RE: [GrizHFMinimill] Digest Number 432
- I think the way I would approach this, based on the need to be *exactly*
centered through the length of your shaft, would be to start out with a
shaft larger than 5/8 - say 3/4. I would chuck it up on the lathe then
center drill and drill through the length of the shaft with the correct
sized drill or reamer. Then, I would remove the lathe chuck, insert a dead
center into the lathe spindle and a live center into the tailstock. Put
your drilled rod between centers and then turn to the final diameter. This
way your hole will be exactly on center with the outer diameter and won't
have to worry about your drill wondering while drilling.
Date: Wed, 30 Apr 2003 17:36:13 -0000
From: "randympowell" <stunter2001@...>
Subject: hole drilling question
I'm making a sort of weird nut. I need to drill a #6 sized hole
exactly down the center of a piece of 5/8" diameter by 2" long steel
dowel (lengthwise). I tried centering it up using a rotary table and
chuck and just drilling the hole down the middle with a drill bit,
but I haven't been able to get it exactly in the center. The piece is
centered on the chuck and z-axis, but the drill bit walks around a
bit and no matter how careful I am, I haven't been able to get it
exactly in the center. This thing is going to have to spin at about
11,000 rpm, so it needs to be as exactly in the center as I can make
The nut itself is, as noted, will be about 2" long. It will have an
11mm hex on one end (about 1/2" of the length) and the rest of the
be turned down to 11/32" with a threaded 7mm hole down the center.
Hope that's clear. I'm pretty new to machining and haven't worked
with steel before. Just aluminum.
Thanks for any help. I've made 3 tries. One pretty close, but no
cigar. I have a couple of other idea on how to get it done, but
thought I'd ask the people that actually know what they're doing.