Sorry, I can 3D print them only up to about 140mm clear aperture.
You need someone with a laser cutter. Try Diego at Sidereal Trading - I think they have a laser cutter.
I have made a few, by hand, from refractors to large Dobs, the templates (PDF) are usually available Online.
There used to be an online app that allowed you to insert your scope specs and it would generate the pattern. It is a time consuming, and intricate process to hand cut them. I used Exacto knives and thin plastic sheets ( usually cover sheets from A4 sized notebooks sourced from newsagents). You obviously need patience and good vision, my eyes are too poor these days for such work now.
Still it is satisfying to c9mplete one if your up to the challenge.
Hi Philip When I last made one I just fill out the telescope info and save it onto a usb stick took it to a sign writer that has a laser cutter and he would make as many as you want. I would ring around and find out which sign writer has a laser cutter and what file format they would want, below is the link https://satakagi.github.io/tribahtin.../Bahtinov.html
