Creating smoother curves?


I’m a long time user of SketchUp and know my way around it quite well. I’ve recently purchased an extremely high detail 3D printer which I use to mostly print 1/87th scale model trains but i’m having an issue which I think may be SketchUp’s fault…

As we all know, SketchUp doesn’t like working under 1mm. So for building these small models, I first build them in meters and then scale down to mm.
The issue is that even when i’ve added as many sides as possible to a curved surface, it’s still showing lines when 3d printed and I know the printer isn’t at fault. It almost seems like SketchUp’s resolution isn’t high enough.
Is there any way to make a surface truly round?
Here’s a photo of a printed model that’s been hit with primer. You can see faces on almost all curved surfaces but it almost looks like a low resolution issue.

Is there any plug-ins that can help or maybe even upgrading to SketchUp pro? (I’ve only ever used the free version).

Thanks, Kyle.


Honestly, that does not look like na issue with the file, but the resolution of your print. Are you printing at the smallest layer height you can?

At this point, were it my print, I would start sanding or filling to reduce the print lines…


I would agree with Aaron. Especially since you can see the same horizontal lines in the “flat” side of the cab and the box between the cab and the boiler.


If the problem was with the round part segment count, here is where we should be seeing it:
The horizontal streaking is from the printer layers.

Note that whatever geometrical method your software uses to create models, when you export the file to STL for printing, it will be converted into a collection of flat faces.

The resolution does in fact look quite fantastic with the rivets etc, remembering that we are dealing with a quite small model. I had a HO scale railway as a kid, and if I rememnber right, a locomotive like that might be about
10 cm (4") long.



thank you for input i have trouble downloading sketch up as i am designer and find it difficult to down load sketch up iam looking for a good sight where i design on that ids easy to down load on


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