Polycarbonate Lens fractures!

[choppa]

Here is a picture, let me know what you guys think might be the problem.

[Fezz]

That has been my experience. Often times we get drill mounts that start spider-webbing around the drill holes due to exposed material getting hit with some sort of chemical.

I don't use poly for drill mounts, but if I did, I would use Chris Ryser's company (OMS) product:

Drill seal!

http://optochemicals.com/main-english.htm

I have used it with great results (used it yesterday actually).

[mdeimler]

Back to the OP...larger, thinner lenses flex in the machine and cause that to happen. "Spider-webbing" is completely unrelated. Slow down the feed or use the slower settings in the machine and keep the blades sharp.

[choppa]

Back to the OP...larger, thinner lenses flex in the machine and cause that to happen. "Spider-webbing" is completely unrelated. Slow down the feed or use the slower settings in the machine and keep the blades sharp.

Thank you, so is the picture I posted a problem with the AR or the poly?

[choppa]

Talked with national optronics, going to give some new settings a try. I guess it is the AR

[AngeHamm]

I have been seeing more cracking in poly in the past two years than the previous 20.

[Fezz]

I have been seeing more cracking in poly in the past two years than the previous 20.

+1!!

[Kara]

I don't use poly for drill mounts, but if I did, I would use Chris Ryser's company (OMS) product:

Drill seal!

http://optochemicals.com/main-english.htm

I have used it with great results (used it yesterday actually).

I don't like using poly either. Unfortunately, since we work on the lab side we get persistent optical accounts that swear by them. Despite, my avid pleading. lol. Oh well, what can you do. I may look into that drill seal though, that sounds interesting.

[mdeimler]

The poly material "bends" under the pressure, whereas the A/R doesn't bend. It's like a tinted window.
If broken, the window (the A/R) cracks but the tint (the lens) can flex and still remain whole.