Sinar geared rail clamp shifting. How can I fix this?

Hi all!

I recently managed to get my hands on a Sinar rig, along with a Sinar pan/tilt head and geared rail clamp.

Once I've locked down the clamp on the head it continues to shift ever so slightly. With the mechanical advantage conferred by the rail itself, lifting the bale on the 8x10 back is enough to make it happen. Not a huge deal - but it's annoying. The clamp does have a screw which seems to be intended to provide additional drag against the platform of the head - however, the platform of the Sinar head is not large enough and the set screw doesn't make contact with it.

Any suggestions on how to stop it?

Dropbox link here to a video of what I mean: https://www.dropbox.com/s/g6dm8269jk...%20PM.mov?dl=0

thanks in advance!

That is annoying, I remember looking for that geared clamp when I shot the P for work, never found one

Try a different camera screw or cut a thin sheet of hard rubber material and place between the head and the clamp

Swapped out one of the set (?) screws for one with a larger head. It seems to have done the trick! :)

Attachment 147883