I need to drill out the lights on some brass diesel engine shells. I have cobalt drills. What speed do I use for a 1/16 in bit? And how do I determine the speed the drill is running.
any, and all, help is greatly appreciated. I don’t want to damage these shells if possible.
RicZ
Start with a 3/32 bit. drill the pilot hole through the center. then see how centered you are. either use the 1/16 to finish it or a file to finish it. and use a pin vise a little slower but controls the speed better. Cobolts are very aggressive in a soft material like bras. high speed still isnt as agressive and a better choice. cobalts are for hard metals. not really soft metals like brass.
shane
I agree with the suggestion to begin by using a pin vise, as it allows better control to keep the drill bit from wandering.
Wayne
Ric,
Personally, I would drill them out by hand with a pin vise for better control. It also depends what gauge wire you plan on using.
I use 34 AWG (0.007" OD) magent wire for illuminating my headlamps so a #78 drill bit is large enough to pass both wires through side-by-side and keep them as unobtrusive visually as possible.
Are you using incandescent or LED bulbs?
Tom