Forum

 

Notifications
Clear all

Banding problem


tangerine
(@tangerine)
Trusted Member Registered
Joined: 7 months ago
Posts: 82
Topic starter  

Has anybody any idea what causes the kind of banding which can be seen in the enclosed photo?

It looks like the whole print had been offset slightly and then returned to its original position again 1cm later. It's difficult to show in a photo but there seems to have been four shifts in total.

If it was just a matter of aesthetics, I'd get the sandpaper out and not worry about it but with this print, it actually stops it working properly because the channel that batteries run through gets narrow enough to stop them from running through.

I had a good look at the previous print I did which was basically just a cylinder and there was no banding whatsoever and the print I am currently running looks fine too. I looked at the file in Cura just in case something weird happened in the slicing but all seems to be okay.

It was a 12 hour print so I don't feel like running it again just as a test.

Any ideas? 


ReplyQuote
Topic Tags
Matthew
(@mbbrewerca)
Active Member Contributor
Joined: 3 months ago
Posts: 9
 

Does it happen on the same height during different prints?  It could be that the belt might be loose on one of your axis.  When I hit that type of problem, I tend to print a test shape with just a single wall to see if I can narrow it down without having to do a major print.


ReplyQuote
kevin
(@kevin)
Noble Member Registered
Joined: 7 months ago
Posts: 1045
 

@tangerine What is your printing speed? Your picture reminds me of my experience. I used 300% print speed and the result is like what you got. Due to the force of inertia, the printer shakes badly.


ReplyQuote
tangerine
(@tangerine)
Trusted Member Registered
Joined: 7 months ago
Posts: 82
Topic starter  

@mbbrewerca As I mentioned, it didn't do it on the previous or subsequent prints but the subsequent print wasn't very high.

I just checked the belts. I don't really know what the correct tension feels like but one length feels very slightly less tight than the others. I don't see anything in the manual about how to tighten belts so I will proceed with caution.


ReplyQuote
tangerine
(@tangerine)
Trusted Member Registered
Joined: 7 months ago
Posts: 82
Topic starter  

@kevin I am using a Cura profile which was created using the process I found elsewhere and posted in another thread. When I first used it, I noticed that the default print speed in that profile is 150% and I have never changed it.


ReplyQuote
tangerine
(@tangerine)
Trusted Member Registered
Joined: 7 months ago
Posts: 82
Topic starter  

I tried a test print and there does not seem to have been a problem - see enclosed photo. I forgot that I had ironing on which accounts for the messy top corners.

By the way, I should probably have pointed out (though it was also probably obvious) that the first photo I posted was with the print at 90º in order to make the banding more visible in the available light.


ReplyQuote
kevin
(@kevin)
Noble Member Registered
Joined: 7 months ago
Posts: 1045
 

@tangerine This print is nice, so I think you have to check your STL file. Is he an entity without any sheet body? File errors also cause print issues.


ReplyQuote
tangerine
(@tangerine)
Trusted Member Registered
Joined: 7 months ago
Posts: 82
Topic starter  

I downloaded it off Thingiverse. I've looked at it and can't see anything wrong with it and nobody has said anything in the comments about this kind of problem. Anyway, it was the 12 AA version of this:

https://www.thingiverse.com/thing:3447866

I'm beginning to think that I might have knocked the desk the printer is on or something. Amyway, I've just printed some squash ball feet to see if I can mitigate anything like tha.


ReplyQuote
Matthew
(@mbbrewerca)
Active Member Contributor
Joined: 3 months ago
Posts: 9
 
Posted by: @tangerine

As I mentioned, it didn't do it on the previous or subsequent prints but the subsequent print wasn't very high.

Sorry that I missed that part. Like you identified, it could very well be that the desk was bumped. The best bet would be to give it another try.  If you'd like to determine if it's the file itself, perhaps you could drop the model down in your slicer software so that the part that went wrong was just above the bed, then print until you get past the part that went wrong.  This can let you see if it's the file or the printer.

As for the belts, which one seemed a little looser than the other(s)? 


ReplyQuote
tangerine
(@tangerine)
Trusted Member Registered
Joined: 7 months ago
Posts: 82
Topic starter  

I fitted the squash ball feet and did another test print which was pretty much identical to the first test print I posted - so had little or no effect. However, the printer did seem to be noticeably quieter.


ReplyQuote
tangerine
(@tangerine)
Trusted Member Registered
Joined: 7 months ago
Posts: 82
Topic starter  

@mbbrewerca It was the top belt (I'm not sure if it is X or Y but I'm printing right now so don't want to interfere) but I think that the difference is hardly noticeable, to be honest and probably nothing to do with it.

I have given up on that print and gone a different route for my battery storage. I tried sanding down all the errors and a regular battery went down the chute quite easily but then discovered that all my rechargeable AA batteries have a very slightly larger diameter than all the regular AAs and the rechargeable ones just won't fit without getting stuck. I realised that I could keep going forever trying to get it to work and at 12 hours per print, probably wouldn't be worth the hassle.

That all said, I forgot to mention something which I hadn't thought relevant. This was the first print (after many dozens, I think) that I had not been there when it finished (it ran overnight) and by the time I checked it, the build plate was cold and the print was detached without me having to lever it off. I thought nothing of it other than it must have happened due to differential shrinkage during cooling but I suppose it is possible that the print moved slightly. I only say possible because there were two pieces in the print and they both showed similar, though not identical, signs of banding.

Anyway, everything seems to be okay now.


ReplyQuote
Matthew
(@mbbrewerca)
Active Member Contributor
Joined: 3 months ago
Posts: 9
 

Thanks for the update! I'm glad to hear that things seem to be ok now.  As for the print lifting off after the bed cools, that's a great feature of some of the printer beds.  I have the Creality glass bed and things just pop right off after it cools.  Makes life so much easier!


ReplyQuote
tangerine
(@tangerine)
Trusted Member Registered
Joined: 7 months ago
Posts: 82
Topic starter  

@mbbrewerca Yes, it is much easier but who can wait another ten minutes after a 12 hour print?! ? 

I'm in there with a hammer and chisel as soon as the print head returns to its home position!

Only kidding, by the way.


Matthew liked
ReplyQuote