Subtracting a solid changes the surface skin made by Curviloft

I am modeling a chair seat and making changes to its shape using the solids tool (Subtract). When I do so, the surface skin of the chair seat changes, so it is no longer a solid. The second object, used to intersect the chair seat, does NOT intersect the surface of the seat. Regardless, the surface is changed, and his requires me to repair the surface skin to make the seat a solid once again. This is very time consuming, and I’m wondering if there is something I am doing wrong that is causing the surface skin to have holes in it, when there were no holes before.

Not knowing other details, I would guess that scaling the object up 10 or 100 times would work. You can also use the Dave Method.

yes, upscaling would work I think. The issue with your chair is that Curviloft created some really tiny faces, and when using the solid tools, these tiny faces are seen as too small by SU and they disappear.

if scaling up your project fixe it, then it is an issue with tiny faces.

(then you can scale down the finished project. or use Dave method with components)

I will try scaling the size up to see if that works. Thanks for explaining the Dave Method.

Thanks! I will try scaling the object and see if that works.

Thank you for your help. The suggestion to scale up the drawing before making changes prevented the mesh from changing. Here is what I was attempting to do.