Derek Arita
04-24-2003, 9:49 PM
I just got a Delta 17-925, variable DP. While setting up the DP, I checked runout on the spindle at .001. When I chucked up a 1/2" drill bit and checked runout on the smooth part of the bit, I got .001 to .003...it varied every time I rechucked the bit. I also have an old Craftsman that I just purchased a new Jacobs chuck for, so I replaced the stock chuck on the Delta for the Jacobs. No matter how I chucked up the 1/2" bit on the Jacobs, I always got .001 runout.
I know that the drill bit is not a "know" bit, but the consistency was amazing with the Jacobs as compared to the stock chuck. I also know that a couple of hundredths of an inch in wood working probably won't make any difference at all, but I just like to make sure that as much as posssible of the error lies with me, not my tools, so the closer I can get them to perfect, the better I feel about it. Now I know why Jacobs chucks are considered one of the best.
I know that the drill bit is not a "know" bit, but the consistency was amazing with the Jacobs as compared to the stock chuck. I also know that a couple of hundredths of an inch in wood working probably won't make any difference at all, but I just like to make sure that as much as posssible of the error lies with me, not my tools, so the closer I can get them to perfect, the better I feel about it. Now I know why Jacobs chucks are considered one of the best.