Asura Curved Surface Quality

#1

I am having trouble with a print with a very large flat curve. When I print the part the curve is not smooth and is made up of a bunch of steps. I dont see this in the model or meshmixer, but if I import the STL into Asura 2.2.2 I see those steps. Then when I print the part I also see the same steps that I see in Asura. What can I do to fix this?

Asura 2.2.2
Asura

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#2

Asura is rendering the object as it is. I think you have to change output setting to keep more polygons from your software @matt3o do you know meshmixer export settings?

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#3

meshmixer exports the model as it is, you need to create the model at a higher resolution to begin with

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#4

The part was modeled in Fusion 360. Here is the STL export settings from Fusion 360 that I was using.

Fusion_STL_Export_Settings

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#5

I have also noticed curved things even with ultra high poly counts seem to still feel rough when printed perpendicular to the built plate. I think the printer is replicating even the smallest facets.

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#6

It’s a common problem with vector based drawing programs like sketchup and fusion360. You can’t really draw circles. You can increase the segment count to make the thing look more like a circle. In sketchup you do it by highlighting the circle and hitting control and + at the same time. You’re supposed to be able to type in the number of segments, but I haven’t been able to make that work. I’ve no idea how to do it in fusion360 - might have to google it.

You aren’t going to be able to make a true circle in either program, but you can get it close enough that you shouldn’t be able to tell. To make it “as good as possible” on the MOAI you’d use 5,000 segments on a 10cm circumference circle. That would make each segment 20um which is the finest MOAI can print I believe. I’m sure it would appear to be a perfect circle well before you got to that many segments though.

At normal zoom, a 10cm circle with only 100 segments looks more like a circle than a bunch of lines to my eyes.

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#7

It’s called tessellation.
Fusion 360 draws perfectly smooth curves and surfaces but in order to use them we have to turn them into a poly mesh. I try to export with far more than 100 facets on a 1CM cylinder if possible.
What I’ve observed is that the resolution of this printer may be so high, you can still feel the facets of you don’t tilt models just a bit to help get the smoothing effects I assume are a result of the laser light blearing through the resin. That’s why in many cases a 100 micron print looks as good as a 50 or less except on more shallow angle surfaces.

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