lenses in the crib

[chaoticneutral]

Would someone please explain why lenses are cribbed? I just don't get it, and cant seem to find any information. Thanks =)

[rbaker]

This process is used to remove excess material prior to edging glass lenses.

[edKENdance]

The SGX I used to use had a cribbing function too for plastics. Assumed it was to remove excess material so the edgers would have less work to do. Mostly had a tendency to knock the lenses off the chuck.

[Outkast]

Most lenses plastic, poly whatever are all cribbed in the lab unless they are for a huge frame and yes cribbing lenses saves wear and tear on the edger, saves on coating costs, and helps with getting a better surface when fining and polishing. If youre LMS and calibrations are off though the cribbing can cause the lens not to cut out correctly when finishing.

[ml43]

on certain generators, such as the NO 2G, when the blade starts to get dull. If you don't crib, there is a higher chance of deblocking, mostly on higher plus powers.

But yes, mostly to reduce edging time and wheel wear and tear. Fining/polishing, especially on high back curves tends to be less problematic as well

[MikeAurelius]

Less surface area to grind and polish. Less wear and tear on roughing diamond wheel.

[scriptfiller]

Less edger rotations less instance for the lense to get twisted off axis.

[Uncle Fester]

This process is used to remove excess material prior to edging glass lenses.

This guy's old school.

He sounds like a ringer too me!

Now who wants to show their age and explain a "ringer"?

(Except for some truly interesting jobs we made by hand at school I've never since hand cribbed.)

[nicksims]

Well on plus lenses, it is nice to handle a lens that doesn't have razor sharp edges. But I really thought the lab just wanted to send me lenses that were too small to edge.

[harry a saake]

Well on plus lenses, it is nice to handle a lens that doesn't have razor sharp edges. But I really thought the lab just wanted to send me lenses that were too small to edge.

cribbing goes all the way back to the old days of glass lenses, at B@L where I started in 1965, we constantly cribbed lenses, especially dualens, as it saved wear and tear on the generator and the edgers. In fact B@L even had a specially made by them cribbing table. The table had a concave drawer that pulled out, and you cribbed the lenses over it and the glass pieces would fall down to the bottom most part of the drawer.

Somewhere around 1970 Coburn came out with an automatic cribber, in there patented green color, that you could chuck the lens on it, and have the lens come out any size or shape you wanted.

[rbaker]

This guy's old school.

He sounds like a ringer too me!

Now who wants to show their age and explain a "ringer"?

(Except for some truly interesting jobs we made by hand at school I've never since hand cribbed.)

How about hand rocking cylinders in glass lenses?

[harry a saake]

How about hand rocking cylinders in glass lenses?

rocking, yes, I have done that also, I think if I remember right 6 cylinders and higher

[MikeAurelius]

Better still: going down to the local hardware store to buy different diameters of steel pipe to mount in the lathe to grind plano cylinders. Now that's hardcore LOL!!

[waynegilpin]

cribbing goes all the way back to the old days of glass lenses, at B@L where I started in 1965, we constantly cribbed lenses, especially dualens, as it saved wear and tear on the generator and the edgers. In fact B@L even had a specially made by them cribbing table. The table had a concave drawer that pulled out, and you cribbed the lenses over it and the glass pieces would fall down to the bottom most part of the drawer.

And pinching the fleshy part of your palm with the cribbing pliers was just part of the fun.

[rbaker]

I still have scar tissue on the back if my hand from a hot pitch spill in the sixties and I spent two weeks trying picking the hardened pitch out of the holes in my new wing tip bluchers.

[Gizzo]

This process is used to remove excess material prior to edging glass lenses.

I still have my cribbing pliers. Scary Days. There never was any money in the mud pan...

[himmeroo]

I remember drilling glass lenses with the diamond bit with the cooling oil. Those were the days. Also, losing all your arm hair when the photogreys exploded in the generator.

[chaoticneutral]

Well, that makes a lot of sense of course, to make the lens smaller so the edger's don't have to work as hard. Thanks everyone!