Extruder stepper motor clicking. Please help.

I searched around, but could not find anything specific. I have a Nema 17 with an MK7 gear to feed the filament. Only when printing, read hot extruding, it will skip and make awful clicking sounds. I changed the steps in the firmware so 10mm feeds 10mm. It runs fine through the entire length of the bowden tube and never has any issues when retracting. Not sure if there are setting in Slic3r or Repetier that I need to alter as well; I'm think temp maybe too. I'm using PLA and it is rated 190-220C and I have it at 215. I'd think it was hot enough to punch through the hotend without complications. I'm currently uploading a clip of the issue to my Google Drive and will share the link with it once it uploads.

Update:

[drive.google.com]

Update:

Speed settings in Slic3r

Perimeters - 30
Small Peri - 7.5
External Peri - 50%
Infill - 40
Solid infill - 10
Top solid infill - 7.5
Support material - 30
Bridges - 30
Gap fill - 10
Travel - 130
First layer - 15
Acceleration control - all zeroes


These are all half of the defaults. Still skips. What was weird is that there were instance with the default settings where it sped up, honeycomb fill sections, and it did not skip. I would expect it to skip more in those sections.

Update:

Halved the speeds again. The temp looks fine, as in the thermistor seems to work fine, though I'm not sure how to test it. Other than halving it AGAIN, not sure what else I could do.

Edited 3 time(s). Last edit at 09/27/2015 05:22PM by jobzombi.

Tension on the filament?

Not sure what you mean? I increased the temp. The thermistor is not in that normal cavity the J-Head has, I just have it pushed up close to the copper, covered in the orange film tape a few times and then covered by a fiberglass/silicone sleeve. I might have to look into setting the thermistor in the firmware though just to be safe, but as of now, I've gone up to 265 and it still clicks, but when I use my finger to help it get through it comes out fine, not beady like it should when heated too high. I'm siding on the possibility that it is a thermistor issue.

Update:

Increased temp. Changed firmware setting TEMP_SENSOR_0 to 1, for 100k thermistor. I set it to 265C, not to actually print something but just to test and it seems correct as it came out more or less boiling and smoking a bit. So it is HOT..HOT...HOT!, but it still skips. I'll try tighteing the MK7 gear to the bearing just in case the teeth are not biting deep enough, but I think it is as a close-up of the fed filament looks like those worm gear clamps you use on car intakes.

I'm giving up hope here.

Update:

Used a contact thermometer...turns out my expensive multimeter (on sale when Radio Shack was closing) has a temp reader. Put it right next to the thermistor and heated it....Both read about the same temps. Obviously REpetier only updates the temp reading every M[something] so there was some variance but +-2. So the thermistor is not a problem. I Since I took the thermistor apart I'll be drilling the hole on the J-Head Mk V-BV Hot End with 0.35mm Nozzle for 1.75mm Filament with a 3/32 bit to fit in there and sealing it in with some thermal putty. I'm assuming arctic silver is a no-no but it is hard to find thermally conductive, high temp, low electricaly conductive adhesives. Then I'll be moving over to the tension, which looks fine as it bites the filament pretty well. BTW, the hotend has the vents and I have a fan running from start of print to end; running at 35 as set in the custom starting G-code, then slic3r takes care of the rest keeping it between 35-50. When I heat the hotend, filament does extrude by hand fine. So seems that from hotend to the Bowden tube, to the hobbed gear. I started from 205C to 265 and still the same bucking. At this point a print that takes 30mins with defaults speeds takes 4Hrs, so not acceptable, but I gave it a try.

After I put the hotend back together I'll check the pressure between the hobbed gear and the bearing. Is this what was meant with filament tension?

Edited 2 time(s). Last edit at 09/27/2015 10:42PM by jobzombi.

I'd say if your stepper is clicking, you have probably have enough tension on the filament. If you don't have enough tension, the drive gear will grind away the filament.

Check the temperature of the extruder stepper motor... if it's hot (too hot to hold your finger on), that will cause it to miss steps.Try turning down the current to the stepper. Also, if you turn down the speed of the X & Y motors in Slic3r/Cura/whatever, the step rate for the extruder will correspondingly reduce, which may be enough to keep it cool enough to work.

If the extruder stepper is cool, it may not be getting enough current to step. Try turning *up* the current to that motor.

If the hot-end temperature is too hot, filament can clog in the hot end (especially during retraction), and cause the stepper to click. I print PLA at 190... 215 may be too hot. Try feeding filament by hand, wait a few seconds (or pull pack a few mm), then push again. On my printer, this would cause a clog. This is particularly bad if you have an all-metal hotend... I only solved it by getting a PTFE-lined heat break. Another thing is that you should have a fan on the heatsink (this should always be on)... I think the fan you mention is for cooling the filament after it has been extruded.

It is lined with PTFE. The fan does cool the extruded filament, but I don't think it does it on purpose as the majority of the cooling is felt on the grills of the hotend. I do know that there are some different mounts on thingiverse for the fan, but to print something out I'd have to get it to work first...catch 22. I will be checking on the stepper itself. I haven't bothered checking the temp on it, but I will, since it would start skipping from the beginning, as in, it had no chance to overheat or anything.

I don't recognise that hot-end, but that's not surprising. However, the heatsink looks much smaller than mine. So it may be that overheating of the "cold end" is the problem, so improving the fan cooling might be significant.

That fan should be running all the time, at maximum speed... just wire it directly to the +12 supply.

You can make temporary fan ducts out of cardboard or tape or whatever... it would at least eliminate that from the list of possible causes.

I am having the exactly the same problem. Clicking sound, losing steps, pushing by hand helped. Most of time printing result is good even with clicking. blocked twice so far out of about 10 prints.
I do electronics for living, so I 99% sure I have isolated the problem from step motor and its driver. I printed a cooling duct to increase the airflow. Didn't help.


Need other pros here to help. I think we are not the only 2 having this problem.

Edited 1 time(s). Last edit at 09/28/2015 08:58PM by bonmotwang.

What extruder drive design do you have, and what are the extruder steps/mm?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
What extruder drive design do you have, and what are the extruder steps/mm?

I took a few pictures of the extruding system.









Extruder motor is 80.5 steps/mm

Thanks

I found the fix for my problem....I'm an idiot. I forgot that it was a new ramps set....so I had to increase the current on the pololu. It dawn on me when I was going through my kit and I found the old RAMPS kit. Good thing I kept that too, because tinkering with the shield I shorted it so I pulled out a spare pololu from the old kit. I'm assuming this was what was meant with tension, as it not takes a whole lotta force to make it skip. I could push an extra 20+mm of filament outta the stepper before it skips due to back pressure at the J-head; when cold. Now the issue I am having is possibly Repetier related as I upgraded a few weeks back to Win 10. RH will give me an error that RH closed due to an error, in the middle of a print. Hotend stays on and all so I have to run to reopen and stop it. Might opt to install an sd reader. I'm seeing other fellas, and ladies, are having similar issues with win10.

Edited 1 time(s). Last edit at 09/29/2015 11:42PM by jobzombi.

Quote
jobzombi
I found the fix for my problem....I'm an idiot. I forgot that it was a new ramps set....so I had to increase the current on the pololu. It dawn on me when I was going through my kit and I found the old RAMPS kit. Good thing I kept that too, because tinkering with the shield I shorted it so I pulled out a spare pololu from the old kit. I'm assuming this was what was meant with tension, as it not takes a whole lotta force to make it skip. I could push an extra 20+mm of filament outta the stepper before it skips due to back pressure at the J-head; when cold. Now the issue I am having is possibly Repetier related as I upgraded a few weeks back to Win 10. RH will give me an error that RH closed due to an error, in the middle of a print. Hotend stays on and all so I have to run to reopen and stop it. Might opt to install an sd reader. I'm seeing other fellas, and ladies, are having similar issues with win10.

Glad you found the bug. I will take a look at my current settings.

I found my problem too: current was too low. LOL. Now printing at 180C, no clicking.