I want my setup to do this when I move a joint it moves other things as well.
How do I go about setting this up?
A simple solution would be just setting up a Set Driven Key relationship between them.
Depends on how you are going to use this though, there are several possible solutions.
set driven key for the outer plates as Emil cleason already told.
or you can do it with a locator parented to both joints and then use pointconstraints to keep the plates on the correct position on the locators.
then use pointconstraints for the middle plates with different weight values to get the correct sliding.
Just keep in mind, if you use Driven Keys, that if you get into complex rotation, your driving axis could be a bit unpredictable. (talking about gimbal lock and euler rotation order.) You would want the driving axis to be the last letter in your joint’s rotation order.
Assuming you are rotating in Z, you’d want your joint’s rotation order to be xyz or yxz.
If this is an elbow (for example) and it is only rotating in one axis, this won’t be a problem.
Thanks alot for you kind replies I will try set driven keys out.
you got it is for a knee and elbow range of motion. What would you do for knee the same method cause it should still work with IK leg right?
Yep, it would be the same. When you bend an IK leg, you can still use the rotation values of the leg joints as a Driver.