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Countershaft Repair and Improvement
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(Added 07/04/2003)
The 2 step and 4 step pulleys run directly
against the housing on the newer Atlases with no intermediate wear
surface or bearing. The
lathe had a
small amount of free space between the pulleys and the housing.
This
caused some banging, and the end of the 4 step pulley was peened over a
little.
Also neither pulley had been correctly secured, and they had spun on
the
shaft (apparently more than a few times), and the bores were quite
messed
up. To fix this I bored both out on my old lathe and installed, a
flanged
(to run against the countershaft housing), and sleeve (to fill out the
rest
of the bore) sintered bronze bearing to restore the pulleys. The
end
of the 2 step pulley with the sleeve bearing showing is seen in Figure
1.
Figure 1
The original countershaft was also ruined, so I
replaced it with a length of 3/4" CRS. The original slot in the 4
step pulley for the Woodruf key was removed in the reboring, so I
choose to use just a
slot cut in the shaft for the pulley setscrew to sit in. I cut
the
slot in the drill press using an endmill and a X-Y vise. To
insure that
the pulleys would not shift away from the countershaft housing , and to
aid
adjusting the bearing clearance I threaded the 4
step
pulley end of the shaft, for a 3/4" NC nut. (Figure 2). Loc-Tite
was
used to secure the nut. in place)
Figure 2
When I went to install the headstock belt
guards, the new threaded end interfered with one of them. Using
the brute force approach I ran the lathe and used a hacksaw to shorten
the shaft and nut.
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