As I posted a while back I made some "spindle" mounts for rotary hand pieces and it worked ok. I overcame the tramming issues to some degree by making two mounts for each spindle and clamped them to the spindle of my mill spaced a couple inches apart. They work ok for some things, but I plan to make a router mount next to see if that higher RPM and horsepower can benefit me for cutting time either in feedrate or depth of cut or both. The math says it should.
Anyway, with your one inch piece of plate made into a clamp how easy was it to tram your spindle?
Is there anything you would have done differently in your build to make it better?