Rotation of Bone deforms mesh

Hi there,

I did make a simple padlock. When I would rotate the shackle it deforms itself very strange.

So it should be look right:

But the result when I rotate it show these both pictures:

I dont know why? – That why I ask you here,

kindly regards

Kind of really hard to tell what is going on from the angles, but it kind of looks like the shackle is scaling in size. Is that correct?

If so, and if you have an armature modifier on the mesh object, then you might have a loc/rot/scale mismatch problem. The loc/rot/scale of the mesh object, and the armature object (in object mode, obliviously) should match. Best practice is to have the loc & rot = 0 and the scale = 1 on all axis. This information is found at the top of the transforms panel in the 3d view. Ctrl A should be the hotkey to apply/reset the loc/rot/scale.