Filament Jams

[jroen 0]

Hello all, I've been printing with my new UM2 for a few days now but the last 2 days have been a true hell. It ruined about 6 or 7 of my latest prints. And support is down in the weekend?

The filament jams. I thought the feeder caused the problem but now i'm sure it's somewhere in the nozzle area.

For some reason the filament won't go forward OR backwards. When i release the bowden tube above the nozzle there is a small clod as large as the outside diameter of the bowden tube. Why does this happen? I think the lockingsytem of the bowden tube is much too weak.

When i search for some specs about the tube i find this file: https://github.com/Ultimaker/Ultimaker2/tree/master/1266_Bowden_tube_(x1'>https://github.com/Ultimaker/Ultimaker2/tree/master/1266_Bowden_tube_(x1'>https://github.com/Ultimaker/Ultimaker2/tree/master/1266_Bowden_tube_(x1'>https://github.com/Ultimaker/Ultimaker2/tree/master/1266_Bowden_tube_(x1)

and is tells me there is a flared edge on the inside of the bowden.

But my UM2 tube is not flared, it's just straight.

But the document also tells me this is a ultimaker original bowden in the UM2 github section. https://github.com/Ultimaker/Ultimaker2

What can i do to solve this?

Why do i need to tinker a brand new machine?

Thanks

 

[IRobertI 521]

The flared edge will be at the feeder end if they're still doing that for the UM2. I know this was done on the original but I haven't actually checked it on the UM2.

First, is the "third fan" running? By third fan we mean the fan that is in the back of the print head. It should be running as soon as the printer is turned on.

When you removed the bowden tube, did it look like there were scrape marks or other damage around the area where the white collet is supposed to bite in and secure it in place? If there is damage you should cut off a small section of the tube so that the collet gets a fresh section to bite into (make sure the cut is straight). Also check that the small metal teeth inside the collet aren't clogged or damaged.

If everything looks good you can re-assemble. Undo the four bolts that holds the head together a few turns. Re-insert the bowden and make sure it sits all the way down into the white teflon piece. Put the little blue/red horse shoe back and then re-tighten the bolts. You'll see tube move up slightly as you tighten the bolts and if you tug at the tube there should be little to no movement up and down once you're done.

 

[illuminarti 18]

See here for my advice on how to reinsert the Bowden tube in the hot end...

http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/?p=40399

As Robert says, once it's all assembled, the Bowden tube shouldn't move either up or down. It may be that the Bowden tube has been scraped by the retaining clip during the removal and reattachment process. If so, cut a few mm off the bottom of the tube, so that the retaining collet has fresh plastic to grip.

 

[jroen 0]

Thanks for the quick response guys, i'll give it a try.

 

[gr5 2,268]

Please photograph the problem with the filament being too large if it's not too late. Also I agree that this sounds like your 3rd fan (the rear fan) is not working. Or maybe the bowden is slipping too much or maybe both.

The 3rd fan should come on when you turn on the printer - even before the lights come on. Make sure it is turning the correct direction - blowing air towards the front of the machine.

 

[jroen 0]

Still no answer from support but I think I got it under control now. The Tube coupling collet and it's clip were the main problems. Because they don't lock properly the bowden cable can move up a little bit above the nozzle. As a result the filament reaches a big diameter at the end of the tube and can't move for or backwards anymore. First idea was to increase friction in the feeder but that causes another problem, grinding. Now when I push in the bowden cable all the way, I pull up the coupling collet with my nails till it locks real good. I notice the blue clip is not high enough to lock it. It looks like a festo air-coupling but then you have air pressure to lock it and there there isn't of course. I have to find out how to post a picture but don't have enough time right now.

Thank you all!

 

[gr5 2,268]

You can get it even tighter if you loosen the 4 thumb screws 3 or 4 turns, do what you describe above, then tighten them back up. If the bowden keeps slipping even after that, you should take it out, cut off the last 2mm and put it all back together again.