Rob I made some vacuum chucks for my lathe using big 1 X 8 nuts. What I did was draw a outline on the back of 2 X 6 round piece of maple. I use a forstner bit to drill down on the inside of my lines. The depth was about 2/3's of the nut. Then I took a wood chisel and cut the corners out that I traced from the nut just so the nut fit tight in the hole. I epoxied the nut in the hole then mounted it on the lathe once dried. I trued up the maple to run true. I drilled a hole for the vacuum to work but you wouldn't need to. They run as true as they come. I am on vacation with the grandkids. I could take pic's when I get back next week.
Retirement: That’s when you return from work one day
and say, “Hi, Honey, I’m home – forever.”
To succeed in life, you need three things: a wishbone, a backbone and a funnybone.