Hi, so basically i would like to create a solid that follows the inside and outside curvature of a cylinder. You can imagine this solid as a curved stringer for a staircase. I’m trying but it seems to be impossible with my very limited skillset to come up with a solution. I have already tried to create this shape from scratch but i can’t create the needed faces since everything is curved. Is there anyone that can help me out? thanks for any advice.
First, let’s clean up your profile. There is no SketchUp Classic. What version are you using? Is it desktop or web? Pro or Studio? Is there a reason you are not using the 2026 version? The correct information is needed to provide the correct answer to your question. This is due to the differences in the versions available.
Ooops yeah sorry it is indeed the SketchUp Pro 2025 version. I’m not using the 2026 version because i didn’t need the new features yet for my regular use of sketchup to draw anything woodworking related and the 2025 version is running fine on my oldish work laptop.
This is harder than it looks. I’m too many years from my last geometry class to be sure, but it seems like the outer curve of the spiral won’t be a circular or elliptical arc. it will be a parabola or something.
The easiest way to approach a solution would be to draw radial lines from each segment point of the outer circle to the center, and then mash push pull many many times by the rise factor. Arc segment length * (7/11) for stairs as an example. You’ll end up with a stepped surface that follows the correct curve. Then you can blend that into facets if you want. It’s sketchup so at the end of the day it will be facets regardless.
One method
Thanks, that’s a fast and uncomplicated solution.