Weird problem - UM2 starts grinding filament after 15 minutes and prints in the air...

[frederiekpascal 193]

hello,

I got a strange problem with my UM2 now...

The print starts perfectly each time but after 15 minutes or something the filament starts grinding and the printer stops pushing filament through the nozzle.

I have no clue what this can be, I already changed the nozzle with another nozzle (0.4 mm) from Olsson (so no chinese nozzle). And after I change it, it starts printing again for a few minutes and then again it starts printing in the air and the filament is grinded again.

Anybody who can help me out, I have no clue how to solve this one.

I already have a nice collection of prints, but all of the sudden it's not working anymore.

Thanks in advance!

here are a few prints :

[ultiarjan 1,223]

First thing to check is deformation of your Teflon. Unload filament, do an atomic, take off the nozzle and push a piece off filament in the block from below. Feel if you have more than normal friction.

Or even better take out the teflon and inspect visualy.

[frederiekpascal 193]

It's a DupTef Coupler combined with an “I2K” – Insulator  from 3Dsolex (http://3dsolex.com/teflon-replacements)  I'm using and it's not very old, my guess would be 100 print hours max with it...

Edited October 11, 2015 by Guest

[stu_le_brew 42]

just wondered how much filament is there on the reel, as this can sometimes cause a problem - my thinking is that some filaments remember being tightly wound round a reel and this can cause increased friction in the bowden tube

I had this problem once and even went to the trouble of heating the last 10+ meters of filament in hot water and straightened it out - the prints returned to normal

[frederiekpascal 193]

it's a brand new filament (PLA from Colorfabb) that's on the spool.

[frederiekpascal 193]

anybody who has an idea what's going wrong with my precious?

[ultiarjan 1,223]

I know you say your teflon is new but did you do the friction check anyhow?  you only need to remove the nozzle so it's a quick check ...

Edited October 11, 2015 by Guest

[Labern 774]

Do you have the stock feeder? Sometimes the feeder drive wheel can build up with plastic and require cleaning.

Have you tried adjusting the feeder tension?

Have you printed with this new roll before successfully?

[frederiekpascal 193]

First thing to check is deformation of your Teflon.  Unload filament, do an atomic, take off the nozzle and push a piece off filament in the block from below. Feel if you have more than normal friction.

Or even better take out the teflon and inspect visualy.

 

hey,

I opened up the printer to check the coupler and it was still crystal white as expected.

How exactly do I do that friction test?

[frederiekpascal 193]

Do you have the stock feeder? Sometimes the feeder drive wheel can build up with plastic and require cleaning.

Have you tried adjusting the feeder tension?

Have you printed with this new roll before successfully?

 

I've had troubles with my feeder from the start, the white indicator was in the middle but that cause the feeder to "glock" when I was printing fast. (I have the low friction spool holder with bearings).

So now my white indicator is back on top on the feeder and I gave it another try.

I didn't print successfully with this particular roll but I'm using PLA colorfabb all the time.

But I changed it to a used roll now just to make sure indeed.

[ultiarjan 1,223]

 

First thing to check is deformation of your Teflon.  Unload filament, do an atomic, take off the nozzle and push a piece off filament in the block from below. Feel if you have more than normal friction.

Or even better take out the teflon and inspect visualy.

 

hey,

I opened up the printer to check the coupler and it was still crystal white as expected.

How exactly do I do that friction test?

 

When a PTFE is damaged it's usually collapsing at the bottom (where the heat is coming from).

The test without having to disassemble the head is just remove fillament (cold pull) take of the nozzle, and manually put some new fillament in from the underside (through the olson block) this way you will feel extra resistance when your ptfe is really damaged.

[frederiekpascal 193]

this is what's happening (sorry for the bad image, that's because of the plexi door)

 

this video is from today after trying some tips of here above...

[stu_le_brew 42]

Do you have the stock feeder? Sometimes the feeder drive wheel can build up with plastic and require cleaning.

 

can't see your answer to "Labern" question about the stock filament feeder, so I assume you have the standard one

I would suggest opening the feeder and check for filament debris inside, also maybe a drop of thin oil on the bearing inside the feeder

If you haven't removed the feeder before a word of caution you would be best advised to take the back left cover plate off first as the feeder stepper will drop down as you remove the last screw holding the feeder in place.

Edited October 11, 2015 by Guest

[frederiekpascal 193]

yes I have the stock feeder, but I cleaned it with a toothbrush and air pressure

[DidierKlein 729]

Hi Frederiek,

Is it happening on every prints or just a particular one? Does it have a lot of retractions? The filament might be flattened because it retracts a lot, and colorfabb is a bit softer.

[frederiekpascal 193]

I changed the coupler this morning anyway (couldn't see anything wrong on the other one though...), loaded a new (other) model on the printer and changed the filament

keep you posted

[frederiekpascal 193]

Hi Frederiek,

Is it happening on every prints or just a particular one? Does it have a lot of retractions? The filament might be flattened because it retracts a lot, and colorfabb is a bit softer.

 

yep the model had massive retractions imo.... this was the model : http://www.thingiverse.com/thing:919475

I tried it 3 times with no luck :(

[ultiarjan 1,223]

Try to limit the # retractions on the same piece of the fillament.

Cura (15.04) expert settings;

[frederiekpascal 193]

Try to limit the # retractions on the same piece of the fillament.

Cura (15.04)  expert settings;

 

I'm using Simplify3D, any settings I need to change for this model?

[neotko 1,417]

For simplify3d they have a great guide. I think was @rigs who posted it

https://www.simplify3d.com/support/print-quality-guide/#not-extruding-enough-plastic

They explain in depth many settings

[frederiekpascal 193]

For simplify3d they have a great guide. I think was @rigs who posted it

https://www.simplify3d.com/support/print-quality-guide/#not-extruding-enough-plastic

They explain in depth many settings

 

awesome, thanks a lot @neotko!

[frederiekpascal 193]

Does it have a lot of retractions? The filament might be flattened because it retracts a lot, and colorfabb is a bit softer.

 

that's the reason of the fail prints imo, how do I solve this?

[neotko 1,417]

For lots of retractions lower a bit the speed of the retractions also helps but if it's too hot it can make blobs and strings.

[frederiekpascal 193]

For lots of retractions lower a bit the speed of the retractions also helps but if it's too hot it can make blobs and strings.

 

it's already only on 30mm/sec, lower it to how much?

[neotko 1,417]

Umm dunno I only had that problem with a very dry filament months ago. I think 20 should be ok. Less might make a mess on the print.