How to modify 3D model of body? I'm relatively new in the field of 3D printing and design. By now I've created and printed some technical objects with TinkerCAD, but now I've a task, which I don't know how to solve.

I have the following model as STL-file:

Now I want to "adjust" the arms of the model, as shown in the picture. I want the arms to hang besides the body.

I know that I could cut and rotate the arms and then merge them again with TinkerCAD but the outcome dosn't look good and the workflow feels wrong.

So what is the right tool/way to get this task done?

*Disclaimer: I'm not Denis Almaral, but he released this model unter CC license. So I kept his name on the image to credit him, as requested via CC.

The correct/good method to achieve this is called "rigging", but it is not an easy feat (as pointed out by others), as it requires plenty of knowledge about the software being used to edit the model, and a good understanding of the theory behind it.

Skeletal animation requires the designer to set up a skeleton (also called "rig", hence the slang term "rigging") for the mesh and define the variables controlling the motion range of the joints and and the geometry and deformation of the mesh.

It's quite some job to perform, so - unless this assignment is the first in a series of assignments having to do mesh movement for this model, or you have a keen interest in the topic - I would suggest you to take a shortcut and edit the mesh directly in a "one off" not reusable fashion.

(Rigging would conversely allow you to create a "rag doll" or at least a "rag arm" to freely and intuitively move around as you please).

The tool I would use for either task is blender.  If you want to take the shortcut, maybe a less complex software like meshmixer could also do the job (I don't have direct experience with it, though, so I'm not 100% sure).

The blender foundation have a nice series of videos on the topic, called "humane rigging".


What causes these blobby corners Contrary to a lot of other corner related problems (where the corners are bulging), I seem to have a different problem where the corners (ONLY) seem to stick out and appear blobby in the x/y plane. This only happens for corners/edges with a fillet radius greater than 3-4mm and only in the x/y plane. Anything smaller than that radius (such a sharp corner/edge) seems to be fine.

Any ideas what could be causing this?

Conditions

CR-10s
Ultimaker Cura v4.2.1
Material: ABS
Nozzle size: 0.4mm
Bed temp: 80 °C (I can't go any higher than this)
Nozzle temp: 250 °C

What I've tried already

increasing nozzle temp from 240 to 250 °C (seemed to help slightly?)
reduced flow rate from 100 % to 80 % - had a negative effect on overall print quality

Thank in advance for any ideas/suggestions

I suspect you are printing through a usb or network connection,  and the communication rate it's to slow for any of many reasons.   A curve consists of many tiny linear movements,  each requiring a command exchange between the PC and printer.

If you can,  try printing from an sd card plugged into the printer (I'd the printer is so equipped).

This could be worse if the uses a Bowden extruder,  since there is now compression and windup in the filament.


How could I print a large sphere-like object? I have a STL file with a rather large roughly-spherical object. I'd like to 3D print it to be fairly large, and hollow inside. Since the printer I'd be using has a max size of (18–20 cm)^3, I'd have to print this in pieces and then reassemble them into the sphere-like shape. The textured surface of the object is important, but small seams would seem unavoidable.

My Question

How could I 3D print a hollow sphere or sphere-like object that's too large for the available basic 3D printer?

Because this would need to be done in parts, it's more complicated than the designs I've made. Because the final product is roughly spherical and hollow (i.e. nothing is nicely angular), it's trickier than some other designs.

(I have little experience with 3D modelling/CAD, so I'd somewhat prefer solutions with minimal advanced steps such as designing my own joints and whatnot...but advanced steps are definitely okay if part of a great solution!)

My Ideas So Far

I know I could cut the sphere roughly in (e.g.) eighths via planar slices, print the eight pieces individually, but then the question is how to attach them. I am also concerned that the seams might be too noticeable. (Perhaps there's a better way?)

I could just glue the pieces together. My fear then is that it would lack internal structural support if they were attached only at the outer layer (unless the skin thickness were excessive, at least near the boundary).

I imagine I could give the pieces internal supports with dowel joints or snap-fit joints (e.g. these), but I lack knowledge of how to do that and don't know whether that would even work well.

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

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

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

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

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


Anet A8 with Marlin firmware: Auto Home is crashing into bed I got things moving from the answer to a previous question. Now, since the base-video I'm following is non-English, I want the next phase fixed: Probing failed

Auto Homing showing failing Z-homing

After the final adjusted firmware upload, and bringing the sensor up, I see that the extruder pushes the bed down a bit when I auto home and then the LCD screen says probing failed.

If compare to the latest (v1.1.9) Configuration.h file from GitHub, here are the changes:

#define FIX_MOUNTED_PROBE // Line #0719, Uncommented

#define X_PROBE_OFFSET_FROM_EXTRUDER 16  // Line # 0779, Was 0
#define Y_PROBE_OFFSET_FROM_EXTRUDER 58  // Line # 0780, Was 0

#define Z_HOMING_HEIGHT 5 // Line # 0870, Was 4

// #define MIN_SOFTWARE_ENDSTOP_Z // Line # 0907 Commented

#define AUTO_BED_LEVELING_LINEAR // Line # 0977, Uncommented

#define LEFT_PROBE_BED_POSITION  (X_PROBE_OFFSET_FROM_EXTRUDER + MIN_PROBE_EDGE) // Line # 1027, Uncommented
#define RIGHT_PROBE_BED_POSITION (X_BED_SIZE                   - MIN_PROBE_EDGE) // Line # 1028, Uncommented
#define FRONT_PROBE_BED_POSITION (Y_PROBE_OFFSET_FROM_EXTRUDER + MIN_PROBE_EDGE) // Line # 1029, Uncommented
#define BACK_PROBE_BED_POSITION  (Y_BED_SIZE                   - MIN_PROBE_EDGE) // Line # 1030, Uncommented

#define Z_SAFE_HOMING // Line # 1144, Uncommented

From the above changeset, lines 1027-1030 are from the other SO question I mentioned above, the remaining are following the video.

After completing the steps up to the point where I push the firmware and have to lift the ROKO up I followed instructions in this video, my "Auto Home" operation is failing.

Update 1

I used Pronterface as recommended by @dgrat in comments below and got this result:

>>> M119
SENDING:M119
Reporting endstop status
x_min: open
y_min: open
z_min: TRIGGERED

I did not get the Probing failed message this time.

What's next?

Update 2

I also went ahead and tried out the second answer, where @0scar is recommending to uncomment #define MIN_SOFTWARE_ENDSTOP_Z.

The results are exactly the same: The head hits the hotbed and goes back and then comes down slowly hitting and compressing the spring a bit before stopping. I did not get the Probing failed message this time.

You should un-comment the following line to get rid of the Probing failed error message:

// #define MIN_SOFTWARE_ENDSTOP_Z // Line # 0907 Commented

to

#define MIN_SOFTWARE_ENDSTOP_Z

You have basically disabled the use of the minimum Z endstop, while in fact you are using one, the difference is that it is a sensor now, not a mechanical switch.

Please note the distance of the sensor to the bed, it looks as though it is pretty far away. Before sending an auto home command, it is better to test the endstop triggering beforehand; an external application (e.g. Pronterface, Repetier-Host, OctoPrint, etc.), USB cable and a laptop/computer can be used to send G-code commands through the terminal of the external application. Code M119 will output the endstop trigger status to the terminal.


Ender 3, why only 3 limit switches? Why does the Ender 3 only have 3 limit switches instead of 6?
How does it handle crashes on other sides?
Is it worth adding them with a new mainboard?

You only need 3 switches to determine/fix the position of the carriage (carrying the hotend) with respect to the printer frame (for X, Y and Z i.e. 3 dimensions). Firmware setup, by defining the offset and the traveling distance on each axis, determines the minimum and maximum displacement. By default the printer carriage will not go outside the boundaries and will not damage anything. That is sufficient for most printers, but, for those printers that have weak steppers and printers that produce prints that suffer from layer shifting, the coordinate system might be messed up, and the carriage may travel outside the initial boundaries, this can damage your printer, using maximum endstops will prevent the printer from destroying itself.
Why use only 3 switches? The reason for this could also be related to costs, you need half the amount of switches, cables and a less extended printer controller board.

I've had one printer setup with max limit switches, but they never got triggered (unless self triggered for testing), never had a layer shifting either.


Marlin on Arduino Mega 2650 and RAMPS 1.4 I have been messing around trying to flash marlin 1.1 onto my Arduino Mega 2650 and RAMPS 1.4. I have Managed to get it to upload fine however it will not upload with the LCD I want. I am trying to upload it and have it set to a "RepRap Discount Smart Controller". When I uploaded the firmware it was on the stock Anet LCD, however when I try to change this in the file and verify it I get an error that I do not understand. I have done some digging on google but haven't really been able to figure out the answer. Here's the error:

sketch\ultralcd.cpp:4860:3: internal compiler error: Segmentation fault

   DEFINE_MENU_EDIT_TYPE(uint32_t, long5, ftostr5rj, 0.01f);

   ^

Please submit a full bug report,

with preprocessed source if appropriate.

See  for instructions.

lto-wrapper.exe: fatal error: C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.21.0_x86__mdqgnx93n4wtt\hardware\tools\avr/bin/avr-gcc returned 1 exit status

compilation terminated.

c:/program files/windowsapps/arduinollc.arduinoide_1.8.21.0_x86__mdqgnx93n4wtt/hardware/tools/avr/bin/../lib/gcc/avr/5.4.0/../../../../avr/bin/ld.exe: error: lto-wrapper failed

collect2.exe: error: ld returned 1 exit status

exit status 1
Error compiling for board Arduino/Genuino Mega or Mega 2560.


Setting the startpoint of the EZABL 3x3 mesh How do I set the startpoint of the EZABL 3x3 mesh. The startpoint is hitting my bed clip.

The "EZ" company (TH3D) is trying to make flashing firmware easy by making choices in the configuration for people to set based on printer type. While this makes the flashing more accessible to more people, it does not help people to understand what actually happens in the firmware or what is meant by certain settings. See it as an automated process to add automatic bed levelling to a number of printer models.

To change the bed probing area, you need to modify some specific lines that specify the probe area. How you should change this is explained in this answer on question "How to set Z-probe boundary limits in firmware when using automatic bed leveling?". It would be best to set or increase the constant MIN_PROBE_EDGE. This effectively makes the probe area smaller so you will not hit the bed clips.


The BLTouch is hitting the bed on the double-probing When double-probing, sometimes the BLTouch will hit the bed before the z-axis goes down:

The BLTouch deploys
The bed goes up
The sensor triggers
The BLTouch stows
The BLTouch deploys and crashes the bed before the z-axis goes down for the second probe

It happens only on the second probe of double-probing (slow speed) - the bed can't move out of the way fast enough.
This happens in 2/16 probe points.

Probe Accuracy Test result:

Mean: 0.023075 mm
Min: 0.018 mm
Max: 0.027 mm
Range: 0.008 mm
Standard Deviation: 0.002584 mm

First, make sure to check if stow, deploy and the trigger are working correctly.

Second, check the pins files to make sure you put it in the correct pins. Black and White probe pin might need to go to Z-min or probe pin depending on. Make sure to check that.

Third, add "BLTOUCH delay". It might be triggering too slow or too fast for the next one to react. So after the first trigger, there should be a time for it to "re-setup" for the second. But if there is no time to do that then it won't trigger.

To add examples: If you have SKR 1.4 Turbo, then use BLTouch probe pins (black and white) on the board. IT will NOT recognize. You have to use Z-min endstop pins. Reason for this?:

#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN

If this has been used, Z-min probe will use Z-min endstop pin instead of Z-min probe.


What is the next step after measuring the bed levels? My Creality CR-10 Max is equipped with a BL Touch sensor for bed leveling.
The bed size is 450 mm x 450 mm.
Here is the 16 measurement points taken from a 4x4 grid:
float  v[] = {-1.15625, -0.7625, 0.1525, 1.13,
-1.1150, -0.5150, 0.2125, 1.650,
-0.8525, -0.215,  0.510, 1.4425,
-0.4125, 0.2649, 1.0350, 1.9050};

Which looks like this:
The bed doesn't look flat or level.  To what extent should I try to make the bed flat and level?
It's now a day later, and the bed looks like this (image below) after turning the four knobs using AUX leveling (a helper to locate the nozzle above the knobs), so that the nozzle barely scratches a sheet of paper:
float  v[] = {0.0849, 0.0599, 0.1549, 0.2874,
0.2674, 0.0624, -0.0425, 0.0699,
0.3374, 0.1199,  -0.0150, 0.0199,
0.5399, 0.3349, 0.1899, 0.2074};

I also notice that the bed is slightly concave in its center: using a straight edge (a steel ruler on its side), there is enough room in middle ninth (center square) under the ruler for one sheet of paper.

Now that you have leveled the bed you are ready to start printing. To enable leveling for printing, you need to add G-code G29 directly after G28 in your start G-code of your slicer.
The array values you reported are just for information or visualisation of the level of the bed. Although you have ABL you always need to provide a bed that is as level as best as you can, the ABL will take care of the final dents or skewness.


ABS Filament safety concerns I have the XYZPrinting da-Vinci-1.0 with ABS filament. I am concerned about ventilation. If this is used inside, what safety precautions are necessary, which are recommended, and/or which are optional?

Yes... The issue with all 3d printing materials. Not just ABS, but worse with ABS is the fine air particulate and Ultra fine it creates during the 3d printing process. PLA is considered safer than ABS. But I fear people will use this as justification, it is like saying I only smoke one cig a day instead of two so I am safe and healthy. No it really should be taken seriously.

There are a number of scientific papers and articles proving that this is an issue. Specifically that 3d printers release ultra fine particles into the air. Which can damage the lungs over time. I would STRONGLY advise not using a 3d printer around children, or at least putting it in the garage where you will not contaminate your homes air supply.

I.E.

http://www.sciencedirect.com/science/article/pii/S1352231013005086
http://built-envi.com/portfolio/ultrafine-particle-emissions-from-3d-printers/
https://www.ncbi.nlm.nih.gov/pubmed/11139166
http://www.3ders.org/articles/20160201-new-study-shows-health-hazards-of-3d-printing-suggests-pla-could-be-your-safest-bet.html

Lot of these have some scary looking graphs. Note that I am being a bit sarcastic when I say "scary looking graphs" the take away is ABS has twice the Fine Partical emission as PLA. However should you be worried, is still up to debate. The idea is that FPE can maybe contribute to cancer or other illnesses. FPEs are thought to irritate the lungs.

These graphs are of the ultra fine particle emissions.

as you can see PLA is MUCH safer in this regard.

I cannot find the paper at the moment, but the recommendation is a full air cycle several times an hour. As someone that lives in a Cold state I personally just use PLA and am rolling the dice.

There is another SO where I cover my future plans for an air scrubber.

I will note that other materials such as Polycarbonate should just be plain avoided.

I also want to provide these links on WHY ultra fine particles are bad. In summary they really upset your lungs and are thought to cause lung cancer over time.

Wikipedia on Ultra fine particulates.
White paper on ultra fine particulates.


Ender 3 X-axis belt orientation What is the correct orientation for the X-axis belt?

I first thought to place the smooth side down to match the tensioner bearing, but then changed it to match the motor pulley.

Sadly, the Ender-3 assembly instructions were not clear on step 7, what the right direction is (teeth on inner side of the loop):

The Belt has teeth that need to engage the teeth of the hobbed gear on the motor, just like in the preassembled Y-axis. The teeth have to go aim to the "inside" of the loop. This way, the belt will not slip on the motor side and the movements will be repeatable.


How does this multiple-curve-beam flexural pivot work? I found this in Handbook of Compliant Mechanisms (2013), page 162, or at the start of "Chapter 11, Elements of Mechanisms," subsection 11.1.2 Revolute
I don't understand how it's supposed to go from 1 to 2 when b rotates around c.
The description reads:

This element is a rotational flexural pivot constructed by three
curved beams to achieve a large range of motion. Theoretically, this
element will rotate without axial-drift motion, because of the
symmetric arrangement about the axis.
(1) Rigid body a is fixed. Rigid body b rotates about c-axis.
(2) Deformed configuration
(3) Photo of the device.

It's unclear which part of the beam is attached to what. I can understand how one curved beam could switch its curvature (in general, like they do in  bi-stable latches), but I don't see how they could both at the end of of the rotation end up curved in a way that's opposite to how they started.
How could c2/c3 go from the configuration in 1 to the configuration in 2 ?
Or could they be two different iterations of the same idea ? I can see how (1) or (2) would resist rotation of c around b, and snap it back to its original position.  The text claims (2) is the deformed configuration though. I can also see how (1) with just c1, c3, c5 would deform to (1) with c0, c2, c4 if (b) was turning anti clockwise.
Also, what would be an ideal material to print this kind of compliant mechanism ?

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


How to build the extruder motor holder for the Kossel Mini I'm building a Kossel Mini, and I'm stuck on the extruder motor holder.

My Kossel came without instructions, I was given a set of instructions by a friend (the "Kossel Build Guide" by Blomker industries). I also found some instructions on the net. However, my components are different from  those in the build guides.

The question is how these components fit together.

I'm pretty certain the stepper motor should be connected to the big black components (labeled (1) and (4) in the picture). The 4 holes in these components correspond to openings in the stepper motor; and the stepper motors for the vertical carriages, were connected in a similar way to their respective holders.

The round thing, second from the left on the bottom, (labeled (2) in the picture) presumably goes on the axis of the stepper motor. Once again, a similar procedure was needed for the motors that will move the vertical carriages.

The screws on the right, labeled (3), are 1 cm long and 3 mm wide.

The other screws are 2 cm long and 3 mm wide.

The stepper motor is a Wantai Stepper Motor Model 42BYGHW811 .

I have e-mailed the company where I bought my kit and am awaiting their answer. Meanwhile I'm hoping to get some advice here.

Apparently the usual stepper motor for a Kossel Mini is Nema 17. Searching  on "42BYGHW811" I mostly find datasheets. Using "Nema 17 mount" or "Nema 17 mounting screws" as search terms, I find a lot of images with a component like (1). But nothing on how this and the other components should be put together for the motor holder for an extruder for the Kossel Mini.

Have a look at the image provided in this seller's part description. it probably says more than my words could (which would also only rely on images - your parts just looked like I saw them somewhere before).

3D printer parts right hand Bowden Extruder kit set no motor compact extruder aluminum alloy for


What is the benefit of using an ARM based electronics? Most electronics use micro-controllers like an AVR, but I'm seeing ARM chips in new electronics. ARM chips are said to be more powerful, but in what areas related to 3D printing could this help?  What are the features that the AVR struggles with and where an ARM could be better?

High Speed movement? Delta printers? Graphic display?

And is the AVR really the limitation there?

3D printer controllers have to do a lot of stuff very, very fast. Performing kinematics and dynamics calculations while sending many thousands of precisely-synchronized step pulses per second is really, really hard. The 8bit AVR line of microcontrollers used in older 3D printer controllers is basically a late-1990s era Mr Coffee processor. They are completely, utterly maxed out on processor time just executing basic printing functions in simple (eg Cartesian) printers, and adding additional calculation load will bog them down and cause slowdowns, stuttering, pausing, and so on.

"But my 8bit printer works fine," you say. No, it doesn't. Your print performance is limited by it, whether you realize it or not. Slicers now automatically hide a lot of the firmware's performance shortcomings from you. For example, the standard practice of greatly slowing down print speeds on perimeters is largely a result of 8bit processors having inadequate resources for two things:

Performing centripetal acceleration calculations for curves
across multiple gcode segments
Keeping up with gcode transmission/processing and motion planning for gcode with lots of very small segments, such as in organic models or smooth arcs

When presented with a series of very small segments in a smooth arc or complex curve, the 8bit firmware will likely choke on the required command processing rate and introduce stuttering to the print. These incredibly brief pauses allow residual pressure in the extruder to push out some extra plastic, making a little zit on the print. So most slicers automatically decimate curves and output gcode with reduced resolution to lighten the load on the firmware. Problem solved, right?

But there's another issue -- the GRBL motion control algorithms underlying all the major open source 3D printer controllers were designed with lots of shortcuts and hacks to allow 8bit processors to execute fast enough. For example, the basic algorithm only looks at the speed or velocity change at the corner between two segments, and uses that to decide when to decelerate/accelerate along the direction of motion. It does not calculate or consider centripetal/radial acceleration whatsoever. This is a really effective hack when printing boxy, low-res models, but it fails miserably on smooth curves with lots of little segments. The firmware does not detect any appreciable velocity change at the corner of any two nearly-linear segments within the faceted curve, and thus does not slow down for the curve. So complex geometry is effectively printed at constant velocity, with no acceleration.

Printing complex perimeters unaccelerated means the commanded feedrate must be very low to get good quality. Most printers are limited to about 40mm/s or less on complex perimeters, despite being able to run perhaps 80-120mm/s on low-complexity infill before hitting other speed limits.

Between the command processing rate limits and motion planner shortcomings required by low power processors, print speeds must be much lower in practice than is strictly required by the physics and printer hardware. This all comes from 8bit processors. The workarounds and best practices to deal with this problem are so deeply baked into the toolchains and ecosystem that very few people realize there is even a problem. But it's a real limit that can be overcome: a high-speed processor running a more rigorous motion planner could generate higher average print speeds with better print quality.

That said, the ARM-based firmwares are only slowly moving towards more advanced motion planners. This is a big development area right now that is actually driving an upcoming shift away from low-end ARMs like the Cortex M3 towards even faster processors. It's actually not all that hard to max out an 84 MHz Arduino Due by piling on a bunch of firmware features.

The use of 8bit processors also makes printers LOUDER. The biggest consumer of processor time in a typical 8bit printer is the stepper interrupt that fires the step pulses to make the motors move. It is quite typical for >60% of all clock cycles on an Atmega AVR to go to firing step pulses. Because this occurs as an interrupt, other processing tasks that the printer must perform -- like acceleration calculations and heater control -- get squeezed into the brief spaces between stepper interrupt events.

Without careful firmware design, the step pulses will completely "crowd out" other functionality like LCD display updates and acceleration calculations. In order to allow higher motion rates without using all the processor resources, 8bit firmwares have a mode called "step doubling" that fires two (or four, or eight) step pulses per stepper interrupt so that half (or a quarter, or an eighth) as many stepper interrupts can be used to produce the same motion speed. This practice de-bottlenecks the processor, but it causes rougher and louder motor motion because the step pulses are fired in bursts rather than a constant frequency. In effect, the microstepping level of the motor is functionally dropped to a coarser mode when the stepper interrupt fires double or quad steps. So the motors get louder, less precise, and in extreme cases may have problems with resonance.

An interesting side effect is that if you switch a Marlin-based printer from 1/16 microstepping to 1/32 microstepping, and keep the same print speeds, the firmware will simply start step-doubling, dropping your effective microstepping level right back down to 1/16.

ARM-based firmwares also use step doubling, but the allowable step rates are typically ~8 times higher before double/quad stepping is used. That can mean higher speeds and/or smoother motion.

Another issue with 8bit AVRs is the lack of hardware floating point and need to spend many clock cycles on high-precision calculations or handling very large numbers. Delta kinematics, auto-leveling functions, calculating moves with extremely high step counts for large printers, and other advanced functionality all take a lot of clock cycles on an 8bit processor. Poor firmware design or carelessly adding a feature that requires a few extra square roots and trig functions can completely bog down the processor. This kind of feature creep and code bloat has seriously impacted Marlin's performance over time as people ask more and more of the old AVR.

In comparison, a 32bit processor doesn't just have a faster clock and more clock cycles, it is also able to do much more complex math in fewer clock cycles, because it has dedicated hardware functionality that takes care of many of the steps an 8bit processor must do in software.

Do 8bit processors work? Sure, they work surprisingly well for what they are and what we ask of them. But they unquestionably limit the performance and features of modern 3D printers. Even today's current generation of 32bit processors is already being maxed out by high speed printers and math-heavy features. The 8bit processor is already two generations behind what would qualify as a "modern" 3D printer controller.


Thermistor reading 190 °C constantly So to set the backdrop of this post, I was cleaning the hotend of a printer (Powerspec i3 Mini v2, which is a Wanhao i3 Mini rebadged and heated bed added) I picked up for cheap. There was some stubborn residue so I decided to warm the end. However, while it was still plugged in and warming I saw a spark while using the brass brush on the nozzle. Not sure where it actually sparked (thermistor or heater cartridge wires) but now the board constantly reads 193 °C for the hotend whether or not it is hot (or even plugged in for that matter.)
Looking around this seems to indicate either a bad thermistor or a messed up mainboard.  The thermistor will read ~120k resistance at room temp and fluctuate based on temp changes (ice will cause it to go down, heat will cause it to rise), so can I take that to mean the thermistor is most likely still okay?
Doing some probing on the board, it seems the resistor that makes up the voltage divider on the thermistor circuit is out of spec (when probing it with a multimeter it reads only 470 ohms instead of 4.7k). Is this reading while in-circuit valid? Could this have been caused by a short in the thermistor? Can I build a small adapter to splice in a new 4.7k resistor? or will this just throw everything off more? If I were to build a new version of Marlin could I adjust something in there to get the temps back to something recognizable?
I figure since I got the printer for 40\$ I may as well use it as a learning experience.
Also, if anyone has the original firmware from this printer I would appreciate a copy.

Yes, in newest Marlin (v2.0) there are configurable thermistor parameters. You need to set custom thermistor:
#define TEMP_SENSOR_0 1000

for your only extruder (suffix _0) in Configuration.h, and in Configuration_adv.h modify related section:
//
// Custom Thermistor 1000 parameters
//
#if TEMP_SENSOR_0 == 1000
  #define HOTEND0_PULLUP_RESISTOR_OHMS 4700    // Pullup resistor
  #define HOTEND0_RESISTANCE_25C_OHMS  100000  // Resistance at 25C
  #define HOTEND0_BETA                 3950    // Beta value
#endif

But in Marlin 1.x I couldn't find this section, so change would need to be done somewhere in thermistor definition source files. I mention this older Marlin following the discussion on Wanhao Duplicator i3 Mini & Rebrands Support, which refers to some Wanhao source code, but I cannot judge about value of it.
For resistors in the circuit I have similar observations: sometimes they do not give exact readings using multimeter, especially next to capacitor. Isn't heatbed temp probe's circuit the same? - can you compare? But instead...
I would suggest doing following things:

open circuit test: disconnect the thermistor and check readings (I could then see -19 °C)
closed circuit test: connect the heatbed's thermistor instead (in place of hotend's) and check if these readings are reliable (I would try to heat the bed for few seconds to check if changes are noticed, but not too long because it will be uncontrolled process)
thermistor test: connecting the hotend's thermistor as heatbed's probe and check on-screen readings for heated bed; are they again 193 °C? do they react to changes? (powering hotend for few secs or warming in fingers?)
you may consider to setup USB connection with serial terminal to directly read measurements using G-Code, just to exclude errors in post-processing of the temperature readings before putting it to screen (I know, it's a bit paranoic)

The worse thing I can imagine is that you could short wires of hotend heating circuit with the temperature probe circuit, which should be galvanically isolated. Then it could damage readings of the mainboard for this probe when received 12V/24V. I found that the mainboard is most probably all-in-one i3mini 0ne+ motherboard, some revision still available in Wanhao store for another $40. I googled for few photos, there are problably few versions of this board. If you are lucky and skilled then you may find some other pin (connected to ATMega) to reuse. Otherwise you would need to replace steering electronics with new board, which could be of great benefit for future improvements: more ports for extra fans, probes, more memory, better stepper drivers, etc.


Communication is dropping when printing on my Tevo Tarantula I am experiencing communication drops when printing from mp raspberryPI (using octoprint, repetitier server). Moreover when printing from Cura (on Windows), the programs freeze (have to kill the window) and sometimes stops the print job.
I was changing the serial0 speed in Marlin from 225k to 9600 and still no luck.
Mainboard MKS 1.4 all in one.

please let me know if you need any  more details

As per long article Marlin firmware  it looks like my system is a victim of closed ground loop via USB connection. It is now clear to me that printing from laptop (connected to different socket) was a ground loop separated case and therefore the connection was stable. Connecting my raspberryPi from same socket using long unshielded cable is the main reason of connection drops.

Will try to run raspberryPi with short shielded cable and also will test raspberryPi powered from power bank.


Are large format prints more brittle? Recently on one of her videos a YouTuber stated that prints from large format printers are more brittle than if you were to print them in parts and glue them together. This seems to contradict the testimonials from the customers of a large format printer, who say that they get good prints from those printers (which print have a print area of a meter square).

Would a print form a larger format printer be more brittle than a print made of smaller pieces super glued together?

(with all other aspects being equal e.g. the nozzle, the temps, the material and the shape of the object).

The YouTube didn't cite any source information to back up her claim.

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

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


Is there a reason for the z-axis M5 drive nut to be super loose on the lead screw? So I bought a prusa i3 kit from a company called folger tech off of ebay. I've built it and even printed out a few parts, but I noticed that a lot of noise seemed to be happening only while the x-axis motor was moving the extruder. Then I noticed if I put my finger lightly on the plastic part of the x-carriage I could dampen the vibrations and pretty much eliminate the noise I noticed. Then I took apart that part of the printer and examined everything and all I could notice that seemed to be loose was that nut that allows the z motor to push up the x carriage. I don't know if I got a bad nut, or a bad screw, or is it's just supposed to be this way? I thought it was kind of a weird way to build things with a screw turning a nut, because I thought that it would bind up. But now I'm wondering if that is why it was so loose fitting (to reduce friction)? So does it need to be that way? Or could I get a different nut? Or is there some better way to go about fixing this issue? Or perhaps it's not even an issue.. idk.

It's probably intentional. Threaded rods are almost never perfectly straight. If the nut is rigidly coupled to the carriage, then the slightest deviation in the screw will either cause it to bind up or appear as artifacts (e.g. z-wobble) in the print. By making the nut slightly loose, it can move around a bit to compensate for wobble. See e.g. this design and this design for how this is commonly implemented in other printers.


Cloning the Marlin git repo while keeping my configuration.h settings? I cloned the Marlin repository and changed all my settings in configuration.h to match my old settings. Now when the RC branch gets updated, is there a way to upstream pull the changes without losing my settings?

Based on this answer, you need the following procedure:

Stash your local changes using git stash
Pull from remote repository using git pull
Merge your stashed configuration file using git stash pop

Of course, if there are changes in the configuration.h file on the remote repository and cause conflicts, you will need to resolve them, but it should be straight forward.


Ender 3 X-Axis Layer Shifting I've been having a problem lately with some minor layer shifting with my Ender 3. It just started recently and I've made no changes to the printer since it was working fine. The layer shifting is always on the x-axis and its not a large amount. Just enough to render my prints useless. The shift can happen in either direction on the x-axis. See attached photo.

Things I've tried:

1 Retensioning the belts

2 Printing at slower speeds

3 Checking all bed connections to make sure the bed is solid

4 Reducing the jerk setting

5 Activating Z-hop

6 Reducing acceleration

7 Increased retraction.

The problem occurs on multiple STL files that used to work fine

Any help would be appreciated

OK I found the answer. I removed the extruder cover and found that the 2 screws attaching the extruder assembly were loose. A very simple fix to a very irritating problem.


RCBugFix what is it? I've posted an issue on GitHub and I have been advised to load RCBugFix.
I have never used it and I do not know what is about.

What is it?
How does it work?

It refers to a specific branch of the current project, named RCBugFix. It's basically the most up-to-date, bleeding edge version of Marlin that contains all of the most recent fixes (it is more up-to-date than RC). However, as it's so up-to-date, it's also not thoroughly tested and possibly quite unstable.

  The latest Release Candidate lives in the "RC" branch. Bugs that we find in the current Release Candidate are patched in the "RCBugFix" branch, so during beta testing this is where you can always find the latest code on its way towards release.

Use with caution.


What parts are suitable replacements for an Ender 3 Pro? I'm new to 3D printing and I recently got my first 3D printer, an Ender 3 Pro by Creality.

I've tried to find information about the type of nozzles should I look for. I'm trying to find stainless steel nozzles but there are so many models (M7, M8, etc.) and I have no idea what nozzle type I should get.

I've tried searching on Google but the only info I could find is that the extruder is an MK-10.

I am also looking for a heating cartridge for the hot end, but I still cannot find no information about the size that I need (15 mm/20 mm/30 mm). Also looked for info about the heated bed so I know what kind of thermistor I need (I found two types and no clue which one to get).

Where can I find some technical information about these?

The Ender 3 takes an M6 thread (metric 6 mm diameter). Measurement of stock nozzle shown.

Most sellers will list compatible printers Ender 2, Ender 3, Ender 4, CR-10, CR-10S, CR-10 Mini, CR-10-S4, CR-10-S5, CR-8, CR-7. Will Also Fit Any Other MK10 Heater Blocks.

I recently bought some titanium alloy nozzles as the brass one got closed over after crashing into the glass bed.


X axis stops working sometimes on my Tronxy X5SA This is regarding the circuit of my 3D printer Tronxy X5SA's stepper motor for X axis.
I had an observation: It has a cooling fan (40X10 24V) which is having issues lately - it stops working sometimes, and when pushed to rotate, spins back.
Problem: Now one of the stepper motors (NEMA 17 ~3.5kgfcm) in my core XY has been malfunctioning, where it misses rotation sometimes out of the blue, which shifts the whole print. I thought this is due to the driver limiting the current to the motor, so I rotated the screw terminal clockwise a bit more to allow more current for the motor. This works fine for a while, but the problem comes back.
Now, I also noticed a few times that this issue occurred when the cooling fan for the drivers stopped working.
Can the stopping of the cooling fan cause the stepper motor to falter?
Another observation is that the stepper motor which is faltering is placed close to another stepper motor. Although I know stepper motors can work in extreme conditions, can this cause the issue?
If you require any more info to investigate the issue, please do let me know

It might be cross-talk with back-EMF from the fan confusing the stepper-motor driver. Do the cables run together, and have you tried separating them?


Prints coming out very stringy So these past few days I have been 3D printing again with my Ender 3 with PETG and 0.4 mm nozzle and while I have been using the same setting as usual I am seeing an unusual amount of stringing between the prints. Does anyone know why? If you're wondering regarding the settings here they are, I'm using Cura for slicing, see options:

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

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

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


BLTouch Z offset needs changes Just installed a BLTouch sensor on my Ender 3 Pro (using firmware version: Ender-3 Pro1.1.6BLTouchV3.1PowerLossContinueEnglish), it all works great but each time I set the Z-offset I need to add it again.  I home it, it requires -2.9 mm to get a paper sheet thickness from bed so I added that to my 0.00 Z-offset.
When I did a test print, the nozzle was way above bed, so I home the head, moved the Z axis and once again it is 2.9 mm to the correct location.  Added this to my Z-offset again...  been doing this now for a while and my offset is current at 11.2 mm! I did it on the screen and saved, hence up to 11.2 on the z offset now. If I power off and back on it once again is 2.9 mm from the correct location?

I can't really follow the information provided but I've read that Creality had some issues with saving settings if there was no SD-card in the printer when saving, could this be the issue?
I would recommend trying another firmware (not from Creality but something like Smith3D.com (https://smith3d.com/ender-3-v2-bltouch-firmware-installation-guide-by-smith3d-com/) which I've used before with success.
If you're willing to pay for precompiled firmware (and support the Marlin developers) I can also recommend https://marlin.crc.id.au/ (which I use now)


How to tell if a nozzle is truly stainless steel? Normally stainless steel is magnetic. But whenever i order stainless steel nozzles from Amazon, they are not magnetic. This makes me think they could be brass coated in something like aluminum. However, there are many types of steel.

I've attached an image of someone who reviewed these nozzles. He says they are not stainless steel because they are not magnetic.

But whenever I order "stainless steel" nozzles, even from other sellers, they are not magnetic. i already returned one pack from another seller and just received a nonmagnetic one from a third seller.

So that's it? Amazon just sells junk now? Or is there a way I can easily tell whether these are something other than colored brass / good for abrasive or high temp printing. Here is the product that was reviewed:
AUSTOR 13 Pieces Stainless Steel 3D Printer Nozzles 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm Extruder Nozzle Print Head for E3D Makerbot https://www.amazon.com/dp/B07CHZMGRH/ref=cm_sw_r_cp_apa_i_XtrNDbRMVH8SW

Let's preface, that there are a LOT of metal identification methods. For example, I found this guide helpful and I had been at the scrapyard lately, where I have been told that 90+% of the time, steel objects that are non-magnetic are the more valuable stainless steels. The kitchen sink I dropped off? Stainless, non-magnetic steel.
Tempering/Annealing behavior
The very fact that the nozzles do change color to a brassy color that is commonly called straw is proof that it is indeed steel: heating up a piece of steel does alter the steel and also alters the surface color in a process called tempering. The color is only the surface, and the mild straw color would become orange-brown, purple, pale blue teal and yellow if you were to heat it higher. Take a look at the tempering colors of steel here:

In contrast, brass acts differently when heated and tempering is somewhat different. Subjecting the piece of brass to heat you will not temper but anneal it and you get colors differently. Instead of becoming straw before blue, Brass becomes dark, starting with its pale gold to go over a dark "antique" look to before going green, teal, purple-blue, red and then losing its color like this piece of a polished brass plate shows:

Hardness/Chip
Another test that would be easy to conduct is hardness. The base idea of hardness is: An item can scratch a piece of equal or lower hardness, but not of higher hardness. If you have a chisel handy, then you have a piece of steel at hand. Most chisels are rated as HRC 58-62 - which is the Rockwell hardness scale. Brass could be all over the place, depending on work hardening. But the identification is not by the hardness but by how the chisel - or better a graver - cuts.
We expect Brass to get a smooth cut with saw tooth edges while stainless cuts smoothly and has sharp edges to the cut.
Sparktest
If you want to scrap one, get an angle grinder or another power tool to grind at the nozzle. Steel sparks red-orange to whitish and depend on the mix, Carbide sparks very short and orange. Stainless creates a HUGE shower of sparks, yellow-white and dense, no burstes and branching. Copper, aluminium and Brass do not spark. Titanium is very bright white. It can tell you what kind of steel you have.
Drilltest
As we are at destroying a pair of nozzles, why not drill them? we should have done that before subjecting it to heattreating and the grinding, but alas... Basically, we clamp the piece down and take an HSS drill to drill out the center.
Brass needs a different drill type but can be drilled and machined without coolant. Typical HSS drills from the home depot have a positive rake, brass wants neutral or negative rake to drill or machine smoothly. If the piece grabs, creates short spials and dusty small flakes with an unmodified, new drill (or under positive rake machining), it drills like brass, as you see here from a Clickspring video on drilling brass:

In contrast, stainless steel doesn't want to be machined without cooling at all and using high speed creates smoke quickly and nearly no chips at all. A moment later your tool starts to glow and gets a dull edge. If your drilling experiment turns a new drill blunt on high speeds or uncooled, you have stainless at your hands. To get chips, you need to work slow and have some sort of cooling. It is still a painfully slow process that needs a lot of pressure, but it gets larger, nesting chips like seen here from a Wayne Canning steel drilling tutorial:


What is the MightyBoard 1280 IO used for? While I've worked on fixing my voltage regulator on my MightyBoard, I've noticed an extra set of pins available labeled Atmega 1280 IO. I've tried finding documentation on what these pin can be used for to no avail. I'm curious if there is any use for them within the scope of MakerBot's Conveyor service or even what sort of functionality with regard to the board itself.

Any links to documentation on this subject would be greatly appreciated.

If you check the Mightyboard RevE files on Thingiverse (http://www.thingiverse.com/thing:16058/#files) you will find the schematics and PCB files (.sch and .brd) for the version of the board used in Replicator 1s and (with some minor mods) most clones. The Atmega 1280 IO header section is a bunch of breakout pins for debug functions. There are eight sets of signal/5v/gnd groupings. Four of them are currently driving debug LEDs that show flash codes for particular firmware failure modes. The other four are unused as far as I'm aware.

The ninth and tenth pins shown in the schematic are located on the opposite end of the board, near the 8U2 chip, to give some hacking access to that chip as well. (The 8U2 handles USB comms and firmware flashing the Atmega 1280.)

If desired, you can build your own firmware using these pins for other purposes, such as signaling to external equipment. But building Sailfish is a little more difficult than just running the latest Arduino IDE (for compiler stability reasons) so the vast majority of Mightyboard users never bother modifying their firmware.


Anycubic Chiron does not print correctly I recently got my Anycubic Chiron.

First I was very exited and set up the printer. I started the first manual leveling as described in the instuctions. After that I did the Autoleveling and started the test print - so far so good.

After adjusting by 2 mm, further down I saw the round circle in the middle is not round and it seems that in some areas the printer does not position the nozzle correctly. As I printed a cylinder I saw the circle has two flat areas opposing each other when the build plate moves towards its end position.

Does anybody now how to fix this? Is there anybody with a Cura 4.0 Machine setting and a 0.05 mm with 0.4 mm nozzle profile?

It is impossible to give a definitive answer without photographic evidence, since your description of the problem does not give enough information. The most common causes of "circular objects not printing correctly" are loose belts and loose grub screws on the belt drive pulleys.

However, you should note that the printer's firmware will not allow the print head to be moved outside the defined maximum printing area under software (g-code) control. This will cause large objects to be truncated if they extend outside of the defined maximum printing area, and I suspect that this is what is happening.


Prusa MK3 heatbed marks I've got some curious marks on my heatbed.

It appears to be from my black Sunlu PLA+ (I can just feel it if I scrape my finger nail over it) but I can't scrape it off with the metal spatula.

When I try and print over it the filament won't stick.

Any suggestions as to what it is and how you get rid of it?

Prusa ships (or has shipped) with two types of PEI build plates.  The original (and what I was shipped in February 2019) is a PEI sheet held in place with an adhesive.  The marks I've gotten seem to be places where the adhesive has been displaced slightly from long term pressure by the object being printed.

In your case, it actually looks like scratches in the PEI.  If, after cleaning with water, then 95% Isopropyl alcohol, and finally acetone the scratches still appear, I'd check if they are a problem.  Do they transfer onto objects printed on the plate?

If you decide you have a problem, I would use a mild kitchen scrubby sponge to "sand" out the scratches.  I have two types in my kitchen.  The yellow ones are too abrasive.  The blue ones are better.  Gently use one to make the surface uniform.

If you have an adhesive based plate, Prusa sells replacement PEI sheets, with adhesive.  The process of changing them seems onerous.  Although I bought two spare sheets when I got the printer, I have never been tempted to use one.  When my build plate becomes unusable, I will buy another one.

Prusa3D also offers a textured build plate, which is more expensive and in short supply.  These are a powder-coating process and from pictures and their blog, I infer they are particles of PEI which are melted onto the steel surface.  I have no experience with these.

I don't know if they are making the current smooth plates with a powder coating process, or if they are still using the adhesive.

The adhesive is the weak link in the heated bed.  It is only rated for 110 degrees C, which is the temperature limit of the bed.  I find that when I print with a hot bed (such as for PETG), the visible ripples in the surface are worse than when printing PLA on a cooler bed.


Incorrect inner dimensions of 3D prints with Ender 3 I have problem with my Ender 3. Whenever I print, I have proper outer dimensions (accuracy usually better than 0.1 mm, sometimes a bit worse), but every hole, pit or any inside dimension is inaccurate (0.6 - 0.8 mm never less or more).
I have tried extruder calibration. Calibrated extruder voltage and e-steps (in Ender firmware), but this does not change a lot.
Here you can see test dimensions I modeled:

And it will come out with these dimensions:

Aaand the final print looks like this:

As you can see, my estimation (second picture) was almost perfect. 19.3 mm and results are weirdly consistent. Always holes are 0.6 - 0.8 mm smaller than holes in model.
Do you have idea why this is happening?
Specs:

Printer - Ender 3 with original circuit board
Printer software - Marlin 2.0.5
Model cutting software - Cura 4.8.0
Modelling software - Fusion 360

There are 3 effects at work, and you misread your micrometer: the measurement is 19.35 in the picture.
You have a little lip
There's a little lip at the top and bottom of the print. You'd need to clean that up with a sharp knife or sandpaper. That is the biggest part of the error you measure.
Movement errors accumulate
Errors also collect on the center of holes due to the order in which walls are usually placed, resulting in outer walls having the correct diameters but inner holes having a small offset.
Plastic shrinks when it cools
A smaller part of the error is the plastic shrinking as it cools, but that can be compensated for by the slicer - if your printer allows for it: Under Materials, there is a Shrinkage Ratio setting.
There's compensation for that in Cura
The option is under Shell and called Hole Horizontal Expansion. Setting that value to 0.6 mm to 0.7 mm should solve the hole sizing error.


What kind of paint and varnish can be used with ABS? I know that acrylic paint, the same kind that is used to paint miniature figurines, works best for PLA. Does it works on ABS pieces as well? Can I also use the same kind of varnish that is used for miniatures on my painted ABS prints? If not, what kind of paint and varnish works on ABS prints?

ABS is more soluble in solvents than is PLA.  Acetone will dissolve it, which can be a benefit because it allows vapor smoothing, but can be a problem with some paints which have solvents other than water.  Try out any new paint on a scrap piece.  Apply a thick dot of the paint, let it sit for a couple of minutes, and then wipe it off.  If there is a change in the shape or color where the dot had been, the paint may be dissolving the ABS.

Acrylic has a water base and does not attack ABS.

A paint that attacks ABS may be fine, but there may be some color bleeding of the ABS color into the paint.  A translucent (or clear) ABS would minimize the problem, since does not contain any pigment.

Spray painting may work better because the paint is undisturbed once applied.  Brushing on paint will mix the dissolved layer with the unaltered paint.


Creating a heated chamber from a very large heated bed In this instructable, a user creates a heated bed from a wooden plank, some nails, insulated copper wire, and a DC switch. He does place an aluminum bed on top of it, but for our heated chamber, we won't use any aluminum on top of these wires. We aren't trying to heat an aluminum bed, but an entire chamber.

Assume I place a wire loom like this underneath my 3D printer.  (I might place some aluminum foil between the wood and the copper wire, to reflect heat upwards more? Is that safe?)
Then assume I have a cardboard box that has aluminum foil lining the walls on its inside. Assume the total size of my printer is 500mm x 500mm x 500mm. When I place the cardboard box over my printer, do you think it would take less than 1 hour for the top of the cardboard box to reach 60 degrees Celsius?
Do you think there are any other hazards here I am not considering?
Could I, theoretically, do this entirely with cardboard, and no wood?
Could I, theoretically, line the inside of my cardboard box like this? Or might the cardboard ignite?
I'd like to use cardboard because it is both lightweight and insulative. I can remove it easier to check all areas of my printer, unlike an enclosure.

Cardboard is fundamentally paper. Paper ignites - just as Ray Bradbury claims - at around 233 °C or 451 °F.
A thin heater wire usually glows red hot under operation. Not dark red, not blood cherry, not dark cherry, it's usually medium cherry to dark orange in operation, as one can easily tell by looking into a trusty toaster oven, which also shows us how powerful of a heating element this is.
In a typical toaster, heater wires are mounted in a metal frame and backed by some non-flammable material that looks like paper but is not. In a 2004 patent for such a method, they use a sheet of mica. But how hot is our wire? Well, under mains power, the wire of a toaster reaches 700-900 °C within seconds, heating the inner chamber of the toaster despite the slots to about 200-250 °C so quick that the bread roasts deliciously... until the heat controlling bimetal strip releases it up.
We operate these wires for at best a few minutes. In an electric forge, pretty much the same wires with a little more thickness to them are run at lemon glow for hours... and they are embedded in firebrick material to prevent them from igniting stuff touching them by accident!
How we know the temperature? Incandescence charts of course:
Conclusion
Paper or cardboard backing on heater wires is a bad idea. Mounting the heater wire to a metal frame that is as nonconductive as possible and without a chance that something accidentally touches it is needed. Fiberglass or rock material would serve as a good carrier, an aluminium block with radiators would give a good heating-to-surface mix, especially is precautions are taken to make the wire surface nonconductive.
Even using wood close to such a heater is a gamble I would not want to take. It's also best to mount the heating element into an enclosure that can't touch the wooden outer chamber and that stays put if the enclosure is opened or removed.


Slicer line width vs. extrusion multiplier for layer adhesion? My question would like to address what would be better for adhesion and general quality and possibly strength: either increase the slicer line width option or increase the slicer extrusion multiplier for layer to layer adhesion?

This question has a relation to "Why is it conventional to set line width > nozzle diameter?". This answer on that question addresses a phenomenon called die swell to explain that the extrusion width is generally larger than the nozzle diameter even if the line width in the slicer is set to the nozzle diameter. Basically, increasing the line width increases the extrusion multiplier, so why not set that directly?

Generally speaking, both settings result in the same1: The feed rate of the filament gets adjusted. Either you set a general multiplier, or you demand a wider line which does make it set a higher multiplier hidden in the software.
1 - if you don't look at any other factor that is!
But...
There is always a but, and this one is big:
While we can work with the extrusion multiplier to get wider lines, wider lines do change another setting: it changes the distance between the lines too. Let me show you:

If you print 100% at 0.4 mm line width, lines are about2 0.4 mm wide at 0.4 mm distance.
If you print 100% at 0.5 mm line width, lines are about2 0.5 mm wide at 0.5 mm distance.
If you print 121% at 0.4 mm line width, lines are about2 0.5 mm wide at 0.4 mm distance.

2 - ignoring die swell effects
The result is pretty clear: the theoretical lines do overlap, which will lead to the polymer goop getting squished and pressed around to bulge up. Luckily, that stuff usually ends in the infill on the lower layers, but it can result in very messy sides. You pretty much deliberately chose to massively overextrude!
To say it blatantly: line width changes the overall geometry of the slicing to account for the extra material getting extruded, extrusion multiplier does not.
What is the extrusion multiplier for THEN?
Well, using the extrusion multiplier can be done for many reasons, but mainly 2 are interesting:

Troubleshooting. You can just amp it up or down to test your mechanical properties. Like if your gear ratios on the extruder are correct. Or if your print needs a thicker line to get the first layer sticking.
Dialing in Filaments. In its core, it is meant to allow to change the flow because different polymer blends might have different thermal properties. For example, the filler and paint could lead to more thermal expansion and die swell, or they could reduce it. This behavior can be tackled directly by adjusting the extrusion multiplier. This is one thing you should do when getting a new type (color&manufacturer) of filament. While some manufacturers try to keep the properties along their lines similar, some won't.

It might not look too obvious at first, but I once had printed a model from one roll of white PLA that came from China. Then I got my fingers on some other PLA that was transparent from the same warehouse. I tried to print the exact same .gcode with it again and got a hyper fragile object that just could get squished, every time I used it with the same settings as the white PLA. I had to increase both the extrusion multiplier and change the temperature to get the same strength as with the other PLA.


How to 3D print a shopping cart I need to find a way to design and build a real shopping cart for my project. I have not idea where to start from but I'm thinking maybe I can 3D print the shopping cart which will allow me to quickly iterate on the design. How could go about with 3D printing a project like this?
Please I will appreciate other suggestions better than 3D printing

If you need a real shopping cart, please think about actual requirements.
Carts are sturdy devices, build on very consistent frame, because they are meant to carry heavy loads. The built must be focused on good jonts and durable wheels, otherwise forces from load or streatching would quickly damage the construction. Some parts of frame are normally under strain, and a direction of load forces is not always downwards, therefore frame has to be robust.
Cheap additive manufacturing technologies of standard printers are not suitable to produce objects of this size in one piece. If to follow this idea, one chellange would be to design pieces of the print, which could be connected or glued into a ready cart. 3d prints have tendency to snap along layers of print, therefore frame would need to be carefuly built from parts designed to be printed horizontally, rather than vertically. Construction of wheels carrying the cart with assumed load could be not possible, because load forces could mangle them very quickly.
Only the amount of material needed to print the whole thing could exceed cost of the cart. And the same would be about more expensive printing techniques, like printing of metal. The shopping cart is a good example of thing which is not worth printing (at least in 2021).
BTW: Shopping carts have some plastic parts, and printing these could be indeed possible. I suppose they are only protectors, not a part of cart construction frame.
I would advice to look to get a ready cart. Check locally for used, worn out or reconditioned shopping cart for your project.  Maybe even try to rent it somewhere. It would be much easier and quicker then trying to 3d print the cart, even if it is possible to do it within some reduced requirements.


Mixing nozzle vs dual nozzle vs IDEX vs tool changer for pva and pla I am planning to build a 3D printer with dual extrusion. I want to use PVA with one of the extruders and the main material with the other one so color printing isn't important for me and I just want to use dual-material (mostly PLA and PVA). I want to know which of the types below should I use and also the pros and cons of each one, especially oozing and final print quality.

Dual extruder and dual nozzle (eg. E3D Chimera+)

Dual extruder and one mixing nozzle (eg. E3D Cyclops)

Dual extruder with 2 independent nozzles (2 stepper motors on the X-axis each one moving 1 E3D v6 individually)

Dual extruder and dual nozzle using a tool changer and a CoreXY setup (using a servo motor to lock the tool to carriage similar to the E3D tool changer)

I would advise against mixing nozzle - you would have many jams and clogs and you would have to use purge tower which in my opinion is not worth it. Thats scratching point 2.
Point 1. and 3. are similar to some extent. With both types you have to align the nozzles in all three axes. Crude aligning should be done by hardware and fine tuning done in software (too much difference in Z alignment could cause one nozzle hitting the printed part). Anyway, the aligning is pain and you will have to do many test prints to achieve sufficient results.
In my opinion, point 3. (also called Idex - independent dual extrusion, I believe) will give you best results, because while one nozzle is printing, the other one is parked on the side where it can ooze as along as you manage to wipe it when it is getting ready to print. You can use purge buckets. Also you have to home the extruders indepentently as well (one to right and one to left).
Point 1. will introduce a lot off oozing issues. You would have to use ooze shield, or other methods of wiping the other hotend, if you are comfortable with that.
As for connecting another axis to Ramps 1.4, the board has 5 stepper motor outputs (X, Y, Z, E0 and E1). Therefore there is no output for another X axis, since both E0 and E1 will be used. You have two options I can think of:
Creating your own stepper output and connecting it to auxiliary pins on the board (if you are using legacy stepper drivers, you need 2-3 pins - direction, step, (and motor enable)). That requires some basic knowledge of electrical devices and firmware. However, it is doable. Not easy for someone without sufficient knowledge, but not impossible either.
Or the other option is to buy an existing boar with 6 stepper motor outputs such as Bigtreetech SKR PRO. You still have to configure the firmware but it is much easier this time (it has been made/pre-made several times with tutorials).
I would suggest using Marlin firmware as it supports many configuration types and has very strong community - someone has likely solved your solution or can help you solve yours.
I would also suggest not using Ramps board with Arduino Mega2560. That board configuration is so old. 3D printers have moved on, whereas that board has stayed the same for 5 or so years. It is OK, perhaps good for tinkering, but there are far better options (such as the mentioned BTT SKR series boards).
Good luck with your design.
Note: I do not own a dual extrusion printer of any of the mentioned types. This is just my understanding of the theory and how I would do it, if I were to build a dual extrusion 3D printer.


3d printing of which plastic out of polyurethane, e-glass, and PTFE is easiest? I am looking for a plastic which is transparent to radio waves.  I want to place my transmitter in a cylinder. That cylinder would be placed in a big RC plane  ( whose body is made up of cardboard). I want the plane to be both telemetry, and RC controlled.  That cylinder should allow the signals,  should be strong and light.
So which material would you suggest and is that material easy to do 3d print?

For the kind of application you are looking for, transparency to radio signal shouldn't really be an issue, so you are more or less free to choose whatever suits your taste better.

Looking at the 3d printed drone community, the 3 most common materials I see being used there are:

impact-resistent PLA
PETG
ABS

This order also match their "ease of use", with PLA being very easy to print even without heated bed, behaving well with glues in the assembly and being easy to paint on.  The impact resistance of "though PLA" still doesn't match that of - say - ABS, but is typically considered "good enough" for anything but the propellers.

PETG is tougher. Print relatively easy (stringing and oozing being the typical problems) but it is known to be somewhat difficult to glue and paint.  It is also quite dense, so - dimensions being the same - it will weight more than PLA.

Finally, ABS is a classic.  It is strong, durable, easy to finish (with acetone) but it is the most finicky material to print with, requiring an enclosure and proper ventilation (the fumes being toxic).


Anet E10 - Print above 270 °C or "maxtemp" error Hoping to determine the reason for my inability to print over ~270 °C on my Anet E10.
To date all operation has been fine.  Attempting to move to a configuration that supports above 250 °C up to ~300 °C.
The control board is the default V1.5 with no changes purchased ~Aug 2019.
I use OctoPrint to interact with the printer.
When attempting to print with a temperature > 270 °C OctoPrint shows it is stopping with a "maxtemp" error. The same "maxtemp" error occurs if I just set the settings to 270 °C and let is sit there for a couple of minutes at most.
This occurs with or without the bed being heated.
I can print successfully at 260 °C with or without the bed being heated.
I have changed the thermistor to another 100k glass bead and a 100k within a canister. There where no changes in the ~270 °C "maxtemp" stoppage.
I have also changed the heater from what was there (30 W I believe) to two different new 40 W (resistance of about 4.1 Ω) without a change in the ~270 °C "maxtemp" stoppage.
The power supply seems not to be involved here since "maxtemp" stoppage occurs without the bed being heated.
I believe this is solely the reason that the control board has a "maxtemp" set at 275 °C. (but I don't know this since I can't find a statement that the V1.5 has this setting by default).
Is there something I am missing in this scenario?  It seems I need to flash the board with settings that have maxtemp > 275 °C - say for my needs ~300 °C.

Regarding the hotend, I neglected to mention and should have, that I have upgraded it to a Micro Swiss in preparation to print over 250 °C.

Your firmware has set a limit of 270 °C, normally, (default Marlin configured value) this is 275 °C. It appears that the Anet E10 developers have edited the value if you cannot exceed the 270 °C setpoint.
The configuration file for Marlin firmware has the following maximum temperature limit set for the first hotend:
#define HEATER_0_MAXTEMP 275

You can change this yourself, but, you need to flash new firmware, making sure that you're using all the correct settings for this printer model.
As a general remark (for others reading this), you shouldn't simply increase the temperature without changing the hotend (unless it is capable of high temperature printing), if the default hotend is lined with a PTFE tube, the PTFE can form dangerous/toxic gasses at elevated temperatures above 270 °C. But, in your case, an all-metal Micro Swiss hotend is installed that doesn't have the PTFE liner.

Note that the Anet E10 configuration can be found in the Marlin configurations zip file. For the 2.0.7.2 version, the E10 already has the hotend temperature limit increased to 305 °C.


Does the printing substrate have to be glass? If so, what size? I am new to 3D printing. I have just put together my own 3D printer with some help.

I was advised I shouldn't print directly onto the aluminium plate - I assume it's aluminium.

The manufacturer did give me a piece of matrix board (i.e. no cooper at all) to print on. Will this work well?
If glass is better, does it have to cover the entire bed? My bed is 275 mm deep by 220 mm wide. I'm struggling to find glass for it that will come within the next few days.  The only custom cut was on eBay and it's going to take over a week to arrive.

Obviously being in a rush can limit your options, but here are a few thoughts:

Quick solutions:

Blue painters tape (as Carl mentioned) will work directly on your heated bed...assuming it's a flat piece of aluminum with the heating element under it.  Your surface does need to be flat.
Acrylic plate will work but is best with no heat, or low heat.  PLA sticks to it.  It's easy to cut and easy to find at local hardware stores.
Scrap glass is fairly easy to find for free and it's not that hard to cut...or buy some at your local hardware store and have them cut it.  Just be careful, it's sharp. You can sand the sharp edges (wet sandpaper) to make it safer.  No, it doesn't have to cover the whole plate, but obviously covering the whole plate would normally be preferred.

Better (but not as fast) solutions:

Buy some custom tempered glass.  I like One Day Glass because they're fast and very capable.  Like Tom says, many many people print on glass because it's nice and flat and stiff.  It's also easy to clean and holds up well.  You can print on the bare glass with many materials or use various preparations like PVA (glue stick or white glue diluted with water are popular), hairspray, or others.
Touch Screen Glass: Some people like replacement glass for tablets or touch screens because it has a hardened scratch-resistant surface.  I've not tried it, but if you can find one that is the right size, it might be worth a shot.
Specialty products: There are many many print bed products out there that promise an easier/better printing experience.  I've used a few that are okay...definitely better than blue painters tape, but I much prefer my current favorite...
My current favorite is PEI. Use a 3M 468MP adhesive sheet (it handles the heat well) to stick a thin sheet PEI (also sold under brand name Ultem) on top of your glass plate.  I got this idea from Lulzbot and it's what they use on all of their printers.  It works beautifully.  Common filaments stick to it while it's hot and release easily while it's cool.  For other filaments I just use PVA like I would over glass.  For material printing tips and settings that work well on PEI beds, check out Lulzbot's site.  When it starts wearing out or getting scuffed up, I just sand it with fine sandpaper and I'm good to go for another hundred prints or so.


Hotend drops to 175 ºC once extrusion starts (MINTEMP error reported) Hotend drops from 205 °C to 175 °C, and then the printer errors MINTEMP. How can I fix this? Fan is not starting yet.

#define  DEFAULT_Kp 28.65
#define  DEFAULT_Ki 2.80
#define  DEFAULT_Kd 73.33

#define HEATER_0_MINTEMP 5

MINTEMP is 5 °C? It's impossible it's getting that cold.

Sudden drops in temperature curves like in your picture are usually missing readings on the thermosensor:

Disconnecting the sensor from the board registers as min-temp of the sensor while shorting out as max-temp, so it triggers the mintemp/maxtemp security protocol: shutdown.

One could disable mintemp/maxtemp protection, but that wouldn't solve the issue. The issue is usually the wiring of the sensor. To find the fault, put temperature on the sensor but keep the motors disabled. Watch the read temperature. Move the printhead manually and slowly. If it suddenly drops and throws the error, you might have a faulty lead close to the printhead. If not, you need to open the electronics box to check if the connection to the board is ok. In the worst case, you might need to exchange the whole temperature sensor.


When dwelling G4, my printer is oozing, how can i stop that? Here is the sequence of my Gcode, printed in mid-air:

Print (E20)
Retract (E-20)
Dwell (G4 10,000)
Move away (E0)
Print (E20)

See the path on the printscreen below:

When the printer dwells it oozes. How can i stop that?

I am using a WASP 3MT, pellet extrustion, 3mm nozzle, Marlin firmware, Gcode done on Silkworm for Grasshopper.

Gcode around the dwell:

G1 F300 X-25 Y-25 Z30 E15.96
G92 E0
G1  F0 X-25 Y-25 Z30
G1 F1000 X-25 Y-25 Z36 E-89.42
G92 E0
G4 P10000
G1  F0 X-25 Y-25 Z36
G1 F1000 X-25 Y-25 Z32 E0
G92 E0

Ooze is virtually unstoppable. This becomes apparent once you understand why an nozzle oozes. As the filament melts, its viscosity drops and the free flowing filament slowly makes it way out of the nozzle due to the action of gravity (and sometimes thermal expansion). If you make the throat air tight then you can use air pressure to keep the plastic from oozing out. Further you would have to immediately turn off the heat to the nozzle and cool the nozzle as fast as possible (possibly with a blower). Even if you retract the filament all the way out of the throat, there could still be some plastic left inside that will ooze out.


What is the purpose of asterix (*) in Gcode? Doing some low level monitoring, the following sequence is sent to the printer:

N0 M106*36
N1 G28*18
N2 M107*39

This sequence just turns the fan on, homes the printer, then turns the fan off.

Question: What is the purpose of the asterix/star/(*) and the two succeeding digits on each line?

That is a checksum. It's added by the host software to the G-code, to allow some basic verification by the firmware that the G-code was transmitted unchanged. It doesn't change the meaning of the G-code, and what your sequence actually represents is just M106, G28, M107. The N0,N1,N2,... are line numbers, and the combination of line numbers and checksums is used to request a re-send of any lines that were corrupted during transmission.


Marlin temperature sensor problem I have a RAMPS 1.4 and an Arduino Mega 2560. The problem is with 100k NTC thermistor. I've tested it with a multimeter, it results in ~122kΩ.

I am using Marlin 1.0.2 (latest stable). I am using an MK8 extruder and do not receive temperature readings from the thermo-sensor - no matter how I connect it. However, on APrinter firmware it works flawlessly.

In configuration.h, I have tried most of the options, but found "1" is the best one for me.

Executing m105 on Marlin, I get following result:

ok T:0.0 /0.0 B:0.0 /0.0 T0:0.0 /0.0 @:0 B@:0

On APrinter, the result is different:

ok B:-inf /nan T:25.2076 /nan

I have not connected bed thermistor yet.

pins.h

#define TEMP_0_PIN          1  // Extruder / Analog pin numbering
#define TEMP_BED_PIN        0  // Bed / Analog pin numbering

configuration.h

#define TEMP_SENSOR_0 1
#define TEMP_SENSOR_BED 1

...

#define MOTHERBOARD BOARD_RAMPS_13_EFB

After switching back and forth from Marlin to APrinter and back, Marlin stopped woking completely. I had configured the LCD (ReprapDiscount Smart Controller) and all the steppers were working. Right now, it does not even sends self test to Pronterface upon start/connection, or it hangs according to the log.

Pronterface output

Connecting...
start
Printer is now online.
echo:Marlin1.0.2
echo: Last Updated: Jul 25 2016 17:12:39 | Author: (Rustam Rahimgulov, default config)
Compiled: Jul 25 2016
echo: Free Memory: 3971  PlannerBufferBytes: 1232
echo:Hardcoded Default Settings Loaded
echo:Steps per unit:
echo:  M92 X80.00 Y80.00 Z4000.00 E836.00
echo:Maximum feedrates (mm/s):
echo:  M203 X500.00 Y500.00 Z2.00 E25.00
echo:Maximum Acceleration (mm/s2):
echo:  M201 X9000 Y9000 Z100 E10000
echo:Acceleration: S=acceleration, T=retract acceleration
echo:  M204 S300.00 T3000.00
echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s),  Z=maximum Z jerk (mm/s),  E=maximum E jerk (mm/s)
echo:  M205 S0.00 T0.00 B20000 X20.00 Z0.40 E5.00
echo:Home offset (mm):
echo:  M206 X0.00 Y0.00 Z0.00
echo:PID settings:
echo:   M301 P22.20 I1.08 D114.00
start
echo:Marlin1.0.2
ec  (nothing more here, output just ends)

In the actual Marlin Firmware all supported printer boards are listed within the file "boards.h". This file contains the following entries for the RAMPS 1.4:

#define BOARD_RAMPS_13_EFB  33 // RAMPS 1.3 / 1.4 (Power outputs: Extruder, Fan, Bed)
#define BOARD_RAMPS_13_EEB  34 // RAMPS 1.3 / 1.4 (Power outputs: Extruder0, Extruder1, Bed)
#define BOARD_RAMPS_13_EFF  35 // RAMPS 1.3 / 1.4 (Power outputs: Extruder, Fan, Fan)
#define BOARD_RAMPS_13_EEF  36 // RAMPS 1.3 / 1.4 (Power outputs: Extruder0, Extruder1, Fan)

The most common version may be the variant . In this case you have to set the value as the following lines show.

#ifndef MOTHERBOARD
  #define MOTHERBOARD BOARD_RAMPS_13_EFB
#endif

Enable Display

#define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER

Ok, it's time to make the adjustments specific to your 3d printer. You might first check the setting for the amount of extruders at around line 58. Most 3d printer rookies may start with one extruder, so the default entry of '1' is quite sufficient.

// This defines the number of extruders

#define EXTRUDERS 1

At around line 70 you have to set up the thermistors connected to the RAMPS for the extruder and the heatbed. Depending on your hardware configuration you have to change the last value in the defines.

#define TEMP_SENSOR_0 -1
#define TEMP_SENSOR_1 -1
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_BED 0

The define for TEMP_SENSOR_0 determins which thermistor type is assembled at the hotend of extruder 1. This termistor has to be connected to the first sensor input (see also wiring schema). The thermistor for the heatbed has to be connected to the second sensor input. The thermistor type is configured with the define line of 'TEMP_SENSOR_BED'. If you use a thermistor of the type EPCOS B57560G104F (100K, Beta = 4036), you write the value '1' into the matching define. In case you have a thermistor with 100k and Beta = 3950, you have to set the value '60' in the corresponding define. So the defines will look e.g.:

For EPCOS (Beta = 4036) on hotend and heatbed:

#define TEMP_SENSOR_0 1
#define TEMP_SENSOR_1 -1
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_BED 1

For Beta = 3950 on hotend and heatbed:

#define TEMP_SENSOR_0 60
#define TEMP_SENSOR_1 -1
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_BED 60


24 V heated bed from -12 V and +12 V ATX power supply? As long as there's a MOSFET in between, can I supply 24 V bed/extruder heat from an ATX power supply using -12 V and +12 V and ignoring the common rail?

I assume so, I can't think of a reason why not, but want to check.

No, this is not possible with most ATX power supplies. While in principle you can get a 24V supply by combining the +12V and -12V supplies, the rails are not symmetric, and the negative 12V supply is usually designed for a much lower load than the positive supply. In the example in the following picture, there are two positive 12V rails, capable of sourcing respectively 12A and 15A each, but the -12V rail is only good for sinking 0.5A. If you tried doing what you're proposing, using this supply, you'd be limited to only 0.5A from your "24V" supply.

It is very unlikely that you'll find an ATX power supply with a negative 12V rail capable of sinking significant current since computers don't need such large amounts of current from their negative supplies.

There are also issues with using a MOSFET as you describe. I assume that by MOSFET you are referring to a complete board with various support components, and not just a bare MOSFET by itself. Usually these boards have optocouplers and thus they will probably work correctly, but using just a MOSFET by itself this would not work, as the gate needs to be driven below GND (namely: to below -12V plus the gate threshold) to turn the MOSFET off.


How to remove firmware warning I'm operating my Prusa i3 MK3 through Octoprint. Basically, this means I can start prints from remote. However, there's the firmware version warning which requires me to press the knob and confirm that message.

I now found a line of G-Code in Printer Settings / Custom G-code which is probably doing this:

M115 U3.6.0 ; tell printer latest fw version

I'm not very familiar with G-Code yet, so before I remove that line, I wanted to know whether that's all I need to do or if there's something else to consider.

Removing that line will not affect your printer, except that it will get rid of the warning displayed on the screen.

  I wanted to know [...] if there's something else to consider.

You should probably upgrade your firmware to the latest version to benefit from a couple of bugfixes and performance increases.


What is the brand of this 3D printer? Could anyone help me to find out what is the brand name of this 3D printer?

I found this printer while playing Spider-Man on PS4 in the Lab

The printer on picture looks like LulzBot TAZ.
It could be some prototype or a self-made built or just inspired by it (as it is a digital rendition), because there is no sign of any branding on it. There are similar builds on Thingiverse.


Replacement Nozzle options I was working on what should have been a simple nozzle clog, and due to my own clumsy handling it looks like I'll now need a completely new nozzle for my 8 month old printer. Fortunately they're not too expensive: $10 for a replacement direct from the vendor. Unfortunately, the vendor is out of stock.

So now I'm looking at alternatives. I believe I could get a 5-pack for $6. Wow. But I wonder: what's the quality gonna be like on those nozzles. Really... that's the question of the moment: what can I look for to be sure I'm not buying junk? Even if they are junk, at 1.20 each does it matter, or is the risk to more than the nozzle itself?

Also, while I'm here and since I'm gonna have to spend some money, what options can I look for in this area that could provide a meaningful upgrade for my printer? Is the cleaning kit worth the extra 5 bucks? What about brass vs copper vs hardened steel? If I only ever print PLA, is the all-metal hot-end for $10 worth the trouble?

With regards to the nozzle material, it boils down to two factors: thermal conductivity and wear resistance.
Brass and copper are better at conducting heat, but they have very low wear resistance: use them with abrasive filaments (PLA infused with metal, fiber glass or carbon fiber, as an example) and they won't last a roll. On the other end steel is not a good thermal conductor, and hardened steel is even worse, meaning the filament will get colder within the nozzle, possibly requiring a slower extrusion speed or a higher temperature, but they are quite resistant to wear.
There are other options, like the famous ruby nozzle, which is very wear resistant and, being made mostly of brass, provides a good thermal conductivity, but it's expensive.

Another factor is the shape of the nozzle: some have a very short tip, others a longer one and that also influences the thermal conductivity and the flow rate, but also take into consideration the long ones don't play very nice with very sticky filaments like PETG.

It is a matter of compromise between material, price and versatility, I don't think there is a single best choice.

Usually very cheap nozzles are not machined very accurately, meaning the hole might not be perfectly round or centered, but unless you require a high level of precision they can be considered "good enough": don't get me wrong, I'm not saying those are low importance factors, but you probably won't notice a great difference unless you are using very good filament and printing at high-res.

It will be very difficult for you to damage your printer using a non high quality nozzle, but replacing the nozzle incorrectly (no matter the nozzle quality) can cause damage to the heat block: try not to snap the nozzle thread like I did...

UPDATE

As pointed out in the comments, there are a couple of factors you might have to take into consideration when buying new nozzles: the nozzle body length (there are nozzles with a much longer threaded body, usually referenced as volcano) and nozzles with different thread sizes (M6 for the vast majority, some use M7, very few use a customized system).


Print quality: possible Z wobble The printer I am using is an Artillery Sidewinder X1. In the photos attached you can see that I am having a lot of inconsistency between layers.
The problem has never gone away and I always thought it was Z wobble but now I'm not so sure it is because we have tightened everything up, making sure everything is stable and tight.
Is this Z wobble or is it something else. Could it be the filament? Does it have anything to do with the slicer settings?

No, this is not Z-wobble, Z-wobble is usually characterized by a repetitive distortion, from the supplied images this repetitive pattern is not observed. A Z-wobble pattern is typically caused by the lead screws, or the Z drive where carriage follows the X/Y motion of the lead screw nut.
A typical image of Z-wobble on a Benchy would look like:

Your print doesn't look that bad for a low-end 3D printer.


Reducing amount of material Just started doing some design. First project was a replacement handle for my angle grinder, so basically a hollow cylinder. I want to reduce the amount of material used in the print. I could sit here and punch holes through the handle with a smaller cylinder, or some other shape etc., but is there an easier way to do this?

It must be a pretty common requirement, just like in the movies where the spies look at a photo and tell the tech to 'enhance ... enhance'. Ideally you could select a surface and overlay some sort of pattern to remove material.

Updated to match the improved question format.

There are a few ways to reduce material usage. First is what you have touched on. Which is to reduce the design by punching out holes, and removing all material that does not add anything to the structure. Even better is what you touched on, reducing it to the point where your print is more like a suspension bridge, where it is a the bare minimum scaffolding in a geometric pattern.

Most tools you will find for reduction are like this tutorial from Shapeways on Meshlab where you reduce the surface detail. It might be worth exploring these a bet, however probably not what you really need.

Next the more hard core cad tools such as solid works will allow you to preform Parametric optimizations and Topology Optimization.
Topology Optimization. seems to be your real winner

Now from the 3d printer standpoint we just simply tweak our slicer settings. There are entries for Infill. I usually print with 7% infill. AKA my print is 93% hollow inside. I then set a few solid shell layers. Think of solid shells as the skin. Usually that is enough to reduce my plastic usage. The only reason I don't make a part 100% hollow and a few solid skin / shell layers is that I need something to print on top of or if I need the part to be strong . Even low percent infill can be very strong if the correct geometric pattern is used (I.E. triangles).

Generally the reduced infill will be enough, unless you are making thousands of this item, though in that case you are probably not going to 3d print it anyways.

3dprintingforbeginners has a nice article on the relationship between infill, number of shells and part strength. A bit more information about the terminology (infill/shells/etc...) can be found on 3D printing blog.


Using CAT6 cables for 3D printer motor / sensors / fans I'm considering using CAT6 cables to connect my printer's extruder assembly to the control board. They seem like an elegant solution, but I've read conflicting opinions online on whether or not this would be feasible.

I would like to know if CAT6 cables can handle the required current, whether I should be worried about electromagnetic interference or other problems, and how I should pair up the wires. Cable length would be 30cm max.

Here are the relevant parts:

E3D heater cartridge (2 wires)
E3D thermistor cartridge (2 wires)
30mm hotend fan (2 wires)
Z-axis auto-leveling probe (3 wires)
NEMA 17 extruder motor (4 wires)
50mm part cooling fan (2 wires)

[cable A]  I imagine I would use one CAT6 cable for parts 1-4, which form a logical unit (and in the future I might combine them into a removable module). I've been given to understand that power for the fan can be spliced from the z-probe or heater cartridge, so 8 wires should be enough.

[cable B]  I would use a second CAT6 cable for parts 5 and 6. There will be two spare wires, so I could potentially double the bandwidth for the motor.

The ampacity question is not completely answerable because CAT6 does not specify wire gauge, so the current limit will depend on the specific gauge you get. CAT6 can be anywhere from 22 AWG to 24 AWG, and depending on who you ask this can be good for as much as 7A or as little as 0.5A. Given that you will have a bunch of wires in a bundle, this may cause them to heat up more than if they were in free air. For the steppers (1-2A) a single wire should suffice, but for the heater (around 3-4A) you might want to double up.

EMI will likely not cause any problems regardless of how you wire things up. CAT6 cables have the wires twisted in pairs of 2. Some people recommend to take advantage of these pairs: the +12V and GND of the heater should use a pair, each of the two coils of the steppers should have their own separate pairs. The reasoning behind this is that with equal current flowing in opposite directions in each wire of the pair, the generated electromagnetic fields will cancel out.

Twisted pairs are usually used when dealing with multiple pairs of wires that are carrying high frequency signals that might affect each other. The main concern for crosstalk in this application is if the stepper motor might cause the endstop to be erroneously triggered, but this is only a concern during homing when the feedrate (and thus frequency of the signal) is low anyways.


Methods for smoothing 3D objects How do I smooth 3D printed objects? What is the best / common method to do this?

Abrasive blasting is the only other method I can think of which you haven't said you don't want to try.

It is certainly the easiest method provided you have access to one.

Different forms of abrasive blasting include:

shot blasting (metal shot) - I suspect it would be far to abrasive but I've never tried it.
sandblasting - you have to be careful but this is basically sandpaper attached to a wand. I've used it with great success.
bead blasting - using plastic beads. It might actually be the best option but I've never tried it.
media blasting - usually uses ground up shells. Might work but I've never tried it.


Getting wrong measurements on my Kossel Linear Plus after installing SKR 1.3 with Marlin 2.0 So I've switched the Trigorilla board in the printer with a SKR 1.3 with TMC2208 drivers and installed the latest Marlin 2.0, with a config based on this one. You can find the Configuration.h here, the only thing I changed in Configuration_adv.h was the pin of the hotend fan.

Now when let the printer autocalibrate the delta settings, it tells me that the height is 141.35 mm, instead of the actual ~300 mm and I had to set the radius to 78 mm, instead of the actual 115 mm so that it doesn't try to probe outside the bed.

What settings could I have set so horribly wrong that I get these results?

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