Leadscrew Shear Pin Replacement - Grizzly G0750G Owner's Manual

Leadscrew Shear pin
Replacement
A straight 4 x 42mm brass shear pin (see figure
130) holds the leadscrew and the drive hub
together. the pin is designed to break and disen-
gage the power transfer to the leadscrew to help
protect more expensive lathe components in the
case of a carriage crash or the lathe is overloaded.
Contact grizzly Customer service at (570) 546-
9663 to order a replacement shear pin (part
p0750g0960).
drive hub
Brass shear pin
figure 130. Leadscrew shear pin.
Tools Needed
hammer ............................................................. 1
dowel punch ⁄ " ............................................... 1
3
16
drill Bit ⁄ " ......................................................... 1
1
8
hand drill .......................................................... 1
Wood screw #8 x 1" (or longer) ........................ 1
pointed Center punch ....................................... 1
standard pliers .................................................. 1
-76-
Leadscrew
optional
Alignment
Marks
Qty
To replace the leadscrew shear pin:
1. disConnECt LAthE FroM poWEr!
2. unlock the half-nut lever and turn the top right
gearbox dial to "n" (see figure 131) so the
leadscrew can be rotated by hand.
N
2 3
1 4
figure 131. gearbox dial set to "n" .
3.
rotate the drive hub, and inspect it to see if
R V
the pin is still stuck in both sides of it.
—if one half of the shear pin has fallen out
and the leadscrew shaft can be seen
through the pin hole, rotate the leadscrew
until you see the end of the inner sheared
pin. use a ⁄ " dowel punch to tap the pin-
3
16
out through the other side.
—if the shear pin halves are stuck in both
sides of the drive hub, center punch one
of the pins and drill an
approximately ⁄
1
4
screw into the hole until the screw begins
to thread into the brass. using pliers, pull
the pin from the hole, then drive the rest of
the pin out, as desribed above.
4.
Align the holes in the drive hub with the hole
in the leadscrew, and tap the new shear pin
into position until it is flush.
Tip: For easy shear pin replacement in the
future, use the center punch or a scribe and
mark the end of the drive hub and the side of
the leadscrew with a timing mark to indicate
where true hole alignment is located. Next,
scribe a line on the leadscrew just where it
enters the drive hub, this line will indicate cor-
rect depth of leadscrew. Should the pin ever
shear again, line-up the marks, and drive out
the pin pieces, and tap in the new pin.
Model G0750G (Mfg. Since 11/12)
pointer set to "n"
⁄ " hole in the pin
1
8
" deep. thread a #8 wood