You can establish the OFFSET-center a number of ways depending on the
precision you want for your taper. (1) you can simply eye-ball it and drill
it out in the drill press. (2) You can mount in a 3 or 4 jaw chuck and
center-drill an exact center for your datum. Then remove and measure with a
ruler a distance from the datum to the offset-center location. Center punch
it and then center-drill it a drill press. (3) The most accurate way (but
very quick) is to use your cross-slide to establish the amount of offset.
Your cross-slide will be graduated in 0.001" (or mm). With the stock chucked
up take a slight skim cut on the O.D. of the bar stock or turn a slight
shoulder to a known diameter. Anything is ok just so you know you
cross-slide dial reading true. Don't touch the cross-slide but move the
cutting tool (i.e. carriage) slightly away from the face of the bar stock.
Now move your cross-slide IN the exact amount you want your 1/2 offset.
Turn on the lathe and move the tool to just kiss the face. It will leave a
fine scribe mark (Circle) on the face. You can put a center-hole anywhere
on this circle and your offset will be accurate to within .002"-.010". It
might seem tedious but you can do this faster that it took me to write this.
As mentioned, this method will not be as accurate as the other two but it is
fast, and easy. For things like a gear shift or other parts where you want
a tapered look, but don't necessarily care about the precision, the
OFFSET-CENTER method can't be beat. Good luck and have fun with your new
toy.
-Elon
Date: Mon, 29 May, From: "Keith Turk" <kturk@ala.net>
(Snip. . . ) So Dahlgren sent me this little lathe down here... and I'm
trying to sort out how I'd make a taper on a 1" piece of bar stock that is
supposed to end up looking like a shifter handle... picture a 1/2" taper
over 8"...
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