Rolleiflex crank arm does not stay up (or down)

I think there's a shim, or other small parts just under the pivoting hinge at the base of the crank that creates friction to keep the crank arm in position.
The arm on my 3.5F just "flops".

What replacement part or material can be used to put friction back in and hold the arm in place.

Cork is a common material, used by Rollei at times. One typical Rollei setup was a flat metal spring with a piece of thin phenolic-type plastic on top.

Two things are needed- a little 'spring' action and slipperiness. The hole in the wind lever is slightly off-center so that as the lever is sticking straight out away from the body there is a bit more thickness than when the lever is against the body. This is what the springiness is for- to be able to be slightly compressed as the lever is moved out and relax pressure as the lever reaches either end of its travel.

The slipperiness is to allow the lever to move.

There is no absolute must-use material. If the metal spring is in place, I've used the clear plastic used in packaging- polyethylene maybe? Slippery, long lasting. Cork is used because it has slight compressibility and is smooth (or quickly smooths out in use). Others here might have found other materials.

Watch this video from 26:00:

Thank you Dan and JPD. Exactly the info I was looking for!

Be aware that on your F, the metal spring parts are basically 'built in.' There is a flat piece of metal under the center disk that has two 'ears' sticking to the sides and are bent to form springs. So the small dark blue parts Chris Sherlock is installing as the base under the red pieces are already in your camera. Or should be! Maybe someone forgot to install it and this would cause the floppiness.

Dan Daniel said:

Be aware that on your F, the metal spring parts are basically 'built in.' There is a flat piece of metal under the center disk that has two 'ears' sticking to the sides and are bent to form springs. So the small dark blue parts Chris Sherlock is installing as the base under the red pieces are already in your camera. Or should be! Maybe someone forgot to install it and this would cause the floppiness.

Click to expand...

Good to go - took the crank arm off, added two pieces of thin plastic underneath, put the arm/pin back.

Thanks again!