Mounting a Caltar II-N lens on a wooden lens board

[Jeff T]

Hello,

I took a Caltar II-N 210 with Copal No.1 shutter from a Cambo board and trying to mount it to a 4x4 inch wooden board I made with a router. The Cambo board is only 1/10 inch in thickness. The problem is that the wooden board I made is much thicker so the threads on rear of the lens does not quite long enough to screw the retaining flange on rear of the lens.

I had to grind down a recess area around the hole to for the flange to sit into. While it works, there is little comfort knowing that the lens board is only about 1/8 inch thick around hole.

I thought about mounting the lens on a small metal lens board then mount the metal lens board on the wood lens board but that seems redundant and I don't have metal cutting tools.

Is there a better way to mount modern a lens with short threads on a wooden lens board?

https://drive.google.com/file/d/1gfx...ew?usp=sharing

Thanks

[Roger Thoms]

Yep you need a counter bore, 1/8” thickness on the wood is fine, it would take a lot of force to pull the shutter out of the board.

Roger

[jim_jm]

I agree. You'll be fine with 1/8" thickness as long as you're using decent quality hardwood or plywood. Not balsa or anything too soft.

[Jeff T]

I am using 3 layers 1/4 inch plywood, but two layers a gone with the counter bore. Will do a field test Saturday.

[B.S.Kumar]

Use a threaded flange mounted on the front. Simpler, and more reliable. Plus you won't need a retaining ring. Japanese camera makers supplied boards with flanges if the customer asked.

Kumar

[Tin Can]

Sometimes I build up lens boards, usually with hobby store plywood.

Drill hole with hole saw first when plywood is full size as it clamps easier.

Use thin, so no counterbore needed... reinforce if needed with strips of presized basswood.

Then build the edge light traps the same way.

I have a hobby mini hand saw that cuts well. They sell it next to the hobby wood.

But also use a box knife to cut wood.

Glue it together with good wood glue.


Black it with big hobby store magic markers.

I made two 8" lens boards this way, thicker plywood and mounted very heavy lenses.

But ZIMBA1 Lens boards on eBay will make any lensboard in Chicago.

I used to drop in and see him. He will also make metal ones.

Search his store and he probably makes what you want.

I prefer to paint my own.

[Alan9940]

Another idea is to mount the Caltar to a standard Linhof/Technica board, then buy or make a 4x4 adapter board for your camera.

[Jeff T]

Randy, I am beginning to see the wisdom in glueing hobby boards and the benefit of not warping when the board expands with humidity.

Kumar,
Your solution is a good one which I did not thought of before. But some thin flanges are hard to front mount since the mounting screws are very close the edge of the hole, and the hole must be drilled with tight tolerance.



Alan, that makes sense if I had a Linhof board.

[Peter Collins]

Wisner made 4x4 lens boards with a countersunk 'lip' around the hole so that the retaining ring could meet the lens' threads. I owned 2 Wisners, the boards worked fine. I also made 4x4 lens boards with 3mm-thick 'Baltic' plywood--just 3 ply layers I recall--and did not need to rout out a depressed lip in order that the retaining ring could meet the threads.... Baltic plywood at Michael's, the crafty craft store chain.

However, my heaviest lens was a 210 plasmat. If you are using monster lenses, you might see some deflection in the wooden lens board, but at 4x4 total size, I doubt it.

[Graham Patterson]

Coating the thin region with a thin layer of wood glue can add strength. There used to be (and probably still is) a resin product to harden rotting wood - it was just painted on. Not that the lens panel is rotten - just a way to add hardness and stiffness to thin wood.