help rigging mech. arm

i’m trying to rig a mechanical arm, it’s with an IK but at the joints this system twists the arm out of the hinges and i can’t get it right with constraints.
Could anyone please look at the file, and give me tips how to get this right.


ps I want to keep the IK if possible because it’s very slow to animate without.


2.49 ostriod TEST.blend (183 KB)

I bet Revolt Randy can fix it . Looks like your object points may be moved away from the mesh. Its conflicting constraints. Whats the second bone ( small one) in the upper arm, a shock ? you have only the upper arm parented to the body? Maybe a unnecessary parent is holding the forearm.

hi thank for the reply.
I’ve checked for the things you told me but it dident help.

today i made a new version and its works a tiny bit better but not really. I have discoverd a new feature in the IK sys: lock rot. bus even that dident work perfecty

please please please look at the blend file and tell me why the bones are stil rotating when i "locked " them.



2.49 ostriod TEST.blend (606 KB)

As far as I can see, Bone.001 is superfluous. If you just delete it, everything seems to work fine. If I’m missing something, and you need to keep it, then make sure its axes are precisely aligned the way you want for the rotation locking: they are currently not exactly along the direction of any of the moving parts.

Best wishes,

I spent a bit of time playing with this. And quite frankly, it’s acting a bit buggy. I can’t quite put my finger on why, but some of the things that normally work for IK chains, aren’t working here. The particular problem I encountered was this:

In the Armature bones panel, in pose mode, you will notice some fields - I’ve attached a screenshot with the fields circled. They are controls for the IK chain behavior. They don’t seem to have any effect on the IK chain. Further more, if I set the chain length to 1 so it only affects one bone, the fields shouldn’t be present for bones not part of the IK chain. But any bone that was part of the IK chain before I changed the chain len still has those fields… Not sure why…:spin:

Currently, my thoughts are to delete the armature, re-arrange the meshes so the arm is extending straight out along the x-axis, and start over. I don’t know any other way…

If anyone else checking this out can figure out the problem I describe above, please enlighten me…