Ultimaker 2; Stochastic hardware problem unfixable? Anyone experiances with warranty issues?

[d1rkster 0]

Hello Community

I bought a new UM2, about three weeks ago. I have a big problem with drifting layers, so that my prints aren't normal in the x-direction. I know, this topic has been before, but mainly for ultimaker 1 and all the nice advicec aren`t very useful in my case. Since it's a UM2, I can't adjust the axes or belt tension. If I move the printhead per hand (machine off) I do not feel unregular resistance and I lubricated all linear bearings with sewing machine oil already. I even tried checking the G-Code of the failed prints. Some prints fail, some don't.

 

In my pictures, you see my latest print. Printed in the order: Front item, middle item, back one. You see the first item being normal in the first 3 mm and the thr drift began. The secont one is perfect and the third one totally failed.

 

I do not have any more ideas and I'm totally pissed meanwhile! If I knew 50% of my prints fail, I wouldn'n have spent that much money.

 

Did anyone ever try, to change a UM2 by warranty? Would be nice to hear about your experiances!

 

Greetings

Dirk

Ps: How can I post pictures anyway? Is there now way to just upload an image?!

 

[IRobertI 496]

How to upload pictures:

http://umforum.ultimaker.com/index.php?/topic/4525-how-to-upload-an-image-to-the-forum/

I can't be sure without seeing pictures first but it sounds like you're seeing a sudden shift in the X-direction? Usually this is due to pulleys not being secured well enough to the shaft. There are two small set screws on each pulley, make sure these are nice and tight (probably tighter than you think they should be). To make sure this is the issue you can put a mark on the pulley and a matching one on the axis, then, after a print fails inspect your marks and see which pulley it is that is having problems.

If you're seeing a gradual shift (so that it looks like the print is leaning) it's more likely friction causing trouble. Usually it's either the belt of the pulley making contact with the side of the machine. If this is the case you can undo the pulley on the motor and move it closer to the motor (while still leaving a tiny gap) so that it is no longer rubbing against the wall.

 

[gr5 1,837]

Robert has good advice. The big question is: Is it sudden or gradual shift. If sudden it's probably the pulley on the motor. If the shift is X direction it's therefore the X motor. The second most likely pulley is the other pulley on the short belt.

It's tricky to get at the motor pulley - you have to first remove the right rear metal cover. It's held on by one screw.

Then you might be able to tighten it without removing the 4 screws holding the motor in place. Mark the shaft and pulley while you have it apart. And tighten the hell out of that screw. The steel wrench should twist.

 

[d1rkster 0]

Hi Guys,

Thanks a lot for the quick answer.

I checked the belts and the pulleys for unwanted friction already and as well I tightened the pulley screws. But until now only these on the axes and not on the short belt.

And maybe I was to frightened to tighten them really that hard. Even such a little thing can be very helpful device!

I'll try this today and mark the pulleys and the axes.

I hope SO much, this will solve the problem.

Greetings and Thanks a lot

Dirk

By the way: Meanwhile, one should be able to see the pictures in my gallery.

I was really just not validaded and couldn't upload thusly.

Could anyone please check and tell?

gr5 edit...

dirk - to add pictures click 'my media' next to smile face

 

 

[gr5 1,837]

I finally saw your pictures. This is *not* a sudden shift so it might not be the screws. But definitely tighten the one on the x motor. And actually see if you can slide the pulley closer to the motor. Someone had trouble with their brand new UM2 where the pulley on the motor was touching the side of the UM2 and was causing this same lean issue although for them it was the Y axis.

So definitely look for the short belts rubbing the side of the UM2 somewhere. And check for possibly the larger rods (two on the X axis) possibly being too tight against the ends. When you loosen a Y pulley on the long belts (there's 4 pulleys) then can rotate on the axis freely but also they can slide along the rod. Make sure they aren't too tight against the side of the UM2. This can cause extra friction.

 

[illuminarti 18]

I don't think that, for practical purposes, it's possible for the long belt pulleys to end up too tight against the sides of the printer on a Ultimaker². The pulleys that directly touch the bearing have slight standoffs on that side, and the rest are in separated by small diameter plastic spacers. So all that any of them ever touch is the rotating part of the bearing anyway.

It is definitely possible for the motor pulleys to be incorrectly assembled such that the outside of the pulley rubs on the side panel, introducing friction, and causing these sort of skipped step problems.

The other thing that is worth checking is that the pulleys are all on the right way round, since if they are not, that can lead to twisting and wear on the belts. All the pulleys have two ends - a thick end (with the screw) and a thin end (just an end plate to keep the belt lined up). In all cases but two, the fat end should be towards the nearest wall.

The exceptions are the two short belt top pulleys. For the y-axis (back left) it's a single piece with two sets of teeth, and two thin ends. For the x-axis (back right), the short belt pulley has the thin end towards the back wall.

 

[d1rkster 0]

Wow, so nice to get advice from experts.

I checked the belts and the pulleys and I didn't find any extra friction that could caus problems.

But anyways, to tighten the pulleys really strong seems to solve the entire problem finally.

Thank you so much for your help.

My UM2 finally generates really nice prints

For any further comments. I'm gone for the next three days and can not check the forum unfortunately.