I need to cut a disk like this http://www.dfocussystem.com/images/marking2_thumb.jpg.
It can be nylon, polythene, kevlar, etc. The big diameter is almost 100 mm ( 4 inches) and 5 mm thik. I have thought two aproachs. With a round bar. Here the problem is to part it on the lathe. The other aproach is with a plate. Cut a cirle and put it in the lathe. Here the problem is that is very thin and can bend in the chuck.
Thank you very much!