Dale Allen
Member
This is as basic as it gets and the results are acceptable to me.
I use an HF 36" lathe that has a .002" runout in the headstock.
I used a 2.5" piece of aluminum rod, 6061 I think, and drilled a 7/16" hole through it. The drill bit is a jobber bit made by Irwin.
The wall thickness is about .027" on either end. It varies from .026 to .029 which is largely due to the runout.
Don Davis posted about having problems drilling soft metals.
http://www.penturners.org/forum/f166/need-help-drilling-metal-rods-center-153638/
I think the most important part is to get the stock centered as precisely as possible. I use a dial indicator to get the stock turning in the pin jaws of a G3 chuck so it is spinning as true as possible. Then I make sure the bit starts with absolutely no wobble and stays that way throughout the process.
It took about 6 plunges to get through. The shavings were getting built up a lot toward the last.
I use an HF 36" lathe that has a .002" runout in the headstock.
I used a 2.5" piece of aluminum rod, 6061 I think, and drilled a 7/16" hole through it. The drill bit is a jobber bit made by Irwin.
The wall thickness is about .027" on either end. It varies from .026 to .029 which is largely due to the runout.
Don Davis posted about having problems drilling soft metals.
http://www.penturners.org/forum/f166/need-help-drilling-metal-rods-center-153638/
I think the most important part is to get the stock centered as precisely as possible. I use a dial indicator to get the stock turning in the pin jaws of a G3 chuck so it is spinning as true as possible. Then I make sure the bit starts with absolutely no wobble and stays that way throughout the process.
It took about 6 plunges to get through. The shavings were getting built up a lot toward the last.