Wood Field Camera repairgreenspun.com : LUSENET : Large format photography : One Thread
Just got back from a three-week trip, and spent half the time lugging the 4x5 as simply dead weight, since it broke on day 11.
The camera is an older Zone VI, and several years ago, one of the back spring screws pulled out of the wood. I replaced it with a threaded insert and brass machine screw and was waiting for the other wood screw to go. To my surprise, the threaded insert pulled out of the wood instead. I suspect I have a soft piece of wood, but now that I'm back home in Arizona, I have plenty of time to fix it right. To do the best job, I thought I'd put the question here for more input.
Obviously, the commercial threaded insert is inadequate, and I now have a much larger hole where the screw used to be. The primary choices I see are either to plug the hole from the back with a glued-in tapered plug, drill for a screw and replace the original screw, or else to make a tiny T-nut, drill the hole all the way through the wood and secure the bolt from the rear. There may be other solutions; I am not wedded to either of these. I do want the repair to be permanent, not some temporary fix.
Ideas? Thanks for the thought and input.
-- Anthony J. Kohler (firstname.lastname@example.org), June 06, 2001
It sounds like the original pilot hole for your threaded insert was slightly too large for the insert. Threaded inserts are often a challenge unless you use the correct tap hole, a specialized insert tool, and some type of lubricant on the threads. If this is the case, you might use the same repair technique with a larger size insert. Try to buy one that gives you specific pilot hole information for hard and soft wood and, if you don't have one, pick up a threaded insert tool.
Your other two strategies also sound workable. If you have a drill press and a plug cutter, the first approach might be the best in terms of cosmetics. I would try to cut a plug from cherry or a similar hardwood. I'm not sure which wood Zone VI used, but I would certainly cut a plug from material that will provide a good solid grip. You might search for some specialzed screws that give better holding power than ordinaty brass woodscrews. The other option you describe might be the strongest. If I read your post correctly, it sound like you would countersink the back of the wood and insert a threaded t-nut. The t-nut would sink into the wood and be held tightly from the reverse side by some type of bolt. My only question would be whether or not you have enough thickness in the wood to countersink and mount a t-nut. I suppose you can get a t-nut with a smaller diameter "neck" but I'm not sure you could find one less than about 5/16--particularly if you need to use a 1/4-20 or larger t-nut. Let me know how it goes and good luck!
-- Dave Willison (email@example.com), June 06, 2001.
You might give Richard Ritter a call. Here's his site:
-- Geoffrey Chen (DB45TEK@AOL.COM), June 06, 2001.
Tont, I thought the Zone VI cameras had a lifetime warranty. Why don't you contact Calumet Camera, they bought out Zone VI. Try 1-800-CALUMET. Good luck.
-- Pat Kearns (firstname.lastname@example.org), June 06, 2001.
Hi Tony, I don't have a clear picture of what is going on, but it sounds like you stripped out a wood screw? If this is just a question of missing wood in a small hole, often this repair is made by just gluing in a plug (whittled stick) with white glue and shaving the surface flat with razor sharp chisel and then redrilling. This is all very straight forward. If you don't like to mess with this kind of thing or have the tools, any fine wood worker, such as a instrument maker or furniture builder would have the tools to do it quickly. Best, David
-- david clark (email@example.com), June 06, 2001.