Acratek plate on Custom Brackets Gimbal head problem

[Frank Kolwicz]

I had a disaster with my 600/4 this week: it fell off the tripod onto pavement and did some serious damage, although I don't know how serious ($$$), yet.

On examining of the way the Acratek plate fits the dovetail slider on the Custom Brackets Gimbal head, I found that the relief cut into the bottom of the plate allows the edge of the plate to fall into the gap between the moving jaw and the quick-mount body and will be jammed there without being locked-in - that is without the dovetail engaging; part of the dovetail will jam against the flat upper edge of the plate and it *feels* secure, but isn't.

I have advised Custom Brackets and Acratek about this, too.

The remedy is to fill the relief cut-away level with the outside bottom of the plate so that it can't fit into the gap in the head - I used a simple fitted piece of wood glued in. By the way, I really like both heads for their given uses and this probably only applies to the long Acratek plates used on the long telephoto lenses, I haven't examined the short plates because the CB Gimbal head doesn't accommodate camera bodies easily and I don't use it that way.

[Bob Atkins]

Glad to see the forums are still working but sorry to hear of your mishap. After looking at the clamp design I can see how it might happen.

I use an arca swiss head and QR plates. Normally I only open the jaws of the clamp enough for me to slide the plate out. I don't open them wide and lift the plate off. That means I can mount the lens on the head and there's no way I can be clamped on the wrong part. Also, if I happen to let go of the lens while I'm mounting it and before I get the clamp tightened, the only way it can escape is to slide though the jaws of the clamp. So far no accidents!

Hope any damage to your lens is superficial and not too expensive to fix. The long telephotos are pretty tough.

[Frank Kolwicz]

Thanks, Bob,

I find that wrestling with the 600/4L is quite a hassle nowadays (shoulder problems), so it helps to have the jaws of the quick-mount wide open so that I don't have to support the camera/lens any longer than necessary when getting it mounted, thus the kludgy fix with the wooden insert rather than your option, which never occurred to me.

So far no estimate on the repair.

Frank