Infinity focus issue on 6x9 Folding Camera (Adox Sport) - why does this happen?

[Ellyrion]

The packaging plastic used for batteries and such things- the clear parts- can make a nice shim material. Steve906's idea of making three sections, not a full circle, is good. You'll need to make the sections stick- glue or tape- for assembly.Bottle caps of assorted sizes are worth trying as templates for cutting- vitamin bottles or such might be the right diameters. Oh, the retaining ring!

The notches in the lens board are... well, I am not certain why there are two. Haven't seen that before. But one is for a pin on the back of the shutter to go into and stop the shutter block from rotating. Most likely the pin was removed by the previous owner and lost/forgotten. I see a hole in the back of your shutter that might be for a pin, but it looks as if it is 180 degrees off from the orientation on the lens board.

Awesome! I'll see if the seller produces any spare bits, but if not I'll probably use some 0.24mm Acetate sheets I have for the shims - might do some research into it first as I don't know if it might compress over time under the pressure when everything is tight.

Yeah it does seem like that could be the case - when reinstalling the shutter I have to make sure it lines up correctly so when the lens is deployed everything works as it should. EIther way it seems good for now - just need to sort out those shims!

Thanks