Banding and visible layers with specific model
For some reason, when I print the attached model, it has terrible banding and layer lines as you can see in the photo. I have printed a ton of test cubes, Benchy's, and the Extruder Multiplier calibration cube multiple times with the same filament and they look good.
It seems like anytime I have a model that is almost all perimeter and really narrow like this, it causes problems. I've gone through the usual fixes including: checking and tightening belts (using the printed gauge), checking for loose axis, greasing bearings, checking for smooth sliding X and Y, redoing calibration, cold pulls.
Like I said, given that the printer is capable of printing many models with minimal banding, my guess is that this is just somehow challenging.
I was wonder if there's a trick to printing things like this or if there's something up with my printer?
RE: Banding and visible layers with specific model
Well, it won't let me attach the STL or 3MF files for some reason so here's a link to the model:
https://www.thingiverse.com/thing:2764274
RE: Banding and visible layers with specific model
Save your current 3MF project file, zip it up, and attach it to a reply here so we can see your part & settings and give better recommendations. Attachments must be zipped.
You might want to do a quick search on the term "buldge" (yes, it's dumb) to see if any of those discussions capture your issue.
RE: Banding and visible layers with specific model
Save your current 3MF project file, zip it up, and attach it to a reply here so we can see your part & settings and give better recommendations. Attachments must be zipped.
You might want to do a quick search on the term "buldge" (yes, it's dumb) to see if any of those discussions capture your issue.
Thanks, I'll check that out.
What's confusing to me is that I generally get good prints without any real banding issues. Vase mode prints look really good, even with that same filament.
Attaching the 3mf zip.
RE: Banding and visible layers with specific model
[...] What's confusing to me is that I generally get good prints without any real banding issues. Vase mode prints look really good, even with that same filament.
Keep in mind, those are sub-mm variations. That lighting really highlights the issue. A matte filament might hide most of the visible problems.
See if the variations correspond to any internal changes in the print. Transitions from sparse to solid infill or perimeters to gap infill commonly cause minute but visible external wall variations.
I always recommend simply slowing down as a quick test. Dial speeds back 50% with the front knob mid-print and see if everything evens out. If so, you know slicer solutions will work. If not, you don't want to overlook physical variations. Also, calibrate your extrusion multiplier for each filament. Very slight mismatches between slicer settings and the real world can result in minute over extrusion which will show up as the internal print structure changes.
If the basics don't give satisfactory results, you might have to do a bit of settings twiddling. Adjusting perimeter extrusion widths will frequently help reduce variations.
RE: Banding and visible layers with specific model
@bobstro
Thanks. I did checkout the articles you mentioned on bulging. I do think these variations are showing up with a bit of a pattern around the spacing of those tabs that stick out and require the supports.
As you can see in the 3MF, the perimeter speeds are dialed back to 20mm/s which is pretty slow already. I do get a slightly different result if I rotate the part 90 degrees so that the long axis is on the Y. I know there's the infamous "602" issue that causes this type of inconsistent extrusion. I have also done the extrusion multiplier calibration for this filament and get around 1.04 as the ideal value. It didn't seem to make too much difference on this print though.
I think what I will do is remove the parts that require supports and leave just the tall thin section that is all perimeters. My theory is that when the printer switches to doing the supports (which are printed at a fairly high speed) and then back to the perimeters, there's some minor variation when it returns (probably a little mechanical play, as you said it's sub-mm really). If it can focus on just tracing perimeters it should be cleaner and confirm my theory (of course it will not be a usable part).
Vase mode is the epitome of this theory and prints nice and clean for me, so clearly the steppers and filament can make a nice perimeter under the right conditions.
RE: Banding and visible layers with specific model
Ah, interesting that you see a change with rotation. The Y axis moves a lot more weight, so will be more prone to ringing defects. Is it better in X or Y directions?
You could try reducing acceleration and/or jerk in one or both axis. No matter how slow your speeds, the amount of acceleration and jerk remain the same. If adjusting speeds won't help, perhaps rate of change will?
RE: Banding and visible layers with specific model
@bobstro
It prints better with the long side parallel to the Y axis. This makes sense as you say b/c the precision of the X axis is probably higher than the Y axis give it has less mass to move.
I modified the part to remove all the support requirements and it printed significantly better. It's hard to tell in the photo, but looking directly there is no visible banding vs. the original.
I might try lowering the accelerations and see if that makes any difference. Also, I'll try slicing in Cura just to see if the defaults there might produce a different effect. It's really just a learning process for me at this point as even the ugly one works for fixing my Xbox controller 😀
RE: Banding and visible layers with specific model
Looking at how much better this model prints without the omitted components would indicate that perhaps at least some of your problems are related to the infamous "buldge" issue.
RE: Banding and visible layers with specific model
Looking at how much better this model prints without the omitted components would indicate that perhaps at least some of your problems are related to the infamous "buldge" issue.
Yeah, you are probably right. I had a friend of mine print the original model on his Mini+. I'm curious if it looks different in any way.
I'll dig into the "buldge" and try some of the fixes there to see what that does for it.
RE: Banding and visible layers with specific model