Proper "simple" wrist rig?

I’d like some feedback on a wrist setup for a human-type arm.

This is what I’ve got(blend file attached)

WristRotation.blend
UpperArm and Forearm IK linked to the Hand target. (straight forward and works)
Hand does a copy rotation of the HandTarget. (again, simple and works)

The question comes down to the wrist and it’s ability to coherently track rotations of the hand and give proper twist to the characters forearm given that it needs to not only track Y rotations but also implied rotations from the other 2 axes.

I’ve got it setup to copy rotation of the Hand then do a damped track back to the axis of the Forearm. This seems to work properly for both IK and FK rotations of the hand. Yet because it’s so simple, I’m afraid I’m building myself a tripwire.

Does this look like it will hold up in general use? Any feedback is appreciated.

When moving the HandTarget i saw the Wrist Rotation was not syned with the Hand.
It mabey better to use the Pose Space on the Copy Rotation bone constraint.

I dont fully understand, i guess you will be using the Wrist bone to influence the mesh deformation, for twisting a forearm.

I see what you have going on there. Looks like a good attempt, but I’d like to point you in a couple of directions to learn about rigging.

Look at b-bones, they are segmented bones that can be locked down so they would only bend on a bone’s y-axis, which would give you the forearm twist you want. But I rarely see this method used.

Rigify, the add-on that generates a bi-ped rig, uses 3 bone layers for the arm. Get used to using bone layers to separate out which bones are which. One bone layer is the fk bones, next layer is the ik bones, and another layer is the deform bones that actually deform the mesh. The deform bones copy the rotation of the fk or the ik bones depending on the mode the rig is in. The deform bones of the lower, and even the upper arm, are 2 bones, instead of the single bone as you rig, or the fk or ik bones. This now gives you 2 bones for the lower arm bone that deforms the mesh, and constraints control the rotation based on hand and upper arm rotation of these 2 deform bones.

Randy