ST-30/35 Sub-Spindle Motor Replacement

Introduction

This procedure shows how to replace the sub-spindle motor on ST-30/35 machines. This applies to the following service kits:

93-3609

This kit contains the following parts:

6K RPM Servo Motor
Drive Sprocket Flanges
28T Drive Sprocket

IMPORTANT: This kit is for ST-30/35 reboot machines only.

Motor Removal

1

CAUTION: Press [EMERGENCY STOP] and then Push [POWER OFF] before working on the machine.

Set the main circuit breaker to the OFF position.

Lock the main circuit breaker. Use an approved lock with an approved safety tag.

2

Remove the right enclosure panel [1] and so that you can access the sub-spindle motor. Remove the sub-spindle back cover [2] and motor shroud [3] Disconnect all cables from the servo motor [4].

NOTE: The right side access panel [1] is shown in the image. Other enclosure panels may need to be removed for easier access.

3

Remove the 4 SHCS [1] so that the existing servo motor can be uninstalled from the motor mounting plate [2]. Once the motor is removed, make sure the drive belt [3] is sitting properly on the spindle sprocket and is hanging as shown so that it can be tensioned properly onto the new motor.

NOTE: When removing the motor, make sure to slide the drive belt off the sprocket attached to the motor shaft.

NOTE: Make sure to keep the 4 SHCS since they will be used to fasten the new motor in place.

Install New Motor

1

Fasten the new motor to the motor plate [2] using the 4 Socket Head Cap Screws [1]. When fastening to the motor plate, make sure to loop the drive belt [3] around the motor drive sprocket [4]. Manually pull the drive belt to verify that it is sitting properly on the sprockets.

NOTE: The bottom view of the picture shows how the motor and drive belt should look like from inside of the sub-spindle casting.

2

Torque the 4 mounting SHCS [1] to the motor mount plate. Check the drive belt [3] tension using the Gates Sonic Meter [5]. The sub-spindle drive belt should be tensioned to 183N-227N.

To adjust the tension of the belt, untorque the 4 SHCS [2] that mount the motor plate to the sub-spindle casting. Then adjust the CAM alignment bolts [4] until the belt is at the correct tension. Make sure to torque the motor plate mounting SHCS [2] after the belt tension is within specification.

NOTE: For more details on how to use the Gates Sonic Meter tool, refer to the SPINDLE TENSION ADJUSTMENT - AD0710.

3

Run the Sub-spindle to verify that it is working properly.

Refer to the Lathe Operators manual for more details.

4

Reinstall the sub-spindle motor shroud [1] by fastening the 4 SHCS [2] to the mounting surface of the sub-spindle casting [3]. Fasten the sub-spindle back cover [4] with the SHCS [5]. Also, reinstall any sheet metal that was removed to gain access to the sub-spindle assembly.