you can download from official website
Next, make the file you downloaded executable chmod +x *.AppImage
Next, start it from terminal or by clicking in navigator
Ok, proceed as is and then Help ▶ Show Configuration Folder.
It will show 2 folders we need ~/.local/share/cura/4.8
Ok now download ZONESTAR_Cura_Resources.zip from here.
Then copy all files from ZONESTAR_Cura_Resources TO ~/.local/share/cura/4.8 but remember that directory structure is messed up but can be figured out.


Even though OpenSCAD can import a variety of formats, the file structure will not be accepted by Thingiverse in the manner presented by the OP.

OpenSCAD is a text-based description language. One creates parameters assigned to specific aspects of a model and implements those parameters to create the desired shapes/components by typing in a text editor. The native editor for OpenSCAD provides for some management, but notepad or equivalent would work just as well.

The file format of OpenSCAD is text. None of the CAD type modeling programs will provide equivalent text output.

For your objective, you'd have to learn the basics of OpenSCAD (not particularly difficult) and reference the parameters in the STEP files, then assign them to the appropriate labels in OpenSCAD.

If you have particularly complex designs, it can be a handful. It can also be rewarding when you change a parameter as a test and the complete model follows as expected.


Since the printer supports using an SD card, you don't need to connect it directly to a PC. Serial over USB has been broken in the past in various Win10 builds, I've not tried it recently and I've not tried connecting my A8 to my PC recently either.

If you need to use USB, and can't make it work with Windows, there is always the option of using a Raspberry Pi single-board computer (which you can then connect to by VNC from your PC). Depending on the software you want to use, this might resolve any remaining issues you have.


Custom Infill Pattern Based on Self-Generated Geometry

From my experience, this is hard, particularly because slicers are not made to handle it well. They generally do their infill generation efficiently in terms of 2D geometry, built as a function of the layer height and the outline(s) in the layer. Of course you can actually make the infill pattern part of your model geometry, or use a separate model intersected with the interior of your model as the infill, but having the infill structure be 3D geometry means that the slicer will be quantizing it to layers, and will have a hard time generating exactly-one-line-thickness extrusions that print will for the infill cross sections.
If you do want to do this anyway, OpenSCAD provides the tools to do the necessary intersection of your generated geometry pattern with the model interior.


What kinds of gaps/tolerances should I use when designing pieces that fit together?

I use my clearance values according to my rule of thumb: 0.1mm - to fit with some force, 0.2mm - just fit edge to edge without force.

Examples:

1) 3mm metal cylinder to be pressed into plastic part needs 3mm+0.1mm*2=3.2mm diameter printed hole (clearance from two sides)

2) 3mm screw to fit into plastic part needs hole bigger than 3mm+0.2mm*2=3.4mm that is 3.5mm will be already good.

This is fully experimental but always worked for me on three different printers and both on PLA and ABS.


Marlin, end stops, and position report - possible bug?

Some info on the subject: few stepper motors have any way of knowing their exact position during operation, which means Marlin will have to assume the steppers always are in the right place.

In other words, all g-code commands are executed relative to their current position, not with regards to the real positions. So if you forcefully move the printhead during print, the printer will just continue printing the same patterns in mid-air (this is basically what is called layer shifting).

The only way the printer can know the real position of the steppers is when the endpoint switches are triggered. This is why the homing action is done to before prints in order to reset the internal positional bookkeeping of the steppers in Marlin. So if the endpoints are triggered without the printer actually being at the endstops, you will seriously confuse Marlin.

I agree that is sounds weird that Marlin does not reset the positions of it's steppers when an endstop is triggered (during print?), but then again, if it happens accidentally (and not as part of a re-calibration procedure), I believe the default actions should be to abort all operation since this would indicate the printer being out of control. Perhaps there simply is no routine to handle movement after the program has been aborted - a situation where probably nothing would be right anyway..


You had a faulty BLTouch. Mine experienced the EXACT same behavior and replacing it with a new BLTouch fixed the issue entirely (everything else I kept exactly the same, firmware etc), I simply swapped over the probe + cable with the new one.

When connecting the new BLTouch, make sure you wire the servos connector correctly. In my case with an SKR Mini E3 v1.2 I needed to switch the red wire with the blue wire. If you start the printer with the wires the wrong way around, it may cause damage. I suspect that is what happened to my original one.


What ambient humidity should one target for filament storage?

The closer to zero humidity the better.  Maybe a garage or some place protected from rare precipitation outside would be better.  If one room is considerably less humid than the others, you could use it.  Keep the bags and dry packs the filament comes in and put them back in when not in use.


After homing all is fine, when printing the Z-axis stops advancing

Awesome, I got it fixed!

I've restored to default the Firmware EEPROM Settings in the driver program and it's all fine now. I have no idea how that got changed as I would never go mess around there.

I CAN PRINT AGAIN!!

The program I'm using is Repetier. It has a Firmware configuration setting under the printer settings. The values in there was a bit odd so I took a chance and pressed the Reset to Factory Settings and it worked. There is no version number attached to the setting


Ender 3 unknown (maybe bed leveling) issue

Non-square gantry is a common problem with the Ender 3. You should be able to compensate by adjusting the bed leveling screws so that the nozzle at Z=0 is touching the bed at each of the four adjustment points. This will leave some skew, which you may or may not care about. But the right thing to do is leveling the gantry.
Both sides' Z carriages have some play in how the gantry mounts to them - the holes are larger than the machine screws that go through them - so after loosening the screws you can make adjustments. The screws on the side with the Z motor are hidden between the carriage and Z axis extrusion it rolls on, so to adjust it you need to roll the whole assembly off the top of the printer (with the cross beam at the top removed). Since you can't tighten it in-place, you just have to do your best to get it straight before putting it back on. The unpowered side, however, has screws that are reachable with the whole assembly in place, so you can square the gantry with the Z extrusions before tightening them.
Keep in mind that the whole Z axis system is severely over-constrained, with 6 wheels where 3 should suffice to constrain it. People have a lot of different ideas about how you should deal with this, and I'm still not sure what's best, but I think you want to get each of the V-roller sets tight (using the eccentric nuts to adjust the inner wheels) before leveling and tightening down the gantry. Otherwise the wheels may have uneven tension, causing the assembly to want to twist.


Can I sell a handpainted large scale 3D model of a copyrighted 2D concept art?

While better fitted to our friends at law.SE, the general gist is: No.
Art is protected by copyright, and any adaption (derivative work) requires the OK from the right holders per se. Only 70-75 years after the death of the author (or publication for company works), a work enters the public domain and the copyright expires.
There are some exceptions (fair use/fair dealing/...), but media transformation is not one of them.
Giraud died in 2012, his estate or heirs - or whoever he/they sold the commercial rights to - own the right to ok derivative Works till around 2087.


Linking the 3D printing path coordinates to CAD for modelling

The wording in the paper is quite verbose and somewhat unclear. All it says is they read the G-code file and somehow turn it into a 3D model.

A g-code file is just a list of linear moves. Here is an example snippet I took from a random file (keep in mind a typical file would consist of thousands of such lines):

G1 X140.621 Y114.840 E0.0065
G1 X140.804 Y114.765 E0.0129
G1 X141.016 Y114.737 E0.0199
G1 X158.984 Y114.737 E0.6070
G1 X159.196 Y114.765 E0.6140

Each move is relative to the previous, so the second line of the code (for example) tells the printer to move to X=140.804 and Y=114.765 from the previous position (X=140.621, Y=114.840) while extruding an amount of material equal to 0.0129-0.0065=0.0064 mm of filament.

It appears that the authors have developed a toolchain to turn a G-code file into a 3D model, translating every extrusion segment into a part of a solid body (from the pictures, it appears that for a given move segment, they create an ellipsoidal extrusion and merge all of these together into a single solid body) - see Figure 9 in the paper.


All-metal hot-end Creality Ender 3 Pro jamming issues

The so-called all-metal hotends are sold as upgrades to the lined hotend versions. Actually, they are not. These are different type of hotends that can be used printing at higher temperatures. However, PLA printing at high temperatures is not advised. You rather choose to print at slightly lower temperatures.

What do I need to do to avoid jamming?

This requires that you change the way you operate the hotend/extrusion process. Why? Because the hotend is not lined, the heat from the heating block can more easily creep up the hotend into the coldend. This requires that you have a good performing cooling fan cooling the radiator fins of the coldend. Furthermore, because of the higher temperature (as the liner is not shielding the heat to the filament), the melted and the softened length of the filament in the hotend assembly is substantially longer. This means that excessive retraction lengths can cause soft material to be be pulled back too far. Knowing that the filament diameter is smaller than the tubes or the diameter of the heatbreak, this soft and molten filament can get stuck in the increased diameter section of the heatbreak.
But if it gets jammed,

How should I remove the filament fully without damaging the thermistor and heating element?

You need to ensure that enough heat gets into the hot and coldend to soften all the material. Currently PLA is stuck in the assembly. To soften all the material I would diasble the cooling fan of the coldend and heat up the heater to a temperature of 210-220 °C and keep this warming up for several minutes to allow heat to creep up. You can now try to push the filament through. If this fails wait longer or increase the temperature by 5 °C increments at a time. Too high temperature can cause filament to cook and carbonize. making it effectively harder too clean. If this fails, disassemble the hotend while hot (be careful!) and clean the individual part mechanically or use heat.


Fixing temperature Issues on I3 Mega / Where to find spare part

The plastic looks ok.  If you get the tools and pins to work on the connector, you could replace problem pins.  Many of us build our own cables.  If we verify the connector is Molex, you might need calipers to measure dimensions to get the correct size.  You won't need expensive ones.  I've seen digital calipers from \$10 to \$20.
Have you already verified your sensor and heater aren't an issue?  Maybe you've tried a new hot end, or a new heater block with a new heater and sensor.
You can visually inspect the pins on the connector to see if they have a loose connection.  See the solution at Proper hotend heater for Reprap x400 Pro V3
What is strange from you graph, you seem to be loosing connection to both thermistors.  Do the thermistors to the bed and hot end share one common connection, so that one pin could affect both?
If you haven't already tried it, one quick fix to try is unplugging the cables and plug them in again with the printer off of course.


This is a typical sign, that your hotend wasn't tightened properly. Carefully heat it up and remove all the plastic you can while removing the heatbreak - that's what you call transition screw.

After cleaning, screw in the heatbreak and the nozzle. The nozzle should butt agains the heatbreak, but have at least 2 threads to the heating block. Reassamble the full hotend now by adding the coolend.

Finally heat the hotend on the full assembly to about 240 °C and tighten the nozzle against the heatbreak again. This is called hot-tightening. You can add the PTFE liner after the hot tightening.


Yes and No at the same time
First of all, yes, you can mix resins. However, you should only mix resins that are of the same makeup, as in one brand and type. Why? because different types of resin have different compositions and different polymerization types. Mixing different types can result in unpredictable behavior, and not working at all!
To test, use a tiny amount of your brand and type matched resins and apply to the vat, then print something really tiny, like just 2 or 3 layers of a 20x20x20 mm cube.


Cura G-code Printer G-code settings vs. Extruder G-code settings

If your printer has only one extruder, leave the Extruder G-Code empty. This setting is useful for multi-extruder printing (e.g. multicolor). The extruder G-Code runs each time you switch to and away from that extruder, and can be used for stuff such as retracting a filament when switching.


If you want to replace the PINDA probe (whatever reason for) then you can go with the BLTouch Sensor but only for certain operations.

It will be good for leveling the bed before printing because here, only the bed level is important and not the skew of the bed.

If it comes to calibration of the skew itself, the BLTouch Sensor will not be usable because the PINDA Probe detects the boundaries of the copper circles on the print bed. The BLTouch cannot detect these copper areas.

The PINDA Probe is a proximity sensor.

If you want to do a recalibration you have to mount the PINDA again.

Therefore, it is possible but not recommended.


Why is my 3D printer not extruding properly?

Underextrusion and clogs can also be caused by insufficient temperature in the hot end. You've not reference your temperatures, so consider to use a test model and print at different temperatures. Too low temps can result in the problem you present, while too hot temps will increase stringing and peculiar blobs on the print.

If your slicer changes print speed at the layer of destruction, it may also be too fast, which is related to temperatures. Simplify3D allows speed variation as well as temperature variation at selected layers, but it requires deliberate action on the part of the operator.


You could try import it with blender. It's a free software which should be able to import the files.

First thing is to go the the File->User Preferences->Add Ons tab. In the Import-Export section, enable the 3DS Add-on.

After that you can export it to the desired format. Before exporting you must select the model/mesh you want to export. Otherwise nothing will be exported. The obj exporter is enabled by default in blender.


Which firmware to use on printer settings for DIY printer

Unless you can find a slicer that explicitly supports grbl, you will need to check the G-code specification and see which common flavour is closest to what grbl supports. The RepRap Wiki includes grbl in it's compatibility chart, but it has question marks against a lot of entries for grbl.

The other alternative is to slice a very simple model and see what commands are issued by the slicer, and whether they are supported by grbl.

Note that there is a question as to whether grbl supports FDM printing technology, i.e. 3D printers that use filament. Most slicers are designed to work with FDM printers, and will expect to be controlling at least one extruder. If your printer does not have an extruder that is controlled via G-code, you may encounter real difficulties generating G-code for it using commonly-available slicers.

RepRap Wiki: G-code


Ender 3 nozzle homes off the bed in the Y axis

Yes, this is the "intended" behavior, as the home in relation to the physical limit position is not placed correctly about 7.5 mm into the bed in both X and Y.
to correct this, please look at the Recalibrating Home-position for the Ender3


Problem with grid infill (line positioning)

It looks like a case of one axis affecting the other.  This is a subset of cases where things are not rigid enough.  Basically the movement direction in X is causing an offset in the Y, or whatever you want to call the axes.  It is present in small amounts in all screw-driven setups where the screw essentially acts as a wedge, and can be in others for various other reasons.  The solution is to tighten up your linear bearings/slides so that there is less transverse play.
There is also a chance that you are trying to print beyond the resolution of your printer, in which case it is "rounding" to the nearest within its capabilities, but that seems less likely.


Connecting Anet 8 2004 display with Ramps 1.4 to Aux2 can't seem to figure it out

This answer clearly describes that you need to switch pins 1 and 2. It also describes that the MKS board is similar to a RAMPS board.

First thing to look for is the layout of the AUX2 header:

The pin layout reveals that pin 1 is VCC and pin 2 is GND. These need to be switched to be able to connect the display on AUX2.


Printrbot going off axis when initializing

It is very common that FDM 3D printers "home" their position at the start of each print (as defined by the slicers preprint g-code). This is done by deliberately running the end effector towards its expected X=0, Y=0 position until it hits the endstop switches for each axis. Could it be this behaviour you are seeing? If so, I would suggest checking that your endstops are functioning correctly.

You can manually activate this homing action using the G-code G28 in (for instance) Pronterface. Alternatively, you can verify that your endstops are actually working using the M119-command while pressing each switch manually.


How do I know when filament is getting old, and what things can I do to correct for it?

The primary issue with long-term exposure of filament to the environment is that it will absorb water moisture from the air. When a filament that has absorbed water is passing though the hot end of a printer, the water will turn to steam and cause problems with extrusion:

Small bubbles of steam can form, causing extrusion to sputter - you might hear a sizzling noise and have poor consistency.
Large steam bubbles can cause significant oozing followed by no extrusion.
Extreme cases can cause mysterious jams that seem to clear themselves (the extruder cannot overcome the steam pressure).

In short, this will cause terrible print quality and failed prints. As the effects are not consistent, there is nothing that can be done by slicer settings to "recalibrate" for filament that has absorbed water.

This can be avoided by storing filament in an air-tight container with desiccant to ensure low humidity. Some people use "dry boxes" that allow the spool to be mounted inside while filament can be passed to the printer, so there is minimal exposure even while the spool is in use.

If you do suspect that your filament has absorbed moisture, you can dry it out, by placing the spool in a warm oven or in a food dehydrator for a few hours. If you weight it before and after, you should find that it weighs several grams less afterwards. WARNING: It is important that the temperature does not soften the plastic at all, or it can become distorted or bind on the spool. Most ovens will peak well above the set temperature as the thermostat cycles. Of course, fully melting a roll of filament could destroy your oven or cause a fire.

It's hard to say how much environmental exposure is too much, as every filament and environment is different. When I started out, I had several spools of PLA that I stored in the open for months. I didn't think I was having any problems, but I was also learning much and improving my printer settings at the same time. After getting PETG, it became unusable with oozing and jams after about two weeks but a few hours in my oven was a miracle cure! I then dried some PLA as well, and I found that print quality did improve, but not amazingly so. I have not used ABS, but in theory it is less hygroscopic than PLA, so it is probably not very sensitive to exposure.

I set up a dry storage box, and I am careful to always store PETG or my "good" PLA when I'm not actively using it. I have a couple rolls of PLA that I don't like as much anyway and generally just use for draft prints, and I don't really worry about it that much.

Note: An object that has been printed will also absorb moisture, but in general this isn't a problem.


Ender 3 seemingly speeds up too much on straight long shell lines

Your travel speed is set to 120mm/s so it would make sense the 128mm travel takes ~1 second. You most likely have combing turned on so that it doesn't not need to retract on travels. This makes it ooze plastic as it travels and would mimic underextrustion.


Connecting an inductive sensor to the Anet A8

I am not entirely familiar with the ANET A8 electronics, but it's very unlikely it's any different from how any other mainboard works, so any instructions that work for RAMPS should work for your board as well.
The sensor you linked to has an operating voltage range of "6V to 36V". However, the endstop connectors (on any mainboard I've come across) only provide 5V - not enough for the sensor to work. You could verify that this is also the case for your ANET board with a multimeter.
(Assuming the colour coding is standard) you'll need to connect the black wire to GND, the red wire to 12V, and the yellow wire through a diode to the signal pin of the endstop connector. The anode of the diode should connect to the signal pin and the cathode to the wire coming from the sensor.
The diode is required, because otherwise the 12V signal from the sensor will damage your electronics, which can only accept 5V. Any ordinary diode will do (for instance 1N4148). You should enable endstop pullups in your firmware when using this method (though if your board already has physical pullups this is not necessary but won't hurt either).
Note that if the sensor is inductive, it will also need an appropriate (metal) surface to trigger off. Unfortunately, it is not clear from the product description what type of sensor you have bought, and (amusingly) gearbest doesn't know either:

Question:
Hello, is this Sensor capazitiv or induktiv? Thank you verry much.
Reply:
It is an auto leveling sensor for 3D printers


Marlin Firmware Auto Leveling only re-centers the XY-axis (Delta printer)

You are correct to define the constants AUTO_BED_LEVELING_LINEAR and Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN, be sure to define the following also:

#define Z_MAX_POS MANUAL_Z_HOME_POS

and

#define MANUAL_Z_HOME_POS 300 // Distance between the nozzle to printbed after homing

Note that 300 should be the distance from nozzle to bed after homing.

Please look into the configuration files of this Kossel Linear Plus and compare them with your own configuration files, you may have missed something.


Is it possible to create a completely sealed box?

"Completely" is always relative, but for water at the pressures involved it's probably achievable. Normally you need some sort of gasket (material that can bend/compress to slight imperfections in the mating surfaces), and a means of holding the two surfaces tight against the gasket, to get such a seal.
With 3D printing, it's plausible that the print itself could be sufficiently non-rigid to achieve this, if you have a way of keeping the lid and box pressed tightly against each other - bolts through the lid, clips around the edges, etc. But it's unlikely to work well.
I would either print I suitable gasket in TPU, or cut one from some suitable material if you don't have the capability to print with TPU. Either way you still need to design your box and lid so that they're pressed tightly against the gasket.
One possible frame challenge would be doing a round box instead, with a circular threaded lid. It's likely that you could achieve a decent seal for your purposes without any gasket just by tightening the threads, and if not, you still have a really good setup for use with an added gasket.


This effect you see is called stringing. Stringing can be reduced by changing any or a combination of the following slicer settings:

lowering hot-end temperature, (less heat means less heat input so less runny filament oozing out),
increasing travel speed, (increase in travel speed reduces the time to move to another point implying less filament oozing),
retraction, (increased filament retraction reduces the pressure build-up in the hot-end decreasing the filament oozing)
increasing coasting length (coasting means that you stop extruding filament prior to a move when the head is still printing, this is explained by the pressure build-up in the hot-end; ideally you set the coasting length as such that all the material that is pressed out as a result of the pressure build-up is extruded just before the head moves/travels to another location),
print part cooling, (see this topic)

In order to find the correct settings you will need to print so called calibration test prints. There are a lot to find on Thingiverse, just search for "stringing".

Your print temperature may be a bit high, but some PLA filament brands require that, I don't know if that is the case with your filament, but you could start try lowering that by 5 °C a time.


It's really pretty easy to diagnose a Hall effect sensor. If you plug the sensor into the board (so it has power), then wave a metal object (screwdriver tip should work nicely) very close to the head of the sensor, the light should go on if it's reading. If the light doesn't come on, there's an issue. An issue would most likely be the wiring. You may want to test the same sensor by plugging it into a known good port on your main board. Any of the axis stops should behave the same, but since it's both the x- and y-axis sensors which are not functioning, I'd try attaching them to the z-axis stop.


You are correct, you can over cure a print by leaving it out in the sun. Prints can even over cure just by the ambient light in a room from the sun (though it would take a while).
One easy option to counter this krylon UV-Resistant Clear Coating which can be found at most hardware stores. I have used it but I found that it made my print a little softer this may have been because of the materials in the spray-can, or the type of resin I printed with.
You should check out the answer posted to Clear coating resin 3D prints as it provides some other options you can try as well such as using a brush on option.


How drastic is reversing the polarity of the power supply to a RAMPS board?

Polyfuses on the RAMPS
Fire appears to be the immediate issue, in the poly fuses.
From Reddit: reversed polarity, RAMPS on fire

Sooo I made the dumb mistake of reversing the polarity from my psu into the RAMPS 1.4. As warned the ramps did not like this and smoke began to rise from the board. I am pretty sure I saw smoke only coming from the two ptc fuses (big flat yellow ones).

Replacing poly fuses
Note: Older RAMPS 1.4 have easily replaceable large poly fuses, whereas the RAMPS 1.5/1.6 use SMD poly fuses, see 0scar's answer to RAMPS 1.4, 1.5 or 1.6?

Arduino
According to this user, the MOSFETs and the Arduino Mega's regulator can be fried as well:

it most likely fried the mosfets next to the fuses and probably the voltage regulator on your arduino.

However, the fried regulator would only affect the Arduino's operation if powered through the power socket, or VIN (which the RAMPS board uses to power the Arduino Mega). However, via the USB it should still work. See this post, on the same thread:

The voltage regulator is only needed if you supply power to the arduino via the Vin pin or with a separate power adapter. The RAMPS board does supply the Vin pin with 12V.

So, you would probably have to rely on powering the Arduino via the USB and not the RAMPS
Regarding the Arduino, on Arduino.SE there are a number of users who have fried their Arduino in this manner, and many of them suffer slightly different failures, although most are centered around the regulator. One case I remember was that of a capacitor burnout, see Is my Arduino dead? - although the use case was different. There are many other cases on the Arduino.SE.

Protection Diode
According to this post on RepRap - Reverse Polarity, there should be a reverse polarity protection diode (although it appears not to have work in the above example):

If it was a ramps, those have a reverse protection diode across the input that normally needs replaced after such an incident

Stepper drivers/motors
The stepper motors themselves should survive, as should the stepper drivers.
However, each case can be different and it would depend upon the quality of the board (is it a cheap clone or branded?), and the quality/tolerance of the components used - these factors would determine where in the chain of modules the failure occurs. Obviously, the earlier the failure's location in the chain the better.

MKS Base v1.2
As an aside, this user fried their regulator (the fuses were fine) on a MKS Base v1.2 (not RAMPS), by reversing the polarity, which caused the stepper drivers to fail. However, replacing the regulator fixed it, see this post:

Replacing the regulator chip did fix the board.

Rather helpfully the self same user has posted an Instructables of the repair: MKS Base reverse polarity repair.

RAMPSXB
There is no protection diode on the RAMPXB. From RAMPSXB:

Do NOT reverse polarity on the input pins, as there is NO PROTECTION DIODE. Reversing polarity will not only fry your steppers and FETs, but may even damage your Arduino and possibly even your computer. Triple check to make sure the polarity on your power input is 100% correct!

See also

Arduino Forum: Checking the RAMPS 1.4 for some handy troubleshooting tips for the Arduino and the Stepper.

This user on post #5 of Arduino Forum: Checking the RAMPS 1.4 did manage to fry their stepper drivers, but not due to reverse polarity, by from a loose wire:

I didnt connect the power backwards, but either I had a defective Mega2560 clone, or some stray bit of wire somehow shorted something out, and the Mega2560 literally went up in smoke (almost caught on fire !)
Every stepper driver was destroyed, but the power FET's and other components survived


How to find Printrboard pin numbers in Marlin

As FarO suggested, from github:Printrbot/printrboard/revF2 (via RepRapWiki - Printrboard - Revision History), the EagleCAD board layout and schematics are contained in the printrboard-revF2.zip:

Printrboard.sch
Printrboard.brd

This is the EagleCAD schematic:

EagleCAD board layout

Not quite the annotated diagram that you were after, unfortunately, but it might help.

There are a couple of configuration files on KevinOConnor/klipper, but unfortunately only for revisions B to D (at90usb1286) and G (SAM3x8c)... E and F are not available.


Is this the correct motherboard for my Creality CR-10S Pro V2?

The board that's installed in your machine appears to be the Creality v2.4 / v2.4.1 board, which is the correct board for your printer.
It is distinguishable by the 30-pin ribbon connector, which is used to connect to the rest of the printer.
The board in the tech support pictures is the v2.5.2 "silent board", designed for printers such as the non-Pro CR-10 series. It features two 10-pin connectors for the LCD screen.
It also uses individual connectors for all functions, so, contrary to the "Pro" boards, is also easily swappable with aftermarket boards.
A third type of board (e.g. v1.1.5) exists, mostly for the Ender 3 series of printers, which features only one 10-pin connector for the display.


Solved the problem, I was missing this line:

#define ENDSTOPPULLUP_ZMIN_PROBE

Apparently the sensor required a pull-up to better define the signal.


Looking to use 3D printing to make a master plate for rubber stamp vulcanizing

This would likely not work. ABS has a glass transition temperature of 105 °C. It doesn't have a melting point because it's amorphous. Rather, as you heat the part up, it gradually transitions from a solid to a viscous liquid, but there is no "hard" transition from solid to molten at one particular temperature.

The glass transition temperature, at 105 °C, is significantly lower than the 200 °C "melting point" of ABS you quoted. At 160 °C, while ABS would not be molten sufficiently for 3D printing, it definitely becomes flexible and would deform easily.

I do not think it would hold its shape very well over the long period of time it has to spend in your vulcanizing machine, under high pressure and well above its glass transition temperature.

The surface of 3D printed objects also usually has a somewhat rough finish. If you wanted to make satisfactory stamps, you would probably need to spend a long time manually finishing the 3D printed master before making a mold from it.


It turned out, it was a faulty heater, that wasn't able to reach and maintain temperatures over 195 °C in a stable manner. The order came, had a new 50 W heater, thermistor and a PTFE-Bowden tube. It works just fine again, now!


Whats the difference between a basic rapid prototyping machine and a 3D printer?

All rapid prototyping means is automatically producing a physical part from a cad model. 3D printing is a way to achieve rapid prototyping. There are 2 main methods of rapid prototyping: additive, and subtractive.

A 3D printer is additive- you add materials to an object layer by layer.

Usually, when people talk about a subtractive machine, they are talking about a CNC mill (or lathe), which tend to be extremely large (most are over one ton). You start with all the material there, and you subtract the material that you don't want. This might be what you are thinking of.


Do thermistors degrade in accuracy without hard failure?

Yes, thermistors can drift in value as well as outright failing (usually open).
In my experience this is not uncommon in thermistors operated above 100 degrees C. The drift is typically downward in resistance so the controlled temperature will be less than the desired setpoint, which is exactly what you are observing.


Ender 5 Plus not going "home" (or zero) correctly

Is your BL touch flashing red, or is it solid red? Flashing red means that the bed is raised up too high, there needs to be enough clearance for the measurement probe to fully extend when you start it up.
Even if it is not flashing red, try moving the print head and bed manually:

Remove your SD Card, unplug any computer hooked to the printer's USB cable

Boot UP Printer

Tap Settings

Tap Move

Move Z down at least 50 mm from print head

Move Y so it is resting against the stop switch

Move X so it is resting against the stop switch

Turn it off and wait for a minute or so

Turn it back on

Tap Settings

Tap Leveling - this will make it do the homing function

This should get you to the correct home position, but if you are still having problems, you need to re-level your printer manually and you may need to adjust the Z-offset.
The Z-offset tells tells the printer to Add or Subtract height on the Z-plane to get the nozzle close enough to the print bed that the extrusion sticks.
Let us know if this works for you, or if you found a different solution.


I have experienced this problem.  This picture is one that I could have taken.

It has always been because I was putting too much plastic into the available space.

This has been caused two things: overextrusion -- squirting out too much plastic for the intended layer height, and the bed being too "high" so that the gap between the nozzle and the bed is too thin.

In both cases, too much plastic is trying to be placed in too small a volume.  The plastic has to go somewhere, and ripples follow.  Because the nozzle rubs against the adjacent lines which have already been deposited, an up-bump pushes up the nozzle on the line beside the bump, and a coherent pattern of ripples can form.

The "bump up" is a real effect from the elasticity of the Z-axis, including all the resulting strains of twisting and lifting the nozzle.


That depends on the use. If you have a slate of glass a dip might be better (but the heat transfer at the dip would not be ideal), a bulge would stress and tilt the glass.

If you print directly onto the metal build surface it would not matter if you use a(n automatic) bed levelling system because you can compensate for the bulge or the dip using a mesh of the bed. Without a scan of the build platform you would have issues in getting the filament to stick.

Basically, there is not a better solution, best solution is to get a flat bed if the bulge or dip are making printing difficult.


Have to get this out of the way... Can you just print the hole into the part instead of drilling? That's usually best, when possible.

If you need to drill, you'll definitely want to print an undersized hole and then ream it out with the drill. This both provides alignment for the drill and adds extra plastic around the region you'll be weakening. If you don't know where the hole needs to go in advance, fill the model with a hex pattern of tiny holes in the general region of the future drilling. This is an easy way to strengthen the area with more plastic without making the entire part solid. (Using a slicer that allows localized print settings will also work.)

The hole should be aligned more or less vertical or "across the grain" (+/-45 degrees aligned with the Z axis) to ensure there are nice, strong hoops of plastic around the hole to keep it from splitting. Drilling into a printed part (particularly PLA) from the side / parallel to the XY plane is highly likely to split it. It may even be ok at first but crack later under load or due to creep.

Regular wood drill bits work ok, but you need to go slow and take nibbles, leaving the plastic time to cool so it doesn't melt and stick to the bit. (Coolant is an option.) Use a pilot hole, piloted bit, or step drill to remove less plastic per pass. A really sharp bit will perform dramatically better than a dull bit.

Put something hard and drillable like wood behind the plastic part to help avoid breakage and bit-jamming when you break through the opposite side.


Retuning a very delicate and tricky print after print failure

The print is extremely challenging, as it has a lot of thin diameter items growing up, a lot of overhangs and a rather small surface to hold to the bed. So you need a Brim and support:
As OP found, a Brim is a setting that adds extra material in the first layer around the print to increase adhesion.
Support Structures are to give an overhang something to rest upon. Removing them can be tricky, but they make some things printable at all. Like this bracelet. You'll have to finetune your settings, best by learning with less complex models first or mimicking the settings of others that made the bracelet.
The thin vertical parts can make the print fail nevertheless - you can possibly fix some of the vertical adhesion issues by printing slower. If these parts are too thin, you might be unable to print them at all with a 0.4 mm nozzle! As a rule of thumb, it is really tricky to print pillars slimmer than 2.5 nozzle diameters and almost impossible to print them nicely under 2 nozzle diameters.
My settings
I print my PLA at 200 °C, the bed at 60 °C, but then again I don't have a glass bed.


What are some conductive filaments that can be used in printing electronics?

At this point conductive filaments are a very new thing. All the filiments on the market are PLA based that have been infused with Carbon or Graphine

However I worry you over estimate what you can do with this. You will at most be able to 3d print a simple wire and power a LED. You will not be able to run a microcontroller, and honestly I would expect a complicated print to have too much or too little resistance, maybe burst into flames.

You really should look into the Voxle 8 and other printers. The printer is really the driving factor. Using a conductive filament will not be enough. Note this printer uses a syringe not PLA plastic.

Here is a Voxle8 print.


Ultra high precision and accuracy printing

This is an interesting question. A good thing to note when we start talking about SLA and other jewelry grade 3d printing, that you will have to factor in the materials toxicity when we start talking about medical applications. You can also look into DLP 3d printers but they will not have as good quality.

What can help you right now is these SLA printers I see that form 3 has 25 microns, with a laser dot of 85. Well within your tolerances. Just make sure to get dental grade or medical grade resin.

Note that if there are bends, then you will have issues with SLA printing, depending how steep the angles are.

There are other technologies, such as metal 3d printing or SLS printing, that will likely be out of your price range such as the HP Metal Jet that can do 21 -xy by 50 -z microns. Or binder based 3d printing which will have the best internal geometry, as powder will act as support, and is easily removed.

There are many specifically in the bio printing area that might be what you are looking for as well, this is more an alternative. You can look into what the researchers at Penn has been doing, where they have been using Sugar to create vascular networks. As far as I know they do not sell it as a product at this time. Here is more information about scaling vascular networks

See here for more information about other printing technologies


I would say that the clue is in the name, MiniRAMBo. The Mini part is related to its diminutive size and reduced functionality.
Extending the board would require patching in a secondary board to the MiniRAMBo board via pins1 that may or may not exist, and would probably be more trouble than it is worth.
Looking at the board layout certainly shows that there are not any readily available connections for such an expansion.

If you want two extruders then the RAMBo would be a better bet, as it has 5 stepper motor driver outputs. It would certainly be easier, and quicker (as well as cheaper) than a MiniRAMBo plus a secondary daughter board).
That said, as the MiniRAMBo has two Z-axis controllers, it may be possible to repurpose one of them, if they are wired independently of each other and separately controllable. Although these lines suggest otherwise:

It has 4 stepper drivers and 4 mosfet switched outputs.

and

Differences from Rambo
MiniRambo has:

4 stepper drivers vs. 5

and

Motor Drivers
4 A4982 1/16th microstep motor drivers(2 connectors on Z for Prusa
Mendel and other dual Z printer designs)

So, it would appear that the two Z axis drivers are wired together.

1 By pins, I mean external board pins/connectors - rather than the pins of the µController itself


3D printing related safety precautions for a baby rattle

You're on the right track.  Since you asked for "steps" here you go:

Step 1. Choose a safe material:

Consider chemical safety and physical safety. Food grade PLA should be chemically safe, but could be too brittle depending on the design you choose.  PETG, T-Glase, or similar filaments (depending on dye) are normally also chemically safe and are less brittle than PLA so may be a better alternative.  ABS is NOT typically considered safe for food contact.

Step 2. Choose a safe design:

If using PLA, be sure the design is robust enough to ensure it won't break.  Broken rattles with sharp edges make baby...sad.  Even less brittle filaments can still break with jagged edges if the design is fragile.

Step 2a. Choose a single piece design:

Choose a design that requires you to add the peas (or other safe filler) during the print such that the finished rattle is fully enclosed.  This will minimize parts becoming loose or peas spilling and minimize choke hazards.

Step 3. Consider post processing to improve safety:

Sanding could reduce ridges and minimize crevices that could harbor bacteria, but sealing it with a food-safe sealant may be more effective.  There are many sealants that the FDA considers safe, but polyurethane or food-safe epoxy finishes will work well with PLA. (If you use a different material, test to verify good adhesion.)

Step 4. Test:

Make a test rattle and run it through the paces.  I guess you could chew on it, but since babies don't have teeth, this might invalidate your data...

Step 5. Consider alternatives such as professional printing services:

If your tests don't inspire confidence, professional services can offer additional materials (metals, ceramics, etc.) that could be safer than a typical fused filament printer.


Which common 3D printing materials/methods will suitably replicate (w.r.t. durability) this injection molded Polypropylene item?

No FDM print at all.
The problem of your design will not be the materials, but a basic property of FDM printing: FDM Printers do create a structure by placing a long string of filament next to itself and ontop of itself, creating tons of boudaries.
These boundaries between the layers are the weak points for this application: Even if the material like ABS could withstand the blow handled with such a club, the print will break at its weakest point - which in this case is any layer boundary. This is amplyfied by the basic design we have here: The elongated shape will serve as a lever on each of the weak boundries, until one gives way and results in catastrophic failure and a flying clubhead.
Non-FDM for the rescue.
To counteract this, you need to use a different method than FDM printing to get a more homogenous material than the bound deposited filament. Such methods could be for example SLA (Stereolithography) or SLS (Selective Laser Sintering). Both could easily offer even tiny details.
SLS uses Nylon or metal powders, sometimes even ceramics - Tungstencarbide for example.
SLA/Resin
Using a Resin printer using the SLA methods results in an object almost as homogenous as an injecion molded object. Proper aftercare and curing is required to get the best results. Also, Resin prints usually age under UV light, which can negatively impact lifetime. SLA printers are expensive (for home printers), print shops that offer them relatively rare and costly (in comparison to FDM) but usually offer superb resolution and almost perfect smoothness. A lot of the exact material properties is resin and aftercare dependant.
A way around the aging could be that the results of an SLA print could be used to create green-sand molds countless times, which can be used for casting metal or even some thermoplastics. Remember though, that cooling metal shrinks.
SLS Nylon
Nylon would be a medium rigid, light solution, but it ages and has a quite rough surface. It does offer some flex, almost perfect for this application. While most SLS machines for nylon are commercial to industrial, print technology of this kind is widespread enough to make them somewhat affordable (for an industrial printer) and printshops for these relatively common, prints are not cheap but well priced.
DMLS / SLM
Direct Metal Laser Sintering and Selective Laser Melting - an evolution of SLS - allows to create structures from various metals by sintering/melting powders of metal at the right spot to gain shape. The benefit would be, that you get a part that could withstand much more destructive testing than your bottle used as a clubhead - you get a workpiece of solid metal (Steel, aluminium, Titanium and a lot others are available) after all that has the same properties as a cast item. The big downside is, that only few companies currently delve into DMLS, among them the former patent holder of many of the FDM printing patents, Stratasys. This means, that a machine for this is industrial rated and priced, and that print suppliers charge accordingly.


Important build plate characteristics/qualities

If your printer's heated bed still works, but the sticker has been ripped in some places:

You can try and remove the rest of the sticker, clean the metal plate under the sticker (perhaps with isopropyl alcohol) and then apply a new sticker once there is no adhesive remaining on the heated bed.
You can remove the sticker with the method above, but instead of replacing it with a new sticker, you can buy a PEI sheet and cut it to size if required (read more about PEI here) and then stick it to the metal plate.

Personally, I would recommend the latter option, since PEI is low maintenance and the prints automatically pop off the sheet once it cools down, however just make sure not to print PETG on it, since it sticks too much.

On the other hand, if your entire heated bed is broken, the best-case scenario is to look for a heated bed that was designed specifically for your printer. Especially since your printer's heated bed has 3 mounting screws instead of 4.

If you somehow have a solution for mounting a heated bed with 4 mounting screws on a printer that uses 3, the things you need to watch out for are the heated bed's operating voltage (it should be 24v) and the dimensions must be the same. If the wires are not provided with the heated bed, make sure to get wires that have high enough gauge so that it is able to handle the high currents that the heated bed will need.


Does XYZPrinting software allow the creation of rafts when printing?

Ok. After watching some YouTube Videos, I would take it that the abovementioned software does include the option to create rafts when printing a model.


Teflon tubing in nozzle throat coming out?

It looks like you got too tight nozzle, too cold hotend or extruding speed is too high (all could be in the same time of course).
As filament goes into the teflon tube (coldend) and then into hotend it doesn't have enough time to go out throught the nozzle. So it causes that melted filament accumulates in hotend and pushes out teflon tube.

Check application and arduino settings for

nozzle diameter (increase it), check if it's not plugged with something inside
hotend temperature (increase it), check for your filament settings
extrude ratio (decrease it), check also gearing on extruder motor


Anet A8 Clone LCD not working after flash

According to the link to the fork of Marlin you need to be sure that a bootloader is present before flashing, see pins_MELZI_WYH.h:

/**
 * Melzi (WYH) pin assignments
 *
 * The WYH-128 board needs a bootloader installed before Marlin can be uploaded.
 * If you don't have a chip programmer you can use a spare Arduino plus a few
 * electronic components to write the bootloader.
 *
 * See http://www.instructables.com/id/Burn-Arduino-Bootloader-with-Arduino-MEGA/
 */

From this same pins layout file you can find hints to the usage of the REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER display:

// For the stock M18 use the REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
//   option for the display in Configuration.h

Maybe you can use that one instead of the "Mini VIKI". Though, an internet search, does hint to the "Mini VIKI" being the correct display for this printer, but it does look different from other Mini VIKI displays.

Note that in the Configuration.h, by default this display is not enabled as can be seen:

// RepRapDiscount FULL GRAPHIC Smart Controller
// http://reprap.org/wiki/RepRapDiscount_Full_Graphic_Smart_Controller
//
//#define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER


Is there a way to save a multi part print if one fails?

If you use the OctoPrint print manager, you can exclude regions to be printed using the Exclude Region plugin. The description states that it can be used to rescue partially-failed prints:

The intent of this plugin is to provide a means to salvage multi-part prints where one (or more) of the parts has broken loose from the build plate or has otherwise become a worthless piece of failure. Instead of cancelling an entire job when only a portion is messed up, use this plugin to instruct OctoPrint to ignore any gcode commands executed within the area around the failure.

Other print managers may provide similar facilities.
I'm not sure if it will enable you to rescue your current print job.


BLTouch does not compensate for differences in bed level

The issue was BLTouch i'm not sure what use is this thing if it cannot compensate for differences in bed or frame.
I'm not sure why but the probing seems to be bad. I tried everything clean TH3D install and config, pitch perfect alignment of everything frame, bed, mounts everything. Perfectly calibrated Z offset at the centre of bed. I triple checked the belts. Checked if X axis was off or if any screw was lose, checked wheels to make sure everything was snugg.
Anyhow in the end the issue was with bad BLTouch probing not sure why. I gave up and went and disconneced BLTouch did manual bed leveling with the paper method. Press print and I got a perfect print. Like literally perfect. Even extrusion everywhere.
BLTouch seems to have probed the distance at the centre of bed, I set the offset for it. Than when it went and probed other corners before the print it seems to have read the values wrong.


Just solved my own problem. Instead of looking in Marlin for the command, I found out the reason it was lifting up quickly was because of a custom command embedded in the G-code by the slicer. I got rid of the command and the problem was solved.


Is there a way to make a watertight model? Is there a spray that may work?

There are several ways to ensure water tightness:
Thicker walls
I have experienced that 3 walls and 5 tops/bottoms with an outer shell of Concentric while the core is lines become watertight enough that leakage is almost none.
Lacquer
The oldest known method to seal a piece of porous material is a lacquer, followed by glaze. Glazes require to be burned at some thousand degrees, so are out, but lacquers are simple and easy. Basic clear acrylic lacquer can be used to seep into all the cracks and crannies and then harden out. It's easy to apply and cheap from home depot. Polyurethane lacquers also work. If you look to use it for food, ask if the lacquer is food rated in home depot.


Is it possible to make a hermetic sealed 3D Printed case?

A few thoughts that might help...

Material:

ABS can be vapor smoothed with Acetone which results in the layers sort of "melting" together to form a smoother, and less porous surface.
Other plastics can be smoothed with compatible solvents, but I've not tried solvent smoothing with anything other than ABS.  Be careful if you try.

Print Method:

Consider slightly higher print temps to increase layer adhesion.  You'll likely have to compensate with extra retraction to avoid excessive stringing.
Consider more perimeter layers and more top/bottom layers.
The CF materials are stiffened with chopped CF strands...I think it's a stretch to call them "reinforced" unless you happen to have a Markforged printer or similar.

Sealants: This is probably your best bet.

Epoxy: Generally considered effective for producing hermetically sealed containers.  Dip or brush on.  Mind your VOC's and pay attention to working time.
Plasti-dip or similar sealants: These may be good enough for your application and result in a rubbery coating over your part.  Good for water sealing, and may be close enough to hermetically sealed for your needs.

Design:

To mechanically seal the opening, there are many options depending on your requirements.  O-rings, gaskets, etc.  If you use a rubberized dip, you may be able to skip the gasket.  You could install a few threaded inserts around the perimeter of the opening, put in the screws, then dip.  After drying, you slice around the screw and remove it (this just keeps the coating out of your threads)  Dip the cover as well.  Then when you screw on the cover, it will provide a water-tight seal.  To help make a good seal, apply a silicone grease to the mating surface.

I hope this helps.  :-)


How to have double extruder and double Z motor on a 5-driver board?

I second the previous answer if running second Z motor in parallel, just split wires or buy adapter consisting of two females to one male, Z motor on most printers don't draw huge current (or at least in smaller less frequent intervals to give things time to cool).

Erm I extruder with two temperature zones, hmmm buy a larger heating element, like a E3D Volcano or I believe they have an extreme version now, mine is rated for 40 W+.

Or you could use external MOSFET with separate Arduino PID.


For reference, I have the same printer and am speaking from my experiences.

You have two routes you can take with this, but both are effectively the same result - you need to replace the X carriage.

If you want to re-use your existing extruder components you can pull the MK8 extruder off the X carriage and use it as the extruder to drive a bowden configuration, then all you need is a length of PTFE tube and the couplers between the E3d and the MK8 to hold the tube. This is probably the best solution as it takes a lot of weight off of the X-carriage resulting in significantly better print quality, the only downside is that printing with flexible filaments is a lot more difficult with a bowden configuration, if you intended to do a lot of that.

The other option (and the one I took) is to print an entire new x-carriage/extruder assembly. Because the Anet A8 is based off the Prusa and the Z/X carriage assemblies are basically the same as the original Prusa I3 you can just take any design for the Prusa and fit it onto the Anet, I did this with a gregs wade extruder & E3D hotend mount I found on thingiverse.

I didnt look too hard, but if you are adament on wanting to keep the MK8 extruder on the X-carriage and couple it direct-driven to the V6, you can probably find some x-carriage that lines the two up for this purpose (or you could even design one yourself if you are interested in doing so). I didn't look in to this route myself, so cannot give much guidance.


The grooves (notches, more accurately) are acceptable and indicate that your hobbed gear has a good grip on the filament.

Many factors will cause your probably-correct diagnosis of under-extrusion. If you are confident that your extrusion settings are correct, you could have this problem from under-temperature on the nozzle.

One method to assess this is to increase the nozzle temperature by five degrees C and examine a test print. If the gaps are reduced but do not disappear, consider an additional step or two of five degrees.

If you are so inclined, locate one of the many temperature tower models and modify them accordingly for your printer. This will give you a good range of temperatures for best results.

Also note that different filaments will have different temperatures and the temperatures will vary between colors from the same manufacturer and between different manufacturers.


What’s the best way of leveling the bed?

Generally, there is no best way, there are only the ways that work for you.
I use a feeler gauge, mounted on a detachable holder. I home to 0, lift the Z by 1 mm, and then level the bed to the same number on the screws and corners. Then I home back to Z=0 and perform an extrusion test, and if that is not satisfactory, use a different number for the leveling. The number on the plunger does not generally read 1 mm, as there is an offset between the 0 of the gauge and the printer.
When I don't level from 0 or am in a hurry, I usually only alter leveling by doing about 2-5° turns on all the screws to adjust the 0-height via the nuts, using the visual of the printed line as my aide. This only works because I have the experience how a good first layer should look like.
Another typical method that I stopped using once I had the feeler gauge is the paper, but I found it inconsistent.
Do not do these:

Leveling the bed with a level does not lead to good prints - your print bed needs to be parallel to the movement of the printhead, not to the earth!


How to join pieces automatically using interlocking or similar?

I'm not qualified to advise regarding Solidworks, but can suggest a process and concept from which you may be able to adapt to your software.

As you have the two pieces currently in STL form, it makes things only slightly more difficult. Consider to align them parametrically so the faces contact and the edges are coincidental. The block STL will appear as a single cube, in the example you've provided.

Create and place a mating cylinder piece in the desired position as you've shown in the second image. It is a common feature of many 3D modeling programs to be able to perform a subtraction of one part from another. It is equally common to be able to merge two parts into a single manifold part.

Save the file containing the three parts.

Select either block and the cylinder. You can delete or otherwise hide or deselect the unused block. Perform a subtraction on the remaining pair. Save this file under a different name.

Reload the three parts file.

Select the other block and cylinder, perform a union of the pair. Save this file under a different name.

Rather than saving the three parts in a file, one can frequently save the joined or subtracted part and perform an undo until the three parts return. This is a faster more convenient method.

I have performed the above steps in Meshmixer and know that it can be done in Blender, if one is skilled in these programs.

I've performed an internet search for "perform boolean subtraction solidworks" and found multiple results for this process. One link references the "cavity" feature for subtraction. I did not search for boolean union and leave this as an exercise for the reader.

Consider also to plan for this activity in the future by leaving the block intact, unsliced, place the cylinder, perform the boolean action, then slice it as desired. The sequence of saves and/or undo actions will be different from above, but may be easier than re-aligning a previously sliced "block" or item.


From your comment on the linked question you state:

  As talked about above I just checked my "minimum layer time" and it is set to 10

Note that Cura's default value is 5 seconds.

This means that the print speed is lowered down to the minimum print speed to have layers that print for at least 10 seconds. When it cannot print slower (there is a minimum print speed) and the minimum layer time has not been reached yet, the print head halts until the time value is reached, then it continues. This behaviour is expected when the print area becomes small so that the time per layer drops under the 10 seconds.


Is there a way to print with ABS without enclosure?

There is no requirement for an enclosure when printing ABS. Like many things in FDM, there are improvements to be made, but there is a scale of what is possible.

A heated bed is much more necessary (for similar reasons, the thermal expansion is significant and without a heated bed you have very high risk of warping).

An enclosure is important for high quality, large ABS prints. Otherwise, a warm location which is free of drafts will be fine, particularly for parts which are only a few cm high.

If you're not using an enclosure, the part cooling fan should probably not be used to print ABS. You should also be aware that ABS tends to generate more noticeable fumes than PLA (although this varies with product, and how sensitive you are).


Check your retraction settings. I had a similar issue and it was caused by the retraction, It retracted just about enough so the gears couldnt hit the hole properly to feed the filament into the nozzle. To fix that I lowered the value of mm on the retraction settings.


3D printer test troubles (M999 error, motors do not move)

Two immediate issues I can think of are:

Do the floppy drive and DVD drive stepper motors have sufficient torque to turn whatever you have connected them to? You don't say what sort of printer you have built, but a holding toque of 44 N·cm (62oz·in, 4.5kg·cm) or more, is desirable. Maybe you should consider upgrading your floppy ad DVD drive motors to Nema 17 motors... See RepRapWiki - Nema 17 for more details.
Do you have the correct thermistor selected in the firmware? Check your firmware configuration file.

To further check the thermistor, disconnect it from the RAMPS board, and using a multimeter, check its resistance at room temperature. Then compare it with the temperature characteristic graph of your thermistor type. A general 10K thermistor has the following response curve (source):

Does the reading that your multimeter gives, seem reasonable?

Also check the RAMPS thermistor input, by shorting the thermistor pins on the RAMPS board (using a jumper). What is the temperature reading now? It should be whatever MAX_TEMP is defined as, typically around 400°C. Again, check your firmware configuration file.

In addition, M999 is not an error, but a command used to reset the firmware/printer, after an error has occurred.


Massive over extrusion after changing firmware

Very wise to change the firmware of the stock Anet A8. The stock firmware does not have thermal runaway protection which Marlin Firmware does have.

You should be able to print equivalent or slightly better with Marlin Firmware as you can tweak it better/easier than the closed firmware clone of Repetier that is originally loaded onto the board. My A8 runs perfectly fine on 1.1.9.

To identify if this is over-extrusion, you need to check out the settings of the steps per millimeters that are defined in your configuration.h file:

/**
 * Default Axis Steps Per Unit (steps/mm)
 * Override with M92
 *                                      X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
 */
#define DEFAULT_AXIS_STEPS_PER_UNIT   { 100, 100, 400, 100 }

Furthermore, rather than calculating the flow reduction, you could calibrate your extruder.

From the images it it hard to say whether this is over extrusion or not, it does look like it is printed at a high temperature. Please update the question to include print material and print settings (hot end temperature).


This is a classic example of not enough adhesion. Tune bed temperature (usually hotter), use a brim or add an adhesive layer like glue stick or hair spray or a dedicated print adhesion spray.
The question "Warping of bottom of print" has an accepted answer that explains in detail how and why this occurs.


There are two main special steps to the technique used by most open-source 3d printer controllers:

Divide each linear gcode segment into lots of very small subsegments ("Segmentation")
Use some basic trigonometry or the pythagorean theorem to tie extruder position to carriage height for each of the three towers ("Inverse Kinematics")
to find the target position for each small segment

The inverse kinematics are surprisingly simple. A virtual 90 degree triangle is constructed from two known lengths to solve for the unknown third length:

The fixed delta arm length is the hypotenuse of the triangle
The horizontal distance between the column joints and end-effector joints is calculated from the XY coordinates of the nozzle and the fixed position of the column, to determine the length of the lower side of the triangle
The length of the upper side of the triangle is calculated from the previous two via the pythagorean theorem
The length of the upper side is added to the nozzle Z height to get the necessary carriage height

I think the best open-source reference here is Steve Grave's Rostock Kinematics document, rev3 available for download here: https://groups.google.com/d/msg/deltabot/V6ATBdT43eU/jEORG_l3dTEJ
Some relevant pictures:

These inverse kinematics calculations are performed for each carriage to get a "carriage space" target position, and this is performed for every path sub-segment.

The results from these steps can then be reinserted back into the standard linear path interpolation techniques for the printer, in which it fires steps in the necessary ratios and at the necessary rates to produce the desired straight-line motion and acceleration/velocity profile. (How THAT is done is a different question.)

The net effect is that the printer will move through a series of small "linear" carriage movements (linear meaning constant* speed with respect to time) that collectively approximate the necessary curved (quadratic position with respect to time) carriage motions required to produce a straight-line end-effector move.

*(Constant speed before acceleration slowdowns are applied in order to obey dynamics constraints, anyway. Again, that's the subject of a different question.)

Segmentation is very similar to the process of using a polygon to approximate a circle. If the facets are small enough, the polygon is a good approximation. Higher Segmentation rates produce less path-following error.  The primary conceptual difference between drawing circle arcs and Delta motion paths is that the so-called "faceted arc" with Delta Segmentation is constructed in height-vs-time coordinates instead of the X-vs-Y coordinates you'd use to draw a circle on a computer screen.

This system is used in large part because support for Delta style printers was originally bolted onto GRBL-based motion planners which were written exclusively for straight-line motion paths in Cartesian printers. It was a relatively minimal modification to the existing codebase compared to implementing full quadratic path interpolation.

Techniques have evolved over the years. And alternate approaches are often used: for example, the dc42 fork of RepRapFirmware performs exact path-following without segmentation, by recalculating the proper time for the next step after every step. This is functionally equivalent to approximating a circle with a polygon facet count so high that every pixel on the screen gets its own facet. So it is exactly as accurate as the positioning resolution of the motors allows. The downside is that this segmentation-free technique is fairly processor-intensive, so it only works on relatively fast controllers, not the older 8bit Atmega AVR that powers most existing consumer/hobbyist printers today.

Other techniques are possible. The academic parallel robotics control literature is a whole other world of mathematical techniques and complexity in order to produce generalized control algorithms that work for a wide range of robot mechanisms. The version we use in open-source 3d printers is quite simple and application-specific in comparison.


The extruder advance feature is probably not enabled on your printer, so this code effectively does nothing (and you don't need to mess with it). Extruder advance is a feature that tries to compensate for the delay between feeding (or retracting) the filament and the point at which it actually starts to extrude, but it's generally not used. The fact that the manufacturer left D_FILAMENT at the default of 2.85 probably means they didn't enable this. You can check whether it is enabled by seeing if there is an (uncommented) #define ADVANCE.

The reason D_FILAMENT appears twice is because they're computing the cross-sectional area of your filament, which proportional to the square of its diameter.

The arc interpolation settings have nothing to do with extruder calibration at all, but define the resolution at which G2/G3 approximate arcs. G2/G3 are currently not supported/used by most slicers, so you can safely ignore these settings since they don't do anything that would influence regular printing.

The only thing that you should change is the following line in the Configuration.h file:

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

Leave the first three values as-is (they may be different for your printer) and change the last one to 417.

You could also avoid changing the firmware at all, and use M92 E417 to set the steps per mm for your extruder, or (if you have an LCD) use the LCD to adjust the steps per mm.


You will really need to specify your constraints better because the short answer is yes, what you describe is entirely possible, but without knowing whether you are limited to a particular budget, process, or aesthetic, it's not a particularly useful answer.

Some machines (ex. Stratasys Connex 1000) will print models up to 1m in length, so sure, you could print an entire hull with the dimensions you specify.

Pros:

Monohull construction
Excellent surface finish
Many resin options are UV and salt water resistant with decent enough durability

Cons:

Ridiculously expensive machine with decently expensive resins
It will waste plenty of support material in printing (which means added cost too)
Not really easily accessible, but some design studios will have them and will print things for you, for a cost

Other machines (ex. Ultimaker 2 Extended) will print models up to 30cm along the vertical axis. It would require some assembly in the end, but you could segment your build and get a boat hull in the end.

Pros:

Easily accessible
Fairly low cost (Maybe under \$1000 for the machine vs nearly \$1M and many filaments cost 1/10th that of polyjet resins or sintering powders)
The materials themselves can be UV resistant and salt water resistant

Cons:

Joinery and seams create passageways for water ingress, so you'd need secondary sealant
The FDM process itself isn't always watertight, so you'd need sealant anyway
Low interlayer adhesion limits the tensile strength along one axis and the shear strength in one plane, so you'd either need composite hull panels with varying print orientations (in which case, just do a composite layup instead) or a fairly careful analysis of principle hydrodynamic stresses

There's significantly more to the discussion as well, but without really understanding your design constraints, it's difficult to give any concrete advice.


Infill failure at the far corner of two different prints

Now that you are using Ultimaker Cura, the default (probably hidden) parameter Z Seam Alignment is set at Sharpest Corner, so it will always start in a sharp corner. The default retraction settings are pretty high in Ultimaker Cura (I think about 6.5 mm as default Retraction Distance). What happens here is that the filament is not available for printing in time (this is dependent on the extruder type), so the distance should be less than the current value.

It is highly recommended to print a retraction test to find what is best for your setup. For me the 6.5 mm works very well on my Ultimaker 3 Extended and my large custom CoreXY printer as they both use a Bowden extruder setup using 2.85 mm filament, this can be different for your printer. Choosing a different Z Seam Alignment option, e.g. random prevents the use of the same location at every height, but could result in a less aesthetic print.

Furthermore, you could try to visualize the G-code in a viewer, this can be done in the Ultimaker Cura slicer itself, but online viewers are available. After slicing your product, change the combo drop down box from Solid view to Layer view to show the sliced object. Nowadays there are 2 sliders to interface with the model; the vertical sets the layer, the horizontal the progress of the layer. It is advised to play with this to understand how your print is actually printed.

About your settings, print speeds are not high (could be increased), travel speed is fine (is only for non-printing moves). The brim is looking good and the level of your bed is also good.


What is the functional difference between an e3D-Style nozzle, Makerbot MK8 and M6 Chinesium Nozzles?

Differentiation

The main differences between the e3D-Nozzle family and the "simple" Nozzle are the wrench size, body length and thread length of the nozzle. In fact, I have come across 2 different "Chinese" styles of nozzle, a "big" and a "small" one.

Comparison

For comparison, take a look at this photo, where I aligned the lower ends of the bodies to line up under the wrench needed to handle them.

In words, left to right:

Chinese Big M6 Nozzle

size 8 metric wrench, 4 mm thread length, 1 mm clearance, extends a minimum of 8 mm from the heater block

Chinese Small M6 Nozzle

size 7 metric wrench, 4 mm thread length, 1 mm clearance, extends a minimum of 8 mm from the heater block

e3D v6 normal (aka NOT volcano etc)

size 7 metric wrench, 6 mm thread length, 2 mm clearance, extends a minimum of 5 mm from the heater block

Replaceability

Chinese big to Chinese small nozzles in either hotend

Due to the dimensions, one can easily swap the big and small Chinese nozzles for one another. They are virtually interchangeable but differ in the wear patterns.

Chinese nozzles in e3D Hotend

The 3 mm shorter snout and deeper butting with the heatbreak of the e3D nozzle in its designed hotend make it hard to swap a Chinese nozzle into an e3D setup: neither does the thread allow to screw the nozzle in the right length sometimes, it also extends much further. To accommodate, the whole heater block has to be screwed about 3 mm more onto the heatbreak, then the nozzle gets screwed in. The result is equal in overall length.

e3D Nozzle in Chinese Hotend

However, the long thread of the e3D Nozzle allows it to be mounted in a hotend designed to hold a Chinese nozzle without trouble - the 3 mm of difference in the body are used for a longer thread and clearance between thread and body, resulting in the same overall length without changing the mounting position of the heater block on the heatbreak.

Internals

Stefan of CNC-Kitchen recently tortured a couple of nozzles for science and investigating wear and tear (video). He found out a couple of differences on the internals:

The Chinese nozzle had a non-straight pattern on the inside
The angle in the feeding cone is 60° in an e3D and 90° in the Chinese sample

Conclusion

The Chinese Style nozzles can be interchanged for one another. an e3D style nozzle with standard length (aka not-volcano) can be swapped in for any Chinese Style nozzle. A Chinese Style nozzle needs to have the heater block shifted if mounted into an e3D hotend.


Classifying method of control of 3D printers?

The question is if robots classification terminology the textbook sketches applies to 3D printing?

Servos (closed loop) are used in robots to guarantee position (you don't want to accumulate an error after repetitive movement), most 3D printers use open loop steppers that are instructed on a point to point basis through G-code instructions, implying that the use of servos is not a "requirement" for point to point control.

It is a requirement if you want to be absolutely sure that the position is reached. In 3D printing where the loads are generally low, this requirement is frequently dropped. But, there are printers that use servo control.

Note that many CNC machines (operating at much higher loads than a 3D printer) even don't use servo's but (open loop) steppers, these are generally larger and more powerful (more torque).


First, you shouldn't need a raft for most PLA prints. That will help you get better bed adhesion at lower temperatures.

Second, you can reduce the stringing by increasing travel speeds (120 mm/s is not too fast) and a small amount of retraction: around 1.5 mm for direct drive and 5-6 mm for bowden.

With those settings, you should be able to print most PLA with a bed at anywhere from 50-60 °C and an extruder at anywhere from 190 to 215 °C.