John.
In the pic, I was machining a brass flywheel, not the perspex, which I used successfully, with a high revolving centre pressure, as friction drive material!
For the present lightweight project, with
no centre hole, I used double sided tape, with a driver over the point of the centre.
It floated too much when using 10thou passes.
Masking tape sounds just the ticket!
Thank you!

EDIT.
Later......
Using insulation tape between component & chuck jaws, and also between component & centre driver (an old screw head). Perfect!


Once again...... Thank you!
