Oh i wish you could regrind my gregorian telescope mirrors. They are a 13.1 inch Coulter F4.5 and Orion 4 inch F4 to give F-20. Actually looks very good but i think the 4 inch should be a parabola ellipse.
It's not aimed at a particular point on the glass, the larger wheel simply needs to cover both the center and the edge during the stroke so that you don't raise a hill or a lip. The smaller wheels need to cover the center and are only to help speed up the otherwise slow curve change with the larger wheel.
Nice job!
Nice , I am also made 8 inch F2.8 mirror
Oh i wish you could regrind my gregorian telescope mirrors. They are a 13.1 inch Coulter F4.5 and Orion 4 inch F4 to give F-20. Actually looks very good but i think the 4 inch should be a parabola ellipse.
Is the axis of the grinding tool aimed at a particular point along the axis of the spinning blank?
It's not aimed at a particular point on the glass, the larger wheel simply needs to cover both the center and the edge during the stroke so that you don't raise a hill or a lip. The smaller wheels need to cover the center and are only to help speed up the otherwise slow curve change with the larger wheel.