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I've developed an oddity lately. None of my round perimeters are closing up anymore but square perimeters are just fine. It doesn't seem to be slicer related (at least I don't think it is). I've printed this part 3 times, one using S3D v2.2.0, one using S3D 2.1.2 and finally one using MaterControl v1.2.0. All suffer from the same problem. I'm using a .35mm nozzle. I've played with several settings in my slicers (extrusion width, nozzle size, infill overlap, extrusion multiplier, filament diameter, speed, etc) and I cannot seem to get rid of it. MatterControl prints round perimeters slightly better but the problem still exists. As for hardware, belts seem tight, Cheapskates aren't loose (perhaps I have them too tight if anything) and using Trick Laser carbon fiber arms with zero lash straps (no evident play in the arms). Rostock Max v2 with stock hotend. I have this problem on all outside round perimeters and perimeters around holes. Goofy!

Anyone have any advice for me?

So what would happen if you made the same size part with the same settings except a square outside and circular inside? It would be interesting to see if the inner circle had the same problems.

0110-m-p wrote:So what would happen if you made the same size part with the same settings except a square outside and circular inside? It would be interesting to see if the inner circle had the same problems.

It happens to any round perimeter...so, the same thing would happen. I've already confirmed that.

It's hard to tell, but it does look a bit like you are under-extruding. When zoomed in it looks like there are gaps between each row of material on the top layer. So increasing your extrusion multiplier didn't help at all?

I'm actually trying that right now...and I'm not being gentle with it. I've cranked up my extrusion multiplier pretty high just to see what happens. If good then I will work downward from there.

In the infill tab in S3d bump your outline overlap up, I have mine set to 40% generally.

Update to the latest S3d, you can also try the thin wall behavior gap fill as well.

The thin wall problem shouldn't be an issue here. I'd suspect under extrusion, caused by the normal things:

-Too low extrusion multiplier
-Too low hotend temp
-Nozzle issues (partially clogged, improper geometry, etc)

Judging by that top layer its probably one of those things. They are rated in order from most likely to least.

On the screen I'm using to view your image, I can't make out enough detail to weigh in on whether on not under extrusion is the culprit.

I can see the perimeter gap. I'd try raising the hot end temp. Also, in Matter Control there is a setting under infill that is something like "overlap" or such. Basically, how far into the perimeter the infill move is "pushed" to anchor it. With no or insufficient overlap, the reversal of travel tends to pull infill material away from the perimeter. That may or may not be a factor here. The perimeter gap looks pretty even, and overlap or lack of it usually appears related to movement axis.

Well, it took all day but I think I have it whipped into shape again. My round perimeters are closing up nicely and my final top layer has even improved. I pretty much just started from scratch in my slicer (S3D). Started with single wall calibration cubes, moved onto full calibration cubes and then onto calibration cylinders. I've tweaked nozzle size, extrusion multiplier, and extrusion width mainly. Thanks for the tips everyone. Things are looking great!

Material: ABS @ 230°C, .18mm layer height

heathenx wrote:Started with single wall calibration cubes, moved onto full calibration cubes and then onto calibration cylinders.

How do you know where to start, what models to start with, etc.? Is it something you've just built from personal experience, or are you following a guide somewhere?

Nice looking prints now, great job in getting it tuned in!

BenTheRighteous wrote:

heathenx wrote:Started with single wall calibration cubes, moved onto full calibration cubes and then onto calibration cylinders.

How do you know where to start, what models to start with, etc.? Is it something you've just built from personal experience, or are you following a guide somewhere?

Experience and things I've learned from others, I'm afraid. I have several calibration objects that I've modeled and downloaded.