Instead of going through the hassle of milling angled parallels so you can then machine a taper on your bar, maybe it would be easier to use a couple short pieces of round stock of different diameters to arrange a temporary sine bar setup.
Set it up to be close to the correct angle in the vise, tighten it loosely so you can still move the pins by tapping. Put an indicator in your spindle, establish a 0-point for the long feed, and sweep over the bar to see how much z-axis movement you get as you sweep over the top of the bar precisely, say, five or six inches. Use trig to figure how much it is supposed to rise, and tap the pins in or out to adjust & re-check if necessary.
Less time spent on making the part, unless you need to make a bunch of them. In that case your idea sounds right to me and it should work. You'll have to do something like I described above to mill your angled parallels to the correct taper.
[This message has been edited by vinito (edited 03-01-2004).]
