I've never checked the precision of my drill press (Delta 14", model
14-070). So I picked up a piece of drill rod at McMaster-Carr (convenient having a distribution center on the north end of the town I live). I chucked it and could tell visually that there was substantial runout. I pulled the chuck off and measured runout of the taper and got 0.002" TIR, which I think is pretty good. So, now I'm considering replacing the chuck. Trouble is, the instruction manual doesn't specify the size. I started off assuming this was a Morse taper, but I think I'm finding out it's a Jacobs taper. I measured the part on the drill press to have a minor diameter of 0.767" and a major diameter of 0.814". From what I can tell, this should line up with a Jacobs taper #3. Does that sound right? Grizzly sells a precision 5/8" x JT3 chuck for $40. Anywhere else to check for a replacement chuck?todd