Cutting custom plastic lenses

[Hellbore]

Does anyone know of a good way to cut your own round plastic or Lexan flashlight lenses?

I have a few flashlights with cracked or otherwise damaged lenses but that either can't use glass due to risk of breakage, or they are an uncommon size in which no one makes glass lenses, it would be nice to be able to buy some lexan and make some lenses for them.

I know there are circle cutters for cutting glass but I'm guessing they operate on a principle that would make them unusable on plastic... am I wrong?

 

[Mr_Light]

I have cut plastic lenses using a hole saw and a portable drill. Pick hole saw 2-3mm bigger than the lens. Drill hole through 3/4" board, remove pilot drill from hole saw, place plastic sheet on top of a second board with the board with the hole on top. Clamp the two boards with the plastic between and use the top board to guide the hole saw through the plastic. You will need to sand edges.

 

[Hellbore]

I have cut plastic lenses using a hole saw and a portable drill. Pick hole saw 2-3mm bigger than the lens. Drill hole through 3/4" board, remove pilot drill from hole saw, place plastic sheet on top of a second board with the board with the hole on top. Clamp the two boards with the plastic between and use the top board to guide the hole saw through the plastic. You will need to sand edges.

Thanks for the advice I will have to try this!

 

[LukeA]

Cover both sides of the plastic with tape if it does't have the factory coating still on.

I have cut plastic lenses by scribing the desired circle on the plastic, bandsawing it close, and using the stationary disc sander to get to the final diameter. I haven't had any problems with melting.

Of course the hole saw method requires less $$$ in equipment.