S E R V I C E

 

13" Heavy 13® Gearhead Lathe

For Machines Mfg. Since 5/11

 

 

 

Leadscrew Shear Pin Replacement

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 128 to fabricate your own.

 

9mm

 

7mm

5.8mm

3mm

 

0.5mm

0.2mm

0.2mm

NOTE: Shear Pin Material = S45C (SAE 1045)

Figure 128. 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

If you fabricate your own shear pin, make sure to use the material and dimensions specified in Figure 128. 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.Rotate the shroud washer on the leadscrew shown in Figure 129, so that the cutout lines up with the shear pin head.

Shear Pin

Shroud

Head

Washer

Cutout

Figure 129. Shroud washer and shear pin alignment.

3.Put on safety glasses.

4.Move the retaining ring shown in Figure 130 away from the shroud washer.

Figure 130. Shear pin access.

5.To make enough room to remove the shear pin, move the shroud washer away from the shear pin and against the retaining ring, as shown in Figure 130.

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Southbend SB1049F owner manual Leadscrew Shear Pin Replacement, To replace the shear pin