Bowden tube keeps popping out of the extrusion head

[gigagrain 0]

Hi

I finished putting together my ultimaker two days ago. I managed to print 2 small pieces, without trouble, but now I am having trouble with the bowden-tube. It keeps jumping up from the extrusion head. I tried to push the bowden tube well in to the white Teflon tube (The white plastic that is in the peek). But after some printing the bowden tube jumps up a couple of centimeters, so the filament is visible.

Is there a way to get it to sit better in the Teflon tube?

Could the problem be that I am extruding too much? I am using default setting for everything.

Thanks,

 

[msurunner 2]

Double check your clamp fitting is installed correctly on the printhead with a horseshoe clamp to ensure a good "bite"

 

[urban 0]

the same thing happens to me, it moves out of the white teflon part of the extruder and once in a while it pops out completely.

I will give the following a try:

http://www.thingiverse.com/thing:11864

I haven't yet tested this one personally but it's very similar to what I would have done.

Another thing to keep in mind is that the extruder tube is forced in different direction and it has a tendency to wiggle it self out, especially when printing with retraction.

 

[gigagrain 0]

Thanks for the responses.

MSURunner: I am pretty sure I put it together correct.Please see my hot end:

https://skydrive.live.com/redir?resid=4A8877A8AF499313!1112&authkey=!ABgzrr18lZ9pTO4

The blue clip is not 100% like the one from the build guide, but it is close. This is the image in the build guide:

http://www.flickr.com/photos/ultimaker/8643110880/

urban: Thanks for the thingiverse link, but it does not look like it works for a v2 hotend.

I will try to print without retraction, or maybe add some tape on the bowden tube to make it thicker!

 

[gigagrain 0]

I seemed to have solved it. I did it by putting the blue clip upside down. This liftes the white-bowden-tube-clamp alittle more. It seems to do the trick, at least it printed for two hours without poping up.

 

[msurunner 2]

Looks good to me, though if you wanted to be certain, you could mock up a spacer clamp to print out while it's functioning now with a slightly taller height to put more of a bite on the bowden.

 

[astrodenny 0]

Running into the same problem -

Can someone confirm what end the bowden tube should be inserted into the hot end? My tube came with a taped side and I may currently have this backwards (taped side going into the material feeder).

Also, I'd like to print this bowden clamp eventually :http://www.thingiverse.com/thing:11864 but I'm afraid it will pop out again. I'm new to 3d printing, I've got most major mechanical issues figured out, but this tube has been somewhat problematic and preventing me from moving forward printing this right away.

For now, I'm going to reinsert the bowden tube and try to figure out a temporary fix to hold it. I also found this and wondering if at least it would make a difference

http://wiki.ultimaker.com/Jamming

It's ultimately for jamming/clogging, but wondering if it may help keep the tube stable.

Currently the extrusion end of my tube seems to be a bit knurled on the outer surface. Regardless it keeps popping out of the hot end during a print. The horseshoe clamp holds the rest of the tube in place, but the popping out of the teflon has been preventing me from finishing a decent print. Can't wait to finally print the new clamp!

 

[owen 19]

Hi astrodenny

taped side going into the material feeder is correct

Double check from the wiki you have everything assembled correct. parts not upside down etc. as most V2 don't pop the Bowden tube.

You can put a 7mm thread onto the tube and put a nut on it and then hold that down in various ways too

 

[phanc60844 0]

Have you tried giving the tube a sharp pull after fitting to engage the grips inside the fitting? please bear in mind that if the tube has pulled out already, the tube will probably be damaged and will have to be trimmed back to fresh material

paul

 

[astrodenny 0]

Hi Owen,

Ok, the taped side is through the material feeder so that seems correct. Ive checked the wiki and it seems as if the tube was inserted correctly into the teflon. Its as far in as it can go. When I think I have a tight fit, it gradually slides upward during a print. I have the horseshoe clamp on (top of extruder head), but this to does not seem to grip well. To keep the tube in place.Im going to disassemble tomorrow and check closer. One thing I immediately noticed was that the nut on the front right side of the extrusion head digs into the tube a bit. Ive rotated this nut so it is flush, but the problem persists. For the 7mm thread can you please elaborate as far as whers to place it?

Hi Phanc60844,

The tube is definitely damaged. Starting at the extrusion end and upward inside the extrusion head. Ive noticed when inserting the tube, its not a straight shot downward... I have to really get inside and nudge the tube into the teflon. Once inside the teflon, it xoesnt seem like anything is gripping it. Perhaps im not pushing hard enough? Ive only been trying to insert while the head is completely assembled and connected to the axes. As far as trimming, how much could I trim? Any shorter and it seems as if i wont habe enough tube to move around the print area without pulling or tension on the tube itself.

Thanks in advance for your responses!

[owen 19]

Trim just enough to get to a clean piece of tube. Try this first. You can trim a total of about 30mm or so but don't do that in one go. Also inspect your horseshoe clip and see if it looks OK.

 

[phanc60844 0]

Trim the tube and try again, if the fitting gives way with a sharp tug, I wound say either the tube is still damaged (possibly undersized but unlikely) or the fitting is damaged.

paul

 

[francis 0]

A slightly higher (thicker) horsshoe helps a lot. I use this:

http://www.thingiverse.com/thing:46157

on BOTH sides of the bowden tube. The bowden hasn't crept up anymore since this is installed.

Francis

 

[astrodenny 0]

Thanks Francis I will check this out as well...

Paul - In order to reinsert the tube into the fitting, as well as diagnose the issues, is it generally safe to just remove the print head completely from the axes? I feel like too much pressing down will push the slider blocks or bend the axes?

Thanks

 

[astrodenny 0]

Trimmed the bowden tube by 5mm - the end of the tube was a mess - it definitely had chew marks around it.

Removed the front right extruder housing screw and nut - the nut digs into the side of the tube.

My extruder housing is pretty tight due to the increased surface thickness from the paint, so just left it off.

Since my horseshoe had issues fitting underneath and staying put, I filed it down to reduce the thickness. It is now stable, although I will consider printing the one from Francis (Thanks again!)

I printed a calibration cube at 220 and 100 mm/s speed - it stayed in nice and tight!

Thanks!

Thanks!