Leadscrew shear pin replacement – Southbend South Bend 16 SPEED GEARHEAD LATHE SB1053 User Manual
Page 84
-82-
For Machines Mfg. Since 3/11
16-Speed Gearhead Lathe
S E R V I C E
10.
Push the pedal lever down to verify that the
cam lobe pushes the brake switch plunger in.
When pushed in, the switch should click.
— If the switch does not click, loosen the
switch mounting screws, push the brake
pedal all the way down, then move the
switch closer to the cam lobe until it
clicks. Secure the switch in place at this
location.
Note:
When the brake pedal is released, there
should be an approximate 3mm gap between
the switch plunger and the cam lobe.
11.
Re-install the motor access panel, connect
the lathe to power, then test the brake pedal.
— If the brake does not operate correctly,
properly repeat this procedure until it
does.
9.
Locate the brake switch on the right side of
the brake pedal (see Figure 137).
Figure 137. Brake switch and pedal cam.
Brake
Switch
Pedal
Cam
Leadscrew Shear Pin
Replacement
9mm
7mm
5.8mm
0.5mm
0.2mm
0.2mm
3mm
Shear Pin Material = Steel JIS S45C/SAE 1045
Figure 138. Shear pin specifications.
Tools Needed:
Qty
External Retaining Ring Pliers #1 ....................... 1
Magnet ................................................................... 1
Safety Glasses ....................................................... 1
Blow Gun w/Compressed Air ................................ 1
Light Machine Oil .................................. As needed
The leadscrew is secured to a connecting collar
that is part of the headstock drivetrain with
the use of a soft-metal shear pin. The shear pin
is designed to break and disengage 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 South Bend to order a replacement shear
pin (Part Number PSB10530934) or use the
specifications in Figure 138 to fabricate your
own.