Ok, yet another option, will try it, thanks.
I uploaded a test Sketchup Free file to 3D warehouse, exported to DAE, converted to FBX using website above, and imported in to Hitfilm.
As usual, doesn’t work. I get a one pixel by one pixel file. When I rotate it I do see some colors flash around a bit, but no detectable model.
My model is just a cube with a hole cut in in it, and I could at least see the model when I converted STL to FBX to Hitfilm.
I’ll try the other converter and report back.
Tried the FBX converter from Autodesk, same result.
Anybody got another rabbit to pull out of their hat? 
This is my life in 3D, I spend almost all my time just trying to move a model from one place to another, rarely getting a useful result.