i have a 3m 9700 which i have taken apart to use the frensals and triplet lenses for a diy projector... i am working on making plans for my new projector but need to know what size these lenses are, including the triplet lens.... they are stuck together and don't seem to want to come apart, how can i get them apart? and how can i test their sizes if i can't get them apart? also, what about the triplet? thanks

Do you mean focal length of the lenses? The distances are already set when the ohp was put together. Measure from the stage to the lamp (bounces off a mirror so keep that in mind) and that's your lamp to fresnel length. The field fresnel side is adjustable so you'll just have to accomodate about 2 inches either way. I used a 3m 9200 and have the same kind of "dual focus" fresnels you do.

so if i measure from the lamp to the mirror to the lenses, that's how it should be in my enclosure(even though it's now a 400w mh) and then from the fresnal to the triplet(about center of the arm i guess) and same for the enclosure? right?