How much small should your drive dogs be than the slot on the tool? I'm curious about machine design and thinking about making some custom tooling. I'm looking at spindle drive dogs and I'm wondering how much smaller they should be than the slot in the tool, what is a good margin? Obviously the tool has to have enough play so that it fits into the spindle nose easily but not so sloppy that it becomes ineffective, this would be an atc. It's a bit of a random question but i'm interested, thanks. Anybody tell me the size of a set of bt30 dogs and the tool slot size, I don't own any otherwise I would go and measure them?! Thanks have a good one.