e stepper stalling  

Re: e stepper stalling

just as another test, you could mark 100mm above the extruder, then run the e motor 100. see if its close.

is your PTFE tube loose? print head in correctly?

Re: e stepper stalling

I will run the 100 mm test.

question: In order to check the other items you mentioned, do I need to disassemble the extruder?

Re: e stepper stalling

yup 🙁 you can look and see if its lined up correctly just by taking off the front cover/ fan stuff. I'm 100 sure the manual has a picture of the heat sink lining up with the body. just things to check. checking the PTFE tube means you have to pull it out. but after you've done it a few times its not so bad. maybe the tube is loose and moves when it retracts.

Re: e stepper stalling

Thanks for the prompt replies and ideas

I'll take apart the extruder this weekend to verify alignment and PTFE security.

baffles me that this is the source of the stepper stalling....but I'll sit back, do as you suggest and let you help me diagnose this problem.

thanks again

Re: e stepper stalling

Hey Chris!

I'm not happy with you!!! you're idea to take apart the extruder and put back together appears to have fixed this!!!

The only extra thing I did is I used the pliers to lift the lock to make sure the PTFE is secured.

I don't understand WHY that was the source of ALL my troubles....but it was. good job, and thanks again.

I'm off to printing and have a Merry Christmas. My students will be thrilled to get the Christmas ornaments done that they created on tinkercad.

Re: e stepper stalling

Chris,

I spoke too soon

I was happy that the live Z calibration went smoothly for the first time so I thought we had fixed the stalling E motor issue.

Now I'm trying to print one the objects on the supplied SD card using the prusa PLA and the stalling has reappeared.

Any other ideas. I want to up the current or voltage....but I will be patient and work through your ideas first.

any other suggestions?

Re: e stepper stalling

If I raise the Z and simply feed the plastic via settings. I get some stalling, then if I assist the plastic by pushing the filament into the extruder, I can overcome the stall and the plastic will flow for a bit and stall again. I've marked the shaft to see if this happens at a particular point in the 360 degrees of rotation of the e stepper.

Re: e stepper stalling

well I was right, there is about 45 degrees of bad extrusion. could be a problem with the gear or maybe a bent shaft..

Any thoughts?

Re: e stepper stalling

45 degrees every rotation? I forget if the extruder motor shaft has a flat spot for the setscrew. but maybe that. or the pressure idler (on the door) has an issue.

Re: e stepper stalling

There is a thread discussing the idler pulley shaft. If not pushed in past the plastic support, if often doesn't contact the other side. This results in little or no tension on the idler. Thus, no extrusion. Open the idler door - check that the idler shaft connects to the door on both sides of the pulley.

Re: e stepper stalling

The e stepper has a flat and I've looked at it, loosened the the set screw and re-tightened. I watched it turn with the idler turned out of the way.

Both the idler and the drive side appear to be turning smoothly without any deviation.

the fact that the stepper stalls in a predictable section of the arc tells me this is mechanical. But my only solution is to go electrical and try upping voltage and/or current.

Very frustrating right now to have a brand new machine with everything working but this.

When I drive filament manually through the setting menu, the problem is not as bad

But when I print it gets worse. even the beginning strip of plastic to prime the nozzle comes out blobby due to e stepper stalling.

When I reload the filament it runs great at first, even through the bad section of the arc....then things get worse

I've tried loosening and tightening the idler and I get no change

Any new ideas

Re: e stepper stalling

if the motor turn good with the idler open but not closed maybe loosen tension on the idler tension (screw heads flush without filament and slightly in when filament is loaded.

after that maybe you could plug that motor into another motor plug on the motherboard to see if it fails when its underload. just be real careful doing that.

Re: e stepper stalling

Again - there is a known issue with the idler pulley axle. It is too short, and if it isn't pushed completely through the axle support as you install it, it doesn't mate with the second support. When this happens, as it has with several builders, the extruder doesn't work and clicks as the teeth gnaw on the filament.

Easy to check, easy to fix.

There is a video in this thread.

https://shop.prusa3d.com/forum/general-discussion-announcements-and-releases-f69/prusa-mk3-working-solution-for-clicking-extruder-u-t25901.html#p116293

Re: e stepper stalling

I had this issue as well and I believe it is the e axis motor that is heating up and causing the filament to soften and jam as it blobs up and hardens just underneath the extruder. Are you using an enclosure? If so I started leaving a panel off of my enclosure and that fixed the problem.

If your room is very hot I guess this could also happen? I saw some guy who made a fan for his e-axis and said that worked too. The only other thing I could say is your nozzle may have a problem.

Re: e stepper stalling

The other problem I found was my hotend wasn't assembled correctly. It took me 4-5 rebuilds to get it built correctly. Here are the instructions that allowed me to fix that part:

https://e3d-online.dozuki.com/Guide/V6+Assembly/6

Re: e stepper stalling

Chris!!!!

Thank you for your help....I'm pretty sure I've figured out the issue.

I have the big heavy part of the extruder gear driving the plastic instead of the the toothed groove!!!

I believe that I have the extruder gear completely misaligned. I'm at work right now....as a teacher so I cannot verify until later. I'm on tenterhooks waiting.

I might have a working printer tonight!!!!!

I'm going to check the manual to see if there was a step I missed

Thanks again for assisting me through this issue

Joe

Re: e stepper stalling

Wow. THAT would mess things up.
Be sure to check the idler isn't also backwards in your build.

Re: e stepper stalling

Chris,

thanks for all your help

turns out I had the drive gear on the e stepper miss-aligned...I had the big gear part driving the filament instead of the grooved section.

Dumb mistake on my part. Unit is running beautifully now

Re: e stepper stalling

nice