Pits or dings in lenses edged by Santinelli 9000

**Ruth** · 02-19-2003, 10:48 PM

First I want to thank those of you who responded last month when I posted to Aaron's thread in his search for a choice of patternless edger. You were really helpful.

It turned out there WAS an electrical problem, which has been fixed. The wierd problems with the machine (axis & size settings not holding) continued, though, so I finally got Santinelli to give me a loaner and take the original machine to their shop for diagnostics on the computer chips, motherboard, etc.

One of the problems we had experienced was that, on rare occasions, perfect lenses came out of the edger with "pits" or "dings" in the front surface.

The responses I got on the subject suggested it had something to do with the blocks. But the blocks are plastic and couldn't have created these dings, and besides, the dings were not near or under where the blocks were placed.

So yesterday, another lens was ruined ("dinged") in the loaner machine!

The folks at Santinelli claim they've never had a customer having this kind of problem. We find that really hard to believe, having now experienced it on 2 different machines.

So, please, let me know if you've had this problem, and, if so, what it took to fix it!

Thanks!

**Jeff Trail** · 02-20-2003, 12:04 AM

Ruth,

Is it an air chuck or electric chuck system? .. Usually in a ding or chip the up near the leap block BUT after the lens is released from the chuck it appears "away" from the block the chuck is "binding" the lens and it is warping it ..next time you clamp a lens in and hit the chuck see if it appears to be warping the lens way to far.. another thing to do is after you chuck the lens take a very fine point marker, mark several dots around the chuck.. than release the lens and see how far those dots move away when the lens relaxes back to it's original base curve...
Just some thoughts to start running down the problem

Jeff

**Augie** · 02-21-2003, 10:28 PM

Here's a question? what are you using to unchuck the lens? I have used several diffrent 9000's in the last few years and the only time I have seen dings was...ready for this? The person was unchucking the lens with a chappel(sp) plier. They used only half eye chucks and never got a "normal" unchucking tool. It seemed to only happen on poly as well.

**Ruth** · 02-22-2003, 09:21 AM

Thanks, Jeff & Augie, for your responses.

I tried Jeff's suggestion about marking the periphery of the chuck pad and didn't see any sign of warpage. However, I did discover that, at least for the latest "dinged" lens, the dings were just at that edge.

To answer Jeff's question, the chucking system is electric.

To answer Augie's, we use the plastic dechucker provided by Santinelli.

We do mostly polycarb, and we thought it was a problem related to that, but this latest lens was CR-39 polarized.

Part of the frustration is that this only happens occasionally; hasn't happened now in about a week.

Does anyone think it's possible that debris while edging could be getting caught by the leap pad and jammed into the lens? My lab manager says some of the dings were too far away from center for this to be the answer, and that one of them was very center and had to be under the chuck, so we're really confused.

Any other ideas?

Thanks!

**Jeff Trail** · 02-23-2003, 01:36 AM

Happens every once in awhile huh? ...ok than your next step is to check the "power" and base curve of the lens that is dinging (is that a word :)) ... maybe that is why it is happening only every so often.. another thing to track is does this ever happen in SV or just bi-focals etc., etc..
I know on higher adds sometimes I'll fold a leap pad over and place it above the seg line than the leappad/block set flush and not at an angle ..I also have electric chucking.. it has two settings first click to really seat the block than back a click for edging.. can you calibrate the pressure in your edger in the chuck? Might want to run a little chart to see if the dings are coming from all powers and curves types of lens (SV,BF,PAL etc.. ) or you might just see a pattern start to develop that will tell you where the problem is at..
I think running a chart.. or if you tossed the lens with the dings in a box to the side checking them I bet you'll probably find a pattern to the lens type and base curves..that is why it seems to be appearing is "random" dings :) not running the same exact stuff constantly.. might be worth checking..

I know how frustrating it can be..

Jeff "been there about a million times" Trail

**Ruth** · 02-23-2003, 02:05 AM

Hi Jeff, and thanks again for your interest!

Can't tell you base curves, but all affected lenses were either SV or PALs, so we can rule out segs as a cause.

This is especialy frustrating since noone else has posted that they've had the same problem! Lots of lookers, only 2 repliers! Anybody, please help! I would appreciate it so much!

Thanks!

**Augie** · 02-24-2003, 09:50 PM

I just thought of something else, what about the wheels? The finishing stone, because you said that it is only happening on the edge of the lenses...just a thought.

**Ruth** · 02-24-2003, 10:50 PM

Thanks, Augie, but the dings are not at the lens edges. The most recent were at the point where the chuck pad met the lens. Anybody have any other ideas? Thanks!

**Rich R** · 02-25-2003, 11:16 AM

Sounds like a chuck pressure or have you checked for any sharp edges on one or more of the leap blocks that could be digging into the front of the lens.
Rich R

**harry888** · 02-25-2003, 10:50 PM

What about when you dot the lens in the lensometer? I've had staff ram those little pins into the front of the lens like a jackhammer.

Harry

**Ruth** · 02-26-2003, 01:27 AM

Thanks, Rich and Harry, for your responses.

The chucks are plastic, and I have inspected them, can't find a problem there. And all but one of the dings are nowhere near the lensometer dots. Go figure!

I will ask Santinelli about the chuck pressure, though.

Thanks again!

**Ruth** · 03-08-2003, 09:06 PM

Hi everyone,

Thought I should give an update. I've tried a few things since I last posted, and haven't had a recurrence yet, although that doesn't mean much, since it has always been a rather rare occurrence.

The Santinelli "1/2-eye block" is a rectangular shape, slightly larger that the new smaller "1/2-eye" 3M leap pads. Half the techs at Santinelli say it's good to use the smaller leap pads, the other 1/2 say we could damage lenses using them. So we don't use them, and, instead, cut away the excess of the regular pads.

We had been using a pattern-cutting scissor to do this, until I noticed the other day that it left the pad edge in a serrated condition, & it occurred to me that that rough edge might be collecting debris which might occasionally get jammed into the lens. Now we're cutting with a regular scissor.

Simultaneously, we reduced the chuck pressure, so now, of course, if the problem has been solved, we don't know which action fixed it, or if it needed both!

I'll let you know if we have a recurrence, if this thread is still around when it happens!

Thanks again for all your help! This is a truly wonderful web site!

**OdTech** · 03-12-2003, 07:18 PM

Hello Ruth:

I may have some productive info, which you've already did.

i spoke to gerber-coburn member and told him about the problem like:
"Marks on the lenses which are coated and which are progressive etc.." what is the cause of it?
i told him about the "Chuck pressure" like electric chucking.

He told me that gerber company making and fixing the chucking system so it would be "slowly going, not fast" that is why if it's fast it will make a mark on the lens and rip off the coating on the lens.

i hope this is helpful to you.