my question/problem is;
I need to drill 7/8" holes in homebrew plexiglass and aluminum bearing blocks (to fit R6Z bearings -a silly Van deGraff Generator project).
If I chuck my 7/8" bit (1/2" shank) in my el-cheapo drill press, the concentricity is something akin to a spirograph.
I have a drill chuck for my 3-in-one lathe/mill, but was thinking that the concentricity/alignment with a drill chuck on the mill still isn't as good as say, an end mill holder?
Mill is an MT3, & I only have a 3/8" end mill holder right now.
Would it be silly to buy a 1/2" end mill holder & grind out a bit of the 1/2" shank (of the 7/8" bit) - for the setscrew - to be more precise in the drilling?
Or should one buy the end mill holder and a 7/8" end mill? (unemployed bum budget considerations here)
Thanks in advance! :-)B