old lenses in metal boards

[Herb Cunningham]

I have a few old lenses, Turner Reich triple convertible, Cp Goerz dagor, red dot artar, and the like. I had to have a lens board or two bored out at a shop to get the right fit.

These lenses were originally in wooden boards, and one can force tighten the mounting flange on the lens board, but it seems like it would be a good idea to drill the hole pattern of the flange on the metal board and use machine screws to firmly fasten them down.

Any thoughts on this pro and con?

[John Kasaian]

Herb,

Thats how one of my lens is mounted to a metal pacemaker graphic board as well as an enlarging lens of dubious parentage thats mounted on a metal lensboard. They both stay on just fine so it would probably work for you, too.

[Ernest Purdum]

To me, either method seems acceptable.

[Harold_4074]

I did this for a large portrait lens a while ago, and was surprised to discover that the mounting ring, which appeared to be contemporary with the lens, did not have the screw holes evenly spaced around the ring. For wood screws into a wooden board, this wouldn't be a problem, but unless you can measure the locations on the ring, I would suggest transferring the centers rather than asking a machine shop for X number of holes on a Y.yyy diameter circle. The errors I encountered were just enough that drilling and tapping a new hole would be difficult, so I wound up enlarging the mounting ring holes to match a precise layout on the board. This is particularly awkward when the original mounting holes are countersunk for flat headed screws...

[Tracy Storer]

In the absence of a flange, Steve Grimes actually bored and threaded a metal board to accept an old lens of mine. This depends on the board being thick enough. I recently bought a small lathe and am working on the skills to do more of this type of work myself. (there comes a time when having SKG do all the lens mounting you want done exceeds the, well...it adds up)
I've seen, and used, lots of lenses mounted the way you describe, again, if the board is thick enough, you can tap mounting holes directly in the board, Otherwise, put nuts on the back. Just use some common sense on what seems like proper support.

[Kevin Crisp]

This works fine if you get the hole size right so the lip on the back of the flange goes into the hole and the flange fits flush. Anybody with a power drill can drill small holes and with self-taping screws this is a very secure way to mount them. A couple ways to screw it up: Make sure to mark the position of the flange so that when the lens is screwed in, it is "right side up," whatever that means to you. If you like your cable release at the bottom, for example, screw the lens in all the way to the flange, then mark which clock orientation you want it on the board before you drill. Second way to screw it up, especially with large, older lenses, is to have the lens come out in a position where some part of it blocks easy access to camera parts like the slides for holding on the lens board. I've thought about threading the hole itself but haven't attempted that since I had the flanges.

[Ernest Purdum]

I had to thread a lensboard once because the lens was too big for normal mounting to the lensboard. I wouldn't suggest it when not absolutely necessary because there is no way of controlling which side of the lens will be up. Shims seem possible, but not very practical.



If anyone is going to try this, be very careful. It is extremely easy to cut too deep. I lucked out. When I made what I thought was a first check of the threads, I found I was already.finished.

[Tracy Storer]

Eugene,
I'm not 100% sure, but I think with careful setup and careful observance of where the threads end up on the lens and the thread indicator dial on the lathe, you SHOULD be able to orient the lens as desired. I'll be trying to mount my 11.75" Heliar on/in a 4"x4" aluminum board here in a while, and will make an exercise of trying to control that. (the beauty of it all is, with most boards being square, you'll never be that far off anyway)
Tracy

[Tracy Storer]

ERNEST!
Sorry!
Once again, I'll blame my caffeine deprived brain for that.

[Tracy Storer]

Okay. I am a self-taught (novice) machinist, and I am definitely NOT good enough (yet) to control "which way is up" on the metal board threading operation. This morning I managed to bore and thread a 4"x4"x 1/8" aluminum board to accept a 9"FL Pinkham and Smith barell lens. This lenses flange was too big to fit my 5x7 Deardorffs 4"x4" boards.
At the moment, I find that pretty exciting.

[Jim Galli]

Tracy, there are at least 2 people that find that exciting. I'm sure a lathe is in my future also. There's so much hair brained stuff I could combine if I had one. Like Cooke 162mm f6.5 wide angles and Copal shutters. Don't tell my wife. jg

[Herb Cunningham]

thanks to all- I solved the problem by boring a metal board and bolting the flange to the board.

the metal boards I have are way too thin to thread, and if I had to pay somebody to thread a thicker metal
board, I expect it would be more than just boring, which cost $15/board at a huge machine shop-I think I got lucky.