Leadscrew Shear Pin Replacement - Grizzly G0750GV Owner's Manual

Leadscrew Shear Pin
Replacement
A straight 4 x 42mm brass shear pin (see Figure
126) 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
P0750GV0960).
Drive Hub
Brass
Shear
Pin
Figure 126. Leadscrew shear pin.
Items 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
-74-
Leadscrew
Optional
Alignment
Marks
Qty
To replace leadscrew shear pin:
1. DISCONNECT MACHINE FROM POWER!
2. Unlock half-nut lever and turn top right gear-
box dial to "N" (see Figure 127) so leadscrew
can be rotated by hand.
N
2 3
1 4
Figure 127. Gearbox dial set to "N" .
3.
Rotate drive hub, and inspect it to see if pin is
R V
still stuck in both sides of it.
— If one half of shear pin has fallen out and
leadscrew shaft can be seen through pin
hole, rotate leadscrew until you see end of
inner sheared pin. Use
tap pin out through other side.
— If shear pin halves are stuck in both sides
of drive hub, center punch one pin and
drill ⁄ " hole in pin approximately
1
8
Thread a #8 wood screw into hole until
screw begins to thread into brass. Using
pliers, pull pin from hole, then drive out
rest of pin, as described above.
4.
Align holes in drive hub with hole in leadscrew,
and tap 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 G0750GV (Mfd. Since 03/18)
Pointer Set to "N"
⁄ " dowel punch to
3
16
⁄ " deep.
1
4