I have read some on here about using the score and snap method but I doubt that would work well with a fused set from an OHP . Is there a "perfect tool" out there for cutting the fresnels down to the size I need? (it's for a 7" screen) I am thinking a table saw but I would hate to destroy them by guessing.
thanks

I have used a table saw twice and it works great just put a board underneath so you dont scratch it up when sliding it.

hey when you do seperate them can you tell me what the focal lenghts are I always get like a 330 and a like 450 or so can you tell me what you come up with.

Tablesaw with a fine-tooth blade will work fine.

Be careful to keep the center of the fresnels in the center of the final lens when you cut though.

Anyone ever try a hot knife?

Thanks guys, I don't have one so I am going to have to call in a favor with a handy friend. These lenses came from a old school 3M model 300 OHP, they are very strange because you can't see concentric grooves...it's like fine lines running at differant angles. I know they work well because I have tested them on my current rig.

What is a hot knife? (lol, as I google it) ok, "Hot Knife":
The Creative Hot-Knife comes with 2 blades and a tool stand. This is also an on/off switch for added safety. The Hot Knife blades are made with one piece construction for easier use and saftey. The blade cuts through foam core board like butter, also can be used with plastic foam, candles.

Seems like a mix of a soldering iron and a an Exacto-knife. If I can't get my handy buddy to carve these things up this is option #2.

Well this is my experience with the hot knife it was not hot enough and I couldnt cut thru it at all but somebody did have a good experience with it so good luck.

I have always found that applying masking tape top and bottom to the plastic can lower the likelihood of chipping and also makes marking the cut line much easier. Hope this is helpful.

great suggestion, I found the buddy with a fine tooth table saw and he wants me to repair his laptop