Boolean Difference - Frame Design

The attached file shows an object I am trying to create.
When I get to the Boolean Difference to subtract one solid from another I do not achieve my desired result. Any suggestions why. My process is as follows:

Design is broken down into the following elements.

  1. Frame Profile
  2. Rail
  3. Crenels segments

Creat frame profile with polylines and curves.
Sweep 1 Rail to create Frame solid.

Create geometry of crenel segment using two circles and two lines.
Join curves into a closed polyline.
Make Planar surface
Polar array surface.
Extrude surface ‘straight’
Boolean Difference - ‘extruded surface and ‘Frame Solid’

I am trying to subtract the Crenel solid from the frame to product the effect shown in the jpeg - I had success once and tried to repeat the process but without success. Any ideas where I am making a mistake?


Test 003.3dm (1.4 MB)

If you decrease your document tolerance setting to 0,001 units, this seems to work on this end.

I revolved the cross section curves after changing the tolerance. (Also, I would recommend to either explode the section curve into its individual parts and revolve those or set the SplitAtTangents setting to Yes).

Hello Wim
Thank you for your help with this. I decreased the tolerance in Settings to .0001. I exploded the profile and revolved the curve 360 degrees - as I think you suggest. I re-extruded the crenel segments. I then tried to Boolean Difference. No result. Am I supposed to Join the revolved curves to produce a solid first?
Thanks Matthew

Hi Matthew,

Well, that’s what I did, yes. In theory, it should be possible to boolean the surfaces as well. I’m not sure why this doesn’t work. @pascal, in the attached the intersections between the solid and the surfaces are clean curves that can be used the split or trim the surfaces manually. What’s up with the boolean operation here?
Test 003_No-boolean.3dm (128.9 KB)