On my spindle moulder one of the methods of securing the cutter block uses a collar. This collar used to have a small keyway/lug that slotted into this groove.
but as you can see from this picture, it has snapped off.
It looks as if it was a pressfit through a hole in the collar. Now I'm not convinced that it actually does anything. The cutter block is held down and prevented from slipping on the spindle by a large bolt, washer and friction. There is nothing else on any other part of the block to engage with the collar that had the lug. And if you think about it, when I use a block that has the countersunk bolt that allows you to fly the tock over a tenoning head then that fixing arrangement has no lug at all.
So I'm thinking not to worry ? Seems to work just fine. Anyone any thoughts ?