Even More Too Many Projects

Last week we had a sneak peak at the Moviecam SuperAmerica and the two Showscan CP65 cameras as a couple of the many ongoing projects on my plate right now. On my list of tasks this week were: sourcing and ordering new batteries for the SuperAmerica camera and magazine digital counters; begin planning the baseplates and the accessory blocks for the Showscan cameras; and continue work on building the second display rack for the showroom. In the middle of all of this, a long-time customer brought his two Fries Mitchell cameras in to show me an interesting problem. He had bought some modern PL mount lenses where the diameter of the back of the lens wouldn’t allow the lens to fit far enough back on the Fries PL mount to lock the lens in place. I spent a little time looking at the lens and evaluating why these lenses wouldn’t seat completely.

It turned out that on the Fries version of a PL mount, the locking ring has a tapered front end where the taper wouldn’t allow this lens to fully seat in the mount. The problem with this lens and mount combination was twofold: I needed to figure out how much material I could machine away from the lens locking ring and still have enough material left to reinstall the lens locking tabs. The compromise was to leave a little more than 1/16in wall on the outer edge of the Fries locking ring and machine away enough of the front of the locking ring to allow the lens to fully seat on the PL mount. This left most of the threaded holes that hold the lens locking tabs in place so the tabs could be safely reinstalled. I installed a set of copper soft jaws on the lathe, indicated the lens locking ring to run true and parallel within 1/1000th of an inch, and began machining away the front surface of the mount 10/1000th of an inch at a time, until I got to the dimensions I had calculated. Once that was done, I reassembled the mounts and lo and behold, this lens now mounts fully and locks in place! This detour in projects kept my long-time customer happy and only took 4 hours out of the day. Now back to work on … everything else.