If you've made it this far, I'll presume that you've got your mirror polished out, with no hint of frostiness or pitting. Hopefully your Ronchi testing shows fairly straight lines, indicating a spherical (or nearly spherical) surface. You now are going to modify that surface just a teensy amount to convert it into a nice smooth parabola, and then you will be done!
All materials on this website are Copyright 2001, Mark T. VandeWettering. Permission is granted to reproduce and distribute these files for non-profit, personal use.
Mark T. VandeWettering <markv@telescopemaking.org>