Extruder skipping - LOTS

[keukpa 5]

OK, I'm getting totally fed up of trying to fix this problem, it seems that ALL the failures with my prints are down to the extruder motor skipping backwards, this is causing under extrusion, failed layers, and first layers not sticking to the bed.

I've tried LOADS of solutions and none of them work, I've tried cleaning the head using the atomic method, and printing at higher temperatures, if I print at a much high temperature this helps but then causes all sorts of other problems.

PLEASE PLEASE PLEASE can someone help me here....

I'm printing in PLA (faberdasherry and Ultimaker) @ 210C

 

Thanks,

Keukpa

[swordriff 119]

How old is your printer? how many hours?

Have you printed ABS and PLA also?

Are your settings in Cura of nozzle size and

layer height sensible?

Does the nozzle get HOT, like is it dripping when heating up to 220?

[keukpa 5]

How old is your printer? how many hours?

Have you printed ABS and PLA also?

Are your settings in Cura of nozzle size and

layer height sensible?

Does the nozzle get HOT, like is it dripping when heating up to 220?

Printer is about 6 months old. I've not tried ABS yet, just PLA.

Using Cura, nozzle size is 0.4mm, layer height, I've tried 0.1, 0.06, 0.15 and 0.2

Yes, nozzle gets hot, at 230C it starts dripping a lot.

Keukpa

[swordriff 119]

This is what I want you to do:

Loosen the 4 long vertical screws. Are they very tight?

Then ighten them again "lightly +", with the force to be expectes by the fingers of a female..

Try printing now.

[keukpa 5]

I've tried that, they aren't very tight. It still skips backwards.

I've taken the bowden tube off and manually tried to push the filament through, there seems to be a fair bit of friction.... how can I reduce this?

Keukpa

[swordriff 119]

I see 3 causes:

Most likely: Teflon collapses onto filament when hot.

Take it out and inspect it from under side and inside. Whould be a clean hole, no edge inside.

Less likely; Still need to clean hot end inside (you say you did that. Do the cold (80-90C) pulls come out really clean?

least likely; mal-adjusted feeder.

When you manually feed, is it from extruder motor end?

could be something insde tube then. Try it! Try pushing through the tube.

next thing, dismount tube on hot end side (maybe need to heat up to get it off and the filament out.

Then start feeding using MOVE MATERIAL.

The Material should push VERY STRONGLY out of the tube end.

IF it does and not skipping while you try holding it with fingers strongly, then you know its not the feeder or tube.

Edited May 16, 2015 by Guest

[keukpa 5]

I'll check the Teflon spacer and see how it looks.

I've cleaned (using cold pull) the hot end and yes, comes out clean.

How can I check the feeder? What would I need to look for?

Thanks,

Keukpa

[swordriff 119]

When you manually feed, is it from extruder motor end?

could be something insde tube then. Try it! Try pushing through the tube.

next thing, dismount tube on hot end side (maybe need to heat up to get it off and the filament out.

Then start feeding using MOVE MATERIAL.

The Material should push VERY STRONGLY out of the tube end.

IF it does and not skipping while you try holding it with fingers strongly, then you know its not the feeder or tube

[keukpa 5]

Thanks for this, I've tried the 'Move Material' and it comes out of the feeder and down the tube with a LOT of force, so I guess it is something on the hot end side....

Any further tips / ideas??

Thanks!

Keukpa

[swordriff 119]

Ok Only 2 possibilites then:

Teflon spacer defective or intermittent temp sensor error,

so that due to this wackel contact the heater is turned on and off and you never get to maintain proper printing temperature over time.

My guess is the Teflon is cooked. Replace.

[keukpa 5]

OK, I'll give that a go, I guess I can get new ones direct from Ultimaker??

Thanks for your help!

Is this the part I need? - http://3dgbire.com/collections/spare-parts/products/ultimaker-2-ptfe-coupler

Keukpa

Edited May 16, 2015 by Guest

[swordriff 119]

Look at it first ..

[swordriff 119]

Exactly! But only if that is the faulty part. Suggest you dismount it, and look at it. It should not have an "inner lip", look thinnish and fragile in the lower end. Good luck!

[swordriff 119]

Something wrong in forum: keukpa posts at 9:26, then me at 9:23 then me at 9:31

[keukpa 5]

Exactly! But only if that is the faulty part. Suggest you dismount it, and look at it. It should not have an "inner lip", look thinnish and fragile in the lower end. Good luck!

Thanks for all your help with this....

I've looked at that part, and there IS a lip inside, I've used a hand drill to remove it, and now it is very smooth, I will rebuild the hot end and see how I get on....

I will report back here,

thanks again!

Keukpa

[gamerfanatic 1]

I'm having a similar issue but on when the feeder "ticks back" a small amount every so often. Im starting to think there is an issue with the feeder mechanism so I should print Rob's feeder which is quite popular around here.

Make sure to read everything before you take it apart, turns out you need to make a run to the hardware store for some stuff before its ready to be replaced...

https://www.youmagine.com/designs/alternative-um2-feeder-version-two