National Optronics 7E

[FullCircle]

Just curious - I have a 6E, and my main complaint against it is the relatively short blade. If you have a large blank with a thick edge, or a steep back curve, it will overreach the blade and make contact with non-cutting surfaces and ruin the lens.

Yup. That's our one complaint. Well, that and a small light inside so you can see bevel placement would be nice. Best thing we can do to counter the thick lens issue is hand edge the back edge until the edge thickness doesn't hand over (think really heavy safety bevel)

The one area we did have problems was lenses with really small B measurements. It would start edging the lenses so far to the left that it was cutting on the polish wheel! Come to find out, the front side feeler was touching the leap pads and using that to calculate the front base curve. So now we make sure the leap pads are flush with the top edge of the block

[DragonLensmanWV]

Yup. That's our one complaint. Well, that and a small light inside so you can see bevel placement would be nice. Best thing we can do to counter the thick lens issue is hand edge the back edge until the edge thickness doesn't hand over (think really heavy safety bevel)

The one area we did have problems was lenses with really small B measurements. It would start edging the lenses so far to the left that it was cutting on the polish wheel! Come to find out, the front side feeler was touching the leap pads and using that to calculate the front base curve. So now we make sure the leap pads are flush with the top edge of the block

One tip: For the itty bitty frames, we cut the leap pad flush with the block all around so the probes never hit the pad.

[uu|cd]

DragonLensmanWV,

We had this same problem, I called Optronics and they told me to change the Rough Offset from 5.0 to 10.0. This will allow the full blade to be used during roughing. Yes it will hit the bevel part of the blade but should have no impact at all. You can get to this by hitting the "Advanced" button then select "Setup" and you should see it there, hopes this helps.

[fjpod]

We found those disposable blades to be only good in cases of dire emergency. We've got the diamond blade from CDP and are in absolute love. I rarely use slip stop pads, crazing and twisting barely happen. We run CR39, poly (majority material), 1.67, other hi indexes, and AR without issue. I don't recall the amount of cuts we got off the last blade but I know we get it well into the yellow before we begin to see the beginnings of potential issues.

The problem we found with the diamond blade was that you can't predict when you are going to start having trouble. I think you are supposed to get 6000 cuts, but we started to have issues around 2800. Which means we had to "waste" the blade and change it because we had difficult, expensive jobs stacking up. We wouldn't know we had to change the blade until we ruined a few jobs. With the disposable blade, you know that as you approach 300 cuts, you should put aside your really expensive, hard to cut jobs and do them right after the blade change, which will be within a day usually. This way, we never ruin a job.

We found the cost per cut with the diamond blade, and the unpredictability of when to change it, not worth it. How many cuts are you getting out of a diamond?

[FullCircle]

At least 4000. I'll have to look and see when we change the blade again. Bossman and I base it more off sound and job qaulity more than cuts. We cut probably (roughly) 70% poly and poly/AR, maybe 5% High Index (including 1.67) and the rest CR39.

As I work for LC, we can't put jobs aside so the longer lasting blade works out better for us. The disposable blade didn't give us a very long usage before problems would arise. We had to change it every few days. The chattering was unnerving especially when using it in place of the diamond!

ETA: I think the reason we gt such great life span from our blades is the settings we have for material. We've got 2 CR39 (1 AR, 1 not), 2 Hi Index (1 AR 1 not) and 5 poly settings (poly, thick poly, very thick poly, poly Ar and Thick Poly AR). The different feed ratios and speeds really makes a difference. Choosing the right material for the job is crucial to job quality as well as blade life.

[DragonLensmanWV]

I tried a diamond blade and I changed it around 3000 cuts. When I looked at it you could see a couple of small chips in the edge.
I have the best luck with the extended life blade - around 1500 cuts reliably.

[Wes]

We've had that problem in the lab a few times. If I think it'll be a problem, I'll take the lens down on one of our horizon II edgers. If that isn't helping you what you can do is remove some of the material with a hand edger(safety beveler) before you edge it. We have 4 7e, 4 6es, 4 6e, 4 horizon II edgers, 2 4t tracers and a dell set up as a server for the 7e machines. We cut 600-1000 pair per day. Ft Jackson optical lab.