SGX Plus.

[dave.fant.lab]

Hello!

Here recently our SGX went down and we upgraded to the SGX Plus. One feature that we took for granted until we received the SGX Plus was the recut lap setting for generating foam laps. This feature seems to be no longer included with the SGX Plus, thanks Coburn! Ha. I have yet to test it, but has anyone tested to see if its feasible to recycle the laps at all in terms of a second use? It seems like such a waste throwing some of these laps away that we no doubt used to get a second cut on with the regular SGX on the lap.

Any input would be greatly appreciated.

[dcf]

Hi Dave,

I did not write the original SGX software, but I have poked around in the code rather a lot. I don't recall any foam lap recut feature. But, it is possible that someone at your lab setup a set of cutting parameters on the your old SGX for foam laps under the lens material list. There is a "lens" material called PLAP1 that is used for cutting hard plastic laps (as opposed to foam laps). One of the lens material parameters is called "Lens is lap." That indicates that the material parameters will actually be used for cutting a lap rather than a lens. From the Job Edit screen you would select PLAP1 as the Lens Material and leave the LapMaster field in a no cut state. This gives you the ability to describe the lap dimensions as if you were describing a lens blank. That gives you the flexibility to specify a center thickness that will cut deep enough into the lap to eliminate its previous curves. The PLAP1 parameters probably aren't great for foam lap cutting, but it gives you a place to start.
Of course you will have to be careful about cutting too deep into the foam laps. The plastic lap adapter extends well into the center of the lap. I haven't tried reusing foam laps so I can't say how secure they will be on the adapter.

[Stephen Brown]

Hi, I reuse foam laps all the time. I never take them off the lap adaptors and get about 4 or 5 ( depending on curve change from lap to lap) out of each one.Just go into foam lap settings and change lap space from 11 down by 2mm or so an each recut of lap. You can go down to 3mm. As for sgx plus softwear YOU can change eproms. They will tell you that it cant be done but it can ( I have done it). In uk we had sgx lite and turbo. The lite had restricted curves and settings but apart from the eproms, is the same.

[MakeOptics]

Hi, I reuse foam laps all the time. I never take them off the lap adaptors and get about 4 or 5 ( depending on curve change from lap to lap) out of each one.Just go into foam lap settings and change lap space from 11 down by 2mm or so an each recut of lap. You can go down to 3mm. As for sgx plus softwear YOU can change eproms. They will tell you that it cant be done but it can ( I have done it). In uk we had sgx lite and turbo. The lite had restricted curves and settings but apart from the eproms, is the same.

You could probably have an enterprising young computer programmer clone that upgraded eeprom and have two upgraded machines.

[RT]

Bearing in mind that your lens quality will never exceed your lap quality, you want to be careful about reusing the foam laps. There can be quality issues if the foam lap isn't rigid, or isn't rigidly held by the adapter.

It can be done, as Stephen Brown notes, if you never take the lap off the adapter, and you play with the foam lap settings. That isn't practical in laboratories that process more than a small number of jobs per day. You may also experience difficulty trying to reuse a foam lap on which you have cut a steep curve on the first cut. And I would inspect the lap prior to reusing it, and discard any that have been obviously beat up during fining/polishing, or that exhibit looseness on the adapter.