Have you looked at my list of focuault testers at http://nav.to/bobmay yet? I did a search for them about 6 months ago and got a bunch of them listed. Actually the design is pretty simple when you sit down and think of what you have to do for the motions. I suggest you do the slitless version as it's the simplest to do. I might note that I've been quite successful in getting shadows from just the edge of a LED!