Polishing convex maksutov correctors

Is there any easy way to get a steep convex curve on a Maksutov corrector to go MORE CONVEX (by a few fringes) with a polishing tool? I find that even with a long stroke (2/3) COC, the horizontal motion of the tool planes away the center of the glass and keeps flattening it out when I'm actually trying to get it to go more convex. What about putting a lap off to the side and letting it spin? I've has some tries with this, and ended up with zones. Any specific help would be greatly appreciated. Thanks, Bob Piekiel

If you have a machine, use a subdiameter lap and offcenter it. You may get zones but you have to move some glass. As you get close, use a larger lap or adjust the stroke to be more centered. Once you get the radius where you want, then focus on smoothing it.