Extruder Motor Skipping and Inconsistent Layers
-
@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?
-
@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.
-
@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?
-
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.
-
@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.
-
That looks pretty normal for a cold pull.
-
@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.
-
@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.
-
@mendenmh I have resistors on hand, I will try this and see what happens.
-
@mendenmh Alright, I made a 100K resistor jumper and a 1K, tested them both out and got temperature readings of 25.4C for the 100k and 163.6C for the 1K. So it seems like the ADC chip is fine. At this point, really seems like there's something up with the readings coming off of my thermistor, or my heater cartridge isnt working properly. But seeing as both of my V6 hotends are doing the exact same thing...this seems to me to speak to some form of software issue...just not sure what.
-
What's you duet input voltage? If I'm correct, the heater outputs run at the input voltage.
The Prusa heater cartridge is expecting 24V, so if you are running your Duet board at 12V input, you're running you heater at half power. This would result in the symptoms you've been seeing.
So verify that the hot end heater is rated for the actual heater output voltage you are using.
-
@mikeabuilder If I recall correctly, Prusa switched to 24v with their MK3 system. I'm running a MK2S, which is running 12v. I know this because the bed level probe I'm using is 12v which I direct soldered to one of the the PSU output cables.
Now your question does make me wonder about my PSU and whether or not I'm providing enough current to my duet board. The PSU I'm using has 2 12v output leads. For the previous board which the duet is replacing, Both of those output leads fed into the board directly and then all the peripherals were powered off of that.
For the duet board, I took one of the 12v leads, tied it into Vin and took the other and used it to power my Z probe. Could it be that I'm not giving enough current to my board?
-
The very first step that you should have done is to actually verify your operating temperature on your nozzle as reported by the temperature graph on the Duet web interface. I don't recall if you have reported that as having been done but it would be silly to start any thread complaining about poor extrusion if you haven't even verified temperature as reported by the temperature graph. I therefore assume this was actually done..
If you are running a 24V heater with a 12V input voltage then you are actually running at (I believe) one quarter of the rated output power and not at one half. With such a low output power, you would never achieve a proper nozzle temperature and your Duet board would shut down with a temperature fault.
In other words, it is highly unlikely that you have a heater to input voltage mismatch.
Please confirm that the temperature graph reports the correct temperature that you have set for your nozzle and that it doesn't wildly dip as soon as the part cooling fab starts up or you start printing (I am pretty sure that any of these fault conditions would result in an immediate heater fault that shuts down everything). -
@jens55 Thank you for your input. I do not have a voltage mismatch, as my board is being powered by a 12v PSU which came standard for my model of Prusa printer. I am using with it a 12V 30W E3D heater cartridge. I initiated a print just now, closely monitoring the temperature graph as the print went, and it stayed stable the whole time despite the extruder skipping. Temperature is not dipping upon start of print or upon turning on the part cooling fan. We are staying stable. I have not received any heater faults throughout my use of this board/printer combo, and if I request a print, it initiates. The only problem I am having is my extruder skipping when feeding filament whether extruding through DWC or upon printing.
-
Late to the game here.
A 30W heater is pretty weak. Do you have any higher rated ones?
I would focus on getting smooth, even extrusion in mid-air.
The things that can affect that are:
- the stepper
- the extruder
- the connection between the stepper and extruder
- the extruder heater
- the extruder fan
- the part fan
- the spool of filament
- the spool holder
Have you tried removing the stepper and feeding the filament by hand. If it is not feeding smoothly you will feel it.
Do you have any means to measure the temperature of the nozzle directly?
Frederick
-
The suspense is killing me .... could we have an update please ?
-
@jens55 Yes, sorry. No meaningful change has occurred yet. Here's what I've done since my last post.
- Took apart the hotend and checked for any sort of blockage. None could be found.
Swapped nozzles again to a fresh 0.4mm.
Double checked extruder motor wiring to make sure there was no loose connections. none found.
Swapped heater block from 12v 30W heater to 12v 40W heater.
Removed Filament feed gear from extruder and cleaned it thoroughly.
Changed to another roll of PLA.
Verified that my hotend fan was set to always on.
Fed filament by hand through the hotend, no rough feeding was felt.
Unfortunately none of this has yielded any meaningful change and my extruder motor is still skipping when extruding into air or if attempting a print. Unless I'm still missing something, it seems like there's no hardware left to test and that this issue must be originating from something in the software somewhere, but I don't understand where. That's where I'm at right now.
- Took apart the hotend and checked for any sort of blockage. None could be found.
-
@secretasianman7 said in Extruder Motor Skipping and Inconsistent Layers:
@jens55 Yes, sorry. No meaningful change has occurred yet. Here's what I've done since my last post.
- Took apart the hotend and checked for any sort of blockage. None could be found.
Swapped nozzles again to a fresh 0.4mm.
Double checked extruder motor wiring to make sure there was no loose connections. none found.
Swapped heater block from 12v 30W heater to 12v 40W heater.
Removed Filament feed gear from extruder and cleaned it thoroughly.
Changed to another roll of PLA.
Verified that my hotend fan was set to always on.
Fed filament by hand through the hotend, no rough feeding was felt.
Unfortunately none of this has yielded any meaningful change and my extruder motor is still skipping when extruding into air or if attempting a print. Unless I'm still missing something, it seems like there's no hardware left to test and that this issue must be originating from something in the software somewhere, but I don't understand where. That's where I'm at right now.
Well you can always step back to 3.3.0 firmware - which is what I use. Doing so would allow you to rule out 3.4.x as the problem.
What is the part number of the stepper motors you have tried. There is much more info that controls how a stepper performs than just the current rating.
How long is the wiring to the stepper? What gauge wire is it?
Based on my past experience it seems like the stepper is not up to the task.
Frederick
- Took apart the hotend and checked for any sort of blockage. None could be found.
-
@fcwilt The stepper motor I started with was a Prusa LDO 018 stepper This model. The one I'm running currently is a creality 4240
Wiring on each is about 20-24 inches and it looks to be 24 gauge wire.
Here's why I dont believe it to be a stepper motor issue though. The machine I'm tweaking started its life as a Prusa Mk2S. The only hardware changes I've made to it thus far since installing a duet 2 wifi board have been the extruder stepper and an EZABL bed probe, instead of the PINDA the machine came with.
The machine functioned just fine before the board swap, and only developed these problems upon installing the duet 2 wifi. So with that in mind, how can it be a hardware problem when the same hardware functioned fine on a different board, right?
