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FK arm breaks past 90 degrees

Hi guys, I’m very new to mGear but have been trying to rig a model for a project. I seem to have run into a problem I couldn’t find a solve for online, I apologize if it’s already been addressed here.

My issue is with my FK arm, when i rotate the elbow/forearm control past 90 it breaks the rotation of my elbow joints as well as my bicep joints. They twist 180 degrees on their x axis. Im not sure what else to provide but I’ll try answer any questions to the best of my ability.

Hello @Pneuma

can I know the axis that you are rotating?


Also, which arm component you are using?


Hi guys thank you for the quick reply!
I rotate the forearms Y axis control, it effects every rotational axis on the joint itself. How would I go about changing it to the Z axis?
I’m not sure what you’re referring to by component. I used the standard Biped guide to build the rig and made no changes to the arms. Sorry my terminology is lacking.
I hope this helps:

The biped template is just an example as a starting point. There are many different rigging modules that you can use in your rig. The biped template uses arm_2jnt_01.

In the biped template, the orientations are different than what gets built. (I just noticed this. It’s probably a bit confusing.)

To get an elbow that bends on the Z, you need to move your elbow backwards in translateZ, on the plane that is parallel to the plane of the wrist, in the biped template’s default pose. You can also rotate the guides. But you’ll want to rotate them in rotateY, which will result in a built rig having a rotateZ axis.

Move the guide in translateZ, or rotate in rotateY

If your model is not shaped that way, then you can rotate the guide. Rotate arm_L0_root so that the bend in the arm is translateZ. Then it will build in the correct direction.