Adapting a countersink drill

I fit my resos with Grover metal tuners. The extra weight doesn’t matter since the body with the cone and cover plate is so heavy, and I think the metal at the peghead balances the shiny cover plate visually. 

But fitting them is a bit complicated. The shaft of the peg is just over 4 mm and the bushing just over 8. So I want a stepped hole and have found a counterbore bit that is the right diameter for the bushing, but the drill bit going through is 5 mm. And I want 4. 

So I need to shim the bit and I choose a beer can. Those of you who remember the episode from ”Zen and the art of motorcycle maintainance” may smirk now and think of the elderly Baron von Krupp. 



Wrapping enough of the can to get to 5 mm. This was easier than shoving the assembly through the hole in the counterbore. 



But with some swearing and a few sore fingertips I prevailed. 



And it works exactly as it should. 



With the hole for the shaft on the tight side I got a really nice action in the pegs.