Dear Friend: I am a professional CAD user specializing in mechanical engineering design models for feasibility analysis
I have recently created a Reduction Gearbox using Involute Geometry for the actual teeth profile and this has been created from Trig & Dimetral Pitch Calculations before modeling as the gears are actually Spiral (Helix) Gears
As you can see from from the photograph attached I have modeled the gears in full mesh.
The problem is that such a model is complicated to create and due to maths involved takes a great deal of the computers memory (even though I use the fastest graphics computer Dell manufactures)
To save memory I have used Prof. Unwin's Geometry to represent Pure Involute Geometry (as this technique uses arcs rather than multiple splines)
Now the question is because the gears are actually Chevron Gears I have had to model each half separately before performing the Boolean Operation of 'JOIN'
When this is applied I get a message declaring unable to perform as the geometry is 'ILLEGAL'
I Have created many gearbox design models from Spiral Worm Gears to Rack & Pinion Drives and I have never seen this message before