9x20 Locking & Tramming the
9x20 Lathe Tailstock
Last updated on
Thursday, March 29, 2018 05:31:45 AM
Eastern US Time Zone
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Tailstock Lock, Set screws, Handles, Tailstock Tramming, Tramming Animations
Tailstock Lock
This Craftsman wrench allows the nut to pass all the
way through. Ratcheting direction is quickly changed
by flipping the small lever on the
wrench. When the nut is loose it will not work the ratchet so
a short strong
spring was installed, with washers on both sides, between the bottom of the tailstock base
& the
locking plate.
The ratchet now works even when it is loose. This is a
fast & strong method to lock the tailstock securely.
See 9x20 Tailstock DRO
Set screws
Replaced the 5mm set screw. Under
heavy drilling,
e.g.,
using a 1" bit, the original
set screw threads
would cut the inside of the groove it
engaged. Used an 8mm set screw with the end turned to 5mm.
Removed
all the burrs on the groove edges. Used aluminum
anti-seize compound on the lock & pin.
A 2nd set screw
placed 0.7" toward
the spindle, keeps the tailstock from rotating if
it is overextended.
The thrust bearings
are just steel against steel. Made an oil-impregnated thrust bearing (washer)
that
fits inside on the lead screw (far right). Now, the tailstock moves in &
out smoother & with less effort.
Handles
Added
a chrome-plated
steel revolving
handle.
Drilled out the
M5-0.8 thread
then &
then tapped for a
1/4-20.
Die-cast zinc Kipp adjustable ratcheting locking levers (M6-1 threaded bolts) with
a brass washer.
The carriage lock also has a brass spacer that loosely fits the original
counter-bored hole.
A tight fit could possibly bind when it gets grimy. Dissimilar metals can work
more smoothly.
For a smoother finish, lock the carriage when
performing facing or cutoff operations.
Tailstock Tramming
A method to tram (center) the tailstock is to mount a dial test gage in the
spindle & an MT2
dead
center
or
just indicate the inner surface of the
tailstock taper. Rotate the spindle
front &
back while
adjusting the tailstock offset screws (replaced with US
manufactured), making
half-the-difference changes
between them until there are no front-to-back differences. The vertical
top/bottom
error was corrected using
brass shim stock because it was low by a few thousandth's.
Interapid dial test indicator
312B-1 (Swiss) shown.
It is the tailstock that is moved
horizontally (typically opposing set screws) and/or
vertically (shims or grinding) into proper position as indicated by the dial
test gage.
Shimming or milling the top of the cast iron tailstock
base may be required to tram
top to bottom.
The dial test indicator needle moves in the opposite direction when tramming the inside surface.
Tramming Animations
Front/back tailstock tramming animation.
Top/bottom tailstock tramming animation.
Tramming using a dowel pin.
Tailstock Lock, Set screws, Handles, Tailstock Tramming, Tramming Animations