Need info on "Alphax Synchro" shutter

[Drew Bedo]

I have a Wollensak 15' f5.6 lens in an Alphax Sychro shutter. . . .but no retaining ring.

Trying to figure out what ring it needs. What shutter size is this, #4 or #5, and what are the specs for the thread?

A proper ring will cost over $50.

Is there a hardware store workaround at hardware store prices?

[Whir-Click]

It’s an Alphax #4; needs a 2.62”x30tpi flange or retaining ring. I don’t know of any off the shelf substitutes.

[Peter De Smidt]

Does a Betax No. 4 use the same ring?

[Whir-Click]

Betax #4 flange/ring is interchangeable with the Alphax.

[Jim Noel]

Get a piece of PVC pipe very slightly too small in diameter. Screw the shutter into it, then remove the shutter and cut off the threaded portion. This mounting ring will last as long as you do. Another alternative is a piece of model plywood (probably 8-11 ply) and do the same thing.

[Greg]

Get a piece of PVC pipe very slightly too small in diameter. Screw the shutter into it, then remove the shutter and cut off the threaded portion. This mounting ring will last as long as you do. Another alternative is a piece of model plywood (probably 8-11 ply) and do the same thing.

Have done this many times to test out lenses. I also put a ring of glue from a hot glue gun around the threads on the inside of the lens board. Very secure mounting of a shutter or a barrel lens onto the lens board, and the glue is easily removable.