Service Home How To Procedures 50-Taper - Inline Spindle Motor - Replacement - AD0036
Last updated: 05/16/2023

50-Taper - Inline Spindle Motor - Replacement

AD0036

Introduction

This procedure tells you how to replace the inline spindle motor on a 50-taper vertical machining center (VMC). 
 
  1. 50-Taper Inline Spindle Motor
  2. Mounting Plate
  3. Mounting Adaptor
  4. Tool Release Piston (TRP) Assembly

Tools Required:

  • Lifting device capable of lifting 400 lb (181 kg)
  • (4) 4" x 4" x 12" (102 mm x 102 mm x 305 mm) wooden blocks

Removal

1

Remove the spindle head covers.

2

Remove the terminal block cover and disconnect the power wires from the terminal block.

3

Remove the spindle motor shroud.

4

Disconnect the (3) air hoses from the tool release piston (TRP) assembly.

5

If equipped, disconnect the Through-Spindle Coolant (TSC) drain tube.

6

If equipped, remove the TSC union assembly.

 Note: The TSC union assembly has left-handed threads.

7

Disconnect the (2) TRP proximity switches from the connector panel on the rear spindle head cover.

8

Disconnect the ground wire from the encoder body.

9

Remove the encoder cap and disconnect the encoder cable.

10

Remove the (4) bolts from the encoder to release tension on the encoder belt. Remove the encoder belt.

11

Remove the (2) bolts shown from the front and rear TRP retainer tabs.

12

Loosen the remaining bolt on each TRP retainer tab.

13

Move the front TRP retainer tab away from the coupling.

14

Move the rear TRP retainer tab away from the coupling.

15

Remove the (4) 1/2" bolts connecting the spindle motor, mounting plate, and TRP assembly to the mounting adaptor. Attach lifting straps to the encoder plate eyelets. Lift the assembly straight up until it clears the mounting adaptor. Move the assembly away from the machine.

16

Remove the coupling insert.

17

Remove the transfer tube.

18

Support the motor/TRP assembly. Remove the (4) 1/2" nuts, washers, and spacers to separate the TRP assembly from the mounting plate.

19

Remove the (4) 1/2" bolts to separate the mounting plate from the spindle motor.

20

Support the spindle motor on (4) 4" x 4" x 12" (102 mm x 102 mm x 305 mm) wooden blocks. Make sure the spindle motor coupling does not touch the ground. Remove the lifting straps.

21

Remove the (4) nuts and washers to separate the encoder plate from the top of the spindle motor.

Installation

1

This procedure tells you how to install the inline spindle motor to a 50-taper vertical milling center (VMC).

Remove the top of the new spindle motor shipping crate.

Use (4) nuts and washers to install the encoder plate to the top of the new spindle motor.

2

Attach the lifting straps to the encoder plate eyelets.

Lift the new spindle motor from the shipping crate.

3

Use (4) 1/2" bolts to install the mounting plate to the new spindle motor. Hand tighten only.

4

Attach the magnetic base of a dial indicator to the new spindle motor coupling.

5

Sweep the mounting plate to within 0.001" total indicated runout (TIR) of the spindle motor coupling. Torque the 1/2" bolts to 50 ft-lb (68 Nm).

6

Find and mark the high spot of the spindle motor coupling.

7

Find and mark the high spot of the spindle coupling.

8

Install the new spindle motor and mounting plate assembly to the mounting adaptor using (4) 1/2" bolts. Align the coupling high spot marks within 0.001" of each other. Torque the bolts to 50 ft-lb (68 Nm).

 Note: Do not install the coupling insert or transfer tube.

9

Tape the couplings together.

10

Attach the magnetic base of a dial indicator to the spindle coupling. Maximum coupling-to-coupling deflection should be less than 0.001" (0.025 mm) during a full revolution.

 Note: For clarity, the mounting adaptor is not shown.

11

If the coupling-to-coupling deflection is not within 0.001" (0.025 mm), loosen and then hand tighten all of the 1/2" and 5/16" bolts on the mounting plate couplings.

12

Tap the mounting plate with a rubber mallet or brass hammer to remove runout.

13

When the coupling-to-coupling deflection is within 0.001" (0.025 mm), torque the (2) rear 1/2" bolts to 50 ft-lb (68 Nm).

14

Torque the (2) front 1/2" bolts to 50 ft-lb (68 Nm).

15

Torque all 5/16" bolts to 25 ft-lb (34 Nm).

16

Check the coupling-to-coupling deflection during a full revolution. Repeat the alignment process if necessary.

 Note: For clarity, the mounting adaptor is not shown.

17

Remove the (4) 1/2" bolts connecting the new spindle motor and mounting plate assembly to the mounting adaptor.

18

Use (4) 1/2" nuts, washers, and spacers to install the TRP assembly to the spindle motor and mounting plate assembly. Torque the nuts to 50 ft-lb (68 Nm).

19

Install the coupling insert to the spindle coupling.

20

Install the transfer tube to the spindle coupling.

21

Use (4) 1/2" bolts to install the new spindle motor, mounting plate, and TRP assembly to the mounting adaptor. Align the coupling high spot marks as near to each other as possible. Torque the bolts to 50 ft-lb (68 Nm).

22

Push the front TRP retainer tab toward the coupling.

23

Push the rear TRP retainer tab toward the coupling.

24

Install the bolts in the front and rear TRP retainer tabs. Torque the (3) bolts on both TRP retainer tabs to 25 ft-lb (34 Nm).

25

Connect the (3) air hoses to the TRP.

26

If equipped, install the TSC union assembly.

 Note: The TSC union assembly has left-handed threads.

27

If equipped, install the TSC drain tube.

28

Connect the (2) TRP proximity switches to the connector panel on the rear spindle head cover.

29

Install the encoder belt and bolts to the new spindle motor.

30

Connect the encoder cable to the encoder and replace the encoder cap.

31

Install the encoder ground wire to the encoder body.

32

Install the spindle motor shroud.

33

Connect the power wires to the terminal block and install the terminal block cover.

34

Install the spindle head covers.