disappointed with Ultimaker

[mtmvetultimaker 1]

I posted some pictures and a little movie at the gallery.

this is the kind of problem I mentioned.

http://umforum.ultimaker.com/index.php?/gallery/album/550-problem/%C2%A0

 

[aaronalai 2]

Thanks for posting the images and video, I can barely see that really thin strand but the calipers help.

I would think the texturing from the knurled wheel would help in gripping any excess material that might be located inside the bowden tube. Any thoughts? Also, how do you think the thin filaments are generated? Do you think the filament is getting snagged on a deformation to the interior of the hot-end, from the filament as a whole naturally stretching, or something else?

 

[IRobertI 521]

Oh, it's just a thin strand. Well, that's kind of hard to avoid. Put a spoon in a jar of warm honey, now lift the spoon without having any honey drip off the spoon. Impossible, right? Same thing here. What you could do I guess is to make sure the extruder motor is unpowered (like after power cycling the printer), heat up the head manually and then yank the filament out by hand real fast. That might break the strand off quicker so that it isn't as long.

I've actually started loading filament that way, but in reverse, I find it's faster than letting the machine do it for you.

I take no responsibility for any damage you might cause by doing that however

 

[dgsharp 0]

I get these lumps and hairs all the time when I pull out my filament to change it, and I know I've seen other posts about this (people disassembling their hot-ends to remove them and such). I always just let them run through the extruder and it hasn't been an issue. I occasionally have to "move material" to retract and re-extrude a few times when it doesn't seem to prime properly, but then everything is good. I suspect my bowden may not be seated as well as it used to be before I disassembled it a few times (nasty clog issue a while back), as I seem to see the retraction more visibly than before. If the bowden weren't seated very well it might invite filament lumps to get caught there...

 

[aaronalai 2]

Thanks for the answers guys :smile: It's something to keep an eye out for I suppose when priming the nozzle. From what I understand now though, it isn't a very big deal.

 

[mtmvetultimaker 1]

thanks for the answers. the new filament was not capable to push the lump all the way until the nozzle, and started damaging the filament at the feeder. One time, when I opened the nozzle side, I could see the hair and the filament coming out from the tube, but only after I retracted the filament all the way to the middle of the tube, I could pull the hair out.

I totally agree with dgsharp that the bowden tube must be the right place..

Now, I always pay attention to the tube and will try different ideas to minimize the problem.

 

[francis-dufort 0]

Dear Mario

What problems you have had!!!. I question the professional nature of these machines. My problems are different. Actually the 3mm filament is fine for me. Grub screw fell out. Check yours is not loose... did you check the tightness? Definately should NOT tighten feed screws for 3mm filament. I did this and it would not feed at all.

Its a new market and we are the guinea pigs! I definately would not want to be the manufacturer...