Hi

I'm working on a locking hinge similar to the model I've made here. I've given it Concentric and LimitDistance mates, but don't know how to create a mate that will stop the upper tongue from passing through the body of the lower portion, unless I create a Coincident mate, between the edge of the tongue and the top surface of the lower part, which then won't let it drop into the groove.

I've played around with Collision Detection, but it is slow and doesn't seem to want to work even when I leave a lot of clearance.

Any suggestions?

Thank you.

Garnet