cw2 CW2 Filament Slipping after few hours of printing / when hot

[Badmaster]

Hi all 

 

Setup Infos:

voron 2.4 r2 350mm, stealthburner cw2, vitali cnc aluminium tap, phaetus dragon sf/st hotend, fully enclosed (no exhaust, as I have no space behind the printer, ptfetube goes out a hole in the top panel). printing esun abs+ @ 163C/90C (temp tower calibrated)

Ever since I have upgraded from Afterburner to Stealthburner I have had issues with underextrusion.

It took me quite a while to realize what it was though. For the longest time I thought it was an issue with filament printing temperature or the roll of filament itself(ABS+ White).

After finally switching to a "known good" roll of filament (ABS+ Black) in which I had printed the parts for the Stealthburner upgrade, I started realizing its underextrusion, likely caused by the extruder.

So I started measuring the maximum flow rate until which I see "dropped" filament. CW2 never "clicks" or misses steps for me, it simply slips on the filament (even with maximum squish and thingymagic very deep/low).

I rebuilt the CW2 twice, once with new parts, new motor (LDO-36STH17-0354AHG). But I had to tighten the tensioning screw all the way down in the first rebuilld, in order for the filament to have a firm hold.

I have ordered the 20mm version as well, but I think the 17mm should work, as the other two versions linked on the official Voron Sourcing guide are 100% 17mm motors!

Then again, when you google around, all shops I've found that sell CW2 Kits ship the 20mm version? 

 

After the second rebuild with fresh parts (printed very slow to make sure I have no underextrusion), it seemed I could finally get 12mm3/s (not quite 15mm3/s but acceptable).

Also this time the tension screw was more "reasonable" to have a firm grip on the filament, and even the thingymagic was not completely screwed in!

note: I followed both videos, regarding meshing and screw adjustments in both CW2 rebuilds!

BUT already on the second print, I started seeing the same old underextrusion again!  

This time though I was lucky enough to witness it live, something I was not able to beforehand for weeks! check attachment for this state.

After pausing the print, I realized there was:

1. no nozzle/hotend clog (easy to push through by hand)

2. filament was not stuck on spool or whatever

3. filament was slipping in CW2 all of a sudden

So I had to tighten the screw all the way to in order for it to not slip. (yes I would extrude parts again to make the sure filament was not ground down)

 

Not sure how to eliminate this issue, as it seems I am not able to build a CW2 working for more than ~10 hours 

 

Checklist:

- follow both youtube videos for meshing/thingymagic adjustment 

- extruder Motor Current on 0.3a

 

could it be that the filament gets too soft from the chamber temp so it slips?

The extruder motor sure gets hot, so maybe the gears also get hotter? Not sure how I would combat that though...

Thanks a lot in advance for your inputs on what I might need to check/improve!

 

Edited September 29, 2023 by Badmaster
Added more details

[claudermilk]

They still show the  17? As I recall it was quickly determined you really want the 20. I have the LDO 20 (this one) and it works fine. I eventually settled on a voltage of 0.6 to make it happy.

[claudermilk]

I suspect it. I can't say for sure because I read the comments at the time and swapped my shopping cart to the 20mm. It's $20, so not a huge investment. It wouldn't hurt to hit the Voron Discord and ask there--lots of people far more knowledgeable than I can give feedback there.

[atrushing]

I agree with the 20mm motor suggestion. The current really needs to be pushed to the limit to get a 17mm stepper to even perform reasonably, and then the stepper starts running hot, especially in enclosed printer. My 20mm motor is currently set at 0.55 amps.

Another thing to double check is that the grub screw for the hobbed gear hasn't backed off.

[Badmaster]

3 minutes ago, claudermilk said:

They still show the  17? As I recall it was quickly determined you really want the 20. I have the LDO 20 (this one) and it works fine. I eventually settled on a voltage of 0.6 to make it happy.

The first link points to the stepperonline 17mm version 

The first alie link goes to a listing with both 17mm and a 20mm version, but the 17mm version selected.

The second alie link goes to a 17mm moons motor....

 

So you think it could be the motor size?

[Badmaster]

35 minutes ago, claudermilk said:

I suspect it. I can't say for sure because I read the comments at the time and swapped my shopping cart to the 20mm. It's $20, so not a huge investment. It wouldn't hurt to hit the Voron Discord and ask there--lots of people far more knowledgeable than I can give feedback there.

Thank you.

Its like a 2€ difference, I figured I'd go with the official docs.. but well...

The issue is getting too complicated for discord, I already checked many things and others said their 17mm motor worked fine, hence not conclusive.

34 minutes ago, atrushing said:

I agree with the 20mm motor suggestion. The current really needs to be pushed to the limit to get a 17mm stepper to even perform reasonably, and then the stepper starts running hot, especially in enclosed printer. My 20mm motor is currently set at 0.55 amps.

Another thing to double check is that the grub screw for the hobbed gear hasn't backed off.

Thank you, i used threadlock and on inspection while mounted it was still in an okay position.

 

Just wondering how ppl are able to use the 17mm version when it heata up te filament up so much it starts slipping - that being my only explanation atm.

 

Hapy to take more thoughts/hints!

[Badmaster]

 

~~Appears i was finally able to solve the problem (corrected: NOT):~~

Installed 20mm version of the stepper.

The 17mm version got to 113C and heated up the gears, which in turn heated the filament and made it loose grip.

Conclusion: they should really remove the 17mm version from the sourcing guide, not sure why it has not been done yet.

Edited October 7, 2023 by Badmaster
Failed again on second print

[Badmaster]

 

nope, second print started slipping again.

Could be chamber temperature being too high? Should not really be an issue but....

first print were orbiter 2 mount parts.... sooooo looking forward to resolving this issue, but appears cw2 is not working for me.

 

[liselotte111]

An older thread, but could your problems be caused by the esun abs+? It has a very low softening temperature (vicat) and poor layer adhesion. Causing your cw2 to deform