Nick,
Did you do your facing cut by moving the compound or the cross
slide?
Taper when turning between centers is indicative of tailstock
offset, tedious to eliminate on the 7xX lathes with their Achilles
tailstock.
You need a test bar for troubleshooting. If you don't have a
known straight, smooth bar, adjust the tailstock to turn one between
centers. Once you've got one, chuck it up and see what your
indicator shows.
Roy
--- In 7x12minilathe@..., Nick DeFeo <ntdefeo@y...> wrote:
Roy:
The spindle shows fore/aft of .0005" difference. There is
basically no runout of the face of the spindle when in motion. All
gibs for the carriage, compound, and cross slide are adjusted with
minimal play. I have not locked down the gibs on the compound/cross
slide when taking these facing cuts. Taking a face cut at the hs,
shows no concave/convex, which leads me to believe the hs/compound
alignment is true. This lathe cuts a .020" taper from the ts to the
hs, no matter the method of securing the stock; 3 jaw, unsupported at
ts, 3 jaw, live center at ts, dead center, live center at ts. Pretty
vexing situation. I have spent considerable effort and material in an
attempt to get the lathe fairly accurate, and am convinced that it is
time to swap this unit with a replacement. Perhaps there is something
minor I am overlooking? Any thoughts would be greatly appreciated.
Nick
SNIP
