Petg post processing sanding

I have mechanical parts that are printed and slide on each other and the layer lines and small imperfections are an issue I know you can sand and polish it which is the way I want to go but I don’t want to spend a lot of money on a bunch of grits of sand paper and polishing compounds and such. Any recommendations?


If the layer lines are an issue, I would suggest first lowering the layer height, it will increase your print time but the operation will be better. Another option is to increase the tolerances for the slider.

A quick thought though, please forgive me if I sound pedantic it’s not meant that way in the least.

If you print a 20mm calibration cube is it actually coming out at 20 mm +/-. It could be that one of your axes needs an adjustment to be perfect on size, If the X-axis prints 19.8mm and Y prints 20.25 then all of your tolerance on your engineering model would be gone. The second part to that is some filaments have a shrinkage factor and you may have to take that into account during the design process. Lastly have a double check on your belts, sometimes if a belt is too loose it can cause loss of accuracy.

Just a couple of my thoughts about similar situations.

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Thanks I will check my belts I never thought that would be something that would cause that issue and I’ve accounted for the shrinkage but thanks for that. Also my layer height is 0.20 should it be smaller? If so how much I’m using a 0.4 nozzle.

you can lower it to the point where you are happy with the result, Just remember if you go from .2 to .15 and your print took 1 day, you are now looking at it taking 1/4 as long again, so about 30 Hrs instead of 24. All other things being equal of course.

I would suspect however that its maybe a belt just a little loose of you could increase the tolerance just a “smidge”

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I haven’t played with it before but there is a setting in Cura where you can make your infill twice the layer height. That way it only prints infill every second layer and can speed up print time when using a finer wall layer height.

Not sure if that’s particularly helpful here but I feel like it’s a lesser known setting

Chasing a different track. There are a few high yield epoxy coatings that will smooth and fill all the layer lines and add strengh to the surface. Products like XTC 3d by smooth on.

I routinely ream out holes on printed parts to get the right dimension for that hole but I can say that turning the outside diam. on a lathe does not work at all. Shredded plastic everywhere.

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I don’t know that thanks.