Extruder Motor Skipping and Inconsistent Layers
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@phaedrux I'm running firmware version 3.4, any chance that either rolling back to a previous version or trying out 3.4.1 would affect things at all?
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Try disabling the print cooling fan in the slicer and see if the problem persists.
I'm using extruder acceleration of 3000 mm/sec, and extruder jerk speed of 50 mm/sec. You don't want either set too low because if the extruder can't keep up with the printing speed, the controller will limit the printing speed to values that the extruder can keep up with.
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It still seems like your temperatures are out of whack. Can you try increasing the temperature by 5 degrees at a time and testing the extrusion into free air? Keep upping the temp if it still isn't smooth. Stop after 50c or so if it still hasn't improved. The theory is that the hotend isn't actually as hot as it is reporting, so you're not actually melting the filament completely.
Also, how fast are you extruding when you test into free air? Is a slow 1mm/s smoother than a fast 5mm/s?
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@phaedrux Ok we're getting somewhere. I did as you asked, taking note of how much skipping occurred per each set temperature, from 205 to 250, as I extruded into the air. At 205 skipping was constant. Frequency of skipping began to reduce as temperature increased. At 250, skipping occurred noticeably less frequently than at any temperature below that. Though the skipping did still occur enough to mess up any print I would have done.
Also regarding feedrate, yes there is significant difference in skipping with feedrate. 1mm/s provides the least skipping, 2mm/s skipping is very much worse where extrusion barely happens at all, and at 5mm/s motor just vibrates in place with no rotation.
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Alright, then we need to determine if your thermistor is actually a genuine item from E3D or actually something else. Where did you get it?
If the thermistor is something else and the temps are wrong, we'd need to determine what values to actually use. Or perhaps there is something wrong with the assembly causing temps to report incorrectly. Photos of the hotend?
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@phaedrux The current thermistor being used came with the E3D V6 hotend kit which I had purchased from Matterhackers and had shipped to me. I would also like to add that this problem still existed with previous hotend before performing the swap, the previous hotend was an E3d V6 which had came with the original prusa machine which I had ordered in 2018 direct from prusa. For pictures, the hotend is pretty well encased in the extruder assembly. I'd gladly disassemble and take photos, can you please detail exactly what you'd like to see?
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Ok, so it sounds like it's a genuine E3D thermistor, and we have you using the correct settings now.
This may sound silly, but are you sure you're using PLA? Do you have different filament to test with?
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@phaedrux I am sure I'm using PLA as the roll I'm using came as a two pack and I'm using the other roll in an anycubic i3 mega S right next to my machine in question. The problem persisted with a roll of white SUNLU PLA
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@phaedrux An important data point to add. This machine and duet board combo hasn't always produced this issue. Upon very first installing the board and getting things up and running for the first time. I was able to print two decent benchys that were free from this issue. From there, I updated firmware to the latest and ran a pid tune of the original hotend that came with the machine, and that is where this issue began surfacing. At this point hardware feels out of the question to me and this seems to be some form of software issue. Any chance I can factory reset the firmware but keep my config file?
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@secretasianman7 said in Extruder Motor Skipping and Inconsistent Layers:
Any chance I can factory reset the firmware but keep my config file?
Well sure, that's the normal update process. Just upload this zip file to the system tab in DWC as is, don't extract it first.
https://github.com/Duet3D/RepRapFirmware/releases/download/3.4.0/Duet2and3Firmware-3.4.0.zip
The PID tune will only help the temperature stay stable. It doesn't change what the reported temperature is.
The fact that increasing temperature helps it extrude makes me think either the temp reported isn't accurate or the plastic isn't actually PLA and requires a higher temperature.
Are you able to perform a cold pull on the hotend and see if you get a clean imprint of the nozzle? Perhaps there is a blockage.
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@phaedrux I don't have any high temp filament on hand, but could perform a cold pull with some PLA. In regards to firmware, what I meant really was, could I roll back to whatever version of firmware was on my board when I first got it, before I had performed the update to 3.4? Is there any special process I need to perform to make that happen?
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@secretasianman7 said in Extruder Motor Skipping and Inconsistent Layers:
Is there any special process I need to perform to make that happen?
Generally you just upload the zip file for the version you want to use. The config file changes needed between Version 2.05 and earlier and 3.0 and later make it a bit trickier and you'd need a config file for the older syntax if you intend to go back that far, but I don't think that's going to make a difference here.
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@phaedrux so this brings me to another completely unrelated problem I've always had with this board but didnt mention here. The firmware upload process from DWC has never worked for me. It always fails some percentage in to the updating process. So what I did was unzip the file plug the SD card from the board into my computer and manually overwrote the contents. Then ran the m997 command to perform the update process. Was that proper technique or should I have performed that differently?
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Please try uploading the 3.4 zip I posted above and let's see what happens.
Can you confirm that your DWC version is the same as your main firmware version?
Even so, whatever firmware version is actually installed should still behave normally.
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@phaedrux @phaedrux Ok, I just successfully uploaded and installed the 3.4.0 firmware you provided. Confirmed that the DWC version matches the firmware version. Also performed several cold pulls to remove any debris that may have been in the nozzle. After cold pulls, tried feeding different PLA. After all that, the problem persists. I noticed something about the cold pull, not sure if this is significant or not, but upon pulling the filament, I noticed that the diameter thins out a little for about a 2 or 3 millimeters of filament length. Picture Attached.
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That looks pretty normal for a cold pull.
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@secretasianman7 seems like youve tried a lot with your hotend and motor, but have you checked the extruder mechanism? Could be some debris got in the gears so they don't run as smooth?
Home-built CoreXY, Duet Wifi, Chimera direct drive, 2x BMG, 300x300x300 build volume
i3 clone with a bunch of mods -
I lot of your issue points to (as many others have suggested) a temperature measurement problem. Have you tried checking the input on the Duet board? If you have a 100k ohm resistor on hand, replace the thermistor and see if it reads 25C. Also, a 1k resistor should show about 161C. If these numbers are way off, you may have a damaged ADC channel.
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@engikeneer Yes last night I pulled the extruder gear and gave it a thorough cleaning. No missing teeth and I cleaned out all the plastic in it. After doing so, the same problem presented.
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@mendenmh I have resistors on hand, I will try this and see what happens.
