Standard pla odd print issue

Hi, I’m having an issue printing 3dpc standard dark blue pla. Looks like some kind of ringing?? and tiny tiny holes. The whole model has these imperfections.
Printing on a stock prusa mk3s+ with prusa slicer
0.4nozzle,0.2 layer height
3 perimeters
20% infill
seam position: nearest
retraction length 0.8mm, retraction speed 35mm/s
extrusion multiplier: 0.98

Model is a barn birdhouse by PA1 Maker on Patreon

Any tips are greatly appreciated!

Thanks, Alex

edit: I guess I should note that my printer is in an enclosure on foam/concrete slab and the enclosure is on wheels

Check the tension on the belts. It is some kind of ringing but producing that repeating pattern it does not look like regular ringing. Is everything tight? belts adjusted not too much or loose.

Are you getting that with other filaments too? it could be inconsistent size, or extrusion being out. have you calibrated the extrusion multiplier?

Thanks for the reply kite. The belts do feel somewhat loose. I’m going to tighten them then do the calibration and I will report back in!

The only other thought I could add would be to try to move the seams to the corner, Just to verify it’s not the layer change causing it.

So, when I look at your enclosure to my eye it looks like it’s made from an IKEA cabinet of some sort. Which means the panels aren’t going to be very rigid. Those little casters also look like they have a lot of potential play in them.

That means the possible energy transfer from the concrete block to the enclosure is going to get very complex, very quickly. The foam should absorb a lot of that, of course, but not all of it, and while the other block will act to keep the enclosure from starting to move, it will also act to keep the enclosure moving once it does start.

So, it seems to me that one possible source might be the enclosure vibrating? If you managed to hit a harmonic frequency it could end up with a really regular oscillation.

By no means am I certain of this, but it feels like a fairly easy thing to check on - take the printer out of the enclosure and see what effect this has.

So Ive tightened the belts and did a belts check and they seem to be fine.
Printed out a few calibration cubes and got that looking good.
Printed a ringing test and it was still really bad so I start tweaking acceleration and jerk and this is my best result so far. It looks much better but im sure it could be improved even further.

I will try taking it out of the enclosure and printing another ringing test…I hope its not the enclosure :open_mouth: …perhaps i should take the casters off?

it is looking pretty good up to this point, I hope it’s not the enclosure either but you can adjust the ACC and jerk to mitigate it if you need to, I would use it in the environment you will ordinarily use it in.

Ive printed a ringing test with the adjusted acceleration and jerk settings outside of the enclosure on the floor and im seeing a very slight improvement. Slight but its somehting. Wondering what I could do to my enclosure to make it more sturdy…maybe just removing the wheels/casters? Or those rubber feet used under washer/dryers maybe?
I’d really like to use this enclosure as ive already sunk tons of cash into it and I have nowhere else to put my printers.

I’d take the castors off. There is a moment where you will need to decide cost/ effort/ gain at how much cost and effort is it worth for what gain. I personalty decided with my prusa to keep the speed as prusa sets because I print more functional prints and printing slower and getting slightly better quality wasn’t worth it for me.

Try cutting speed in half and see what happens. It might resolve many of the issues then you can decide how much time is worth how much ‘noise’ on the print. some have found liner rails make a some difference but it is a fair bit of effort.

1 Like

Okay, I want to be clear that I’m not at all an expert on this, I’m just working with some high school physics from 30 years ago. So my ideas are just ideas and should be investigated before any major investment is made.

If taking the printer out of the enclosure reduced the ringing, then the goal is to reduced the movement of the enclosure. That movement could be coming from several places.

The castors are certainly one obvious place. Castors revolve in 2 axes, and cheap or old castors will usually have a lot of play around each axle. Taking the castors off would eliminate all of that. But I don’t know how important it is that you be able to move the enclosure around.

If taking the castors completely off isn’t ideal, try immobilising them instead. remember you’re not just trying to freeze the motion off the wheel, but also the pivot.

The frame of the enclosure might also be flexing and vibrating, inducing more motion that’s causing ringing. Removing the castors might help with that, as the frame would presumably be sitting on the floor and thus have less space to flex in.

Replacing the body panels of the enclosure is probably cost-prohibitive, so we’ll set that to one side.

Having additional bracing might help. I don’t know, I’m just guessing.

Finally, the enclosure is moving because of energy transfer. Which means that either the printer is managing to get that cement block moving and then the block is transferring energy into the enclosure, or else the cement block isn’t absorbing enough energy in the first place. (I’m sure I’m screwing up the engineering here.) Anyway, the next experiment I’d consider is changing that mass. Does the ringing get worse if you take out the cement block? If it does, does it improve if you add another block, either under the printer itself or just as ballast in the enclosure? What happens if you take out the foam? Things like that.

And, of course, all of the energy is originating in the bed moving back and forth, so of course slowing down the Y-axis speeds ought to reduce the ringing. No, I don’t have any idea if one can change just Y-axis speeds without changing X-axis, nor do I know if you’d want to. But, basically, for anything where final appearance matters, you might consider just slowing the printer down.

At the end of the day, science is trial and error, plus taking notes. Time to do some science!

1 Like

a couple of thoughts I had to deal with the caster issue

or this type of Caster, We use them pretty regularly on the larger printers

I know you can get them cheaper but just wanted a quick pic of one to show you.

1 Like

Update! I’m installing some feet on my enclosure that I designed and printed out of petg and tpu. I’ll do some test prints and update on print quality afterwards

that’s an awesome idea, should help to dampen a lot.


Question - have you ever put your printer on the floor of your basement (ie on grade) and run prints from here to compare against what is produced by the printer in the cabinet? I think its been suggested, but I don’t see you explicitly commenting on doing this.

I know it’s unlikely, but before you start doing more modifications to your cabinet (and buying more and more expensive castors), I think it would be worthwhile to make sure that printing in your cabinet is causing problems.

Did you try printing slower? it might not be ringing at all.

I installed feet ont he enclosure and printed this ringing test…

then i printed the same test outside of the enclosure on the floor…

both are printed at 40mm/s

I dont see a difference in either but they look much better than the blue birdhouse I printed.

I think the main issue for the weird ‘ringing’ was because the enclosure was on cheap castors.

I’m going to print another birdhouse, should be done tomorrow then I will post some pictures here!

1 Like

Here are my results… kind of looks the same as the blue one. Not really sure if this is ringing now…

Have you tried a diferent slicer?

I have not no. I will try that today. Thanks for the suggestion