Edger chipping lenses

[Kurt Brandon]

One of the edgers that I use at work is an A.I.T Mark 5 Deluxe.

On several of the plastic lenses that I have edged, I have noticed edge chipping sufficient to make the lense unusuable.

These lenses were not mishandled or dropped.

What sorts of things should I look for by way of solution? I have already decreased the pressure, which was around 30 pounds. Is there anything else?

[shanbaum]

Originally posted by Kurt Brandon:

One of the edgers that I use at work is an A.I.T Mark 5 Deluxe.

I'm tempted to say, "well, there's your problem," but I'll resist the temptation (oops, I didn't).

First of all, determine whether the excessive chipping occurs on the roughing wheel or the finishing wheel.

Having determined which wheel is the culprit, hone that wheel - a LOT, use at least an entire dressing stick (4" - 6"), assuming it's a bonded wheel. Do NOT hone an electroplated roughing wheel - there's nothing you can do to "fix" one of those, you just have to replace it.

If it's the finishing wheel, you'll need a diamond tool to dull the wheel afterwards, or your bevel will be uncontrolled. But before you do that, see if the chipping persists by edging a throwaway lens.

On second thought, the Mark V usually has a bevel guide, and a wheel profile that pushes the lens against it (so that the bevel follows the front of the lens). If that's the case, you may not need to worry about dulling the finishing wheel after sharpening it - unless the wheel takes too large a "bite" out of the lens as it slides across the wheel on its way towards the guide (in which case, you have to dull the right side of the wheel).

If that doesn't solve the problem, you may need to replace the offending wheel (or better... the offending machine :) ).


[This message has been edited by shanbaum (edited 08-08-2000).]

[Jeff Trail]

Robert,

I would lean more towards it being in the roughing wheel.. probably a bad "spot".. I know I run into the same problems (chipping) when I get a spot on my wheels on the Briot..
It usually is more of a problem on the higher indexed lens and plus PAL's ...
Oh well it's a guessing game on our part really.. but from my experience I lean towards the roughing wheel as the culprit .... oh one other thing, Kurt did you just replace any of the wheels? or is it a combination wheel on the rough (Poly/Plastic) ?

Jeff" grind em if ya got em" Trail

[This message has been edited by Jeff Trail (edited 08-08-2000).]

[EyeManFla]

[QUOTE]Originally posted by shanbaum:
[I] I'm tempted to say, "well, there's your problem," but I'll resist the temptation (oops, I didn't).


You were more diplomatic than I would have been. I actually was running one of those about a year ago as a back up glass edger.....I was only one of two people in the whole company who knew how to fix them.

I remember when they first came out in 1897.....I was trained by Messers. Bausch and Lomb personally...................

Assuming that the machine is in good shape, and they usually are, yes, the roughing wheel would be my first suspect...expecially if it is a smaller wheel.......

The best way to fix it would be to get a Briot........