I'm having a little issue with this rig I have set up. It's a pumpjack rig with a wheel on the other side.

  • The gears are driven by a driver but that has no relation to the pump itself.
  • The armature for the pump in the video is parented to the horizontal arm above
  • The top bone is parented to the tall cylinder/vertical shape
  • The second bone is parented to the pump below it
  • The empty is being tracked by bone 1 and is parented to the pump as well

Hopefully that makes sense, here's a small video that demonstrates the issue I'm having.


After a bit the arm constraint breaks and go into a weird location. I followed this tutorial on YouTube https://www.youtube.com/watch?v=t1GmLAVeySY

Part Distinguisher

Bone 1 Constraints

Bone 2 Constraints

Empty Parented to Pump

Also to add bone 2, the lower bone has "Inherit Rotation" disabled and "Connected" Disabled.


1 Answer 1


After a few days I have managed to fix it. If anyone comes across the same issue I believe my answer should help.

Again following the tutorial by Max Berends at https://www.youtube.com/watch?v=t1GmLAVeySY

You must have your tracking empty exactly on the pivot point between the lower pump section and the connecting arm. I recommend using:

  1. Object>SetOrigin>OrigintoGeometry/(Shift+S) to set the origin to the mesh.
  2. At your new origin point, create the new empty.
  3. Once you have an armature from the top point of the arm, go into edit mode for the armature, select the second point and go to Object>SetOrigin>SelectedtoOrigin

Exact Pivot location

I think the discrepancies in location can slowly throw out the animation in this case because of the "TrackTo" constraint, as seen in the video in my question post. Having the empty in the exact location has fixed it.

Hope this can help someone.


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