I have been through many hours of youtube tutorials and still am stuck creating a mechanism rig. I'd like the end of one bone to be parented to the middle of another. See video for details... https://youtu.be/lBbqpHNukQ4

I understand parenting and bones with character rigging, but with mechanisms I parent bones to one another and I don't get the result I am looking for. There seems to be very little mechanism rigging tutorials as everything is geared towards character rigging. Would really appreciate some help with this!

I used two ik constraints as shown in the following video and now its working 100% correctly. youtu.be/XbEvTEXeXLc


1 Answer 1


You can add a "stretch to" constraint to the bone:

enter image description here

Bone.002 has a constraint on the armature that makes it stretch to Bone.001.

The head/tail ratio is 0.5, so it is at the middle.

Original length is the length of Bone.002 when in rest position (edit mode length).

If you want Bone.002 point to without stretching, use a track to constraint instead (same principle):

enter image description here

  • $\begingroup$ Thanks, lemon. That's very close, but I need bone.002 to be of a fixed length and not stretchy. How would I do that? $\endgroup$ Commented Nov 8, 2020 at 16:02
  • $\begingroup$ You can use a track to constraint instead. Same principle $\endgroup$
    – lemon
    Commented Nov 8, 2020 at 16:07
  • $\begingroup$ Thanks again. I tried that and it now is fixed which is great but the problem is that bone.002 goes straight through bone.001 and I need it to stay attached... like this youtu.be/myj_1HFFvU4 $\endgroup$ Commented Nov 8, 2020 at 17:15
  • $\begingroup$ oh... ok.. you want the head to be attached to the middle of Bone.001 (not its tail)? I've understood the opposite from the first video... $\endgroup$
    – lemon
    Commented Nov 8, 2020 at 17:49
  • $\begingroup$ I think I might have solved it. I used a "track to" constraint like you said, then I created an empty at the head of bone.002 and parented the empty to bone.002. Then I created a track to constraint for bone.001 with the empty as the target. $\endgroup$ Commented Nov 8, 2020 at 18:03

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .