how do you rig a machine? i get how bones are used on animals,

>>511883
>but with a machine you can't skin weight
why couldn't you ? you usually just set all the vertices of the part you need influenced to 1 on the right bone.
You may also just parent said part to the bone, but it's bad workflow as you can't pointCache it later

You parent or constrain objects to joints. Skinning is used for meshes that need to deform. I guess you could skin it if it absolutely has to be one mesh object.