edger/tracer question

[Refractingoptician.com]

What is the best equipment to use to edge 18 mm small "b" measurement frames and what is the best choice in equipment to edge high wrap frames and lenses ? Is the high wrap problem confined to the tracer and not the edger ? Is the small "b" edging problem primarily a edger constraint or is it also a tracer constraint ?

I assume that when it comes to modifying shapes by changing the "b" measurement then this is strictly a matter of whether the tracer can edit the shape ?

Are there upgrades to a Nidel 7070 LE built in tracer that would allow it to edit shapes ?

[OpticLabRat]

Almost all current edger models can do an 18 B measurement. I have also made nome modifications to some older models to do the same. "machining down the chucks" etc...
As far as tracers, I have always traced one lens only on wraps by clamping only one side of the frame. This allows the stylus to not have to reach so high while maintaining the correct curve of the frame.

[Andrew Weiss]

As far as tracers, I have always traced one lens only on wraps by clamping only one side of the frame. This allows the stylus to not have to reach so high while maintaining the correct curve of the frame.

Does this work even with tracers that supposedly aren't 3D? I'm using an Essilor Phi.

Thanks much.

[shanbaum]

Does this work even with tracers that supposedly aren't 3D? I'm using an Essilor Phi.

Thanks much.

Are you thinking that the Phi isn't "3-D"?

'Cause, it is.

[Andrew Weiss]

Thanks Shanbaum. I obviously got wrong information (I won't say from whom :)).

[HarryChiling]

Yeah, it works but you sometimes have to size then lens A size down.

[AWTECH]

What is the best equipment to use to edge 18 mm small "b" measurement frames and what is the best choice in equipment to edge high wrap frames and lenses ? Is the high wrap problem confined to the tracer and not the edger ? Is the small "b" edging problem primarily a edger constraint or is it also a tracer constraint ?

I assume that when it comes to modifying shapes by changing the "b" measurement then this is strictly a matter of whether the tracer can edit the shape ?

Are there upgrades to a Nidel 7070 LE built in tracer that would allow it to edit shapes ?

This is a very complex issue. Tracing a wrap frame and edging a wrap frame each have issues. The edging of a 8 base wrap frame using a wet edger with 6" to 8" dia wheels is very difficult to achieve good results. This is primarily due to the fact that the bevel can not be placed on a lens with a flat A dimension. (The V groove of the wheel will cut into the bevel on a lens that is not very round.)

Small B measurements are a result of software design and mechanical design. I like the Optronics dry edger if you don't want to invest in a 4 axis $200,000 industrial edger. The Optronics is only 3 axis but the blade diameter is small enough to allow you to place a bevel on most 8 base lenses. (It is going to be perpendicular to the lens optical axis, and will not follow the radius of the sphere of the lens curve.)

To do the job right the bevel should follow the radius of the sphere so that the bevel is not perpendicular to the optical axis.