Who's of you make flat spot on motor shaft??

I've used the "dimple" method on my motors. If I took a photo you guys would laugh...it's a miracle the shaft hasn't broken given how deep I've drilled! Anyway for my next motor I want the flat spot. If any of you have the perfect method, post it, including any bit part numbers or whatnot. I'm happy to buy the right tool/bit.

Also, maybe as a value add, RC Monster could offer it for a fee with any new motor purchase - hint - hint...I'd certainly pay $10 extra to have it done right.