Desmond QR plate on RRS BH-55 head

My Desmond clamps don't fit my newly purchased BH-55 head. The mortise on the underside of the plate is a hair too small for the tenon on the top of the ballhead.

Anyone have experience and for this? I'm contemplating doing a little machining on the Desmond mortise....
Thanks!

Is the QR clamp a lever or a screw knob?

I ask because the first RRS clamp I ever owned (circa 2006) would not work with a number of my existing plates.
The problem in this case was it simply would not open far enough to allow them to slide in.

In that case, it was a simple fix changing one aspect of the screw to allow it to open further.

I've messed up the terminology in my first post. Apologies.

I bought the BH-55 without a clamp with the intention of adding a Desmond. The undersized mortise is on the underside of the Desmond screw clamp I'm planning to add. Used the Desmond's for a while and really like them. Thanks for your help.

The socket in the BH-55 stem is 1/4"-20 thread size. Desmond clamps come with 3/8"-16 sockets, ordinarily a problem like this can be solved with an adapter that you screw into the 3/8"-16 socket. It doesn't work in this case because one end of the adapter has a lip with cutouts for a screwdriver blade. I also use a lot of Desmond clamps and tried this solution myself just now with a RRS BH-55. What you need is a 1/4"-20 threaded bolt with a flat head cap. That should work.

Maybe use a Dremel tool to enlarge the tenon socket?

jmckayak wrote in post #19105697
Maybe use a Dremel tool to enlarge the tenon socket?

That’s what I had to do. Dremels are wonderful things in the right hands. Just make sure you modify the clamp and not the ball head. Cheaper to replace the clamp if things go sideways.

It's good to know others have encountered this. I came to the same solution and enlarged the Desmond slot. Working great now. Since Desmond is making excellent parts to go (mostly) on other company's supports, they might consider this....

Obviously I completely misunderstood the OP's problem. Below are a couple of my Desmond clamps with the Heavy Duty version on the upper left, the regular version to its right and the RRS clamp that came with the head at the bottom. The RRS screw (1/4"-20 threaded screw with a flat head cap) works fine on these Desmonds.