How to make circular rings, plastic or cardboard.
 

So i am not very artsy or crafty, i need to make a ring out diameter 39mm, inner diameter 36mm with a 1mm thickness, i have tried with cardboard but i can't cut a perfect ring, and i don't want to spend 30$ on a circle cutting machine at michaels. Anyone have any ideas?

I prefer make the ring with plastic, does anyone know any places that does just one little plastic ring? if not i guess i will have to use cardboard, any ideas?

perhaps ppl could help u better if they knew what you were using these rings for.

Trying to make part of a dial for my custom watch

CNC Machine Shop | Custom Waterjet, Plasma, Laser Cutting | eMachineShop.com

Heads up that it won't be cheap for a quantity of just 1.

My friend has a 3d printer. We gonna try that first.

use a string and pen?

Tried the string and a ex to knife but the cuts aren't clean looked very sloppy.