I'm confused on digital surfacing/individual designs

[drk]

OK, here's what I think I know:

The newer individualized surfacing abilities for SV or progressives have power ranges available (such as "up to 4 cylinder, etc.).

There's no "physical" reason that you cannot order outside this range.

The limitation is in the software that has been written to date, but it will expand as time goes on.

How mangled is my understanding of that?


Second issue:
I hear company "Z" has less limitation than company "S" because it "designs on the fly".

What's up with all this?

[kcount]

First issue. Yeah you got it.

Second issue. "Designs on the fly?" thats just scary.

[shanbaum]

OK, here's what I think I know:

The newer individualized surfacing abilities for SV or progressives have power ranges available (such as "up to 4 cylinder, etc.).

There's no "physical" reason that you cannot order outside this range.

The limitation is in the software that has been written to date, but it will expand as time goes on.

How mangled is my understanding of that?


Second issue:
I hear company "Z" has less limitation than company "S" because it "designs on the fly".

What's up with all this?

I believe that both Z and S "design on the fly".

There are physical limitations in both cutting and polishing very steep curves, and the two are interrelated. One of the most significant limitations is the ability of a generator's cutter assembly to overcome momentum and ringing when changing directions very quickly - and the magnitude of the change increases with cylinder and prism.

[drk]

Thanks, all.

Robert, will that limit how useful the digital/freeform manufacturing methods become?

[YrahG]

Thanks, all.

Robert, will that limit how useful the digital/freeform manufacturing methods become?

You'll see improvements on the equipment that will allow for less chatter on the cutter allowing the range to be extended.

[TLG]

OK, here's what I think I know:

The newer individualized surfacing abilities for SV or progressives have power ranges available (such as "up to 4 cylinder, etc.).

There's no "physical" reason that you cannot order outside this range.

The limitation is in the software that has been written to date, but it will expand as time goes on.

How mangled is my understanding of that?

But there are 'physical' limitations, namely lens blank thickness. Most mfg list 4.00 as their max cylinder. Keep in mind that there is usually also a 'max total power'. In other words, if a lens is available up to -8.00D with a -4.00D cylinder, you couldn't order, for instance, a -6.00 -4.00 X ??? because the 'total power' is -10.00. I think some of HOYA's lenses, the iD anyway, are available up to 6.00D cyl.

[RT]

There are physical limitations in both cutting and polishing very steep curves, and the two are interrelated.

I suspect that the polishing limitations are more significant than the cutting limitations. But as you note, the cutting limitations would create a rougher surface, which then stresses the polishing process. With FreeForm Cut-To-Polish, you don't get a chance to correct surface geometry flaws, as you would in a traditional surface-fine-polish process with a hard lap.

will that limit how useful the digital/freeform manufacturing methods become?

Given what small percentage of Rx's lie outside the power ranges, it's not a significant liability.

[shanbaum]

Thanks, all.

Robert, will that limit how useful the digital/freeform manufacturing methods become?

What RT said... and YrahG, too (which is to say, "not significantly, and the limitation will probably diminish over time, though not to zero").

There are limitations in traditional surfacing equipment, as normally configured, as well. Bad things start happening with any of the "normal" configuration by -15.00 diopters.

Blank thickness can be a problem, but there are extra thick single vision blanks available, and when necessary, some of the freeform systems will produce nifty myodisc-like surfaces.

[AWTECH]

ICE-TECH solved these problems of equipment and software calculations, machine tool control, machine software control, etc. years ago. I believe we have the greatest range of offering in the industry. High cylinder no problem.

We do not have to make our software and lens designs work in multiple labs with multiple equipment. It is all produced in our own facility with our own equipment.

[scriptfiller]

Allen, that -17.50 -7.00 came out great, thanks for the outstanding work your lab does. I can't wait until dispense.

[snotbagel]

Any surfacing issue can be solved, but it takes time and $. Would you spend $100,000 on developer time to produce 10 rx's a year? Well, I would, if I had $100,000...
I'd love to be able to order prism differently at near than distance in a progressive (N.B. I have fitted the Unique stress relief successfully, but its got limited prism)
It's possible, given enough work by an engineeer..but how many would we be selling? I see plenty of prism rx's for a small practice, and its still only a couple of dozen a year.

I'd be wary of "on the fly"..sounds like a lab that's playing their own software games..and it may not be nearly as good as the branded stuff.