I made this sketch of a belt drive.  When changing the belt to "Driving" the belt length changes to 693.02 mm from 1033.492 mm.

1) Why does it do this?

2) How can I change it to the correct belt length of 1033.492 mm?

   I've tried redrawing, constraining the tensioner pulley to follow an angle of direction, changed the selection order, etc.   I'm out of ideas to try to fix this.

Thank you for any help you can offer.