Quote:
Originally Posted by legswilly
I hope I can get it calibrated at the local machine shop.
The grit I was quoted for #1000 and #1200 is silicon carbide. Would I be wrong to ask for aluminium oxide?
Thank you Stefan
|
You still don't get it: You don't need to do any calibration of your spherometer because you are not making a sphere, where you would need to measure the sagitta. You just want to compare two surfaces that have been rubbed together. If you get the same reading, it means they are flat, no matter what the actual reading is.
I have not seen/used silicon carbide finer than #800. All the fine grits that I use are aluminium oxide.
What thickness are your discs? If they are not thicker than 30mm, better not waste your time. Even at 30mm thickness, plate glass of that size would not make a precision flat even in experienced hands.