I have a small problem!
I usualy put only poly lenses in 3 piece mounts.
I recently bought a 2.5 line and they claim they will pt any lens material(not glass) in their frame
I was wondering if you going higher in the index of refraction does the lens gets more britle or not?
What would be the second material of choice(not counting the price factor) to put into 3 piece mount frame?
Thanks
You might try the Hoya 1.60 or new Phoenix product in SV or Hoya Wide progressive, they both drill incredably well and rarely chip or crack. Seiko 1.67 is also drillable with few issues. The higher the index the more brittle the lenses are and not always a good choice for a drill mount. Even CR39 is not recommended.
Lenny,
I have sold quite a few of the 2.5 frames from LabItalee and have had no problems with either poly lenses (preferred) or a 1.6 (any).
As with any drill mount, it should be the customers' duty if you will to show reasonable care in the safe handling of the specs, otherwise breakage will occur.
BTW, Italee does a fantastic job at their lab with these frames although they may be a little slow in coming due to their popularity.
Bob V.
Odd isn't it that every lab used to have benchmen who could do three piece drill mounts in glass without problems. The lenses didn't wobble and shake after a few weeks use. Have our hands lost their skills to computerized rigs?
Chip
From what I understand, the Hoya 1.6 Eyas material, was actually designed for four screw mountings, not as a high index , it just happened to be high index!
Chip
I used to take pleasure in making drilled rimless.
I guess I'm really really weird!
It was theraputic to me. It was a matter of seeing how many places I could support the lens with frame when I tightened the screw. No gaps, no nuthin but pure craftsmanship. It was also fun to drill straight through with a burr and have a miniscule countersink so the lens didn't chip on the edges.
Excuse me I . . .
yes . . .
there's another butterfly . . .
gotta go . . .
bye
Got it . . .
It's so pretty!
Lenny, Is there some problem in using CR-39 lenses in drill mounts? We pretty rarely use poly or hi-index. Have had no problems.
Al,It was theraputic to me. It was a matter of seeing how many places I could support the lens with frame when I tightened the screw. No gaps, no nuthin but pure craftsmanship. It was also fun to drill straight through with a burr and have a miniscule countersink so the lens didn't chip on the edges.
If they aren't done right or a customer is tough on their glasses it can be a problem. Many folks don't want to take the time to do the job right. Other folks are afraid of drill mounts and don't understand how to do them correctly as in Alan W's reply.
Jo, I understand what Alan W said, and I know about drill mount anxiety. but what has any of that got to do with not using plastic lenses? i.e. if a pt. wants their -.25-.50 x90+2.00 add Panamic Crizal lenses put in a Silhouette Titan 3-piece mounting, that should warrant them spending the extra money on Airwear or 1.6 ? I'm missing the point of this logic; we've probaly done a few hundred jobs like this in plastic lenses with no problem at all. Now, if it's a -6.00,+2.00 add, there's some really good reasons. I know that Air Titanium recommends NOT to use poly lenses in their mountings.
Poly lenses transfer the stress to the frame. Is that good? Is that bad? It's both.
There was a time when minus lenses as well as plus lenses were made in untempered glass, The minus lenses had a center thickness of 0.8mm
Rarely was there a break unless on inspection, the strap behind the lens was not completely in contact with the back of the lens.
The purpose is NOT to screw the lens to the frame. The purpose is to shape the frame to fit the lens so that when the lens is tightened down the lens and the frame are as close to being a unit as is possible.
What I see happening is the technician drills and screws the lens down without shaping the frame to be a cousin to the lens. In those instances where the technician lacks the tools as well as the skills, the lens is surer to break.
A frame that is NOT in perfect alignment with the lens is apt to break BECAUSE of the frame, not the shock. Poly may save the day, but the problem is still there.
Of course, one can also use all the nylon bushings, springs and cushions there are. There's still no substitute for perfect alignment and craftsmanship.
The tools that make it happen right are Numont pliers and strapping pliers. If you can get your hands on them.
And, yes, it was a pretty butterfly!
:hammer:
"A frame that is NOT in perfect alignment with the lens is apt to break BECAUSE of the frame, not the shock. Poly may save the day, but the problem is still there."
My booboo. Should read . . .
A LENS that is NOT in perfect alignment with the FRAME is apt to break BECAUSE of the frame alignment, not the shock. Poly may save the day, but the problem is still there.
Sorry.
Jo, I guess that's why we like the Titan frames so much; they don't have screws nor bolts to tighten; we seem to have more trouble with breakage or stress cracks on poly lenses.
Al,
My experience has been that most (obiously not all) of the stress cracks around a drill hole on Poly is caused by the bit not being sharp and/or they drill too quickly and induce heat. If the stress cracks, again relating to Poly, are around the edge of lens, then it typically is caused by the edger. The other way of getting edge cracks is the use of a chemical that will crack Poly anywhere around an uncoated area. "Loc-tite" (or similar products, such as nail polish) will cause it just as fast as acetone.
And for Alan.... I agree with the nature of rimless. Always spent considerable time aligning the frame pieces BEFORE drilling a single hole. They made all those pliers for a reason. Great satisfaction is producing out-standing rimless work. The frame and the lens were a matched set when you were done with it. Now, so many drill a hole, then check the fit and perhaps adjust something.... and when the hole is no longer in the correct place, they just tighten the screw more.
Do you remember the old 'Bal-Grip' type with the solder plug and no screws? Of course in those days you could actually solder pieces or extensions on the rimless frames to produce additional supports, etc.
Last edited by JRS; 06-26-2001 at 07:08 PM.
JRS
STOP . . .
I'm getting warm fuzzies!
I get that when I hear from a craftsman. It's a problem I can't resolve. Like bipolaropticianism.
The issue of cracking with poly seems to be ameliorated (a resort in Florida!) when instead of using a regular drill, I switch over to jewelers or dental burrs, which are round at the tip. They come in a variety of diameters and in diamond vs whatever. I like to drill the main hole and then a light countersink that flares the hole edge, preventing unnecessary sharp contact that can chip.
This message brought to you by The International Brotherhood of Ophthalmic Craftsman. (LOGO = screwdriver in a finger!!!)
Oh, I like that.
.
Quote:
The International Brotherhood of Ophthalmic Craftsman. (LOGO = screwdriver in a finger!!!)
Ahhh, but you haven't lived until you DRILL a hole in your finger while trying to converse with the young thing sitting next to you and work on some rimless jobs! Although to be honest, my worst experience was having a steel splinter removed from my eye. Dumb thing to do, and it will only happen once!!!
I can't beat that one.
Many years ago, when I was young and stupid. (Now, I'm old and stupid!), I was edging down a PGX lens by hand. Ceramic wheel got too dry . . . little hot pieces of glass flying off . . . one in my eye. It's Sunday. I learned never to go to the ER with a foreign body in your eye on Sunday! You don't get an ophthalmologist in Vista California in an er on Sunday.
So, I called a friend/ ophthalmologist (oxymoron). He said "come over to the house immediately."
I did. His wife was annoyed over the intrusion. But, then ophthalmologists wives get annoyed over anything.
He says: "Let's go into the kitchen.", nice kitchen...very nice kitchen!
He says: "Honey, get me an ice pick. "
I say: " Oh, S - -t!"
He says: "Shut up!"
I said: "OK"
Then he turns on the burner. Hits the flame to the ice pick.
I'm ready to change underwear!
Rinses it off with alcohol.
Puts a drop in my eye.
I start to pray in Hebrew!
Bad choice of language. He's Iranian! He didn't laugh.
Time to change Haines! (Hainses?)
Next thing I see is his garden window becomming distorted and this thing moving like a windshield wiper on my eye.
He says: "Don't move."
Now, am I going to move? I'm petrified!
He hands me the piece of glass . . . 8 inches in diameter!
Maybe 10!
His wife says: "Yuck . . . what are you going to do with the ice pick now? I'm not going to use it anymore!"
I wanted to smack her.
But, I didn't get a bill!!!!!
:D
How do you pray in Hebrew in Texas? "Sh'ma Y'all"?
Anyway, you guys remember the Will's Edge? Sorta like a dovetail that slides into the top rim. held in place by Canada balsam.
Money carefully refunded
This is a great thread! I can identify with the gratification of creating a spendid piece of eyewear (drill mount). The dream is broken when the patient carelessly sits on them and then brings
them back in saying that we did not make the glasses correctly because they broke from only having them on the night stand.
The dream takes a turn for the worse when the doctor brings the
patient back with an rx change to one lens only after three days.
This does nothing for the ethic that states:
Do it right the first time.
Soon, I see all the incentive for creating these works of art fly right out the window, or to quote one boarder, down the pooper.
I will use the remaining strength in me to offer more mutually pleasing eyewear that uses cord mounts and the like.
I learned to do drill mounts for a Benson Optical Glass lab in the 70s.. Glass only.. Nothing stays with ya like sticking your thumb through a Therminon lens that took two months to get...(That special light aqua tint lens).. I would love to find all the equipment and do drill mounts from my home. Would be a great hobby. But caution on selling drill mounts... I recall a big lawsuit when a child went over the handlebars of her bike and cut her eye on the broken drill mount lens (CR39). Seems poly may be a better choice.
:D Being one of those old timers who has and did use numonts and strapping pliers and did drill holes in glass with a number 40 dentists burr, i,m kind of surprised that there is not enough people around who know how to do this anymore. Al,s post is right on the head when he mentioned about shaping the frame.
One of the interesting things about drilling glass lenses, is that that was one of my first {non-patented, blame B&L} inventions, which was an automatic oiler, as with the old shuron drill setup you really needed three hands, one to bring the drill down, one to flip the lens over front to back and the third hand to apply the oil. If there is anybody out there still doing it like that let me know and ill show you for about 3.00 how you can have an automatic oiler.
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