Age old ..

[sandeepgoodbole]

I do not know, how lenses are cut and edged in US. In india, 95% they are first engraved by a Diamond point and cut manually with cutting pliers. 5% or less use Auto edgers. I am using auto edger since last 12 years.
Last week I saw a new Pattern cutter which will cut the patterns for auto edgers by tracing the Demo lens. I am sure this will also cut and edge Cr and Poly directly and there will be no need to put the lenses on the Auto Edger.
It's very simple, efficient and accurate.

[Pete Hanlin]

Actually, here in the US we often use a "patternless edger" that traces the shape of the frame and then edges the lens (without using a pattern).

From your description, it sounds like quite a bit of craftmanship goes into creating a finished lens in India (I doubt you would find many lab techs here who would be able to edge a lens using a pair of snippers).

Who manufactured the edger you are currently using?

[sandeepgoodbole]

Originally posted by Pete Hanlin
Actually, here in the US we often use a "patternless edger" that traces the shape of the frame and then edges the lens (without using a pattern).

From your description, it sounds like quite a bit of craftmanship goes into creating a finished lens in India (I doubt you would find many lab techs here who would be able to edge a lens using a pair of snippers).

Who manufactured the edger you are currently using?

My Auto Edger is by Nivotronics, Mumbai, India.
We first cut a pattern.
But most people do evry thing manually.
Snippers are used to cut the lense up to the diamond engraving traced as the shape of the frame. Then, Hand Edgers (0.2 to 0.5 HP) . having diamond wheels are used to rough and smooth edging.

[chip anderson]

Dear Sandee:

If it's any consolation, when I first got into the optical business around 1956, things were done in this country (up to the mid '60's) in the manner you describe. The bad news is, I guess this put's India about 40 years behind the U.S. Hope you have a cheap labor pool. Here we would never get enough work out to be cost efficent with our labor cost using the methods you are using. Another example: This week-end I did some bush-hogging (brush clearing with a tractor) and did the work of a hundred men using hand held sythes in the same amount of time.


Chip

[John R]

Hand edging now there's an art.... Me i could never get anything round always looked like a threapenny bit.......Hence sticking to surfacing....
Sandeep, as most are hand edged is this because of the cost of the edgers or that the power supply is not good enough ?

[sandeepgoodbole]

Originally posted by John R
Hand edging now there's an art.... Me i could never get anything round always looked like a threapenny bit.......Hence sticking to surfacing....
Sandeep, as most are hand edged is this because of the cost of the edgers or that the power supply is not good enough ?

Cheap labour is primary reason. Power shortge is a problem in some places. But hand edgers also need the same. Per capita income is low. ($ 460 Latest figure )Avarage cost per spectacle might be around 7-8 $ . That prevents us from going hi tech. Regarding the speed of Auto Edgers, I doubt , if we can compare the difference of Tractor plouging and manual ploughing.

[Pete Hanlin]

Wow! I am taking a wild guess that there aren't many "Glasses in an hour" places in India!

I also feel bad that I have an old Weco edger sitting around in our lab gathering dust. If the thing weren't so heavy, I could just ship it to you and you'd be taking a giant leap forward in convenience!

Also, the next time I gripe about how "long" it takes our Santinelli trace and edge to finish a lens, I'll think about those snippers (and then I'll gripe anyway, because I'm an impatient person! ;) ).

[sandeepgoodbole]

My quiz is, why do you need a Diamond Stone cutting wheel for cutting Cr and Poly. It should be done in much simpler ways like a knife in the butter..what's the latest method used in US ?

[gebe33]

It isn't done hear other than to break the sharp edges so the cutting quickness isn't a factor. When I first started making samples long ago the place I worked didn't have an edger so I world scribe the shape I wanted and use a sanding belt to cut the lenses down. This would be much quicker then a diamond wheel but you would have to be careful of the amount of heat generated on polycarb lenses.
It does make you realize how easy we have it here in the more developed countries!

[sandeepgoodbole]

Is laser used to cut the lenses? I wonder, if it can form the Cornia and scrub Retina, it may be used to Grind, Edge and Polish what ever the material used. That is possible where one can stand in a queue of a Moon Craft !!

[chip anderson]

Sandee:

Lasers don't do too much to tranparencies. They also generate a lot of heat, they actually melt the materials away. When some tried to finnestrate contact lenses with them they left a ledge around the hole which had to be removed. I have read of some holes being burned in transparencies such as diamond to make extrusion holes. But don't look for it in edgeing/surfacing equipement any time soon. Lots of "inspection" is done by laser though. Some companies have such faith in it that they can't concieve of surface defected product (even when the defect can be see with the eye under magnification) if it passed thier on line automatic laser inspection.

Chip

[sandeepgoodbole]

Originally posted by Pete Hanlin
Wow! I am taking a wild guess that there aren't many "Glasses in an hour" places in India!

I also feel bad that I have an old Weco edger sitting around in our lab gathering dust. If the thing weren't so heavy, I could just ship it to you and you'd be taking a giant leap forward in convenience!

Also, the next time I gripe about how "long" it takes our Santinelli trace and edge to finish a lens, I'll think about those snippers (and then I'll gripe anyway, because I'm an impatient person! ;) ).

In India, some people are using Weco . I think , spares equally frightening as the costs.. What are the features of Santinelli which made Weco retired?
With poor quality control of Kryptok Bifocal Fusing in India, one cannot be 100% sure whether a it can be delivered within one hr. if it 's cylindrical or compound . Other wise, for SV and Kryptok spherical, we usually give 1 hr service and in special cases, within 15 minutes ,No Urgent charges, just to comply with customer demand. Some of the skilled snippers in India are really artists.

[Pete Hanlin]

The Santinelli is a trace and edge unit. It has a device that traces the frame and then automatically edges the lens to the frame shape and size (usually on the first go). It also takes into account the curvature of the lens and keeps the bevel precisely at the point selected on the lens' edge. Its a nice machine, and eliminates patterns.

[sandeepgoodbole]

Originally posted by Pete Hanlin
The Santinelli is a trace and edge unit. It has a device that traces the frame and then automatically edges the lens to the frame shape and size (usually on the first go). It also takes into account the curvature of the lens and keeps the bevel precisely at the point selected on the lens' edge. Its a nice machine, and eliminates patterns.

Is the cutting in Santinelli and Waco etc done by a diamond wheel ? or it's done like frate work , I mean like they cut plywood with a blade which goes thru in a perpendicular and follow the shape.

[shanbaum]

Santinelli is the US distributor for Nidek edgers, of which you may have heard.

All patternless edgers have the same fundamental configuration - they're very much like the pattern- (or "former-") driven edgers with which you're familiar; only the former is replaced by a servo or stepper motor actuator. The wheels are (generally speaking) the same. There are now, and have been in the past, a few edgers which utilize carbide and/or polycrystalline cutters, which in some cases have used vacuum instead of coolant to evacuate the grinding swarf. Even in these cases, the mechanism is conceptually similar to that of your edger.

The kind of mechanism that you describe has not to date been used for lens edging. A U.S. company called Optical Machinery and Instrument once made an electronic pattern cutter that had this configuration - basically a router-type cutter mounted on an X-Y table, but very few of these were ever sold.

[Pete Hanlin]

Wow, Mr. Shanbaum! I've seen the machine you are talking about and I had to read that twice (servo motor actuator?). :D

Sandeep, if you have a pattern edger, just imagine a computer driven "arm" tracing the inside of the frame. The computer remembers the shape and instead of a pattern, it controls the arm movements of the edger as it shapes the lens. Our machine does CR-39, poly or any of the high index resin materials, and even puts a polished edge on them! All that, and our machine is hopelessly out of date (they have ones now that will perform drilling and grooving operations and even more!).

[gebe33]

Wow I'vee seen the grooving but I would be interested in seeing one the could do the drilling too. How would it know where to drill the holes? Who makes that edger?
Tom

[Cindy K]

Here in my locale we have a very large population from India and invariably can identify glasses made over there by the unfinished edges and often asymetrical shapes. Well now I know why! Also, I see that most are made of an incredibly thin glass (can't actually recall having ever seen a plastic originating there come to think of it). What's the index you use over there for most jobs?

[sandeepgoodbole]

Originally posted by Cindy Forsyth
Here in my locale we have a very large population from India and invariably can identify glasses made over there by the unfinished edges and often asymetrical shapes. Well now I know why! Also, I see that most are made of an incredibly thin glass (can't actually recall having ever seen a plastic originating there come to think of it). What's the index you use over there for most jobs?

We use 1.523 / 1.7 in Glass . Mostly, by Coring at good places. but in rural areas, they have Chinese, Indian (LOB, donno the long form) , recycled. some years ago, I heard they used to fit bottom of Coke bottle directly to distribute free spectacles to poor and needy catarcat operated cases.
I wonder why it apperaed to you that we are using extra thin lenses? Normally, hand edging requires good thickness to work with. Some times it happens that minus lenses are thinner than 1 mm at centre, as the glass dealers want to offer a bargin and so carves out -2.5 in 3 mm thick blank. Nobody in India speaks if he looses his eye by a pearcing glass fragment in some accident. We all have a spare eye !! But only one toung! :drop:

[Cindy K]

Sandeep--
The 1.7 glass explains why some are so thin and not hardex'd. Over here we generally reserve that index for higher r/x's than what I see coming over from India. Yes, we often see these with significant flaking and chipping around the edges when a + power is mounted in metal frames. I do suspect that many of our Indian clients originate from rural communities so I imagine they use whatever is available. And yes I've measured some of these wafer thin jobs at under 1mm ct.

[sandeepgoodbole]

Originally posted by Cindy Forsyth
Sandeep--
The 1.7 glass explains why some are so thin and not hardex'd. Over here we generally reserve that index for higher r/x's than what I see coming over from India. Yes, we often see these with significant flaking and chipping around the edges when a + power is mounted in metal frames. I do suspect that many of our Indian clients originate from rural communities so I imagine they use whatever is available. And yes I've measured some of these wafer thin jobs at under 1mm ct.

In India 95% people live in rural areas! 98% are mentally rural. They have an attitude.. we call chalta hai! Still It works..
Frames are nothing but lense holders. Glass is the soul. If it gives you sufficiently clear picture, it's all right. But scene is definatly changing fast. People used to fit lenses their Late fathers had used. Now, new generation wishes to switch to new shapes according to Bollywood ( Indian Hollywood) movies.

Secondly, as there are no ristrictions on who should do the business, they would dispense Planos in 1.7 just because, it pays 100 times more than 1.523.

[Pete Hanlin]

Wow I've seen the grooving but I would be interested in seeing one the could do the drilling too. How would it know where to drill the holes? Who makes that edger? Tom

I saw a Weco edger at the last SECO show that was able to drill jobs as they were edged. I've also seen a unit that does nothing but auto-drill jobs (forgot the manufacture of that unit). Very keen!

[Cindy K]

Sandeep--
I'm gonna hafta remember that phrase you used!

Some years back in a feeble attempt to enable easier (ha!) communication with my Indian clients I took a 'conversational Punjabi' course. Most I got when greeting clients with "Sat siri akal' was a quizzical look then laughter. "Tega" is my fav, though, 'cause then everything's ok all the time.

[gebe33]

Thanks for the info Pete, I'll have to keep my eye out for that. I'd like to see how that would work.
Tom

[sandeepgoodbole]

Originally posted by Cindy Forsyth
Sandeep--
I'm gonna hafta remember that phrase you used!

Some years back in a feeble attempt to enable easier (ha!) communication with my Indian clients I took a 'conversational Punjabi' course. Most I got when greeting clients with "Sat siri akal' was a quizzical look then laughter. "Tega" is my fav, though, 'cause then everything's ok all the time.

Sat Sri akal is used by Saradars I mean Punjabis. Another popular ethnic welcome or Hy! is "Raam Raam!!" I be delighted to tell you more . Shubha Raatri.( Good Night!!)