I'm looking for advice on the best method/tool for cutting a 90mm diameter hole in 2mm thick styrene.

if you have some wood you can block eack side then drill though and the plastic wont climb the bit or use a drill bit gage and block one side and clamp the gage down to locate the hole.

Thanks, but the kit bashing bug has bit. I managed to do it with a the back edge of an exact blade and flexing. Cleaned it upp a bit with a file and some sand paper. It's not perfect but it has less slop than a Henlong turret ring.

If your aim was to take up the clearance between the turret ring and the hole in the upper deck, I did this by cutting a thin strip of 0.005" thick styrene sheet and using cyanoacrylate glue, bonded it to the turret ring diameter so it worked like a radial shim. Worked a treat and was a lot easier than cutting a new hole!!


Cheers

CaptB

I think he is building something and plans on this being part of the deck.

I have used a set of dividers to score a circle then flexed the styrene to pop the center out. If you are going to be doing this often go to Hobby Lobby and purchase a circle cutter from the craft section.

FYI - Circle cutter

I needed it to eliminate vertical play on the turret for this...