UM3 Feeder Losing Grip on Filament during fast drive

[norbauer 1]

When loading and unloading, my feeder loses its grip on the filament in the middle (fast) portion of the feeder motion, as shown in this video (make sure you have your sound on, as that's probably helpful to understand what is going on).

 

I have tried all possible feeder tension settings, from one end to the other, and no change to the tension improves or affects the issue.

This is for my feeder 2, using PVA filament.

Any suggestions for what I can do to troubleshoot this issue?

Thanks!

Edited January 20, 2017 by Guest

[ultiarjan 1,223]

How does your pva feel? Does it feel sticky?

Do you store it closed? Pva gets slippery when absorbing moisture.

[tomnagel 126]

Feeder tension should be in the middle position, don't forget to put it back.

Maybe you can try another filament as a test, to see whether or not it has anything to do with the PVA.

Any kinks/sharp bends in the bowden tube that causes extra friction?

[norbauer 1]

How does your pva feel? Does it feel sticky?

Do you store it closed?  Pva gets slippery when absorbing moisture.

 

Brand new PVA that came with the machine. Doesn't feel sticky.

 

Feeder tension should be in the middle position, don't forget to put it back.

 

cool. Thanks; I have done so.

 

Feeder tension should be in the middle position, don't forget to put it back.

Maybe you can try another filament as a test, to see whether or not it has anything to do with the PVA.

Any kinks/sharp bends in the bowden tube that causes extra friction?

 

I will try loading PLA in feeder/extruder #2 when my current print is done, but I don't think it's the material, since the same problem has been happening (albeit to a lesser extent) on the first feeder/extruder as well, where I was using PLA. In both cases the filaments are just the ones that come with the printer.

No kinks or bends in the tube.

Printing is actually working fine, as the feeder is able to keep a hold of the filament at lower speeds. It's only during that brief fast feed period of loading and unload that it loses its grip. Unfortunately, without that fast feed it takes painfully long for filament to reach the hot end.

There doesn't appear to be any visible signs of the motor digging in and spinning in the filament. It almost sounds and looks more like it's a motor that has a clutch and the torque is causing it to disengage.

Edited January 21, 2017 by Guest

[gr5 2,235]

I've heard that noise before. It's nothing to do with the feeder - it's the stepper making that noise. It just can't keep up. I don't know what the solution is. Actually I do - don't load filament that way. Typically the solution would be to try to cool down the stepper drivers a bit.

Instead just push on the feeder tab and manually load and unload filament. I don't use that silly menu item "load filament" or "change" or whatever it says.

[ultiarjan 1,223]

Same here. most of the time I load/unload manually, much faster.... material is retracted anyhow so you can just pull it out... and push new stuff in...

To avoid painful fingers use this thing;

https://www.youmagine.com/designs/wedgebot-for-ultimaker2

Edited January 21, 2017 by Guest

[neotko 1,417]

Just remember not to push in the filament too much, so when it primes the cores you don't actually grind the filament.

Btw the speed of the load/unload I think is easy to edit by ssh/linux. Anyhow... I would open the feeder and clean the bolt, mine was dirty as hell after not many print hours, and having filament around the bolt only increases the chances of slipping.

To know how to open it read:

http://support.3dverkstan.se/article/64-disassembly-of-the-ultimaker-2-plus-feeder