Strange surfacing Problem

[edKENdance]

Thought I would just mention that the "similar" job we surfaced on Monday was fine however someone had ordered a Sola VIP transition lens so it can't really be compared.

Hey Jubilee, we also surfaced an instock flextint semi-rimless which was quite on the thin side. A few extra seconds during the fining process would have nixed it. Still wouldn't be surprised if it comes back with a chip.

[Pete Hanlin]

I tried to read most of the posts to see if this has been covered previously, but I haven't seen it, so...

Was the frame actually traced- or were the only datum measurements given?

[edKENdance]

Hey Pete, the frame wasn't traced but the measured were accurate. BTW we've started adding .3 to our centre thickness which seems to be ok for now.

[Pete Hanlin]

Actually, even with good measurements, you can get thickness errors that are avoidable with a tracing. I have a nifty graphic that shows why (actually, I think its from JRS's files).

Glad you've found a solution, however!

[Jubilee]

I would love to see the graphic. Unfortunately the way our systemes are set up, tracing normally doesn't occur till it is on the finishing end of things. The tracer is on its own system with the edgers only.

If it would be more beneficial to have them traced before hand, since accurate measurements alone aren't sufficient, I think this is something we should get out to as many of our stores as possible. Is it being suggested that all the equipment should be on the same system. So that the tracing information gets fed accurately to innovations? How much better is this than just getting accurate measurements? I am looking from the perspective of, if my store has issues with thickness on a couple to three jobs a week, and so does my husband's, and so does Ken, then logic says that we are wasting lots of lenses, and money every week that might be preventable. If I can get a good arguement for this, I can get it presented to the people that can change it...at the end of next week.

Thanks,
Cassandra

[Blake]

We've started tracing ALL plus lenses over +2.00 - especially rimless. The new job ticket (using tracer measurements) sometimes changes CT by as much as 1 mm!
Too bad there isn't an easy way to get that info. to Innovations the first time. Unfortunately, Eyenet doesn't have a place for ED Axis.


Blake

[zonelinks2004]

Hi all!
i am a new memeber.
Can somebody please let me know wat transition lens are?
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http: www.zonelinks.com
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The Power Link Dimension

[zonelinks2004]

hello every body!
wat is the bone of contention here?


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http://www.zonelinks.com
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The Power Link Dimension

[edKENdance]

Here's a new one for anyone using an SGX.

OD +8.50 -50 x75
OS +7.75 sph

We surfaced with a spectralite 7.75 base and 1.75 add ST28

OS was perfect

OD was messed up, big time. First of all, we have our SGX set to generate multifocals with the reading side in the down position. The specs in the SGX were correct but instead of rotating the axis to the correct "down" position it was 90 degrees off. We don't regularly do these kind of powers instore so we trusted the specs and figured that because it was a small cyl we could always change it if it was off axis. We added 3/10's thickness to the specs because we knew there could be problems.
After surfacing we ended up with a +13.00 about 3mm above the seg with a 5 dipoter swing about 5mm above that to a +8.00. I am familiar with the swing of powers in aspheric lenses but this seemed waay beyond normal. Do you think it was a computer glitch caused by software? I Work for LC but if I was an independant that spent a ton of cash on this machine should I be ticked off? We ended up farming the job out to our lab that will most likely mess it up. Can't blame 'em for it now. It's still bugging me.

[Jubilee]

I seem to recall having that problem once before..What lap did it call for? Did you have to use foam? Does your generator cut foam reliably? ( I know our loaner right now doesn't, we have to comp it)

I am off today, and tomorrow is a trip report, after they are gone and if we aren't busy I may try to run a rxcalc and see what I come up with.

[shanbaum]

Here's a new one for anyone using an SGX.

What you really need to do is contact your Innovations Help Desk.

The first thing they're going to ask you for is a copy of the job ticket, and a transcription of the information that was received by the generator.

The 90-off bit can happen if Innovations is set (as it is by default) to rotate the surface by 90 degrees to keep the flatter curve the base; the generator may do the same thing (depending on the software version in the SGX).

This happens most frequently when grinding a saddleback or convex surface, in which case you could end up with (for instance) a +0.50 base (convex) and a plano cross - you'd be better of with a plano base and +0.50 cross, so that's what we do.

Regarding the power, well, I'd need to see some of the info I mentioned.

[edKENdance]

Here are the generator specs in brief:

blank front curve:7.59
blank back curve:-6.00
diam:80.00 mm
edge thickness:8.9
Base curve: -0.16
Cross curve: +0.33
axis: 75 degrees
centre thickness:9.12

no decentration and no prism power.

Forced aspheric on.

I notice on the job ticket that the base is set to .12 and the cross is set to minus 0.37. Not sure if I copied the info from the SGX correctly because the +/- is reversed. We often see 1/100 increment differences between our job ticket and the specs on the SGX but I didn't notice this untill now.

Let me know if you need more info and thanks for the help.

[bwheeler]

Does the program account for the asphericity and total add of the lens to calculate final thickness perameters? When the lens is too thin, where on the shape is it too thin? Could be a combination of the above mentioned and cylinder power. There is voodoo in the menudo.