i found a place to get everything needed
i think ill start with a 6" since i have a spare OTA and cell for a 6" mirror, will save me building another scope just to test with.
guess i need to start looking at how to build a ronchi tester or would it just be easier to buy one, $60 on the site where i was looking at blanks
i guess it just amuses me how accurate you can make something with minimal tools and home made testing gear