Well, it's one driver with two attributes and 28 driven objects working off that driver. There are a load more SDKs in the set-up as well, but they all seem to be working.

I did a test to check that the thing should work: I made a simple arm of three joints. I used SDK to make a sphere move from 0 to 1 in the Y direction when the elbow joint was rotated 90 degrees in Y. I then set up another SDK so that the sphere moved from 0 to 1 in Y when the elbow was bent to 90 degrees in Z. Independently, these worked fine. I then rotated the elbow through 90 degrees in Y and Z and the sphere moved to 1 in the Y direction. It's averaged. That's what I wanted, and expected from my set-up.

Now, I tried the same logic with my set-up that's not working, and I find that my driven object moves the correct distance when the bone is rotated in the X axis only, and in the Z axis only, but when I rotate the bone in both X and Z at the same time, the driven object moves twice the distance - it's added. AAAGH!

It seems to me that this is spurious behaviour. If I'm to overcome it with an expression, I imagine I'll have to make the movement of the joint drive some new attribute, and then have that attribute applied to the positional information for the driven objects. Thinking as I go here - yup! That might work. I don't think I'll have time to check it for a couple of weeks, but I'll let you know.

Thank you!

You haven't any experience of rigging dangling sleeves without using dynamics have you?

Julian