Film Holders – Progress
Thursday, February 21st, 2008It has taken me a while to sort out the dimensions of the film holders, and actually begin building them, but I am making progress. I assumed the film holders would be the most challenging to build, and they have been.
I started with the plan of only making a few holders. My thought was that because the camera will be so large, I won’t be taking it into the remote wilderness, so having a limited set of film holders will cut down on weight, and clutter. To change film in the field, like with any sheet film camera, I can black out a hotel room, or bathroom etc, or make a huge changing bag to use in a car. I also, concluded, that since this was just the first phase of the build process that they might not come out right, so my intention was to just get a couple working holders for tests and initial trials of the camera. If I decide I need more later, I can remake them, with the added experience, that, hopefully, I will have at that point.
My plan was to start making 5 double sided holders, with the idea that I might only get 3 working holders out of it. I figure 3 holders would be the minimum I needed to conduct tests and shoot my first photos. My assumption about only getting 3 out of the 5 is proving to be right. Film holders are incredibly difficult to build because of the 1/64th inch precision that is needed.
After milling the cherry down to size, I started on the task of cutting the 1/16th inch slots for the slides and septum. I opted to use a slot cutter in a shaper table. The alternative was to mill the slots, but that would have taken me into a whole other world, that I wasn’t prepared to enter. I figured the slot cutter would get me as close as I needed.
The slot cutter approach has proved to be challenging, yet I believe workable with practice and experience (neither of which I had when I started). I took me a day to really get a hang of it, and once I did, I was able to produce the results I needed. In the end, though, I lost 2 sets of rails, due to mistakes, so I am down to the 3 I had been planning for, and I think I am past the most demanding part of their assembly. The slot cutter is touchy on starts and stops and uneven pressure. Plus because I was cutting down the length of the pre-cut rails, any little wobble caused the slot to widen beyond 1/16 inch. I learned that if I cut the sizes down to their rough lengths, they are much easier to handle on the shaper, which is the opposite of other tools like the table saw.
The one major adjustment I had to make in the middle of the slot cutting was that the cutter only went to a 3/8th inch depth instead of the half inch I was told it would. The loss of that 1/8th inch could come back to haunt me, but for now I am going ahead with my recalculations. The new depths are basically scaled to what the tools could provide. The whole process required a lot of advice, and ingenuity in the cutter setup, so a thanks goes out to the shop master, Steve, who showed me what I need to know.
So from here on out, pretty much the rest of the camera will consist of cutting lengths, rabbets, tenon and mortises, plus the box joints for the rear standard; no more 1/16th inch slots, thank goodness. Oh, yeah, and the Aluminum parts; I still haven’t figured that one out yet. Hopefully these tasks will prove much quicker, and more forgiving, but I am not counting on it.