Gap in print at about 11mm mark off the build plate....SOLVED!!!

[cyborgcnc 1]

Hi All

I recently received my ultimaker2 from dynamism , and I have it for about 4 days now...so brand new.

No matter what I have tried, and no matter the part, I always get a visible gap/band around my prints always at about 11mm off the build plate.  This causes the print to be weak at that spot, and depending on the part, it comes apart at that point, ie de laminates.

I have attached a picture to show this on a part I was printing.  The settings of the printer are all at default for printing PLA.

Before that point, and AFTER that point, the part seems perfect, but always at about 11mm off the bed, a band appears.

I have read many suggestions here, and have tried many, but nothing seems to work.  it is as if something is wrong with the Z-axis...at that spot.  The machine jogs fine, z-axis screw seems OK, and it does have proper grease...

Can you offer some suggestions as to what might be the issue, or hopefully you know of a resolution?

I printed at 210 for nozzle and 60 c for bed....again, before that point and after that point, the part is perfect....

Not sure what else to try, REALLY frustrated after spending that much on this machine....

Edited June 18, 2015 by Guest

[JohnFox 25]

Does it appear on other objects?

Try a simple cube and see if it appears then.

What does the model look like in Cura X ray mode? It's easy to get a layer missing that you don't know about.

[cyborgcnc 1]

Yes, it appears in other objects, and I did try a cube, and also a cylinder, with the same results...

Nothing that I can see missing in X-ray mode....any other ideas? Really do appreciate all the help!

[IRobertI 520]

I would try moving the bed up and down by hand with the machine powered off. That makes it easy to feel if anything is binding around that height. Make sure you pull/push on the bed towards the back of the machine so that you don't bend the bed.

If it's binding it could be:

- Crap on the rods, clean them off.

- Bad bearing

- Bad rod

- Misaligned bearing/rods (fixing this isn't hard, but it's fiddly and annoying )

- Damaged z-screw (don't think I've seen this though)

Edited June 9, 2015 by Guest

[JohnFox 25]

I have had similar problems but not quite as exact on one layer as yours, ( mine span 12 - 25mm ).

Follow IRobertI advice and move the bed up and down. I my case I couldn't find anything until I unscrewed the Z bearing races and found that they were jamming around this position. My theory was that I had lubricated the Z pillars and the balls in the bearings started to slide rather than roll. Removing the oil markedly improved the situation.

Unscrewing the bearings is a real pain by the way, you need a long allen key to get at the back bolts.

It could also be the Z nut.

Both of these are behind the UM2 logo at the back of the bed.

Some bad news - I have reported my fault to UM service with a ticket and they are incredibly slow to respond. :-(

 

Yes, it appears in other objects, and I did try a cube, and also a cylinder, with the same results...

Nothing that I can see missing in X-ray mode....any other ideas?  Really do appreciate all the help!

 

[JohnFox 25]

Actually UM have responded and sent me a couple of new Z axis slide bearings. The ones I took off felt really rough.

 

I have had similar problems but not quite as exact on one layer as yours, ( mine span 12 - 25mm ).

Follow IRobertI advice and move the bed up and down. I my case I couldn't find anything until I unscrewed the Z bearing races and found that they were jamming around this position. My theory was that I had lubricated the Z pillars and the balls in the bearings started to slide rather than roll. Removing the oil markedly improved the situation.

Unscrewing the bearings is a real pain by the way, you need a long allen key to get at the back bolts.

It could also be the Z nut.

Both of these are behind the UM2 logo at the back of the bed.

Some bad news - I have reported my fault to UM service with a ticket and they are incredibly slow to respond.  :-(

 

Yes, it appears in other objects, and I did try a cube, and also a cylinder, with the same results...

Nothing that I can see missing in X-ray mode....any other ideas?  Really do appreciate all the help!

 

 

[cyborgcnc 1]

Thank you for those suggestions....I have a new stepper and helical screw/nut coming, so we will see if this fixes the issue. If not, I will try to adjust the slide bearings....

Been reading around and it seems other folks are also having this issue...maybe some bad parts or misalignment on some models being shipped out...very disappointing to say the least, on such a pricey machine....we shall see. I will report back once I replaced the stepper and screw....

[JohnFox 25]

If you are undoing the Z axis nut, just have a go at undoing the slide bearings while you are at it. Try them one at a time, sliding them up and down the pillars. See if the jam up at all.

 

Thank you for those suggestions....I have a new stepper and helical screw/nut coming, so we will see if this fixes the issue.  If not, I will try to adjust the slide bearings....

Been reading around and it seems other folks are also having this issue...maybe some bad parts or misalignment on some models being shipped out...very disappointing to say the least, on such a pricey machine....we shall see.  I will report back once I replaced the stepper and screw....

 

[cloakfiend 995]

You may want to try one print like this just to be sure its not the filament snagging as the feeder is a bit hit and miss and the clicking noise used to drive me up the wall, but i never get it anymore! I only print like this now as i simply had enough of those lines and the clicking noise, all so i can acheive perfect layer height as much as i can get it. (its never perfect unfortunately, even if it looks as if it is).

Good luck....expect lots of problem solving for the next few weeks! lol. but once you crack it. You'll be happy.

Edited June 17, 2015 by Guest

[cyborgcnc 1]

PROBLEM SOLVED! YEAH!!!

All, I wanted to let you know that it was the Helical Screw/Nut/Stepper. I was able to obtain a replacement Z-Axis Stepper (Comes with Helical screw attached) and a new nut. After replacing it the old one, I now get really good results with the printer!! NO MORE GAPS!!! Can't tell you how awesome it was to solve this problem, as I tried just about everything. Since again, it was happening at about the same spot, the z-axis was the suspect from the get go....

Thank you all for your great suggestions and support!