I’m trying to make a fan that spins this way, locked to an axis: 
but it ends up doing… this, with a HingeConstraint: 
The description for hinges seems very promising but I just cannot get them to work. Anyone have any success with making a model like this? Maybe I’m setting the attachments up wrong and it’s a simple fix…
I tried setting the hinges/welds/attachments up different ways in a repro file:
fan repro.rbxl (20.5 KB)
In the file, the small fan is sitting on top of an anchored hinge, and the big one is floating there with AlignPosition. Neither seem to work ):
) , right fan was a failed totally-unanchored experiment