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danielnordin said:How did you manage to drill not one, but TWO holes in that sprocket? I'm going for the exact same setup with the nighthawk wheel as you but the front sprocket gives me headaches. Any advice?
I had picked up a set of cobalt drill bits - found a kit of 6mm - 1.5mm on amazon or something. They actually don't show really any wear after, and I had to use multiple steps.
The first hole the machinist tried and broke a bit so I had a pilot to start and that one cut through fairly easily curling off the metal until the back side and it more or less chipped away at it sending fleck of metal out rather than a nice ribbon.
It took an hour and a half of switching up bit sizes and boring out the smaller holes. I dont want to ever do it again.
Cutting oil, patience, and time are your friend. Once the sprocket started heating up, it seemed to take longer. The 2nd hole took forever compared to the first.