Extruder Motor Skipping and Inconsistent Layers

fcwilt

@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

Secretasianman7

@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?

fcwilt

@secretasianman7 said in Extruder Motor Skipping and Inconsistent Layers:

@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.

Thanks for that.

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?

All of my printers have been kits I have modified to suit my desires or designs of my own. Two of them use the Duet 2 WiFi board, the other three use the Duet 3 Mini.

I have no problems extruding but there are three significant differences:

I use the 3.3.0 firmware - I have never tried 3.4.x
I use 24 volt power
I use Zesty Nimble remote drive extruders. The steppers I use have a rated torque appx 50% more than the CR unit you listed.

These are the settings for the Nimble:

M92  E2750	 	 				; steps per mm                             (suggested 2750)
M203 E3600						; max speed (mm/min)                       (suggested 3600)
M566 E40						; max instant speed change (jerk) (mm/min) (suggested   40)
M201 E120						; acceleration (mm/s^2)                    (suggested  120)
M906 E500						; motor current (mA)                       (suggested  500)

Perhaps the drivers on the previous controller are better suited to your stepper motors.

If there was some sort of terrible flaw in the Duet 2 WiFi it would be well known by now. Is your board a genuine E3D board?

At this point I would suggest first stepping back to 3.3.0 firmware and see if that makes a difference.

If that didn't change anything I would think about using a 24 volt power supply. At a minimum that would involve changing fans. The voltage rating of the CR stepper is reported as 4.8. The steppers I use are 2.8. I seem to recall that the voltage rating of a stepper can play a role in how well it works on 12 volts.

Maybe @dc42 will jump in here and have an idea.

I'll keep thinking on it.

Frederick

Secretasianman7

@fcwilt Thank you for all your thoughts and suggestions. To my knowledge, I am running a genuine duet board. It came from Matterhackers.

I don't mean to imply that there is something wrong with the duet boards, I wouldn't buy that myself. I simply feel that whatever problem I am experiencing with my setup originates with some sort of software misconfiguration or perhaps a mismatch of how my hardware was originally configured to run, vs how it is being run now. I am also very open to the idea that I have some sort of either firmware misconfiguration or poorly setup config file, as this is my first time doing anything with a 3d printer that isn't factory stock. I could have easily messed something up, or just have a lack of knowledge or understanding somewhere that is leading me to have this issue.

fcwilt

@secretasianman7 said in Extruder Motor Skipping and Inconsistent Layers:

@fcwilt Thank you for all your thoughts and suggestions. To my knowledge, I am running a genuine duet board. It came from Matterhackers.

I don't mean to imply that there is something wrong with the duet boards, I wouldn't buy that myself. I simply feel that whatever problem I am experiencing with my setup originates with some sort of software misconfiguration or perhaps a mismatch of how my hardware was originally configured to run, vs how it is being run now. I am also very open to the idea that I have some sort of either firmware misconfiguration or poorly setup config file, as this is my first time doing anything with a 3d printer that isn't factory stock. I could have easily messed something up, or just have a lack of knowledge or understanding somewhere that is leading me to have this issue.

Well reverting to 3.3.0 should be a piece of cake.

3.3.0 files

You should only have to download Duet2and3Firmware-3.3.zip and upload that to the Duet via the DWC.

Have you made any changes to config.g recently? Do you have a config-override.g file?

I don't recall seeing any problems with the config.g file I looked at but it was a while back.

Frederick

Secretasianman7

@fcwilt Alright, I just reverted to 3.3, heated to 215 and tried extruding into the air again, and its the same result. Skipping motor. I do notice that when I put my fingers on the filament and exert some downward pressure, I can get it to extrude with no skipping. I haven't made any changes to the config file since the last one I posted.

fcwilt

@secretasianman7 said in Extruder Motor Skipping and Inconsistent Layers:

@fcwilt Alright, I just reverted to 3.3, heated to 215 and tried extruding into the air again, and its the same result. Skipping motor. I do notice that when I put my fingers on the filament and exert some downward pressure, I can get it to extrude with no skipping. I haven't made any changes to the config file since the last one I posted.

Well good - so now we know that the firmware is not the problem.

The fact that adding external force using your hand makes the symptoms go away reinforces my belief that the stepper, for some reason, is not able to do the job.

Which takes me back to thinking that using a 12 volt power supply with a 4.8 volt stepper may be the problem.

Not too long ago I updated all of my 12 volt printers to 24 volts because of performance issues related to running steppers on 12 volts. BUT I don't recall exactly what the issue was. The problem was described to dc42 and his suggestion was to move to 24 volts - and it solved the problem.

Frederick

Secretasianman7

@fcwilt Sounds like my next test will be to swap to 24V and see what happens then. Thank you for all your input.

EDIT: Upon second thought, I'd really like to avoid swapping to 24v if at all possible, because then I'm going to have to replace a lot of parts like my heater cartridge, bed heater and fans. Secondly, I've got a friend with a duet board printer he built thats 500x500, running 2amp steppers for his machine and he's on 12v running his machine without an issue. Also to add to that, once more, this machine worked perfectly in its original configuration on 12v before swapping to the duet board, so how could the origin on my problem be a voltage issue?

Secretasianman7

@secretasianman7 Interesting update: Just put a temperature probe from my meter under the silicone sock on the hotend and saw a consistent 20C temperature difference between what the duet reported vs what was on my meter. Throughout all temperature ranges tested, the meter reported 20C lower temperature than what was posted on the duet. This leads me to think I've got a thermistor issue of some sort. Any thoughts anyone? Where might I go from here?

mendenmh

@secretasianman7 It's really hard to get good enough thermal contact to get closer than 20 degrees, unless the probe is really clamped in a well, the way the thermistor is. This is close enough that it probably means your hot end is fine.

I had a thought about the extruder motor. Try the following: with no filament in it, send it a command that makes it run for a good long time (5-10 minutes). It doesn't need filament, since with a current-regulated drive, the heating of a stepper is pretty much independent of its load; it is just I^2 R. Multiple short runs, back to back, are fine, too. Now, put your hand on the motor. My criterion for how hard I like to push a stepper (if necessary) is that at this point it is fairly hot. Not so hot that it burns, but hot enough that it is very uncomfortable to hold your hand on for an extended period. This puts the outside of the motor in the 50C-60C range, which is way inside the safe range. If your motor is much cooler than this, you can certainly raise the drive current without any risk.

fcwilt

@secretasianman7 said in Extruder Motor Skipping and Inconsistent Layers:

EDIT: Upon second thought, I'd really like to avoid swapping to 24v if at all possible, because then I'm going to have to replace a lot of parts like my heater cartridge, bed heater and fans. Secondly, I've got a friend with a duet board printer he built thats 500x500, running 2amp steppers for his machine and he's on 12v running his machine without an issue. Also to add to that, once more, this machine worked perfectly in its original configuration on 12v before swapping to the duet board, so how could the origin on my problem be a voltage issue?

Well as a test you would only have to change out the extruder cooling fan and disconnect the part cooling fan.

You can adjust the PWM setting to control your heaters so they don't overheat so no need to change them out.

Can you get the stepper specs your friend used for the extruder? As I mentioned (or meant to) current rating is only one of several specs related to steppers. There are others that may explain why his works and yours doesn't.

Frederick

ziggymanpopo

Hey phaedrux how's it going? It's been a while.
So i got to the bottom of the problem
I stopped by his house and took a look, since i got him his board and kinda started the whole project.
What i had him do was roll back his Updates and two problems disappeared
First it cured the proplem with the extruder
It works fine now.
He had also lost use of the u i on his laptop but not his phone that also works again.
My assumption is that either he missed a step (which i doubt) but its possable or There is somthing about the board that is differant than whats produced currently.
Either way thanks for the help. We'll reinstall the updated one at a time to see where we go south and let you know what we come up with.
Thanks again. Ziggymanpopo

Secretasianman7

@ziggymanpopo This is true. We rolled back the firmware from 3.3 down to 2.05 and the problem completely disappeared. Everything's working as it should now...what a very strange problem this has been, but I'm extremely happy to have a working printer now.

fcwilt

@secretasianman7 said in Extruder Motor Skipping and Inconsistent Layers:

@ziggymanpopo This is true. We rolled back the firmware from 3.3 down to 2.05 and the problem completely disappeared. Everything's working as it should now...what a very strange problem this has been, but I'm extremely happy to have a working printer now.

That suggests a configuration problem we missed or a past firmware upgrade failure leaving the system in an unstable state.

If you are happy then that is great - but I certainly wouldn't recommend leaving a printer running 2.05.

Frederick

mikeabuilder

I gotta say, this thread has been more interesting than many of the TV mysteries I've seen lately. And a great example of why the this forum is so good.

I had a new thought - and I have to preface by saying I'm NOT speaking from experience or expert knowledge here... Is it possible the extruder stepper motor is "one of those" that does not support micro-stepping? I see in the config that it's set up for 16 micro-steps per step, and I've read that micro-stepping does not work on all stepper motors. No idea how to know if a particular model of stepper does not support, but a simple test might be to not set micro-steps for the extruder and see what happens.

Secretasianman7

@fcwilt What are the potential negatives to leaving the printer on 2.05?

fcwilt

@secretasianman7 said in Extruder Motor Skipping and Inconsistent Layers:

@fcwilt What are the potential negatives to leaving the printer on 2.05?

It's very old
It's not being updated as far as I know
It's feature poor compared to v3. Much of how I configuring and control my printer depends on the features in v3
It's possible that getting help here on the forum might be a little more work. I know I have forgotten most everything I knew about v2

BUT if it works for you and does all that you want I think you will be fine.

Frederick

Phaedrux

There's nothing wrong with staying on 2.05 if that works for you and you're content with the features offered.

It does indicate a configuration problem though if it's not working correctly on 3.x

If you do want to try updating again, start with a fresh config file from the online tool.

https://configtool.reprapfirmware.org/Start