Edging Trivex

[charnich]

Hi guys. I'm new to edging and just learning by trial and error. I am wondering how you treat (Hoya brand) Trivex for edging. I have an older Horizon III patternless edger. It has settings for CR-39, poly, and thick poly but no trivex program. The blades are new and have about 40 cuts on them. Would I run trivex on the CR-39 setting or poly? I have been running the Trivex on poly setting but I have noticed that it will cut the Trivex too small. Specifically more noticeable on metal frames. I haven't had it happen on plastic frames maybe because I cut those .2 bigger anyway and hand edge if I need to. I have run the exact same rx on a trivex and poly lens for the same frame. While the poly comes out exactly the right size, the trivex is too small and leaves gaps. Does anyone know what gives here?

Charles

[dave.fant.lab]

I used to have an old Kappa Edger with no trivex macro, I had horrible luck trying to cut trivex on both CR39 and poly settings. One setting would cause the lens to get too hot and the block would imprint on the lens and the other setting would not edge it down well enough, the edge of the lens was not smooth at all. Perhaps you will have better luck with the Horizon III, I am not familiar with the machine. We have the Kaizer Echelon 8000 edger now and it does an amazing job with trivex.

[WFruit]

Wow.... I used a horizon III about 17 years ago... I'd set it for Poly, and just set the size big. Trivex didn't even exist when the Horizon III came out, so it's not really set up for it. I'd just as well be the one to say it, since I know someone else will if I don't: You need a newer model edger.

[charnich]

The thing I notice is that its actually cuts trivex beautifully on poly setting. It just cuts small. I know others are doing it, I just want to know how it handles..

I used to have an old Kappa Edger with no trivex macro, I had horrible luck trying to cut trivex on both CR39 and poly settings. One setting would cause the lens to get too hot and the block would imprint on the lens and the other setting would not edge it down well enough, the edge of the lens was not smooth at all. Perhaps you will have better luck with the Horizon III, I am not familiar with the machine. We have the Kaizer Echelon 8000 edger now and it does an amazing job with trivex.

[charnich]

Wow.... I used a horizon III about 17 years ago... I'd set it for Poly, and just set the size big. Trivex didn't even exist when the Horizon III came out, so it's not really set up for it. I'd just as well be the one to say it, since I know someone else will if I don't: You need a newer model edger.

I disagree. I do not need a new edger. Mine cuts beautifully thank you. I just need to fine tune a little.

Are you saying that you used to edge Trivex on the poly setting? Did you have a similar observation that it cuts Trivex small? Does anybody have an explanation for why it would cut out smaller?

If anyone else could chime in it would be great... Does anyone else have any specific knowledge regarding the intricacies if Trivex?

[Craig]

I disagree. I do not need a new edger. Mine cuts beautifully thank you. I just need to fine tune a little.

Are you saying that you used to edge Trivex on the poly setting? Did you have a similar observation that it cuts Trivex small? Does anybody have an explanation for why it would cut out smaller?

If anyone else could chime in it would be great... Does anyone else have any specific knowledge regarding the intricacies if Trivex?

If you want to process new materials you really do need a new edger. The new edger is the machine that allows us to do 96% trivex and we love it!

I don't process glass on my edger so it makes sense to not do trivex on yours.

Is all your exam equipment outdated as well? Doubt it.

[Pogu]

Trivex is a very tough material. Make sure you have the lenses cribbed as close as possible before edging. Keep in mind how flexible Trivex is, make sure your blocks and chuck match very closely. An oblong block and a 18mm round chuck can deflect the outer edges and throw off bevel/groove placement. Also, just because the lens won't shatter with a 1mm CT doesn't mean its a good idea, the torque generated can easily overwhelm the flexi center. The rest of my technique has to do with water control, so it won't help you.

[fjpod]

The horizon will cut it, but it all depends on how old the blade is and how many cuts of poly and high index it has on it. Nothing will dull a blade like poly and trivex. Add high minus and some AR and you have a recipe for disaster. Run it slow.

[charnich]

If you want to process new materials you really do need a new edger. The new edger is the machine that allows us to do 96% trivex and we love it!

I don't process glass on my edger so it makes sense to not do trivex on yours.

Is all your exam equipment outdated as well? Doubt it.

Not gonna happen. I'm not getting a new edger. There's fundamentally little difference in the cutting mechanism of a Horizon III and an Optronics 7E ( even less difference from the 6E which is basically an updated HIII. ). In fact many of the parts are exactly the same. Yes the programs are modified a little but it is still a high velocity spinning blade that cuts the lens. There's no rocket science there. According to the PPG website, if it can cut poly it can cut Trivex. Why on earth would I spend 40-70k on something that does fundamentally the same thing that my already-paid-off edger does (for my specific needs). I have no desire to have my machine automatically drill or groove. There is something called technique and 5 minutes of extra effort which allows me to do that relatively easily and with very little spoilage. Again...not worth 40K to me. The only benefit to a "new" machine is so that I can have it do those extra tasks automatically. Your logic about your edger cutting glass makes no logical sense. If a 7E can cut Trivex, the HIII can too. Your machine's lack of ability to cut glass makes no difference to me. Again the cutting mechanism is the same. All I need is a machine to cut simple SV jobs. I have no desire to run high index, transitions, bifocals, or progressives. Those will go to my outside lab, as the cost/ benefit curve changes on those materials. I just want to cut 2-3 jobs a day in between seeing my patients. I'm not a production lab. So do I really NEED an edger that won't pay itself off for 10 years, or would I be better off raking in the dough on the simple jobs that I have set out to process??? I apologize if this has turned into a tirade but I asked a specific question about how people handle Trivex and I get several "opinions" about what equipment I NEED. There's no question that the HIII cuts Trivex just fine, as does the 6E, and 7E, its younger brothers. Sure I might have to write a new macro for it but I'm sure once I get it fine tuned it will be a workhorse for me as it already is for CR39 and poly. Many of you might already know that by using the 4T tracer you can cut the majority of modern size & shapes with the HIII. This was not so with the original tracer that came with it.

BTW hundreds of ODs and ophthalmologist use phoropters and slit lamps ranging from 20-40 years old and are much better diagnosticians than many using the Optos and digital phoropter. The equipment has very little to do with the skill of the doc. However, much of the newer equipment leads to the risk of the practitioner becoming complacent and lazy... Some of the most amazing ocular disease specialists I've ever met use older equipment just as the most amazing and skilled optician I know still uses the WECO 440. He is a true craftsman. I personally believe that skill has a lot more to do with it than equipment... There is an artisan quality to making lenses which seems to be slipping away with all of the bells and whistles on modern technology. Just as we see in professions across the board. I'm OK with doing it the old school way.

So if anyone else would care to chime in regarding their specific experience with Trivex , I'm all ears. But if all you are going to say is "you need newer equipment" then I'm not interested in entertaining that idea. I will make use of what I have and it will work really well for what I need.

[charnich]

The horizon will cut it, but it all depends on how old the blade is and how many cuts of poly and high index it has on it. Nothing will dull a blade like poly and trivex. Add high minus and some AR and you have a recipe for disaster. Run it slow.

Yes I agree totally with you. But I feel that is similar to most dry cut edgers. So far I haven't had any problems with slippage or crazing. I limit my minus to about -6.00. Anything over that will go to an outside lab. My issue is really more about the difference in size between poly and trivex. More than anything I'm looking for an explanation as to why. If I need to apply a size correction on Trivex, I'm OK with that but I just don't get the theory as to why that happens.

Thank you for your input, I really appreciate constructive comments like this.

[charnich]

Trivex is a very tough material. Make sure you have the lenses cribbed as close as possible before edging. Keep in mind how flexible Trivex is, make sure your blocks and chuck match very closely. An oblong block and a 18mm round chuck can deflect the outer edges and throw off bevel/groove placement. Also, just because the lens won't shatter with a 1mm CT doesn't mean its a good idea, the torque generated can easily overwhelm the flexi center. The rest of my technique has to do with water control, so it won't help you.

Thank you for your insight!! Very helpful. So in your experience Trivex is more flexible than Poly? What about the way it edges? Is is more brittle than poly? In other words I get the impression that on a molecular level poly seems to be "gummy" for lack of a better term. In other words it seems like the blade gets bogged down so to speak. However, it seems that CR39 is more brittle in that the blades really lay waste to the material and don't get bogged down. From that perspective do you think Trivex behaves more like a poly or a CR39? (I hope I'm making sense). Also, will the Trivex melt easier than Poly? Or are they about the same?

[WFruit]

I disagree. I do not need a new edger. Mine cuts beautifully thank you. I just need to fine tune a little.

Are you saying that you used to edge Trivex on the poly setting? Did you have a similar observation that it cuts Trivex small? Does anybody have an explanation for why it would cut out smaller?

If anyone else could chime in it would be great... Does anyone else have any specific knowledge regarding the intricacies if Trivex?

No, when I used the Horizon III Trivex didn't exist. I'm sure your machine does cut beautifully.... just small. Trivex is, in fact, not poly. When Trivex was released, I remember having to install new cutting wheels on my edger, a different cutter for my generator, and, most importantly, A LOT of software upgrades to both the lab software (Innovations at the time) and to the machines themselves to tell the machines how to deal with the material. Now, I will say again, cut the Trivex on the poly setting, and set the size big. The issue is most likely a combination of factors: blade speed, speed at which the lens hits the blade (too fast and the lens can flex), possibly chuck size and block size, which, if too small, would cause the lens to flex too much. Does it always cut the lens the same amount small? Now, my next suggestion (which I'm surprised no one has said yet), have you contacted National Optronics to see if they have any recommendations or possible upgrades that you could get?

[charnich]

No, when I used the Horizon III Trivex didn't exist. I'm sure your machine does cut beautifully.... just small. Trivex is, in fact, not poly. When Trivex was released, I remember having to install new cutting wheels on my edger, a different cutter for my generator, and, most importantly, A LOT of software upgrades to both the lab software (Innovations at the time) and to the machines themselves to tell the machines how to deal with the material. Now, I will say again, cut the Trivex on the poly setting, and set the size big. The issue is most likely a combination of factors: blade speed, speed at which the lens hits the blade (too fast and the lens can flex), possibly chuck size and block size, which, if too small, would cause the lens to flex too much. Does it always cut the lens the same amount small? Now, my next suggestion (which I'm surprised no one has said yet), have you contacted National Optronics to see if they have any recommendations or possible upgrades that you could get?

Thank you for the info. I know that my machine is running the most recent software updates. I will call Optronics to see if there are any hardware upgrades, that's a great suggestion. I think you may be on to something with the flexion issue. It does in fact cut consistently small, which is nice for me because I can apply a standard correction. What I'm gathering from a few comments is that Trivex is not a very rigid material. Does it tend to flex relatively more than Poly? Are you currently dry or wet cutting the trivex?

[Stan Tabor]

So if anyone else would care to chime in regarding their specific experience with Trivex , I'm all ears. But if all you are going to say is "you need newer equipment" then I'm not interested in entertaining that idea. I will make use of what I have and it will work really well for what I need.

Just have hoya do your phoenix/trivex jobs.

[charnich]

Just have hoya do your phoenix/trivex jobs.

That may be a last resort, but I'm game for trying to solve this problem first. I don't think I'm that far off, especially for the cost savings of doing it myself.

[Pogu]

Thank you for your insight!! Very helpful. So in your experience Trivex is more flexible than Poly? What about the way it edges? Is is more brittle than poly? In other words I get the impression that on a molecular level poly seems to be "gummy" for lack of a better term. In other words it seems like the blade gets bogged down so to speak. However, it seems that CR39 is more brittle in that the blades really lay waste to the material and don't get bogged down. From that perspective do you think Trivex behaves more like a poly or a CR39? (I hope I'm making sense). Also, will the Trivex melt easier than Poly? Or are they about the same?

Yes, I feel that Trivex is massively more flexible than PC, to the point where mounting it too tight will modify optics.

[daveyboy]

I have an older essilor edger with no trivex setting and had some difficulty with trivex too. I found that using the poly setting works well but I was able to speed up the cycle time by allowing the water to flow on the back of the wheel during roughing, but not strong enough to wet the lens. On the finishing wheel I edge dry and polish wet.

This is not much help to you though because you are cutting dry.

I do not know about the horizon but I have used the 7e.

Do you have the same problem after changing the blade? Maybe the lens is being pulled into the blade by a tiny amount because the material is so tough. I know there is a few different blade material types that you can get from Optronics. A harder blade may cut the trivex better. The harder blades are a bit more expensive though.

I am not sure about your edger but I know on the 7e you can lower the feed rate of the cutting. It means a longer cycle time but I used to use this a lot on thicker lenses to prevent chipping on the edge. Maybe you can ask Optronics if this is possible on the horizon.

[Tallboy]

I appreciate the discussion and respect keeping an old machine going. But nobody said drop 40 gs on a machine when they mentioned upgrading. In a world where people are adding 400 dollar holy wheels to 7070s

[ECP]

Hello Everyone !

I have a NIDEK ME1200 new generation edger that has a TRIVEX mode. but unfortunately the lenses get decentered in the Machine and also the final edge polishing does not come out well. Any suggestions to rectify this ?

[braheem24]

Hello Everyone !

I have a NIDEK ME1200 new generation edger that has a TRIVEX mode. but unfortunately the lenses get decentered in the Machine and also the final edge polishing does not come out well. Any suggestions to rectify this ?

http://www.optiboard.com/forums/show...l=1#post421439

[PRECISIONLAB]

Back to the original questions.. Why does Trivex run small and gaps in lens shape? Agreed that the Horizon III can be set to run Trivex here are my thoughts as to cause: Since machine is older a few factors maybe coming into to play which is affecting Trivex jobs. One there may be a backlash issue with servos/gears controlling table movement. As the lens cuts it is being feed and drawn into cutting blade. If the cutting is too fast on finish cycle the lens might be pulled in closer than a poly lens which will affect size. Also gaps are the result of twisting ever so slightly. Another cause might be the set screws on the cutter body. This is the most overlook part of the entire system. Although they appear fine, the threads become worn and allow for loosening ( consider how many blade changes in 17 years) and the blade is not in cutter body as tight as possible. With the torgue required to rough trivex, the blade might "ride" out slightly and affect size.

[charnich]

Back to the original questions.. Why does Trivex run small and gaps in lens shape? Agreed that the Horizon III can be set to run Trivex here are my thoughts as to cause: Since machine is older a few factors maybe coming into to play which is affecting Trivex jobs. One there may be a backlash issue with servos/gears controlling table movement. As the lens cuts it is being feed and drawn into cutting blade. If the cutting is too fast on finish cycle the lens might be pulled in closer than a poly lens which will affect size. Also gaps are the result of twisting ever so slightly. Another cause might be the set screws on the cutter body. This is the most overlook part of the entire system. Although they appear fine, the threads become worn and allow for loosening ( consider how many blade changes in 17 years) and the blade is not in cutter body as tight as possible. With the torgue required to rough trivex, the blade might "ride" out slightly and affect size.

Thank you for this thoughtful and constructive post! I will definitely check the set screws for any play...that is a great line of thinking. I have checked the servos via the burn in graphs and they are all well within tolerance. A few others have mentioned the fees rate etc. I see I can design my own macro. I would like to clone the 7E's program for trivex and see what happens. The variables that I can change are: Rough speed, finish speed, take off, number of revs, lens speed, hub speed, polish cycle, and safety bevel. I was wondering if someone can post the settings that a 7E uses on Trivex cycle. Also, is there a "thick trivex" setting vs a standard thickness? (on my machine there is for poly)

[fjpod]

Now that I am reading some of the other responses...which tracer are you using? The old Saturn or the more current 4T? We had problems with the old Saturn on small rectangular metals..gaps, rounded corners...not just on trivex though.

[charnich]

Now that I am reading some of the other responses...which tracer are you using? The old Saturn or the more current 4T? We had problems with the old Saturn on small rectangular metals..gaps, rounded corners...not just on trivex though.

I'm using the 4T. The saturn is no good but I'm very impressed with the 4T.