Lenses Rotated while edging in the Mr Orange edger

[luxe818]

I have been using the Essilor Mr Orange for 7 years. I found there is so many problems after warranty gone. I changed the roughing wheel not too long ago; however the lenses (hi index lenses only) always twisted and rotated while edging inside the edger. Do any one has the similar problem and knows why?

[Paul Smith LDO]

Super hydro and oleophobic coatings. Tension. If you're getting too much slippage try the handy man's helper; duct tape on the blocking pad and other piece on the ocular surface of the lens prior to mounting in the edger.

[PRECISIONLAB]

Possible causes:

High Index stock lenses tend to be 75mm -80mm..so with decentration there tends to be a large amount of tack off nasal verses temporal. As the lens attempts to rough it loads the wheel and most twisting occurs during this part of edging cycle.

Stock lenses average 1.0-1.2 center thickness so chuck may not be closing completely or applying adequate pressure. This is tricky since crazing can easily occur if chuck pressure set to high.

Typically these types of jobs are polished which requires a constant water flow which may affect blocking adhesion and addition rotations to complete edging.

Possible solutions:

I first run a circle pattern set to 60-65mm which in essence cribs the lens to a workable diameter to start true shape edging cycle. So I rough and stop just before finish cycle. This allows you to check for slippage. If so you have enough diameter to re-mark and reblock lens.

Stack a few finish blocks on the back side of lens..usually 2 will work. Anymore than that may cause the chuck to apply excessive pressure.

Angle water flow directly at the bevel apex and wheel as opposed to at the block on the lens. The flow from the backside should provide ample cooling and polishing.

[Lab-Guy]

I would call clem at essilor support he can run diagnostics for you and see if there is too much pressure on the grinding wheel.