Trimming causes loss of faces

2 way radius.skp (434.4 KB)
I am trying to trim this solid shape, however I loose faces.
Please advise

Thank You in advance

You are running into the tiny face limitation of face creation in SketchUp. The geometry you are trying to create is too small for faces to form. Scale both pieces up by 100, perform the action, then scale them down.

Or research the “Dave Method” of leveraging components to perform the operation on scaled instances of the component.

One of the reasons this is happening is because your two arcs segments do not line up (see screenshot, turn on hidden geometry to see the segments in your model) which results n tiny faces being made to stitch together the mesh again in the trim operations