The Lost Art of the Pin Bevel?

[Aarlan]

This may sound silly, but since when did labs start using a chain saw to pin bevel their lenses? We mainly edge in house, but drill jobs and glass jobs we outsource, and with the few labs we have used the safety bevels seem to come back scalloped, uneven and unsightly (although some labs are definitely better than others.

Just venting...Thanks

AA

[ziggy]

And I thought I was the only one who noticed,, I was at my buddy's shop and picked up a job -11.50 and it had no bevel. The darn thing was razor sharp. The problem is the larger labs have no opticians working for them,,at least not at check out.:hammer:

[Rockstargazer]

If you ask me the skill, art and craftmanship involved with fabricating lenses and adjusting glasses has all but been abandoned. There are still some of us "old timers" out there with the skills and knowledge but too far and few between. I had to stop inspecting my friends and family's glasses, I got so disgusted with what I saw it wasn't healthy.......... and of course they wouldn't follow my advice and have them redone, oh no, I can't ask them to do T H A T....... Yikes.

Pin bevels are a life saver with moderate to high minus Rx's. If you've ever had a patient come in after doing a face plant with their -7.00's on and no pin bevel existed, you'd never send another pair out the door without a pin bevel...........

[apaul]

Hi!

Doh!
Whats a pin bevel?
never heard of it in the UK
chamfer?
Alan

[Jacqui]

Hi!

Doh!
Whats a pin bevel?
never heard of it in the UK
chamfer?
Alan

Same thing, also called a safety bevel

[Leo Hadley Jr]

I used to be able to hold the lens on the diamond wheel making a pin bevel with two fingers and let the circulation roll the lens up my left arm across my chest over the right arm and sail it across the room to land gently on the right side of the tray like a frisbee.

Perfect pin bevel every time!!!

At least thats how I felt

The pin bevel was an art and should still be. It amazes me how many people would upgrade their edgers by thousands of dollars just for a pin bevel, groove, and polish function. Technology will soon kill the human pin bevel as we old timers die off.

I had about a 5 diopter curve in my old ceramic wheel from all those pin bevels:bbg:

[apaul]

hang about a pin bevel is a chamfer?

[HarryChiling]

When I worked at Homer Optical, we turned the pin bevel function on the machines off and did them by hand. When working in a higher volume lab this would allow us to bevel while the next lens was cutting. I still to this day put bevels on by hand even though the machines these days can do it for you.

I also won't let an optician that I am training touch any of the machines untill they have marked a lens center without a lensmeter, ground a blank down into a frame by hand, and neutralized a lens without a lensmeter.

I think thats why all the opticians that I teach always end up having another optician train them. I apparently expect to much from them.

[Diane]

When I worked at Homer Optical, we turned the pin bevel function on the machines off and did them by hand. When working in a higher volume lab this would allow us to bevel while the next lens was cutting. I still to this day put bevels on by hand even though the machines these days can do it for you.

I also won't let an optician that I am training touch any of the machines untill they have marked a lens center without a lensmeter, ground a blank down into a frame by hand, and neutralized a lens without a lensmeter.

I think thats why all the opticians that I teach always end up having another optician train them. I apparently expect to much from them.

As anyone who knows me, knows....I love new technology. I also love that training the way you do, teaches why technology works, or not. Having a real picture of the process makes an optician understand the finished product so much better. Besides, there's something about the feel of the lens turning in your hand over the ceramic wheel.

Diane

[Chris Ryser]

This may sound silly, but since when did labs start using a chain saw to pin bevel their lenses?
AA

Here is a question from an old fox that is totally puzzled:

What is a pin bevel ??????????? anyhow :hammer:

[harry a saake]

Chris , if i rememeber right, the term came from the fact that the width of the pin bevel was about the width of a pin.

Back in the good old days of pin/safety bevels, done on a ceramic stone, i became so good at doing it , that i was able to do one in each hand, at the same time. We would usually save this little scene for the visits from home office and corporate people. I do have to admit that since we were only doing S-7 and S-10 shapes it made it easy.

[drk]

Pin beveling is "touching off" the sharp posterior edge of a minus lens. If done correctly, it will feel soft to the finger tip, and if not done, the posterior edge will feel like what it is: a sharp object.

The trick is to "touch it off" minimally, so you don't get a goofy-looking ring reflection from the front.

It's important cosmetically and safety-wise.

[harry a saake]

DRK, almost right, depending on what material you are working with, in the old days of glass lenses we did both sides, as both sides came out sort of rough. now, i admit a lot of that was probably due to the equipment we had in those days, but pin beveling was done on all lenses, - or +

[Chris Ryser]

Chris , if i rememeber right, the term came from the fact that the width of the pin bevel was about the width of a pin.

Harry, That means that the pin bevel is the equivalent to the safety bevel that was done on all lenses. If you did not have it on glass lenses.........any and all powers, specially plus lenses with the thin edges............they would chip at some point.

If you would not put it on a lens when doing the practical part of the opticians exam.........you would flunk it.

You should actually do such a fine bevel on a ceramic wheel because it is a lot slower to remove material and gives a smoother finish.

[Rheaopt]

I have a newer machine that safety bevels the lenses, but have turned it off for the lack of producing consistant bevels.
I do all my safety beveling by hand. All plastic lenses get a safety bevel on the back side, this includes every index and material. Glass gets safety beveled both sides.

[PNKansas]

I have noticed a significant problem that I have seen with the "auto" process of pin beveling on certain edgers.


Even at OLA last November the machinery that was running on the floor couldn't produce a consistent pin/safety bevel in front of me due to the curvature difference. Meaning if you have a lens RX such as Plano - 2.00 x 180 you'll notice that the nasal and temperal edges will not have any pin bevel but the top and bottom of the lenses will. This is due to the minimum edge settings of the pin bevel. If the edger sees the edge of a lens to be....say....less than 1.8mm then it will completely skip that edge and move on to the edges that are above that measurement on the same lens.Thus one of the reasons for such an irregular and inconsistent "ugly" looking pin bevel.

Technology is great....but in the mean time don't through away your ceramics just yet!!:cheers:

[Aarlan]

Sorry about the confusion...When referring to a safety bevel, I interchange that with 'pin bevel'. Some old optician used to call it that and it stuck for me.

AA

[rbaker]

The geometry of lens edger axis’ precludes their use to consistently“ safety bevel” or “pin bevel” lenses of varied sizes, shapes, base curves and thicknesses. You have to do it by hand and you should do it to all lenses.

[Chris Ryser]

You have to do it by hand and you should do it to all lenses.

Amen

[QDO1]

The geometry of lens edger axis’ precludes their use to consistently“ safety bevel” or “pin bevel” lenses of varied sizes, shapes, base curves and thicknesses. You have to do it by hand and you should do it to all lenses.

im 100% there with you on that one

i rejected a job yesterday - saftey spec's - ons side - a pin bevel (looked like it was done with a chees grater, the other - no saftey / pin bevel at all)

BTW - -5.00 Rx (ish) Aviator - NICE!

[Dave Metzger]

I miss glass , especailly cruxite A or B. running the edge of the lens on the wet wheel creating a soothing whine, irritated my coworkers but I marveled how even and smooth the edge turned out to be. I also started at the left side of the wheel and traveled across the entire wheel so I only had the retrue the stone once in 25 years when i had vacation relief for one week and that so and so cut a groove in the wheel by staying in one place!!!! BTW , those automatic safeties are fine if the machine is calibrated correctly

[Psalls]

If you ask me the skill, art and craftmanship involved with fabricating lenses and adjusting glasses has all but been abandoned. There are still some of us "old timers" out there with the skills and knowledge but too far and few between.

You got that right!!

After 30 years in this business, it's amazing (although not really) how little Opticians actually know about fabrication. Of course when I got started, it was the same way then too

[Maru]

I can't agree more about how some optical shops lack craftmanship.

I had a pair of -6.50 & -6.75 polycarbonate Quantum Transitions lenses and the edges looked very unsightly. I took photos of my two previous eyeglasses to show the store the difference between those and their workmanship. My new lenses are thin at the center but curved very abruptly and steeply towards the edge. As a result, my lenses look like mini goggles - thin at the center with "wings/shields" on the side. The edges were also sharp. In contrast, when I look at my older lenses there isn't a very visible difference in the center and edge thickness (I had an older lens with -6.50Rx which I compared with the new -6.50Rx lens) because the curve rises more subtly. The edges of my older lenses are also nicely beveled softly.

Frustrating. I never thought to ask about craftmanship when I had my new lenses made because, having had no previous experince of ugly-cut lenses, the question just never crossed my mind. I simply thought everyone in the business knows how to cut lenses. I'm trying to convince the store to "fix" my lenses to an acceptable level of workmanship. I don't know if they're going to give me a refund if they can't "fix" my lenses. I hope they do since my graduate student budget only allows me to get eyeglasses made after several years (it's now actually 4 years although I previously had eyeglasses made every other year).

Maru

[Andrew Weiss]

LIke some other old-timers, I started putting safety bevels on glass lenses on a ceramic stone. I still put safeties on both sides of the lens (even on poly), and am especially attentive to grooved rimless lenses. I see too many of these flake because there was either no safety bevel or a sloppy, cursory one.

[loncoa]

Today's business owners want none of this "skill" crap (at least most don't). It costs money. They are way happier with 95% of their employees being straight off the street because skilled labor costs too much. With edger technology (not to mention surfacing technology) being so "advanced" this leaves only the requirement that a minimum number of qualified people be on site. This is a great tragedy which ain't going to reverse itself any time soon. However, we can take some small comfort in that every skilled profession is in the same (poorly-crafted) boat. In my area (which is pretty small) we have shown at least some success with folks who get tired of poorly-made products. Unfortunately the larger the marketplace, the less impact quality-minded type of people have on "big-box" opticals doing high volumes with unskilled workers and driving us out.