Final Check of an ARRI 2B
A week ago, a customer ordered an ARRI 2B camera to learn how to shoot film. As sometimes camera will sit here for a while, I always do a service on them before they get shipped out to make sure everything is in good condition. And I started to do that with this camera. You know how those simple jobs turn out to be the most complicated ones? On most of the ARRI 35 2 series of cameras, there is an inching knob that sticks out through the casting on the side of the camera with the thumb grip. This inching knob has a tiny little screw that threads through the knob and one of the drive shafts on the camera. In order to remove the back of the camera casting to expose the various gear boxes that drive the pull-down claw and the mirrored shutter, this inching knob has to be removed first.
Of course, when I went to remove this tiny screw, the screw head broke right off. While small, this is a fairly complicated screw that is threaded in two separate places. After several minutes of thinking about drilling it out, punching it out, setting dynamite to it, etc., I realized that there was no safe way to forcibly remove the screw and not damage drive components in the process. After walking away for a day and letting it think about what it had done, I thought about a gear puller. You know, those things with three claws that hook on a gear, then there is a screw that pulls the gear off the drive shaft. I have a drawer full of these, but none of them fit. So, after a couple of quick sketches, I designed and machined a quick gear puller that would work just for this purpose.
This worked fine! It pulled the knob off, sheared the screw like I’d hoped, and didn’t damage any of the internal parts. Because the original screw is threaded at both ends, it wouldn’t just come out without damaging the inching knob, so I had to drill those portions out. And because I don’t have metric tooling in that size, I had to drill and tap the holes for imperial sizes and them make a custom screw that would hold the inching knob in place and still fit through the metric hole in the drive shaft. All that done, the camera is now back together and working like a champ.
