Smoothly rotating a part

[thick bison]

https://youtu.be/vJm2v_bSwPQ
how do i make it not go slower or faster when i go left or right or jump
i used a hingeconstraint on a part's attachment and the humanoidrootparts attachment and used a weldcontraint on the bat and the part.

[late hill]

turn on "Massless" property on both the bat and part

[thick bison]

doesnt work