Z-Axis layer error

[taxez 1]

I haven't gotten around to further testing. At the moment I even suspect a firmware related error. Since I recall the problem only appearing after the last firmware upgrade. Or in other words I'm still clueless.

 

[fabiolino 0]

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Edited April 27, 2015 by Guest

[JohnFox 25]

Have you ever lubricated the Z axis slide pillars?

I have just experienced this problem and it was due to lubrication on the pillars. The slides are ball races and need a small amount of friction to rotate. Oil the pillars and they will try and slide, not rotate, causing a jam. I removed all trace of oil and the problem has cleared.

John

 

I've always had an aversion to manually moving such seemingly delicate parts. So I rarely did it. However In my case I just noticed the z-screw moves as if it had sand on it! Especially towards the top. Come to think of it I've only had the z-layer issue since I relubed the screw a few weeks back. I have no idea what went wrong as I used the supplied Magnalube in the way I was told to. But I hope properly cleaning and applying new lubrication will fix my problem.

[cyborgcnc 1]

I have got THE SAME exact issue, with a brand new Ultimaker2 bought two weeks ago.  At around the 10-15mm off the bed, I always get a band around the print, and the model delaminates there if slightly bend...I have tried everything, the problem is always there.  I am waiting on a new z-stepper and helical screw/nut to see if this will fix it.  If not, this thing will get thrown out the window.....very frustrating for such an expensive machine....

[JohnFox 25]

I think I have just replied to the other thread on this topic.

Pretty sure it is due to dodgy slide bearings. Since I changed mine, things have really improved.

I would check these out before changing the stepper.

 

I have got THE SAME exact issue, with a brand new Ultimaker2 bought two weeks ago.  At around the 10-15mm off the bed, I always get a band around the print, and the model delaminates there if slightly bend...I have tried everything, the problem is always there.  I am waiting on a new z-stepper and helical screw/nut to see if this will fix it.  If not, this thing will get thrown out the window.....very frustrating for such an expensive machine....

 

[cyborgcnc 1]

I think I have just replied to the other thread on this topic.

Pretty sure it is due to dodgy slide bearings. Since I changed mine, things have really improved.

I would check these out before changing the stepper.

 

I have got THE SAME exact issue, with a brand new Ultimaker2 bought two weeks ago.  At around the 10-15mm off the bed, I always get a band around the print, and the model delaminates there if slightly bend...I have tried everything, the problem is always there.  I am waiting on a new z-stepper and helical screw/nut to see if this will fix it.  If not, this thing will get thrown out the window.....very frustrating for such an expensive machine....

 

 

Thanks JF!! I actually just changed the stepper/nut and VOILA, problem gone!!!! Very happy with the printer now....

[stanimal 0]

hello i have the same problem

i change evrything motor, axis, electronique card and nothing

i just mount spring very less strong on the heatbed and my jumps have desapear

[stanimal 0]

after many prints the trouble have deseapear completely

[DarthBilly 0]

Hi all, I'm adding my pictures to this issue. I also notice a chip in the bed rods and what appears to be rust on the rods. I've on;y had this printer 6 days :(.[/media][/media]

[DarthBilly 0]

Here's a picture of the rods. Yes, I did use a soft cloth to try and remove it, but I can feel it. It has a rough texture.

Edited August 14, 2015 by Guest
Added information.

[DarthBilly 0]

Ok, here's the latest. I received my new Z shaftes (not the threaded rod). I figured I would trouble shoot this issue since I was going to have some of it apart. I removed the Ultimaker2 plaque and unscrewed the Z nut. I moved the Z nut around the area that has the problem. It felt very smooth. I then moved it towards the top to help hold the plaque. Now that the table was free, I slid it up and down. Here I noticed a snag while going down at the spot of the problem. So I then removed the right-side bearing. I slid it up and down. Bingo, first try, it also snags at the spot. To be sure, I did the same thing to the left side, but it did not snag.

I removed the shaft an put in the new one. To my surprise, it doesn't look any better than the original one. I fed the bearing on and moved it up and down and it feels smooth. I put sewing machine oil on a cloth and cleaned the new shaft. As I fitted the shaft, and tighten the bearing, I moved the table up and down to make sure t was still smooth and it was.

It was late last night, so I did a print and NO missing layers (YEAH!). I'm going to do some more today, hopefully it's all fixed

[DarthBilly 0]

Just a follow up, Second print and still looks good.

[ceoloide 0]

Hello All,

Sorry to resuscitate this post. I am having the exact same issue with a brand new Ultimaker 2. I consistently have something like a missing layer between 10 and 20mm. This happens reliably, even when using different 3D models, speeds and using two different PLA filaments (printing at 210 degrees).

What is the suggested solution to the problem? How to ensure that this is indeed a mechanical problem?

Thanks everyone for your help!

Marco

[WTFockewulf 21]

Hi Marco,

exact same Problem at the same height here. I have an open ticket with igo3d. First try at a solution was to change the motor current but that did not help...

Hope to solve the problem and post the solution here soon. my Ultimaker is 1 week old...

[gr5 2,167]

Move the bed up and down by hand and try to see if you can feel something at that point.

Several people fixed this by removing the 2 vertical bearings that are screwed to the bed and that slide up and down on the 8mm vertical rods. If there is too much oil on the vertical rods it can mess up those balls in those bearings. They need to be cleaned and dried and need no oil at all although one drop per rod shouldn't hurt anything.

[WTFockewulf 21]

Hi GR5,

thanks for the reply. In removing you mean remove and clean and reinstall and not permanently remove, right?

I will give that a shot this weekend.

[markusmaker 2]

Hi guys,

I am also affected by the 10mm z-axis bed drop phenomena.

See here:

https://www.dropbox.com/s/um6mi7pna0srswc/IMG_5361.JPG?dl=0

Very often (but not always) - I get more or less visible gaps at nearly the same height. I already had sent the printer to iGo3D (after about 9 weeks of email conversation before), but they did not really change anything (firmware update, z-axis lubrication and z-axis current) and delivered me a print that apparently was successful (coincidence?). I then thought it was a underextrusion issue. But this can be excluded for now I think - I did plenty of tests, even with loose filament which has zero friction, sitting at the printer the whole time that nothing is tangled or stuck.

I still think that the z-axis is faulty because it is a bit twisted. See the following video:

https://www.dropbox.com/s/qcdv1oopex9qitv/Achse-verbogen.mp4?dl=0

See a sample timelapse here where you can see when the filament is suddenly not sticking anymore for 1-2 layers:

https://www.dropbox.com/s/wz57ypxfeg6yw4g/608_nut_20151005214319.mpg?dl=0

Can anybody please make a video from his UM2 z-axis if it is also this kind of deviation on the top of the axis?

[WTFockewulf 21]

Hey all,

I had some time to tinker with the printer this weekend and I have found some interesting things.

1. With Cura the problem with the "missing" Layer at 18mm persists, no matter what settings I use.

2. The bed has a tight spot at 18mm. You can feel it when you move the building plate up and down.

3. my Z spindle moves slightly sideways too, just like yours, Markus.

I then decided to override the system settings and do some printing with Simplify3D. I am currently printing a model aircraft and the wings are very fragile with 1 perimeter (0,4mm). Needless to say, they have to be perfect so the wing doesnt break in flight. The first prints had the same problem with the standard settings and the wing parts were useless. I then upped the z Axis speed to 60mm/s and voilá, the prints come out perfectly! It seems that the high acceleration and speed "overcomes" the tight spot and the effect vanishes. I have reported this to igo3D and we will see what the answer is.

Edited November 23, 2015 by Guest

[markusmaker 2]

I then upped the z Axis speed to 60mm/s and voilá, the prints come out perfectly! It seems that the high acceleration and speed "overcomes" the tight spot and the effect vanishes. I have reported this to igo3D and we will see what the answer is.

 

You mean the setting on Other tab in Simplify3D "Z Axis Movement Speed" from 16,7 to 60?

Thanks.

[gr5 2,167]

That wobbly Z looks fine in the first video. In the second video i don't see the Z movement change for the "bad" layer but's really hard to tell even stepping single frames.

Did you check to see if the Z stage is hitting anything? Particularly the spool holder sticks through the back of the printer and the Z stage sometimes rubs against that.

I would send it back to igo3d again or since they didn't find the problem have them just send you completely new Z rods, Z bearings, Z nut, Z screw and Z motor (I don't think they can send you the z screw without sending the motor also).

[markusmaker 2]

That wobbly Z looks fine in the first video.  In the second video i don't see the Z movement change for the "bad" layer but's really hard to tell even stepping single frames.

Did you check to see if the Z stage is hitting anything?  Particularly the spool holder sticks through the back of the printer and the Z stage sometimes rubs against that.

I would send it back to igo3d again or since they didn't find the problem have them just send you completely new Z rods, Z bearings, Z nut, Z screw and Z motor (I don't think they can send you the z screw without sending the motor also).

 

Ok, I thought that wobbly appearance can cause extra friction which leads to bed drop. The spooler is still far away from the bed when this happens. but I also checked this :-)

As igo3d was not very cooperative you think they will send me the Z-Stuff for free (I'm still in the guarantee time). Any helpful tuts or resources to disassemble and reassemble the Z-Stuff ?

Thanks!

[gr5 2,167]

They might not be cooperative the first time but just keep bugging them. Eventually they should realize the screwed up.

[WTFockewulf 21]

Hi Markus,

yep, thats the one. Default 16,7mm/s. Just checked again, I changed it to 30mm/s not 60mm/s.

Try that and it should be OK.

Update on my case. I explained this behavior to igo3d and they want me to send the printer back. It is on its way there now.

I will keep you posted.

[markusmaker 2]

They might not be cooperative the first time but just keep bugging them.  Eventually they should realize the screwed up.

 

I contacted UM they contacted iGo3D - we will see...

[markusmaker 2]

Hi Markus,

yep, thats the one. Default 16,7mm/s. Just checked again, I changed it to 30mm/s not 60mm/s.

Try that and it should be OK.

Update on my case. I explained this behavior to igo3d and they want me to send the printer back. It is on its way there now.

I will keep you posted.

 

Thanks. But I wonder if this has any implication for the hardware? The help tooltip says

"Rapid movement speed for Z-axis when machine is not printing, should match actual Z-axis movement speed between layers for accurate print times"