Southbend South Bend SB1042PF - Manual (Page 86)

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For Machines Mfg. Since 3/11 Turn-Nado ® EVS Lathes S E R V I C E
Leadscrew Shear Pin
Replacement
10.54mm
8.75mm
5.8mm
0.5mm
0.2mm 0.2mm
3.74mm
NOTE: Shear Pin Material = S45C (SAE 1045)
Figure 131. Shear pin specifications.
Tools Needed: Qty
External Retaining Ring Pliers #1 ....................... 1
Magnet ................................................................... 1
Safety Goggles ....................................................... 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 PSB10160927) or use the
specifications in Figure 131 to fabricate your
own.
4. Put on safety glasses.
Figure 133. Shroud washer and shear pin alignment.
Cutout
Shear Pin
Head
Shroud
Washer
3. Rotate the shroud washer on the leadscrew
(see Figure 133) so that the cutout lines up
with the shear pin head.
If you fabricate your own shear pin, make sure
to use the material and dimensions specified
in
Figure 131. Otherwise, the shear pin may
not provide the intended protection and lathe
damage could result.
To replace the shear pin:
1. DISCONNECT LATHE FROM POWER!
2. Clean debris and grime from the shear pin
area (see Figure 132).
Figure 132. Location of shear pin.
Location of
Shear Pin