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Leadscrew shear pin replacement – Southbend South Bend SB1051 User Manual

Page 81

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For Machines Mfg. Since 5/11

13" x 40" Heavy 13

®

EVS Lathe

-79-

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, and move the
switch closer to the lobe until it clicks.
Secure the switch in place at this location.

Note:

In the released position, 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 you are not satisfied with the brake
performance, repeat this procedure until you
are.

9.

Locate the brake switch shown in

Figure 129.

Figure 129. Brake switch and pedal cam.

Brake

Switch

Pedal

Cam

Leadscrew Shear Pin
Replacement

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 PSB10121234) or use the
specifications in Figure 130 to fabricate your
own.

If you fabricate your own shear pin, make sure
to use the material and dimensions specified
in

Figure 130. Otherwise, the shear pin may

not provide the intended protection and lathe
damage could result.

9mm

7mm

5.8mm

0.5mm

0.2mm

0.2mm

3mm

NOTE: Shear Pin Material = S45C (SAE 1045)

Figure 130. Shear pin specifications.