[billjam]

Originally Posted by look 171

how are those finger tips?

Could you have mounted that on a larger board and use toggle clamps to hold the piece down?

As slodave already mentioned, don't try this at home!
I have 50 years experience in making and machining stuff, so I have a good understanding of what is possible and what's not, and the risks! This is definitely not for beginners.

In the picture below, its not obvious what the process is, but basically the flange on the plastic block is being used a a guide for freehand cutting the same shape on aluminium plate that is bolted to it. The small roller on the cutter follows the shape of the plastic block as the part is held against the cutter and rotated by hand.
It is scary if you don't know what you are doing, SO DON'T TRY THIS AT HOME.