Most of the newer lenses and cameras I've come across are easily dissasembled with a few jeweler's screwdrivers and some determination. The older cameras and lenses I have, however, need something called an optical (or lens) wrench to apply the even force required to unscrew the large threaded rings used to hold the lens elements in place.

I didn't own one and the commercially available ones were more expensive than I wanted to pay just to satisfy my curiousity about what was inside a lens. I do have an old camera I need to take apart to repair. The camera cost me $9 and I wasn't planning on spending far more than the camera for the single-use tool that is a lens wrench.

As usual, I figured I could just make one. What I came up with worked just fine for my needs and is quite flexible.

Tools:
	A dremel tool and various bits.
	A power drill and bits.
	Files and taps galore.
	ear/eye/respiratory protection.

Parts:
	Steel sheet, 1/8" thick.
	Small bolts and wingnuts to match.

I worked out a schematic for what I needed in my favorite vector-based editor. The file with several size versions can be found here. What I actually made was two of the left componant of the size three version.

I printed out the schematic and cut around the size I wanted. I taped this piece of paper to the sheet steel and proceded to remove the excess metal. The circles were center-punched and then drilled out. The outside and inside edges were then cut with the dremel. After some filing the parts would no longer cut through leather gloves and were perhaps safe to handle. The bolt you've got should smoothly slide back and forth within the grooves you've cut. Turn one piece around and put the bolt through both slots. Tighten the wingnut into place and you have your adjustable lens wrench.

The right componant in the schematic would be made in basically the same way. The two holes would be drilled out slightly smaller and then tapped to fit the size bolts you've got. For this piece, two bolts would be permanently secured by the threads. Each of the smaller parts would then be secured to this part by your wingnuts. I actually didn't make this componant, but doing so will give your lens wrench much more range.

My old lenses and cameras are now falling apart before my eyes. And easily enough falling back together again too.

Eventually I'll get you a photo of my nice new tool. I figure the schematic is simple enough to follow for those of you with useful imaginations, so I'm not in a rush.