text:
Does the color of a filament effect its physical properties?
When choosing which filament to use for a particular print does the color of the filament have any impact on it's performance, or is it purely a cosmetic choice?
For example, are there any side-by-side comparisons available that demonstrate that differences do\don't exist between different color filaments from the same company\range, such as a particular filament needing a hotter bed because the pigment changes it's properties?

It is possible.  But the same properties can change from brand name to brand name for the same color, or even from batch to batch from the same brand name.

Comparing different brands adds an additional complication. It's best to stick to differences within one particular brand. to keep the variables down.

Depending on the pigment size and other additions, the melting temperature and crystalline/amorphous structure of prints vary vastly.
Titanium white, the most common white pigment in the industry, needs to be applied in large doses to get a good coloration. This means that the brighter the white, the larger the percentage volume of the item is made up of the pockets in the polymer structure that contains the pigment, resulting in a more brittle structure.
Carbon black on the other hand is one of the most effective black pigments known to man and can be used very sparingly. It also is an almost perfect UV-absorber, making such prints heat up much more than those of other colors. It also can protect the polymer itself from aging if the polymer chains degrade under UV light. ABS for example does undergo degradation in UV light.
Some polymers also contain some kind of filler to adjust melting temperatures:
I have encountered PLA spools from two different manufacturers in the almost exact same color before printing. However, the one brand printed well already at 190 °C, the other required 200 °C to print decently. The two filaments also looked vastly different after printing: the hotter printing one showed a much higher gloss after printing, which hints that they had a quite different makeup besides the PLA - either something in the one was making melting easier but reduced gloss or something that increased gloss also rose the melting point.
Another thing I found was, that the clear PLA I got from china once printed best at 110 % flow of other PLAs in combination with only 185 °C, making me believe that something in the treatment to achieve the translucent filament also results in altering the flow behavior.

Yes in some cases it does.
It is widely known in communities which are pickier about properties that white filament requires a percentage of pigments much higher than other colours, therefore white filaments are typically weaker (or significantly weaker) than most other colours.
Another exception is black: ABS is not UV resistant, but if you use black ABS, the UV will not penetrate and, unless the surface is continuously scraped away, the UV resistance of black ABS is better than other colours.
I remember some mentions in the Voron discord chats that red (at least from some manufacturers) is better than some other colours from the same manufacturer, but I don't remember the details. You can join the chat yourself and search (before asking!) in the #filament chat.
I remember reading that pure ("natural") filaments are however not always better than filaments with colours added, but I cannot remember the source. It could be that some little amount of extra additives (the colour pigments) offer the polymer something to "grab", so better than nothing. My guess, but I have no support for it.


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Filament Jamming in Hotend. Why?
This has me stumped. I had been printing normally until this happened. Below is an expurgated version of my headache over two days. Some help would be appreciated.
Printer is Hypercube Evolution (CoreXY) using Bowden tube and eSun PLA+ filament. Bowden tube goes from inside the feed cone in the extruder straight through the heatsink and into the feed throat of the heatbreak. Genuine Titan Extruder. Extruder stepper has no label.
Started a new print. Printer was at ambient temperature of about 18 degrees. Printer brought up to temperature, 60° bed and 200° hotend. Bed homed and levelled in gcode. Print speed 60mm/s. Hotend moved to centre of bed and print started. No filament extruded and extruder stepper was making a grinding noise. Normally expect this to be hotend not hot enough. Altered pressure adjustment on the extruder. Made no difference. Cancelled print.
Lowered bed out of the way. Hotend to 225°. Attempted to extrude filament. Nothing other than extruder stepper grinding. Tried to retract filament, no motion and extruder stepper still grinding.
Disassembled hotend. No problem removing nozzle. The heatbreak and the heatsink Bowden connections would not give. There was filament between the Bowden connector and the heatbreak. When this snapped, I could get the parts free. The heatbreak had stretched filament stuck in the feed throat. There was thickened filament in the Bowden tube preventing retraction. It is still in there and stuck. Extruder stepper replaced and VREF adjusted. New all metal 1.75mm heatbreak. Bowden tube replaced. Hotend reassembled.
Hotend to 200° and extruded 200mm of filament. There was some smoke from the hot end at first and the initial filament was burnt. Everything seemed to be working, hotend turned off and Z-offset calculated and stored.
Lowered the bed, hotend back to 200°. The problem was back, could not extrude nor retract, extruder stepper grinding. I was able to withdraw the filament manually. The end was slightly thickened with a whispy "tail". Cut the filament, hotend to 225° and re-fed filament. Acrid smoke initially from the hotend and filament extruded. Hotend allowed to cool to room temperature. Hotend to 225°. Filament would not extrude nor retract. Hotend turned off and left.
Disassembled hotend. Again, heatbreak and Bowden connections to heatsink would not give. Managed to manually feed filament whilst unscrewing heatbreak. The filament found is shown in the attached picture. The small thick bulge would seem to have occurred in the tiny area where the Bowden tube enters the feed throat of the heatbreak. The thin filament is stretching whilst trying to retract. After that can be seen where the filament has thickened again. Mangled filament trimmed and hotend reassembled making sure that the Bowden tube was seated in the heatbreak feed throat. Hotend to 200° and extruded 200mm filament. Tried a test print, not very good, but worked. Tried a second print, the problem was back again.
Has anybody any ideas how to solve this? I have also checked that the thermistor is reading correctly, changed the roll of filament (just in case I had a bad roll) and have replaced the extruder stepper driver.

Are you using the correct size filament for your printer?

The lump at the top of the heatbreak is because there is a gap between your bowden tube and the heatbreak.  Liquid filament is leaking out of the heatbreak and solidifying there.  When you reassemble, you need to close this gap.
There should not be smoke coming out of your nozzle.  Maybe when it is new, there might be a bit of oil that would smoke, but it should only do that once.  If you are getting burned filament, your nozzle temperature is too high.  Either the control system is overshooting and the temperature spikes, or your temperature sensor has a problem.
The thickened filament is worrisome.  With the filament jammed at the heatbreak, if the filament is soft, it might be getting compressed.  But PLA should not do this unless there is enough heat leaking into the bowden tube to soften it.

The gap was troubling me as I had managed to get the Bowden tube seated fairly solidly in the throat of the heatbreak. I had managed to extrude filament, let the hotend get cold, heat up and extrude again a number of times. It turns out I had two problems. 1, the Bowden tube was moving in the connector. This was fixed by putting a clip on the connector. 2, replacing the all metal heatbreak with one using a PTFE tube, this stopped the heat creep that was melting the filament at the top of the heatbreak.

I too have been plagued with stuck filament in my hotend. First, I am using a ~300 mm long Bowden tube on a delta-type 3D printer.  Every time it jams, I can pull the filament back out, I find the end having a slightly larger diameter that is ~2-3 mm in length. I cut this off and feed it back and I am good to go.
A couple of observations:

I replaced my Bowden tube and heatbreak, but I may need to taper the end of the Bowden tube so there will be 0 gaps with heatbreak.  My Bowden tube I.D. may be too large and during retraction, it expands in the Bowden tube.
Next, the filament tolerance is +/-.03 mm.  This may not be tight enough to cause it to get stuck.
Last, the temperature should be reduced to the lowest possible to prevent any heat to migrate up the heatbreak.

Worked out the reason for the thickening filament. A number of sites refer to heat creep and suggest that you check that the heatsink is clear and the heatsink fan is working properly. In my case, they were. However, the fan outlet (where it blows on the heat sink) was full of garbage. Cleaned that out things improved. Also replacing a dodgy thermistor cleared up the residual problem.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


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One rough corner with blobs
Neptune 2, Polyterra PLA at 200/45 °C, Cura 4.11.
I'm tuning the settings and one of the test prints is a keycap, all the corners except one print just fine, that problematic one shows heavy blobbing and is extremely rough, pic related.
I've tried fiddling with the temp, speed (50 mm/s, persists even at 20), jerk speed (3 mm/s), retraction settings (3mm at 70 mm/s), flow (even at 90 %), Z seam related setting... But the problem still persists.
I'll be monitoring this thread for a few hours, any input would be appreciated.

Are you printing from SD card or octopi or something else ?

Which direction is the part cooling fan blowing relative to this corner? This looks like curling from poor cooling. If so, printing outer walls first (a setting in Cura) may make it go away.

I am printing from an SD card. This corner was the top right and the fan is on the left (from a top perspective).

Is the problematic corner the start location of the perimeter?

It does start there, but the first few layers are without the blob, and seam settings are on random, so it doesn't start a new layer on this same side all the time.

Neptune 2 appears to use the Bowden extruder. Typical settings for Bowden are 4-8 mm retraction distance, 20 mm/s to 45 mm/s retraction speed. Your setting seems like a low retraction distance, it might not be fully retracting, and blobbing at the start of a layer could be from that.
You could also mess with the ‘retract on layer change’ setting if you think it is dwelling at the end of a layer and some extra plastic oozes out as it does the Z move to move to the next layer.
Check there isn’t a setting to have extra extrusion after retraction, here you have too much extrusion at the seam.
Side note but you can get rid of the elephant's foot on the first layer by entering a negative value in the setting “Initial layer horizontal expansion”. You want to squish it as you did, but this setting makes it so the edges don’t bulge out further than the rest of the model.

I've tried multiple settings for the retraction including the one you mentioned, but this parameter seems to to work the best for me. I also already enabled the retract at layer change option. I don't think it is the seam, since the seam alignment is on random, so it shouldn't be on the same spot all the time. Huh, thanks for the last tip, but this "elephant foot" was because my Z offset was too low and it squished the first layer too much, but thanks anyways.

Huh, so the defect isn’t the seam. Only thing I could see is a mechanical problem, like something is loose. How’s your belt tension? are the belt pulleys tight on the stepper motor shafts?

From what I checked, everything seems alright, maybe the belts are just a bit loose, but they're very tricky to adjust, I might print a tensioner for them to make it easier. Also, when I pull X or Y axes, it makes a stuttering-ish sound that I noticed after I installed a BL-touch on it along the firmware they provide on their website, maybe that could be a part of the problem? On the other hand, I had this problem before then as well, just the movement of the axes was quieter. Right now I'm leaning more towards the bad cooling explanation... but who knows.

Re: bad cooling, that could be, just noticed the part is printed so the sides overhang. Sometimes overhangs curl and get ugly as the next layer remelts them in a less than perfect way.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Creality 1.2.3 does not recognize M140 and 104?
For some reason, the Creality Slicer 1.2.3 ignores the M140 and M104 commands completely, even if I put them at the very beginning of the start G-code. I have tried different variations (e.g. M140 S60, M140 S{material_bed_temperature}, M140 S{material_bed_temperature_layer_0}, and none work with Creality Slicer 1.2.3.
Instead of starting the heating and not waiting to move to the next line, it waits to reach temperature as if it is an M109 or M190. Does anyone have a similar experience or fix for the M104 and M140 commands in Creality Slicer 1.2.3? Using Creality Ender 3


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Interpreting G-code to answer question about geometry of shape produced
I encountered the following question in a manufacturing course.

G20 G90 G28

M06 T1

MO3 S1000

G00 X0 Y0 Z-0.25

G41 D1

G01 X1 Y1 Z-0.25 F3

G01 X5 Y1 Z-0.25 F3

G01 X5 Y3 Z-0.25 F3

G01 X1 Y1 Z-0.25 F3

G00 X4 Y0 Z0.25

But when you type the G code in NCViewer the shape produced is not a rectangle. Also, I am not sure how the end mill diameter affects that of the rectangle. Can anyone explain how to solve this problem?

people make mistakes.  there may be a line missing.  care to guess what that line would be?

Glad to see my site helping others learn about gcode still! :) Just wanted to help a bit by explaining that in most cases, gcode positions describe the position of the CENTER of the tool, and therefore half the endmill will stick out on each side of the position. For a rectangle you add or subtract the 2*ToolRadius (once on each side) for the final size. A pocket in material is larger(add), a contour outside the material is smaller(subtract). Good luck!

Also just to note I think this question implies the tool is outside the material as phrased, but I could see someone interpreting this as inside material (e.g. cutting a window in sheet metal) so it's a shame the question didn't clarify the type of cut.

There is no rectangle, the assignment is wrong. In order to make a rectangle, the G-code should have been:
...
G01 X1 Y1 Z-0.25 F3
G01 X5 Y1 Z-0.25 F3
G01 X5 Y3 Z-0.25 F3
G01 X1 Y3 Z-0.25 F3 ; <-- missing line
G01 X1 Y1 Z-0.25 F3
...

Then the rectangle would have been 2 by 4 inches.

As noted in the comments, the assignment is even more unclear. The code shows an offset to be taken into account of tool D1 in the cutter compensation code G41. It further doesn't specify the characteristics of that tool. If it is differently than the end mill currently in the tool head, than the difference in diameter between the D1 tool and the current 0.5" tool needs to be taken into account. The power of using cutter offset definitions is that the same code can be used for different tools, you only needs to set the correct offset. If the D1 tool is defined as a 1" diameter tool, the current tool is half that size, as there is a compensation for 1" at play while a half inch end mill is used, the end product will be larger.

There are also further omissions in the assignment. The G41 D1 command sets radius compensation for tool number 1, but we do not know what radius the tool table has for that tool. From the initial X0 Y0 Z-0.25 it appears we are conventional cutting on the outside, but in that case G41 applies the compensation in wrong direction and G42 would be more appropriate.


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Non-Manifold .stl file won't print properly on my ToyBox 3D printer
I am trying to print this really cool flying toy model on my ToyBox 3D printer, but when I try to print the "copter_key-175.stl" file it complains it is a "non-manifold shape". How can I fix this .stl file?

[update START]
Update for future readers:
I haven't tried it yet, but the Free and Open Source slicer software, Slic3r, boasts this feature worth trying:

auto-repair of non-manifold meshes (and ability to re-export them);

Update again: the best slicers, it seems, based on my research, are:

Cura (FOSS and professionally supported),
PrusaSlicer (FOSS, forked from Slic3r, and also professionally supported now).

Articles to look at:

Google search for "slic3r vs cura"

Slic3r vs Cura (Cura wins; Slic3r lags due to no full-time company-sponsored development): https://all3dp.com/2/slic3r-vs-cura-3d-printer-slicer-software-shootout/

Google search for "prusaslicer vs cura"

PrusaSlicer vs Cura (Cura wins, but just barely, since both are professionally supported with full-time developers): https://all3dp.com/2/prusaslicer-vs-cura-differences/

[update END]

Note that I have printed many ToyBox-designed models perfectly with this printer over the last 24 hrs.
I have also split the model (to cut the last few cm off the end and shorten it) using this technique here in TinkerCad, then exported the part as a shorter part so I could print on the smaller bed of the ToyBox printer.

Here is what the "key" is supposed to look like:

And here is how it comes out instead. Notice the misaligned teeth and layers about halfway through. Once I saw it was botched, I stopped the print early.

How can I make it print properly and/or how can I fix the .stl file?
Notes:

My operating system is Linux Ubuntu 20.04
I have Windows 10 running in the VirtualBox virtual machine in case I need to run Fusion 360 or something in Windows
I tried installing Meshmixer inside Windows 10 and it won't open. I had read online it can be used to fix .stl files, so I was going to look into that.

Related:

my comment on Thingiverse
my help request on Toybox
Another person seeking help for this: tinkercad.zendesk.com: Non-Manifold Model

That looks like a problem with your printer, not the model.

This looks like layer shifting, thus a printer problem, not the model.

Update 24 Mar. 2023: the maximum usable print volume of the ToyBox 3D printer is approximately 74 x 79 x 100 mm (width x length x height), and you must add supports to keep tall objects from tipping over and catching
1st, you must add supports to keep tall objects from bending over and catching the nozzle, like this:

Notice the side supports. Without them, this ball will not print properly. Between 60% and 80% done, it's so tall that the nozzle will eventually catch on the ball edge, tip it over, and then get jammed against it, causing it to think it hit the edge of the print volume, and forcing the center point to shift several mm in the opposite direction. This results in print sheering and possibly damage to the stepper motors or gears.
2nd, the digital bed size of the ToyBox 3D printer (when you go to load an object to print) is 75 x 80 x 100 mm (7.5 x 8.0 x 10.0 cm).
When printing large objects up to 100mm in height, it seems to work fine. So, that limit is ok. But, when printing large objects which are the full width, ex: a 75mmx75mm circle, the object will get destroyed once the max diameter portion of the circle is reached. This is because the hard mechanical stops (screws, and metal edges of the print space) and/or limit switches of the printer will be hit, causing the print head firmware to adjust the center print point by several mm in the opposite direction. The object will then print with misaligned layers from that point forward. Since the center point just jumped several mm, the end point will be hit again on a future pass on the opposite side, causing it to jump again. It will jump like this repeatedly until the print is complete. You end up with shifted layers as shown in the photo below. This is a 75x75x75mm ball, which printed fine until the max diameter center portion was reached, at which point the mechanical edge stops were hit, the center point was (presumably) readjusted by the firmware, and the layers sheered:

So, when printing, shrink the object 1 or 2 mm (5%, or 3.75mm of 75mm is plenty, and 1%~2%, or 0.75mm~1.5mm of 75mm is probably enough) and be sure to add an outer ring as wide as or just wider than the max diameter of the object. Ex: here is a manually-added outer ring to ensure the print head starts and stays centered at the beginning:

In conclusion, the maximum usable print volume of the ToyBox 3D printer is approximately 74 x 79 x 100 mm.

Back to my original answer:
ToyBox 3D printer true print dimensions and limit switch problems
So I figured out that the problem is my print area is so small the printer was occasionally fully pressing and triggering the end-point limit switches! This apparently causes it to stop slightly early, shifting the next layer as it prints.
The printer specs state that it has a print volume of 9 x 8 x 10 cm. However, the print design area and viewer at https://www.make.toys/ shows the design volume like this

In the square grid shown on the base plate there is 1 cm per square, except that as you can see, the far left and far-right columns are < 1 square. Therefore, looking at this image, the usable bed area appears to be about 7.25 cm x 8 cm (the grid size shown in the images), NOT 8 cm x 9 cm.
Furthermore, if you do NOT have the "Skip First Ring" option checked on the "Build" tab in the image below, the printer does a "wipe clean" maneuver in the shape of a spiral, circle, or ring around the object to be printed just before beginning the print. This wipes off any dangling stray print material before beginning the print. If your object fully covers the print bed dimensions, however, that ring will be even wider, causing the printer to hit its limit switches.
(The model in this image is 10.4 cm long, which is too long, causing my printer to hit its limit switches, skewing the layers while printing.)

So, the problem is that my part is too big. WithOUT that "Skip First Ring" box checked, the dimensions are probably further reduced by another 5 mm or so on X and Y dimensions, bringing it down to about 6.75 cm x 7.5 cm usable print area. My part was 10.4 cm long. The Pythagorean Theorem says that $A^2 + B^2 = C^2$, so $C = \sqrt(A^2 + B^2)$ = $\sqrt(6.75cm^2 + 7.5cm^2)$ = 10.09 cm max on the diagonal. My 10.4 cm long part was too long. The printer hit the limit switches, botching the layers.
Had I checked that box maybe I could have gotten away with a part closer to $\sqrt(7.25^2 + 8^2)$ = 10.8 cm long, but that's really pushing the limits of this printer. In the end, shrinking the part a bit more to be about 10 cm or less was all I needed to do!
UPDATE: I've also proven conclusively by designing in www.TinkerCad.com and printing on the ToyBox that the max allowed print height is exactly 9 cm, and it will indeed print properly all the way up to that height.

I'd still like a flying propeller
That being said, even though the "key" of the model in my question printed pretty well in the end, the helicopter blade (propeller) printed horribly because the design is flawed and has a bunch of missing material and air gaps around the hub, making the propeller completely unusable!
Instead, I switched to this thing shown below, shrunk it down to 0.6x to fit my printer, set my printer settings from medium to fine resolution, and got pretty good results! I still need to further tweak and edit the design on https://www.tinkercad.com to give the pull key better clearance, and better connection with the hub gear, and I think I'll be able to get a great result! I got it to fly a few times up to 8 ft high or so, but the pull is very rough and inconsistent, so the model needs further tweaking.

Keywords: ToyBox 3D printer helicopter and toybox printer clearances, print dimensions, print volume, specs, print settings

@agarza, thanks for the helpful edits. Just one question: why did you use the HTML   code to add spaces to my answer instead of just pressing Space Bar to add a space ( )?

  is a Non-Breaking SPace that prevents line breaks between characters, specifically like units of measurement. More information is available here, here, and here.

We follow the rule for units having a non-breaking space here. another alternative is to use the unicode to get the non-breaking space (Alt+0160).

I have printed at least 5 of them (Cura Slicer, Creality CR10s) and there have been no problems. So I can't understand your problems. I would suggest to use another slicer (Cura). I have now repaired the file with Meshmixer and added it (copter_key-175_meshmixer-repair.stl). Maybe this solves your problem.
https://www.thingiverse.com/thing:4551901

Welcome to 3D Printing SE and thank you for your contribution. When you get a chance, please take the [tour] to understand how the site works and how it is different than others.

Can you please post exact detailed instructions on how you did the meshmix repair? That seems to have solved my issue entirely (I'm doing some more testing now to be sure). If you didn't want to explain in detail how you did the meshmixer repair, doing it again while screen-recording (see my instructions here) with OBS Studio, and then posting that to YouTube, would also work.

Non-manifold objects are only accidentally solid, as sometimes it becomes unclear what is the inside and what is the outside.  Some slicers attempt to fix this and do a good job of guessing how to correct it.  Also, some non-manifold errors are easier to fix than others.
If your slicer is complaining about a part file being non-manifold or you suspect that this is causing a problem, you should bring it into a surface mesh editor like meshlab or blender and try to fix it with the manifold test and repair tools in either of these programs.
Typical ways an STL file could be non-manifold include:

cracks between faces caused by round off error
missing faces
flipped faces
interior faces
faces that intersect somewhere other than an edge


text:
Appropriate Grease for Z-Axis Lead Screws
I need to lube the lead screw for my 3D printer. I plan on using this grease. I want to know if this will work. There are several other ones like silicone grease, lithium grease, and synthetic grease with PTFE. I am super confused with the pros and cons of each.
Details:

I have a metal lead screw and a metal(brass I believe) nut.
I am using a Lotmaxx SC-10 printer(similar to Ender 3)
I need it to repel dust.

I think it was dry, to begin with. At least I have never greased it before. If I touch it, I feel something on it, but it is super thin and I can barely feel it.

What lubricant is appropriate depends on materials involved and what previous lubricant was in use.   Some lubricants (for example, oil and graphite) may cause problems for each other. If there was no previous lubricant, this becomes an engineering design decision with many answers.

If it's just a light coating of an oil based grease, likely you could wipe it down a bit and then any of your similar semi-liquid greases would work.  Which brings you back to making the engineering decision by weighing the pros and cons of each...

Personally I put a drop of light machine oil on the lead screw just above the Y gantry between prints, while the head is down.  When it prints, the lead screw raises the gantry and the threads spread the oil.
If I was going to do a really tall print, I'd consider adding a little oil higher up the lead screw too where it rarely goes.
A Y axis lead screw is a low speed, low pressure and low temperature application, so anything "slippery" will do, but the dust repelling attribute is important.
Sewing Machine oil, or 3-in-1 oil would be ideal, as would a white lithium grease.  You don't want a petroleum grease like in car wheel bearings because it attracts dust and is viscous/heavy, requiring more force to move around.

Since your existing lead screw is "dry" a wipe with a clean rag should be enough to remove what was there.  I would not use degreaser or solvent, and I would also avoid anything that is in a spray can/aerosol because you want to control where it goes, and avoid overspray.
Your nominated du pont lube looks fine too, though out of stock and it seems expensive.

Should I clean the lead screw with Isopropyl Alcohol first? Many guides say to do this.

@DragonflyRobotics you could if you want,  I wouldn'tbother with anything more than a wipe.  Just let it evaporate for a couple minutes before oiling.


text:
Filament Spool Stalls Extruder Motor Destroying Print
I am having the frustrating problem where my extruder motor starts skipping steps and stops extruding simply because my filament is wound too tightly. There are some parts of my filament that are so tightly wound that even I have to put some effort to pull it apart. I buy the Inland PLA+ filaments and consistently have this problem with all colors and types. I just threw away a 5-hour large print when it was at 94 %! I am thinking of using a large 20 kg/cm servo to pull our filament before going into the printer to make sure this doesn't happen. I want to know if that is a plausible solution or if I should start buying filament from a different company.

When you change a spool on a printer how well do you control the end of plastic, are you securing it to the side of the spool or just fishing it out of the loose loops of plastic around the spool? This sounds a lot like a user caused issue where the end of the line gets tucked other loose loops on the spool.

Or perhaps you need to rewind your spool onto an empty one so it is evenly loose all the way through.

A guy at work had this - he got many cheap rolls of PLA.  They had been stored hot and were subtly deformed, each flake slightly sticking to the adjacent ones.
His fix was first to unspool "enough" filament for the job, but that was not reliable for longer prints.
The proper fix was to wind the entire roll onto a spare roll and then fit that to the printer.  (And to stop buying suspiciously cheap filament)   He make a mandrel for the center of the "reel" and simply wound the filament on with a battery-powered hand drill.  The old roll was on the machine until it was emptied, then swapped over.

As for your 94% job, it is possible to slice the top 6% of your part, and reprint that.  Some careful filing and superglue can give you a useable part, although the seam is never going to be invisible.  That may not matter depending on your use case.


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Ender 3 hot end heater "stuck on"
Forgive this long-winded post, but I thought it would be helpful to include the back story leading up to a very scary situation on my Ender 3.
I was printing a job and everything started out fine just like it normally does. I'm not sure if it is related, but partway through the job, there was a power dip severe enough to trip the alarm on the UPS my computer is attached to. It didn't seem to affect the job on the printer though. (the printer is not on a UPS)
A little while later I noticed the extruder clicking like there was a jam, and the print had started severely under extruding. The hot end temp was showing around 209 °C, which is about what it was supposed to be, so I figured the nozzle was getting old and had probably gotten something stuck in it. I canceled the job, did a cold pull, then went ahead and replaced the nozzle and restarted the job.
The second run started off looking ok, but the clicking and under extruding soon came back. I stopped the job and was standing there next to the printer trying to figure out what was going on when I noticed it reboot itself. Octoprint showed a message (I can't recall the exact wording) of something to the effect of "your printer reset and the job is probably failed".
Weird. It's never done that before. I hadn't restarted since the power dip, so I thought maybe it was just in a bad state and physically powered everything down to start fresh. But as soon as it powered back up, the heater went active and the hot end started warming up. The status display said the temp was set at 0 °C, but the "current temp" reading was rising. I quickly went into the menus to select "cool down" and couldn't find it. There was no cool-down option on the menu!
By this time the hot end was up to around 270 °C and starting to smoke, so I shut the whole thing down again. I let it sit for a little while and powered up again. Immediately upon receiving power, the heater went active and started heating up again! I'm pretty sure had I not been standing there it would have eventually caught fire and possibly burned down my house!
This is the original Creality board, but I did flash it with Marlin U1.R2.7 maybe a year ago. It has been completely stable since. Thermal runaway protection is enabled (and tested), but I don't think it would have done anything in this scenario since the printer thinks the heater is off (hence the missing cooldown option). Even if it did detect an issue, I'm not sure it would have been able to do anything since it seems to be permanently shorted "on".
Has anyone heard of something like this before? Any idea what might have caused it?
I opened the case and inspected the board for signs of something shorting out or a smoked component, but everything appears normal. I disconnected the heater so I could power up and everything seems to work other than the heater terminals always having power.
Obviously, my trust in this machine has been severely diminished. I already ordered an SKR Mini E3 V2 to replace the Creality board since I had been thinking of upgrading anyway. But I would really like to know what happened so I can assess the probability of it happening again.
Ideally, I would also like to figure out some way of protecting against this happening again in the future and causing a fire when I might not be standing next to the printer next time.
My first thought is some sort of thermal fuse (like the ones in hairdryers) in line with the heater that would "blow" if it gets past a certain temperature. A typical consumer printer should never have a reason to get above 260-270 °C, so it seems appropriate to kill the circuit if it goes beyond that regardless of what the board is telling it to do.
Has anyone tried retrofitting something like that? Are you aware of any printers on the market that include such a feature?
Any suggestions on how to troubleshoot the board to figure out what happened?

Your onboard MOSFET has failed, you need to replace the component, yet better the board. It seems the MOSFET isn’t reacting to the signal from the microprocessor, instead it is “always on”.
Note that a MOSFET usually fails short, but can fail open in certain circumstances. See Do MOSFETs usually burn open or closed?.

Agreed. I think it must have blown the MOSFET. Maybe from the power issue. The new board should be arriving today, so it will soon become irrelevant. Maybe I'll see if I can figure out which component it is on the old board and try replacing it just for practice. I probably still won't trust the old board even if I manage to fix it though. The real question is: how to protect against this sort of failure?

My understanding is that the hot end heats until the thermistor signals to the board that it is near/at temperature.
On an Ender V2 with the Meanwell power supply, the unit has thermal runaway protection so if the thermistor fails the board will shut down.
In your case, the failed thermistor never alerts by changing resistance, the board will keep heating the block.  So I think you need to pull the thermistor and test its resistance as the temperature changes.  Connect it to a multimeter with the Resistance setting, then heat it with a hairdryer.
Another possibility is if a failed print has clogged the nozzle area, and the resulting blob of plastic has broken a wire to the thermister.  This might be repairable by soldering.
Thermistors are available as replacement items too, may pay to simply get one along with a spare belt and nozzles.

I don't think the thermistor is the issue. The reported temperature is correct and you can watch it rise. A thermistor problem would be the opposite and would be caught by thermal runaway protection. In this case it's heating as soon as the power switch is turned on, before the firmware even finishes booting. By the time the main menu comes up, the hot end is already at around 50 degrees and climbing even though it was never turned on. After a little more research, it sounds like the MOSFETs used to switch the power will often "fail on" when they go bad. That sounds like what happened here.

@SteveInCO yeah fair enough - if the controller can read the temperature then the thermistor is probably working fine.  Sorry I missed that detail.


text:
Hot end temperature keeps dropping on my Creality CR-10 S4
I have a Creality CR-10 S4.
What causes a "runaway please reset"?
I changed the heating element and the thermistor. When I heat the hot end, the temperature drops down to about 165 °C and I get a thermal runaway.
Could the fan go bad and it's going too fast?

Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.

Hello... any update?

There could be multiple reasons for the issue, but the most common issue is the temperature sensor. We can test it:
Disconnect the hot end from the control board and place the sensor on a warm plate and after some time place a candle closer to your sensor, with a 5 mm gap. If your board is able to display the variable temperature, then we can say the temperature sensor is fine.
Or if you're good with electronics and programming, use Arduino/ATtiny/Arm controller to measure temperature using the temp sensor of your 3D printer.
The next issue could be some component in your control board, it happened with my printer, in my case, resistor and two capacitors were at fault.


text:
Will a 12 V Stepper motor work at 24 V?
I have a Prusa MK2.5 which runs at 12 V, the Prusa MK3 runs at 24 V.
I noticed that on Prusa's webpage, they list the stepper motors as being compatible with both the MK2 and the MK3 even though they run at different voltages.
My question is: are stepper motors typically tuned for specific voltages (like most fans are), or are these stepper motors compatible with both 12 and 24 V systems?

if they say its compatible, chances are high that a current limiter on the motor controller is expected to take effect and prevent frying if set correctly for the motor.  check controller.  big ones have a set of switches.  little ones have a trim pot.

if you use two power supplies.... https://toms3d.org/2019/05/25/use-the-wrong-parts-on-any-3d-printer/

There is an excellent answer found on SE Electronics! Basically there is a difference between the constant voltage applied or one applied through a sophisticated controller! The stepper is probably rated for 4 V (continuous) or something close to that, a good rule of thumb is to use between 10 and 24 times the motor’s nameplate voltage, so it will work at 40~80 V.

The steppers have two voltages in the specifications: nominal voltage and maximum voltage for the electrical insulation between windings.
The nominal voltage is basically never that high. The motors from Prusa are likely rated at 4-5 V operating voltage: the voltage you apply from the control board is higher, but as soon as the current reaches the value you set, the chip starts cutting intermittently the voltage, so 12-0-12-0-12... and the average value never goes above those 4-5 V.
The second value, the insulation, is the one you must NEVER exceed, even when operating intermittently, but it is likely 30 V or more.

Without having the exact model number of the motor to check the data sheet, this can't be answered.  Glancing at the link you supplied, I didn't see either a data sheet or a model number I could use to get a data sheet.
Typically stepper motors overheat when they are run at too high of a voltage.  However, the advertised voltage for the motor could be the lowest voltage at which it works.
For a real answer, you'd have to look at the manufacturer's datasheet for the motor, which should include minimum and maximum voltages and graphs showing current vs. voltage vs. force graphs, and possibly duty cycle graphs.
Also, in some cases, if you run a motor at a higher voltage than it is rated for, it may produce back EMF that is larger than the motor controller is prepared for, and it could burn out the controller.  However, if the controller is designed for 24v, this is less likely of a problem.
Note also that there are conversion kits, where you place a small board between the controller and the motor that fixes the voltage for the motor.


text:
Ender 3 board 4.2.2 BLTouch 3.1 crashes into bed during autoleveling
I'm trying to install a BLTouch probe. I have an Ender 3 Pro with 4.2.2 board and I’m trying to connect a BLTouch 3.1 to it. I've bought a generic (but authentic) BLTouch instead of a Creality kit. I've plugged the 3-pin connector into the correct slots on the board (didn't have to rewire, pins seem to be in correct order), but I'm trying to connect the 2-pin connector to the Z-stop connector.
Wiring seems to be in order (although I'm not an expert), when I turn on the printer, the BLTouch flashes and deploys twice but when I try to autohome or level or deploy it through options, menu probe autohomes X and Y axis, but when it comes to the Z axis, the probe doesn’t deploy and hotend simply crashes into the bed.
I've followed this video when I was compiling firmware (I tried both the normal Marlin build and the nightly release).
My configuration files can be found here. If someone would be willing to take a look.
E.g. from my configuration (Configuration.h) file:
/**
 * Enable this option for a probe connected to the Z-MIN pin.
 * The probe replaces the Z-MIN endstop and is used for Z homing.
 * (Automatically enables USE_PROBE_FOR_Z_HOMING.)
 */
//#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN

// Force the use of the probe for Z-axis homing
#define USE_PROBE_FOR_Z_HOMING

My guess is that I have to force the firmware to somehow recognize the correct signal pin, but then again, I'm out of my depth. I've seen this exact problem mentioned in many places all over the internet but never with a solution attached.

Are you using Creality's pre-built software?
In that case, you must connect the two pins to the BLTouch port. Altogether, you would have all five wires connected there.
Are you using your own Marlin build?
In that case, you must uncomment #define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN in order to plug in those two wires into the Z end stop connector. Otherwise, you need to use the BLTouch port as mentioned above.

Very good spot! I've inserted the code of the OP in the question, you see that this is exactly the problem! Welcome to 3DPrinting.SE! P.S. Please don't forget to vote on questions/answer, voting drives the community!

I've tried a couple more times but there is no improvement. I'm going to buy a 5pin connector and try to connect the probe to the default 5pin socket and see if it works with prepackaged creality firmware. If it does I will try to compile on my own again. I will have to do my own build anyway because I want advanced park features enabled (need to embed magnets easily).


text:
Why is my 3D printer making a loud knocking sound after installing BLTouch?
Everything was working perfectly until I installed the BLTouch. After installing it every time I print it makes a loud knocking/clicking sound. Does anyone know how to fix this? I am using a Neptune 2 a clone of an Ender 3 with Marlin firmware.

Can you describe more when the knock happens?  Is it all the time or only when the printhead is moving?  Is it X+Y  or just X or just Y?   If you jog the printer around from the control panel, does it make the same noise?

If you unload the filament and print normally, does it make the noise?   Does the noise go away as your Z increases ?    Has the quality of your printing changed/dropped since the addition?

Your second "sock puppet" account has been suspended for plagiarism. If you wish to have the two accounts merged, then please notify one of the moderators.

Found the origin of the second sock puppet answer: https://github.com/escknx/Creative3D-Elf-Binaries/blob/master/robin_nano_cfg_eng.txt

@Trish - Well done, I've edited and added the URL to my comment under the second sock answer.

The most probable reason is that your Z offset is too small, the nozzle is too close to the build plate, when molten filament has too much friction to flow out of the nozzle, the back pressure causes the extruder to skip back making loud thumping/knocking sounds. You could increase the Z offset for instance or redefine the bed height with G92.


text:
Are 3D printed containers safe for cosmetics?
So I've seen info about food-safe 3D printed containers, but I haven't seen anything about safety when it comes to containers used for cosmetics.
Would a cured resin 3D printed jar be safe for holding lotion or cosmetic creams?
I know the FDA has rules around containers that come in contact with food, but I haven't seen anything about cosmetics.

I can provide a guidance document of the cosmetics manufacturers to others: https://cosmeticseurope.eu/download/UG14b1RFS01qdlllbFBwdTZlRXRwdz09 and the FDA runs a registration program https://www.fda.gov/cosmetics/voluntary-cosmetic-registration-program - and there's a norm https://www.iso.org/standard/36436.html

@Trish thanks for this. it's really informative. the main thing I'm wondering is if anyone knows of things in the resin leeching into things like lotion or creams?


text:
How to print a cylinder with hundreds of small holes?
I'd like to print a cylinder, 50 mm diameter, 200 mm long, with 1.5 mm diameter holes tightly fit like this:

The holes go all the way through from top to bottom.
I am using a Prusa i3 MK3S. With 0.1 mm detail and 20 % infill, printing one cylinder is going to take 5 days and 5 hours. I need at least five cylinders.

Is the above setting appropriate for this job?
Is there any way I can reduce the printing time?

What's it going to be used for? It might be easier to get some (glass?) tube with a bore diameter of 1.5 mm and 3-d print caps for both ends to hold them.

Why not print it on its side?

@R..GitHubSTOPHELPINGICE, would it be possible to print it on its side and still get good circular holes?

Try a smaller test print and see. There will be discrete stepping in the Z direction but it should be consistent & smooth if that works for you. And you could print the holes slightly undersized and clean them up with a tool to make them more circular.

That's a hell of a print!
You are printing a model that has a highly complex structure there, with about 650ish holes, assuming there is space for about 2 perimeters between each hole.

Taking my standard 0.3 mm layer height and 0.4 mm nozzle using a 0.45 mm wide line, I sliced a 10mm high slice of the model for a first estimate of the expected print time - and came out with 2:21 hours. That means the expected print time with 0.3 mm layer height is in the area of 47 hours - or just about 2 days.
As a result, 5 days and 5 hours are in the order I'd expect from a 0.1 mm layer height print for the same nozzle, in fact, your settings seem to have a faster print speed than I do work with.
In general, I don't think this model is good for FDM printing at all, due to many non-fully formed lines inside the model (yellow) and the red perimeters being a very dense pattern.

Solutions?
Print faster
You might get a faster speed with a high-flow solution, for example, using a long melt zone (volcano-style) or an even higher flow core-heating 3DSolex nozzle. The latter originally only comes in 0.6 mm and up, also mandating fewer holes, but in late 2021 CHT nozzles in 0.4 mm came to the market. This could drop print time some, but it'd still be a several days print job.
Reduced pattern
Besides increasing layer height to drop printing time by the same factor, reducing the number of holes and as a result, spacing them further apart not only can increase the print speed but also make the print form more reliable.
Another alternative would be to alter the pattern from a circle to a hexagonal pattern: by using hexagons, the resulting pattern does not contain thin walls and might print much faster - depending on hole size, you might experience a drop by a factor of 2!

Printed differently
Going from FDM printing to a system such as SLS might be faster and more reliable while SLA/DLP would make this print not only fast and reliable but also trivial - if one can get a 200 mm high SLA/DLP printer, all three models should be able to be printed in one go at the same time!

Changing to hex pattern is a good idea. One way to get efficient tool paths from the slicer is to model the cylinder solid, then in the slicer, set infill to hexagon pattern, and set top and bottom shell/solid layers to zero. The infill is exposed.

The complexity of the design suggests that movement speed, not extrusion speed, is the limiting factor.  I wouldn't expect any speedup from a high-flow printhead, and possibly even a slowdown because of the need to drive the increased mass.

@Mark High flow allows higher movement speeds if you have better paths. A core heating nozzle weighs about 2 grams more than a standard nozzle.

BondTech now sells CHT nozzles in a wider variety than just 0.6mm; I've got a 0.8mm and 1.4mm on hand.

If travel speed is the limiting factor just crank it up. I regularly use >400 mm/s, >5000 mm/s² travel on an Ender 3, and can take the acceleration considerably higher still if needed. Using slow travel just lowers your queality due to risk of oozing. The unretract time after travel gives plenty of time for any vibrations from the extreme acceleration to settle before extrusion begins again.

@R..GitHubSTOPHELPINGICE True, travel speed can be an issue, but in ideal, the model has little to no travel time, especially if hex-tessellating.

@Trish: I meant if the original design produced high travel. Though using the experimental Arachne engine of Cura (upcoming Cura 5) could avoid that with its variable line widths.

Late to the party, but for other people that stumble here with a similar problem i've seen a lot of people use a 0 top layers, 0 bottom layers settings to expose infill structure. That with a suitable infill pattern might give you a different slicing that might be faster to print.

Holes, circles, and curves are slow to print, and get slower as the number of wall segments increase.
Ideally you'd use square holes, but hexagonal-sided ones would be a fair compromise too.
Your slicer should be able to give a breakdown on the times for each kind of line in the part.  Check and see how much of the time is spent on "moves".
Is there a reason for using all these little holes?  Fewer, larger holes will provide better airflow and require less printing, up to the ultimate of one single large hole, where you're essentially printing a pipe/tube.
Do you need the holes to go right-through?  Printing a big "cup" with holes across the floor, and separately a "lid"  then gluing them together would be quicker and you have one large hole in the middle.  If this idea works, you might prefer to just buy plastic pipe of a suitable size, and print only endcaps.
Additionally, if you're printing 5 cylinders because you need a metre total length, then printing two endcaps for a 1 metre piece of plastic PVC pipe should take a couple of hours at most.   And it will save you a lot of filament.

that pattern actually is pretty common for filters or catalysts, so I assume there is a reason for it.

@Trish plausibly there is a reason for the design as-is, but OP wanted ideas to reduce print time, and not printing 90% of it would help that immensely.

The design screams "laminar flow" and is very likely intentional and necessary.

@R..GitHubSTOPHELPINGICE then I would explore printing two end caps, sized to fit on tubes that are already available, like straws.   At a ballpark, 1.5mm holes represent under 25% of the cross section.  There will be very-limited air flow through such small holes.   This kinda feels like an XY question. where the question is about the intended answer, not the underlying goal.


text:
Why is a 3D Benchy considered a good test print for FDM printers?
the 3D Benchy is everywhere. It is one of the top test prints if you look away from a simple cube.
But what makes the Benchy a good test print at all? It does have almost no critical dimensions that would be measurable to see if the printer is calibrated correctly!

the 3D Benchy isn't a specific calibration test
With the Benchy you don't see if your printer is calibrated in any axis, but it is a general use-case test for a model that can show you many of the issues you might face in a normal print. For all intents and purposes, it is more a general Benchmark item than a specific calibration test like a cube, stringing test, or temperature tower, where you go through iterations of a profile to dial in settings and printer properties.
the 3D Benchy is a Benchmark for printer and settings
Most of the printing issues that can be seen on a Benchy are related to the print settings, though some are also related to the physical properties.
Overhangs
The bow of the Benchy has a shape that is very conducive to seeing how much the printer can handle overhangs due to proper cooling and settings.
The arches in the sides of the cabin, as well as the back window, have a rather challenging overhang pattern (the extension needs to be larger and larger), and the front of the Benchy has a short bridge, which shows if cooling is happening properly.
The upper edge of the hull also is a little overhang, which shows how well small oversteps can be printed.
Small Diameter
The funnel of the Benchy is of sufficient small crossection, that with bad settings it can result in printing layers upon one another too fast, which can result in bulging, misinformation, or totally blobing that area.
Sharp corners
The front and back corners are rather sharp and can show the effects of ringing on the area next to them due to bad acceleration settings

Benchy is cute.  That goes a long way in attracting attention.
The benchy is one of the earlier STLs that was freely available to download, dating from April 2015, and was released under the Creative Commons Sharealike licence, which clearly states the requirements and limitations/requirements.
Curiously, a printed Benchy can float in still water, provided no print problems crop up.  It will also sit nicely on a shelf, with no risk of rolling off and makes a nice ornament.
Links: https://en.wikipedia.org/wiki/3DBenchy and one of the earliest download sites https://www.thingiverse.com/thing:763622

I've had my printer for a year now, and have never printed a benchy.

Curiously, the internet is full of examples of benchy not floating - at least until early 2020 - without accessories.

People must have been using some ridiculously high infill, or poor extrusion hardware preventing it from being water-tight, if Benchy wouldn't float. Floating upright is a hard problem, but just floating is the default for any 3D printed object that's not so thin not to admit a sizable infill region.


text:
Using the BLTouch to assist with manual bed levelling?
I struggle with paper levelling and find it to be excessively coarse and unspecific. I bought a 3DTouch, but I still need to make the bed generally level using the knobs. Otherwise, the print will be uneven.
Is there some method that would allow me to probe an area with the BLTouch, see the value, adjust the knob, and repeat? And do this at each corner?
I thought the G30 command in Marlin would achieve this, but I consistently get slanted prints when using G30 at each corner.
I thought this would be a very good approach, since the BLTouch is directly on the carriage, and I would be able see the height of each corner to a hundredth of a milimeter.
I tried searching for this online, but I couldn't find specific resources and what I am proposing seems to be very rare or doesn't even exist.
Is there a way I can use my BLTouch to assist with manually adjusting the knobs of my 3D printer bed?

Did you try bed leveling plugins in octoprint? I've been leveling bed using G30 with X &Y motors disabled for  a long time and it never went wrong.Depending on the relative position you install the 3d touch,you may not be able to probe using G30 at exact 4 corners.

What is strange is that I am getting the opposite of what I would expect with the G30 command. For example, at one of the corners, I probed and got 0.05. This would suggest that I need to lower the bed there to achieve 0.0. However, at this corner, I would expect to have to raise it based on the mesh print. When I do lower it, I end up with a slanted bed according to the mesh print, although G30 says it is at 0.0. So my problem with the G30 command is that it seems like it is telling me to lower the bed when I would think I would have to raise it and vice versa.

How did you use G30 to level your bed? Can you provide an answer with that?

use G30 at middle of the build plate and use that value as relative 0. So if G30 center returns 0.6,at the corner it’s 1.2,then the corner is 0.6higher.Absolute G30 value could be calculated (which I’m not sure) from raw data and a probe offset.Use relative data against G30 in the center should work just fine.

ender3 bed is known to be warped and especially on the corners.Mine has a 0.4higher corner than it’s in the center.It’ll be warped no matter how you level it with G30.This can be only compensated by ABL.

Yes, you can use your BLTouch to assist with 'manual leveling', if your firmware supports it. To avoid confusion, the proper term for 'manually leveling' is 'bed tramming'. Some firmware has a 'Bed Tramming Wizard' like the Marlin-based mriscoc firmware. The mriscoc's Bed Tramming Wizard is well documented.
Below is an example of how it would look on an Ender 3 V2 or S1.


text:
Can't "Send To" Thingiverse from Tinkercad.com
Anyone else seeing this issue? Anyone know a solution?
While editing a part on TinkerCad.com (this part, to be specific), I click the "Send To" button in the top-right --> click Thingiverse --> I see this screen:
I then click on "Authorize". I'm already signed into Thingiverse, so I click "AGREE & AUTHORIZE APP" --> and I get this error window:

It states:

There was a problem authenticating you with Thingiverse
Close this window and return to Tinkercad.
Privacy settings   |
Privacy/Cookies

Anyone know what could be the issue? I've tried in Google Chrome, on Firefox, in Chrome with incognito mode, and even with a 2nd pair of separate TinkerCad and Thingiverse accounts! I get the same result each and every time.
Note: I used the Google sign-in for the Thingiverse account. Maybe I need to use the independent account login?

Side note: this question is on-topic:

Websites (could come under Software and/or Tools)
...

Issues with web based tools   <=== this one is my question

I just sent in some support request tickets to both sites
Update 22 Dec. 2021:
I posted a help support ticket to both TinkerCad here (choose "Tinkercad Account" from the "Please choose from the options below" dropdown menu) and to Thingiverse here (click link --> choose "Other" from dropdown menu for "What does your support request pertain to?"). I'll add an answer here if I get any useful response or solution from either of them. My support tickets on each site essentially contained the following information:

Subject:
Can't "Send To" Thingiverse from Tinkercad.com
Body:
Please see a full description of my problem here: Can't "Send To" Thingiverse from Tinkercad.com
Essentially, no matter what I do I get into an infinite loop of trying to click the "Send to" button to send a model to Thingiverse, and it repeatedly fails with the error shown in the attachment. Again, see the full description at the link above.
OS:
Linux Ubuntu 20.04
Browser:
Chrome Version 96.0.4664.110 (Official Build) (64-bit)

Tinkercad replied to my Zendesk ticket I opened (see the question), and as a a result, they seem to have fixed the issue! The "Send To" --> Thingiverse feature seems to be working again!
I sent my request on 20 Dec. 2021:

Subject:
Can't "Send To" Thingiverse from Tinkercad.com
Body:
Please see a full description of my problem here: Can't "Send To" Thingiverse from Tinkercad.com
Essentially, no matter what I do I get into an infinite loop of trying to click the "Send to" button to send a model to Thingiverse, and it repeatedly fails with the error shown in the attachment. Again, see the full description at the link above.
OS:
Linux Ubuntu 20.04
Browser:
Chrome Version 96.0.4664.110 (Official Build) (64-bit)

I got this response on 3 Jan. 2022:

Nicole Smith (Tinkercad)
Jan 3, 2022, 7:16 PST
Hi Gabriel Staples,
Thanks for writing in to let us know about the issue. I'll pass on the information and see what we can figure out.
Regards,
Nicole
Tinkercad

Then this on 5 Jan. 2022:

Nicole Smith (Tinkercad)
Jan 5, 2022, 15:40 PST
Hi Gabriel Staples,
This should now be working again.
Regards,
Nicole
Tinkercad

Sure enough; it seems to be fixed!
Next time you have an issue with TinkerCad, submit a help request here (I chose "Tinkercad Account" from the "Please choose from the options below" dropdown menu).

The best solution for the problem is to download your Tinkercad designs and upload them to Thingiverse.
Some people had the same issue and as far as I know, the Tinkercad people are not going to solve it.

What file types do people most-often prefer? Just .stl? Or should I also do .obj? What about .glb?

I believe the error is on the Thingiverse side, not Tinkercad.

I prefer stl, you can also use obj


text:
Is it possible to export a model from TinkerCad.com, reimport it, and edit it again as a grouped collection of individual parts?
I have this model, for instance, made in www.TinkerCad.com. It is made up of a bunch of grouped objects. I'd like to be able to back it up by saving it locally, then reimport it and ungroup those objects on the imported model. Is there any way to do this?
(Note: my motivation is permanent backup of my important models. TinkerCad deleted a few million accounts in May 2021 it looks like).
When I export a model from www.TinkerCad.com I get these options: .obj, .stl, .glb.

No matter which I choose for export, if I reimport what I exported, it is now one solid piece and it appears I cannot ungroup its elements to edit them anymore.
Also, if someone else opens up my .obj file in some other tool, like Fusion360 or Solidworks (neither of which I can use right now since I'm on Linux and don't have a license for Solidworks), will they be able to edit the individual components of my model like I did in TinkerCad to build it in the first place? (I think this is NOT possible on .stls, no?--but I don't know about .obj files).

STL and OBJ are formats that define a surface through trigons and a waveform respectively - to make the export work, TinkerCad runs a boolean union operation first. Without this, it would run into the problem of having bad surface geometry - a flaw that happens still when the boolean joining fails properly.
GLB is a container for gITF files and can store file hierarchies as well as cameras and animations. However, even if the structure would allow having all the bodies, TinkerCad does run a boolean union before it.
As a result, you'd have to physically separate parts of the item that are not to be joined from one another as in an explosion diagram. That way the boolean union would result in each part being separated and exporting as separate shells.
Separating Shells into models
If you have an item from TinkerCad that has multiple separate shells, you can open the STL or OBJ in a program like Meshmixer and run a Separate Shells operation. Then you can export the parts from that program as separate files that can be imported into other CAD or 3D-Design software - or sliced directly.
Re-CADing the models
If you have your parts exported and separated, it would be very beneficial to properly CAD them in a program that allows STEP files. For this you'd simply import them into a program and use the 3D Model from TinkerCad as a model to design around.
Fusion360 does allow to import STL and OBJ as a mesh, though isn't the best to edit it.
FreeCAD, an open-source alternative, does allow the import of STL and OBJ too and has a Linux distribution.


text:
Wires in BLTouch connector are loose, how to fold a crumpled pin
I'm trying to install BLTouch on my Ender 3 Pro but I've been pulling the cables in and out so many times that crimp pins (I think that is what they are called, I mean the little metal bits crumpled on the end of the wire) are now almost completely loose and when I try to put the cable into the socket two of the cables are pushed out by pins in the board.
I've got a couple of uncrumpled header pins but I don't know how to bend them so that they clamp wires.
I've attached the part similar to what I have (I don't have a good enough phone to snap a photo of the original part I have).

Is the BLTouch the ANTCLABS brand? Is the image provided the same as the connector on your "BLTouch"?

You need a crimping tool like this so that the pins will be crimped correctly to fix in the sockets and plugs.


text:
Printing ABS on Ender 3 V2, and stopping part cooling fan?
I want to print ABS on Ender 3 V2 so I turned off the part cooling fan.
In doing so the electronics fan stopped, apparently they are connected and I don't want to mess with the wiring.
Is it safe to run the printer with the electronics cooling fan off for long hours?

Probably not a good idea, the electronics fan is there for a reason. Please [edit] the question and state how you turned of the fan... via the UI, firmware, config change, unplugged (unlikely as you state that you don't want to mess with the wiring).

This sounds like a bug in the firmware or the particular board revision in your printer. The electronics fan should either be always-on or switched separately from the part-cooling fan.

turned the part cooling fan from the slicer

Please [edit] your question and put additional info in the question and not in the comments. Also, if possible, can you also post the board revision number and firmware and the firmware version number?


text:
Why do nearly all cheap 3D printers have a Bowden extruder?
It seems that a Bowden extruder is the most used in all cheap 3D printers by far compared to Direct Drive that is very rare under 500 USD machines. But I haven't understood the reason, since in terms of hardware a direct drive doesn't seem to have any impact on price more than Bowden (correct me if I'm wrong).
Why?

As I understand it, there's really no good reason for this except "momentum". At some point in the not too distant past, a Bowden extruder was seen as an "upgrade" over direct drive, which required a bulky toolhead that was seen as limiting speeds.
(This perception was at best accurate only for delta and CoreXY machines at the time even, I think. As it turned out, Bowden doesn't let you print faster, at least not at any quality, because the nonlinear/hysteresis effects of the Bowden tube on the actual amount of material extruded can't fully be compensated with linear advance/pressure advance once you reach moderately high speeds. You can overcome this with the Nitram Bowden but good luck finding a cheap 3D printer manufacturer willing to put in that kind of custom part!)
Anyway, all the cheap printer manufacturers jumped on Bowden as a feature, and they're slow to develop any new designs rather than just making incremental improvements and production cost optimizations to existing ones.
Since then, direct drive designs have improved greatly, and the mass of the good ones has gotten so low that it's hardly a consideration anymore except on the most extreme agility-seeking printers (designs attempting 50k-300k acceleration). Everything should be direct drive, especially since it makes things so much easier for beginners (no difficult-to-load tube, broken filament in tube, loose fittings messing up retraction, etc.)
Teaching Tech has a video, oddly named Why direct drive is not automatically better than bowden tube, where he basically concludes that it is actually better, and goes over some of the history I've touched on.

Delta and CoreXY can benefit from the low mass to reach extreme printspeeds, if the hotend can offer enough flow. But low weight stepper motor solutions are a thing now, especially the hemera.

@Trish I wouldn't call the Hemera "light weight", the Orbiter, however, is a different solution (half the weight of the Hemera).

@0scar compared to other solutions, it is.

Both Hemera and Orbiter are behind state of the art, which would be things like the Sherpa Mini or https://www.youtube.com/watch?v=vjFZiRV01ns

Using a bowden extruder allows the manufacturer to place heavy components lower down on the printer frame. This lowers the center of gravity and reduces the amount of movement that the hot end creates when it tracks across the bed.
This allows the hot end to move\print faster without having to reinforce the printer's frame or to include higher quality belts\motors or dampeners.

This was the theory when it first became a thing to do Bowden extruders, but it really does not apply (then or now). The manufacturers in question are aiming for print speeds of 30-75 mm/s and accelerations of 500 mm/s² or so when the difference between Bowden and direct drive only starts to matter around 3-5x those speeds.

If you look at some of the entry level printers from companies like Creality and Anycubic you will see that one common design choice is that the print head is supported by only 2 struts. While the higher end printers have 4. If you were to put the weight of the extruder onto a two strut 3D printer is would wobble a lot more when it moved so you would need to further reduce the speed to make it stable.

Empirically, that's not the case. Even the massive official Creality direct drive conversion (and likewise the print-your-own adapters to move the stock E motor and extruder on top of the hotend) operates perfectly fine at the speeds their printers are advertised to go at.

Moreover, I'm not sure what you mean by "only 2 struts". At least on Creality printers and all the ones with similar design, you have 2040 extrusions on each side with 3 POM wheels pressed against them, which is more than enough to hold the weight. On machines with only a single side driven (single Z motor), you might get some extra problems with play at the opposite side when using direct drive, and this is already an area of problem for these printers, so maybe that explains somewhat why they don't go with direct drive.

Most entry level FDM printers have a print head that's attached to gantry, and supported by two upright struts mounted either side of the print bed, with the extruder attached to the side of one of these upright struts.. Higher end FDM printers tend to have one upright struct in each corner. Which means that they are more stable.

It's more a matter of what the kinematics dictate than trying to be "more stable". You can stabilize the Z axis of an E3-style bedslinger with diagonals down to the base of the machine if you want, but it's not going to make a difference until you reach very high Z, and it's not going to make a difference in the direction the direct drive extruder would be throwing momentum from its increased mass (X direction).

More mass = more momentum.


text:
Issue milling a circular contour with CNC – 3018 Pro
I have a 3018 Pro CNC and being trying cutting a contour of a simple circular part:

G-code:
(TestKnobContour)
(T1  D=1 CR=0 - ZMIN=-3 - flat end mill)
G90 G94
G17
G21
G90
(2D Contour1)
Z15
S5000 M3
G54
G0 X10.8 Y0.1
Z15
G1 Z5 F10.0
Z1 F10.0
Z-2.9
X10.792 Z-2.938 F10.0
X10.771 Z-2.971
X10.738 Z-2.992
X10.7 Z-3
X10.6
X10.562 Y0.092
X10.529 Y0.071
X10.508 Y0.038
X10.5 Y0
G2 X9.851 Y-3.634 I-10.5 J0
G1 Z-2.75
G2 X8.983 Y-5.436 I-9.851 J3.634
G1 Z-3 F10.0
G2 X3.301 Y-9.968 I-8.983 J5.436 F10.0
G1 Z-2.75
G2 X1.351 Y-10.413 I-3.301 J9.968
G1 Z-3 F10.0
G2 X-5.735 Y-8.795 I-1.351 J10.413 F10.0
G1 Z-2.75
G2 X-7.299 Y-7.548 I5.735 J8.795
G1 Z-3 F10.0
G2 X-10.452 Y-1 I7.299 J7.548 F10.0
G1 Z-2.75
G2 X-10.452 Y1 I10.452 J1
G1 Z-3 F10.0
G2 X-7.299 Y7.548 I10.452 J-1 F10.0
G1 Z-2.75
G2 X-5.735 Y8.795 I7.299 J-7.548
G1 Z-3 F10.0
G2 X1.351 Y10.413 I5.735 J-8.795 F10.0
G1 Z-2.75
G2 X3.301 Y9.968 I-1.351 J-10.413
G1 Z-3 F10.0
G2 X8.983 Y5.436 I-3.301 J-9.968 F10.0
G1 Z-2.75
G2 X9.851 Y3.634 I-8.983 J-5.436
G1 Z-3 F10.0
G2 X10.5 Y0 I-9.851 J-3.634 F10.0
G1 X10.508 Y-0.038
X10.529 Y-0.071
X10.562 Y-0.092
X10.6 Y-0.1
X10.7
X10.738 Z-2.992
X10.771 Z-2.971
X10.792 Z-2.938
X10.8 Z-2.9
G0 Z15
M5
X0 Y0 Z0
M30

Candle shows that everything is fine for this G-code:

However, I am getting weird results (see top right):

What can I do for troubleshooting?

I’m voting to close this question because 3D printing is additive manufacturing, while the question presents a problem with milling (subtractive manufacturing). Some overlap (g-code) is present, but not really 3D printing related.

@fred_dot_u, could you plsease advise other place for CNC related? I couldn't find more relevant in SE
community.  Therefore, I disagree with the suggestion above about closing this question. One more point - you could find here many questions not related to 3D printing directly, like this - https://3dprinting.stackexchange.com/questions/4196/laser-engraving-software-for-boxzy-3d-printer?rq=1, so on precedents basis it also looks like here the right place place not only to 3D-printers related questions, but rather for all gcode-driven machines, like CNC , laser  engravers and so on.

Try milling with more passes. Those straight edges I've seen before when you are trying to mill more the machine can handle. It appears you're milling 3 mm in one pass, I could be wrong, but the most reasonably priced 3018 milling machines need less input than 3 mm.

Yes, @Oscar, initially I was trying milling it in 3 passes to cut a contour, but it just aluminum 2mm, so after upgrading of its motor and milling cutter it seems to be ok even with one pass. Other than that, have tried it directly from a laptop and it cut it without any problems, so I guess that issue can be in offline module. Will try once more without offline module to check that.

CNC is a grey area. Some CNC questions haven't been closed (whilst others have) and it's not really clear why there is a difference. There have been many requests for CNC questions to be on-topic, see Meta: CNC search. Indeed, CNC is listed as being on-topic. However, to counter that, just because there isn't any other SE site for CNC questions, it doesn't mean that they have to be valid here. That said, they might be on topic on SE Engineering

@Greenonline, I agree - it looks like SE.Engineering more suitable for questions for cnc-related questions in general, however, it looks like on SE.Engineering not that many questions and answers about gcode. Therefore I still in doubt here, especially taking into account such a good conversation we already have here, so it would be a bit pity to start it from scratch on another forum. Anyway - thanks for suggesting me  SE.Engineering - I will move there if the majority decides to close this one here.

Personally speaking (and not as a mod), I won't vote to close (I rarely do anyway), as I can't see any harm in the odd CNC question hanging about - they make an interesting change, in a light-relief sort of way... Good luck on getting an answer (maybe if @0scar's suggestion works it could become an answer)..? :-)

does the spindle bend when it tries to do that part of the arc? Have you tried lower feeds?

@Trish, no noticeable spindle deformation, feed rates are at 10 mm/s - no also any noise and any signs that the device is running out of its limits. Other than that, as I mentioned in other comments, without an offline board the same code works well while sending directly from a laptop. So it looks rather like some programming or/and electronics issue, than physical failure.

works from laptop can mean the laptop is doing some cleanup.  check file for special characters, newline differences, etc.

@Abel, checked with notepad++ in “show all characters” mode and nothing suspicious – inly CR LF after each row and encoding UTF8. Other than that, have checked SD card and removed everything else but .cn files (like “system volume information”, etc.) with no luck.

Where did the tool started the circle in your foto?

@0scar in furthest right point (near to bottom-right of red squares) and then clockwise. Other than that, it looks that issue can be in a bit weird code auto generated by Fusion 360, so will try code suggested by Davo - it looks better than autogenerated.

I've ran the code on my own CNC machine. I slightly adapted the code as my machine doesn't understand the movement without the instruction code:
Z1 F10.0
Z-2.9
X10.792 Z-2.938 F10.0
X10.771 Z-2.971
X10.738 Z-2.992
X10.7 Z-3
X10.6
X10.562 Y0.092
X10.529 Y0.071
X10.508 Y0.038
X10.5 Y0

is changed to
G1 Z1 F10.0
G1 Z-2.9
G1 X10.792 Z-2.938 F10.0
G1 X10.771 Z-2.971
G1 X10.738 Z-2.992
G1 X10.7 Z-3
G1 X10.6
G1 X10.562 Y0.092
G1 X10.529 Y0.071
G1 X10.508 Y0.038
G1 X10.5 Y0
etc...

As I used an engraver bit, I made sure the depth was touching the wood (engraving) when running at the lowest depth. The contour it drew was a perfect circle.

The code is therefor working as it should (carve a circle, in the photo above, the circle started at the hole in the top left and followed a clockwise path), the result from your milling exercise shows that the final segment of the circle is not giving you a circle segment, instead the milling path is sort of straight. I've seen such paths where the steppers are not powerful enough to mill through the material. As a result they skip steps, and in this case it results in a sort of straight path. You should try running a dry run (in air), or in softer material (this will determine if the code is producing a cirlce in your machine as well), and add more passes to milling the knob (for the final product).

or simply re-run the code in the same pocket, which by necessity will result in less load on that part of the path, possibly finishing the cut.

Yes, after correction of weird auto-generated commands everything started working fine, however, I prefer the manual version with 3 passes as per your and @Davo recommendations. Have created and tested this way and figured out weird peculiarities of my grbl-based controller - it doesn’t stand z coordinates together with G2 command and doesn’t work without specified flow like this "G1 Z-1.4 F10.0" in a beginning of G1 commands.

It is hard to be sure from the picture.  When I wrote this answer, material you were cutting looked like clear plastic.  When I reviewed it now, the material looks more like aluminum.  It doesn't really matter, since the melting point of aluminum is well within the range of both high speed steel (HSS) and carbide.
What follows is a list of possibilities and things to check.

check the mounting of the spindle.  Does it hang rigidly as you push the tooltip in x, y, and any point in the circle, or does it tip more in one direction than another?  This could be caused by a loose mounting screw.

Are you actually cutting, or are you melting the material?  It is very easy for a tool, especially a tight spiral 4-flute tool, to heat above the melting/softening point, and to then push through the material rather than removing it as chips.  Using a tool with fewer flutes at a slower speed can sometimes help.  You may also want to cool it with some water -- not enough to make a mess of the machine, but enough to help cool the tool.  This happens easily with plastic, and also with aluminum.  I have several times had to peel bits of solidified aluminum from inside the flutes of a carbide cutter.

It doesn't look like backlash.  The 45-degree angle is curious.  To see if it varies with or without load, try putting a marking pen in the collet and draw similar circles.  It doesn't look like a primary software or hardware problem, since the inner circles were round.  Only the outermost circle has the flat spot.

If the departure from a circle is only under load, reduce the load. Step the tool into the work by 1/2 of what you are doing now.  How does that change the result?

Chips remaining near the cut can join in the melt.  Try blowing compressed air on the cut while it is cutting, both for cooling, and to remove chips.

Some things it is unlikely to be, if the shape was intended to be a complete circle, and if the outer pass is the last pass performed:

Skipping steps due to insufficient stepper motor torque
Belt slipping (or lead screws skipping)
Loose belts or backlash in mechanical shaft connections.

Checked spindle and point with melting versus melting - it actually cuts aluminum plate (2mm thin). Other than that, have tried using direct connection from my laptop instead of offline module and it makes cut properly and it's a bit weird, because the concentric internal engraving was done with offline module without any issues. Maybe the thing here is the error in autogenerated gcode as @Davo mentioned?

Parts of the circle are at different heights. When I rendered your 30 or so actual G1 and G2 lines, here's what I got. It looks like a circle from above, but form the sde you can see depth changes. What are those coordinate lines with no G0 ot G1 or G2 or G3 command for?

=============================
Okay, here's a simple gcode I just made by hand do to something similar. Granted, I used all nice round numbers, but this is an example of what I think you're looking for. You'll have to change it as needed; perhaps more paths if your tool is less wide; more iterations at deeper depths, or even different coordinates. Enjoy.

G0 X30 Y30 ; move to start XY
M3 T12 S50 ; spindle on 50%
G1 Z-0.5 E1 ; down to depth1
G2 X50 Y50 J20.0 E1 ; arc
G1 X30 Y30 E1 ; corner
G1 X30 Y35 E1 ; move inward
G2 X45 Y50 J15 E1 ; arc
G1 X30 Y35 E1 ; corner
G1 X30 Y40 E1 ; move inward
G2 X40 Y50 J10 E1 ; arc
G1 X30 Y40 ; corner
G1 X30 Y45 ; move inward
G2 X35 Y50 J5 E1 ; arc
G1 X30 Y45 E1 ; corner
G1 X30 Y50 E1 ; move inward
G0 Z 10 ; move up to clear
M3 T12 S0 ; spindle off

=================================
Or, if I've made a mistake and you want simple circles:

G0 X30 Y30 ; move to start XY
M3 T12 S50 ; spindle on 50%
G1 Z-0.5 E1 ; down to depth1
G2 X30 Y30 J20.0 E1 ; arc
G1 X30 Y35 E1 ; move inward
G2 X30 Y35 J15 E1 ; arc
G1 X30 Y40 E1 ; move inward
G2 X30 Y40 J10 E1 ; arc
G1 X30 Y45 ; move inward
G2 X30 Y45 J5 E1 ; arc
G1 X30 Y50 E1 ; move inward
G0 Z 10 ; move up to clear
M3 T12 S0 ; spindle off

This code was generated by Autocad Fusion 360, have only removed some unnecessary commands, and added return to starting position. Those spikes you mentioned is "tabs" option for "contour" feature in Fusion 360 recommended in one of forums to make a part fixed till the end of contour cut. Anyway, if you see any issues with the code itself would appreciate sending me an edited code to try.

I usually use the Prusa toolchain for 3D printing, and my own, non-gcode tool chain for machining.  The Prusa G-code viewer rejects the gcode you supplied.

It looks like we have two correct answers on my question and unfortunately, I can mark only one as a correct one, therefore, since @Oscar's answer looks a bit better - in addition to suggestions and corrected code it contains test run using CNC plus Oscar suggested cutting in several passes, which works better, so going accept Oscar's answer.


text:
Printing above, not onto the bed
I just got an Ender 3 pro printer and set it up. I have levelled my bed and set the coordinates to (0, 0, 0) with the nozzle paper’s thickness away from the bed. When I started printing the default test dog, the machine moves to (0, 0, 5) which lifted the nozzle up and filament started oozing out without touching the bed. I also tried my own square design and the same happens. Is there anyway to not make it go up? I cannot make my bed go any higher.

Hi, welcome to 3DPrinting.SE! Please update your question to include some (e.g. 32 lines) of the lines of the G-code file of the dog. To be sure, also mention how you level the bed, you need to perform G28 and move the head down to zero height and then level to paper thickness.

Sounds like your g-code is off.

It sounds like you changed the settings for the default z offset from the menu. See if you can reset it, or reset the machine to factory defaults.

Please add the information, else the community votes to close the question and the only way to get it reopened is through the reopen vote after a major update from you. We would love to help but this is a little too less information to work with.


text:
Melting 3D printed scraps: Burns up
Every time I try melting a scrap piece of plastic it ends up turning brown, smelling, and smoking before even melting down completely. My entire home ends up filled with cancerous fumes and there's no way I'm baking any food in my oven ever again. I've tried different types of Nylon, ASA, and PLA and all of them turned brown before properly melting. I placed the scraps inside a glass jar inside an oven and tried both slowly increasing the temperature, and placing it into the preheated oven.
Absolutely disgusting.

I would like to melt it into blocks or cylinders or planes and further process it with my lathe, my CNC mill, bandsaw... whatever, like this guy:

What temperature are you using? You most certainly can't use a stovetop for this because it's not temperature-controlled. An oven is controlled, but not precisely, and might work if you set the temperature significantly below the print temperature for the material then only slowly raise it. Fortunately, at least for PLA, there should be minimal "cancerous fumes" (only possibly from pigments/additives; otherwise it's comparable to burning a pan full of corn).

I wish to be able to explain why so many 3D printing folks are so obsessed with reusing scrap plastic. Processing of plastic needs precise temperatures, and high pressure. It would be beter to use your CNC and lathe with a more machineable material than molten / reprocessed crap plastic.

PLA starts to melt at 100 °C, you sholdn't need more than 150 °C!

@mguima: Probably because of ending up with so much of it and wanting something to do with it other than "throw it in the trash".

air is needed to burn.  you can go a bit hotter with a controlled atmosphere - simplest form of which may be sealed chamber loaded with only plastic (your scraps and some virgin pellets)- may need to grind some scraps to size for better packing too... Connect such a chamber to a device similar to an extrusion head and press into recycled filament...

With a controlled atmosphere, it won't burn the same way.  It'll still decompose, out gas toxic fumes, and carbonize.  It's better to just not let it get too hot.

@R..GitHubSTOPHELPINGICE I put it in the oven. I just placed it on the stovetop to cool and to make the picture.

@Trish It will cristallize at 100 or 150 degrees. It actually hardens. It will only soften up around 200.

Unfortunately I don't have a grinder but I do have an entire 120 liter barrel filled with scraps. And that's only PLA.

Plastic in general and 3d printer plastic specifically doesn't really melt so much as get softer in a range of temperatures (in a state refered to as "plastic" rather than liquid).  Below that range, it is a solid.  Above that range, it decomposes and ultimately burns.
If you want to make a solid block, you need to not only heat it to a specific temperature (which varies by plastic formulation), but also press it into a new shape.

PLA starts to char at about 220 °C. However, it also starts to soft at about 100 °C and becomes sloopy (and printable!) at 180 °C. Putting the oven to anything above 180 °C will, with the heating cycle an oven undergoes, result in air that is above the temperature it degrades into burning plastic.
keeping the temperature at or below 180 °C should prevent charring - you will have to take time though, as the plastic will flow only slowly on its own.

(Agree!) 20+ degree fluctuation on a consumer grade cooking oven is probably typical.  It's scary to put plastic in an oven under those conditions.

I shall try again

Your kitchen oven is for food.  I'd strongly recommend using a different heating device for this.  Your oven probably has oils in it that are contaminating the plastic, and the plastic will make your later cooked-food contaminated.  I suggest cleaning your oven before cooking food, too.
Personally I've had good luck softening PLA with a hot air gun, essentially a workshop version of a hairdryer.  I've not tried forming it into shapes though.
I've been putting all my offcuts, bad prints, brims etc into a 2L icecream tub, and when its full of spidery bits, a 20 second heat with hot air shrivels it all down to 1/4 of the volume.
However I've not tried to make use of the resulting lump for anything.


text:
Best practice: For ensuring a good print with dual extruder machine
I own a Qidi X-Pro that uses a dual extruder.  I just spent the last 45 minutes trying to print, over and over, a simple model I had printed before.  I'm using ABS with a glue stick.  The ABS is fed through the left extruder while PLA is fed through the right.  I had previously printed a different model and had finished it.  I was now attempting to print a different model with the left extruder and ABS.
The ABS print would almost fail immediately with the filament catching on other parts of the model.  Then, I realized that a small piece of PLA was still exposed on the right extruder and it would catch the model as I was printing with ABS.
Is there a recommended way to ensure that this does not happen in the future?  What nozzle 'clean up', if any, should I perform after printing?

Can you provide a photo? Are the two nozzles the exact same height from the bed?

It is unusual to mix ABS and PLA in one print. One drawback is the ABS prints much hotter, so is more likely to melt into the PLA in an unpredictable way. Out of curiosity do you have a compelling reason to use the two together, or is it just the materials on hand?

bed temps are going to make for an interesting combination too. ABS gets close to 100 °C and PLA can handle room temperature in the right conditions.

Trish's question is a good one. You have to ensure your nozzles are properly calibrated for clearance.

Sorry for the confusion I created by my wording.  I've updated the text to reflect that I was not using both extruders when the problem occurred.  And, yes, the bed is level.  I've leveled it with leveling squares.


text:
Y-axis on KP3S Kingroon only moves in one direction
I recently got a KP3S Kingroon 3D printer and have been trying to set it up.
After a couple of test prints, the Y-axis seems to only move in one direction. At first, I thought it was a motor issue, but when I go into the manual move directions for the Y-axis it seems that both inputs lead to the motor spinning in the same direction.
We have ruled out endstops as a possible issue. I think it might be a hardware issue but lack the skills to confirm the exact issue.
Send:17:40:57.724: @moveRel Y10.00
Send:17:40:57.724: N31 G1 Y10.00 F6000
Send:17:40:57.728: @updatePrinterState
Send:17:41:00.824: @moveRel Y-10.00
Send:17:41:00.824: N35 G1 Y0.00 F6000
Send:17:41:00.828: @updatePrinterState
Send:17:41:07.445: @moveRel Y10.00
Send:17:41:07.445: N43 G1 Y10.00 F6000
Send:17:41:07.449: @updatePrinterState
Send:17:41:09.482: @moveRel Y-10.00
Send:17:41:09.482: N46 G1 Y0.00 F6000
Send:17:41:09.486: @updatePrinterState

Even though it states that it is increasing and decreasing by 10 it only decreases by 10.
I have updated the firmware to Marlin.  I tested switching X and Y inputs and believe the breakdown occurs at the Y input signal.
attached is a picture of the mother board.

I am unsure of how to best fix this?

The answer might just be replace the mother board.
If I understood everything correctly there are 5 things to check to break down the problem:

the motor,
the cable,
the stepper connection,
the software input, and
the firmware.

Using Repetier I disproved that the software was broken. By switching the X stepper and Y stepper cables, the motor and connection cable were proven to work. By flashing new firmware it was shown that it was without question that the firmware was the issue.
The backup extractor (E1) is not operational on this board. So it is either the stepper of the mother board.

What "tests" did you run that made you come to this conclusion? Please [edit] your answer to provide these additional details.

@agarza, If i understood everything correctly there are 5 things to break: the motor, the cable, the stepper connection, the software input, and the firmware. Using repetier i disproved it was on a software that was broken. By switching the x stepper and y stepper cords the motor and connection cable was proven to work. and by flashing the firmware it was shown that it was without question firmware. the backup extractor (E1) is non-operational on this board. So it is either the stepper of the mother board. Any other ideas are welcome.

@doombringer175 Great comment, but that would be even better to fit the first line into the answer. I've taken the liberty to include this into the answer. Feel free to change it! Note that you could have changed the X stepper driver with the Y stepper driver, they are Polulu breakout boards, so you can even work out if the board or the driver is the issue! Do you mean that the E1 is not working because there is no driver, or did you also put a driver in?

The question body has changed to rule out broken endstops. As a generic answer for steppers only going into a single direction, if an axis of a 3D printer only moves in one direction it usually implies that the end stop of that axis is triggered. If triggered, the firmware doesn’t allow the stepper to move to the direction of the end stop.
Check the end stop lever and cables. Optionally connect a USB cable and send the G-code M119 over a terminal.
If the endstops are functioning correctly (reporting “open” or “triggered” corresponding to the state of the endstop), a Google search on the World Wide Web shows that people that had these exact problems had issues with the controller board, replacing the board helped their issue. If this is a recent purchase it is advised to contact the seller for support rather than fiddling with the board or the firmware.
In case the board has a spare unused stepper driver (not very unlikely if you have this controller board), the firmware could be altered to use the spare for Y movement. E.g. E1 could be used for Y.

I appreciate the help, and these exerciese did help me learn more about the system. I think the system is reading both y inputs as the same command, are there  codes you know of to move the y axis? it might help me figure out if its a hardware (what i am currently assuming) and a software (doubtful but really want to rule out). and if it is hardware what would be your next step?

@doombringer175 Swap the X and Y stepper connectors to see if X now only moves in one direction. Do it at your own risk, I’m not liable for damages. Also, see the bottom part of the answer, you could try to use the spare stepper driver slot. Best if you use a new driver though, but you could try with the current one. Do note if you use a new driver, you need to make sure it is the same and set the correct Vref.

My skill set is more on the software side so i'd wager its not an impossible fix, but i don't think its going to be quick. I'll do some research. again i think both the motor and the cable are fine (given that it worked fine when plugged into the x drive) so i'll give it a shot.  something to the effect of this right:  https://3dprinting.stackexchange.com/questions/3925/how-to-switch-motor-outputs-and-use-e1-as-x-in-marlin-firmware?noredirect=1&lq=1

@doombringer175 There are a few ways to tackle this, 1) the previously mentioned switch of the X and Y cables only one of the connectors each cable, 2) swap the cables completely, 3) with the cables working and swapped you could pry out the X/Y stepper drivers and swap them. This should give you information whether it is cables, steppers, or the board/processor. 4) change the firmware and proceed with using the spare slot with a new driver.

Comments are not meant to last forever or extended discussions or help, you are very welcome in our public 3D Printing chat room! There are more people to help you there!


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How to stop scratching the bed and print properly on an Ender 3 V2
I am new to 3D printing, and I just put together the printer yesterday, and I spent a while trying to level it, but if I move the bed too low when it moves it gets stuck on the motor for it in the back, but if I move it just barely high enough to not do that, the nozzle hits the bed while printing and scratches the bed.
When I used Auto Home though, the nozzle was right around 1 mm above the bed like it said it should be, what should I do?

How do you level your bed?

Send it back. You printer is FUBAR.