Cut a perfect lens pattern for edger

[frizz]

I usually use patternless edger in my practice. But now I'm required to learn to cut lens pattern for pattern edger. The problem is I just can't find a way to cut a perfect one. All the lenses made will not fit the frame perfectly. Either too big or too small. There are some holes between frame and lens when I fit into a frame. Any tips to cut a better one?

[MikeAurelius]

If you are having overall size discrepancies, you need to check the calibration of the pattern cutter vs the frame tracer. Get your hands on a known good frame and pattern, trace the frame, then cut a pattern. Compare shape and size to the known good pattern. Check the C-Size. Then adjust the tracer or cutter and try again. Keep on testing until you get an exact size.

Good luck!

[waynegilpin]

Are you using a electric pattern tracer and cutter, or tracing and cutting by hand?