Custom Flanges

[Len Middleton]

ic,

Typically external threads get rolled, as it moves the material rather than cuts it. Much stronger threads and no swarf debris, but lots of oil and pressue.

Len

[Two23]

Here's what I'm trying to do. I'm having trouble find a Petzval lens that covers 4x5 AND the flange will fit on my small Shen Hao lensboards. Have found one that might work, but the flange is just a tad too big. It will interfere with the sliding lensboard lock. I do not have the heart to start cutting on a 150 yr. old flange! I would cut a newer one to fit though, and just save the older one.

Here's another thought I had. What if I took a standard Shen Hao lensboard and attached a one inch long piece of thick plastic pipe to it? Pipe would be ~4 inch diameter. In effect it would be a short extension tube. I could then attach a flat piece of wood, brass, whatever to the open end of the tube and attach the lens to that with no problem. I think it would work. Might look just a bit Mickey Mouse, but what the heck. I'm trying to figure out if my best bet is to have a custom flange made, do the plastic extension tube thing, or just keep looking for a lens that won't need this kind monkeying around.


Kent in SD

[eddie]

Yes.

Attach the regular flange to a "spacer" piece just cut an indent so your lock levers hold the board.

I have been begging chamonix to put a larger front lens board on the 45N cameras. It would then be perfect for wet plate and fast portrait film shooters. Chamonix are you listening?

[Steven Tribe]

Squaring up the flange is an old art - several of the lens I own have these signs of previous use. I wouldn't consider it detrimental to the "value". The only exception are some German makers who insisted on copperplate with vital information on their flanges. Some of the original flanges are not original, either!

Spacers are good idea with lens like the Heliar and Petzvals with lots of "behind the flange" barrel.

[Ernest Purdum]

One cost factor is the material. It is very difficult to find an appropriate piece of brass from which to make one flange. Aluminum alloy is not a problem,