cutting these plates on a manual mill?

[Neil C]

I need to put a couple of connection parts onto an assembly of this kind:



At first, I thought just to drop them onto a rotary table or indexer and run a 90 degree cutter back and forth every 15 degrees or so, cutting the teeth out radially from the centre but I quickly realized that that would mean contact only on the very outer edge or circumference of the part. So they would look like they are locked together but in fact, none of the faces on the inside would be in contact at all as they would all be falling away from each other.

This one left me really scratching my head. I’ve not cut gears or anything like this before so there may be something obvious I’m missing. Any advice appreciated.