Layer shift same layer two attempts in a row.

The new for 2016 Rostock MAX v3!
jevs
Prints-a-lot
Posts: 22
Joined: Sun Dec 17, 2017 1:30 pm

Layer shift same layer two attempts in a row.

Postby jevs » Thu Jan 18, 2018 8:25 am

I got a layer shift for the first time. It occurred about 10 layers in. I thought it was something I did on the computer since I was printing from USB and I was messing with another printer via USB at the same time, but I printed from the SD card and it did the same thing on the same layer.
I printed the same thing the night before with no issues, except this time I tried to print 32 parts instead of 16. This put the printing farther out to the edges of the bed than I have printed so far. I believe the layer shift may be because I am printing more at the edges of the bed and maybe on that 11th layer it just goes a tiny bit farther out and has a mechanical issue, but I cannot say for sure.
I have not checked anything yet, but plan to look at it tonight. Suggestions?

jevs
Prints-a-lot
Posts: 22
Joined: Sun Dec 17, 2017 1:30 pm

Re: Layer shift same layer two attempts in a row.

Postby jevs » Thu Jan 18, 2018 7:01 pm

I may have figured this out since I had time to think about it and look at the prints that I left on the bed. It seem there is a part of the print that starts to curl up as it builds up the overhang. I think when I print 16 , they stay hot enough that the nozzle just pushes them down on the next pass. I think when I went to 32 parts that they may have hardened enough to get the nozzle stuck until it could work its way through causing the shift.

Anwyay. I need to check the belt tension and stuff anyway since I never did. I will double check that and then either go back to printing 16 or see if I can somehow stop the ABS from curling on the small feature overhang.

jevs
Prints-a-lot
Posts: 22
Joined: Sun Dec 17, 2017 1:30 pm

Re: Layer shift same layer two attempts in a row.

Postby jevs » Fri Jan 19, 2018 1:09 am

3rd attempt at 16 parts that I successfully printed before. I added support on the overhang part. It did the same thing and shifted on the same layer (about layer 10-11). I might try to print just one tommorow night and see what happens.

I did pull on the cheapskate carriers to see if the belt slipped on any axis, and it did not seem to. Seems odd that it would shift on the same layer each time and even using a different setup for the parts......

User avatar
Jimustanguitar
ULTIMATE 3D JEDDI
Posts: 2631
Joined: Sun Mar 31, 2013 1:35 am
Location: Notre Dame area
Contact:

Re: Layer shift same layer two attempts in a row.

Postby Jimustanguitar » Fri Jan 19, 2018 8:17 am

Can you share a picture or two? If you don't have a rolling resistance or mechanical smoking gun, my guess is that you're overextruding, and the print head is hitting the previous layer hard enough to knock it out of whack.

jevs
Prints-a-lot
Posts: 22
Joined: Sun Dec 17, 2017 1:30 pm

Re: Layer shift same layer two attempts in a row.

Postby jevs » Fri Jan 19, 2018 8:55 am

I printed a batch of these in a lot of 16 and they came out great. The next round I wanted to make a larger batch and that is when this layer shift started. 2 batches of 32 both layer shifted about the same amount on the same layer. Then I redid a batch of 16 like the good batch shown here and it layer shifted in the same place also.
Pictures of a layer shifted part attached. This last time I even added support under the part that was curling a little which seemed to keep it flatter. It still layer shifted.
I am going to try to print just one part next time I get a chance and see what happens. I did review my settings in S3D and it seemed okay.
Attachments
Good Ones2.jpg
Good Ones.jpg
20180119_001032.jpg
20180119_001023.jpg
20180119_001016.jpg
20180119_001011.jpg

jevs
Prints-a-lot
Posts: 22
Joined: Sun Dec 17, 2017 1:30 pm

Re: Layer shift same layer two attempts in a row.

Postby jevs » Sat Jan 20, 2018 2:40 pm

I printed one part and it came out nice. So, I figure I would setup an 8 part print. It layer shifted again. I am not sure what to do now except tear the printer apart and try to find something wrong.

jevs
Prints-a-lot
Posts: 22
Joined: Sun Dec 17, 2017 1:30 pm

Re: Layer shift same layer two attempts in a row.

Postby jevs » Sat Jan 20, 2018 5:56 pm

I pulled the top of my printer to inspect things. So far I found that my printer has dampers and they are causing the motors to sit cocked. One is worse than the others. I am going to have to remove the dampers. Unfortunately, this may be louder, but it may make better prints and maybe stop a belt slip in the case of the worst one.

viewtopic.php?f=100&t=2608&p=107495#p107495

I think I may flip the belts too just in case any teeth are worn.

Two of my plastic arm springs also broke on me trying to remove them. I have a mod that replaces the broken section with a metal spring that i am going to try that uses the original balls.

jevs
Prints-a-lot
Posts: 22
Joined: Sun Dec 17, 2017 1:30 pm

Re: Layer shift same layer two attempts in a row.

Postby jevs » Sun Jan 21, 2018 3:54 am

Okay, after all of this, I think I have my machine very well tuned and aligned mechanically.
It is a little louder without the dampers, but I think it is better off without them since my pulleys are not cocked due to the dampers flex.

I did tighten the belts a little more than they were and I flipped them. I did not see anything wrong with teeth on the belts though.

I tried to print some more of these parts and I got the curling again and sure enough layers shifting. I did some tweaks to my settings to run the fans at certain times during the print (yeah ABS). This seems to have helped with the curling, and there are no shifting layers when the curls are not there.

I did find out that that this bed (onyx Rev 8) cannot keep up on its temp while running the fans when trying to maintain heat for ABS. At some points with the fans only at 50% on the lower layers, it can only hold 80 degrees or a little less. The first time I set it to 95 for the whole print and the print stopped and shut off the extruder and the the heaters at some point. There seems to be a check in the firmware and if the bed is too far off, I guess it thinks it is not working and shuts down.

Anyway, I am at layer 26 on a batch of 16 with no layer shift now that those curls aren't in the way of the nozzle.

I needed a good excuse to go through and check the belts and adjust everything anyway. I will do some more printing to see if getting rid of the dampers helps the print quality. It might not make much difference, but at least I know my motors are straight.


Return to “Rostock MAX v3”

Who is online

Users browsing this forum: No registered users and 1 guest