Service Home How To Procedures 50-Taper - Spindle - Replacement - VMC - AD0244

50-Taper - Spindle - Replacement - VMC - AD0244

12.1 50T - Spindle - Replacement

Last updated: 05/12/2025

50-Taper - Spindle - Replacement - VMC

AD0244

Introduction

When you replace a 50-taper spindle do not remove the drawbar. 50-taper service spindles have (2) lubrication ports. This procedure applies to machines built from: September, 2015.

Parts Required:
  • P/N: 54-0150 DRV BELT PCGT 8MGT-1280-21; Set of (3) Belts.

     Note: 7.5K spindles have 3 belts.

  • P/N: 54-0153 DRV BELT PCGT 8MGT-1280-21; Set of (2) Belts.

     Note: 10K spindles have 2 belts.

Tools Required:
  • Spindle Shim Kit
  • Belt Tensioning Tool 50T P/N T-1805
  • Gates Sonic Tension Meter model 508c or 550.
  • 6" x 6" x 6" (152 mm x 152 mm x 152 mm) wooden or aluminum block

VMC - 50-Taper - Spindle - Removal

1

Remove the spindle-head cover panels.

Change Parameter 76, LOW AIR DELAY, to 999999999 to override the LOW AIR PRESSURE warning

2

If the machine has through-spindle coolant (TSC), disconnect the TSC hose. Remove the bearingless TSC Union.

Remove the TRP assembly [1]. Refer to VMC - 50-Taper - Tool Release Piston - Replacement for more information.

If the machine has a mid-belt shield [2], remove it.

Remove the screws [3] for the motor mount.

Move the motor assembly forward far enough to release the tension on the drive belts.

3

Disconnect the oil tubes.

 Note: Some spindles have (1) oil tube. All service spindle have (2) oil tubes.

Remove the fittings [1] from the spindle lubrication ports.

Install a 1/8" NPT plug into each of the oil fitting port on the spindle. Install the plugs flush or below flush with the surface of the spindle. This prevents contamination of the spindle.

Disconnect the encoder cable [3] and ground wire [4] from the encoder read-head [2].

Remove the non-contact encoder assembly. Refer to "VMC - 50-Taper - Non-Contact Encoder - Replacement" step in the 50-Taper - Non-Contact Encoder - Replacement procedure.

4

Put a wooden or aluminum block [1] under the spindle.

 Caution: The block is necessary. It prevents damage to the spindle when it touches the table in the next step.

Jog the Z Axis in the negative (-) direction until the spindle touches the block [1].

Remove the (6) spindle screws [2].

Jog the Z Axis in the positive (+) direction until the spindle head clears the spindle.

Remove the shims [3].

VMC - 50-Taper - Spindle - Installation

1

Clean and stone the surfaces where the spindle flange [1] and the spindle casting [2] touch.

2

Turn the spindle until the oil fitting ports [1] point to the rear of the machine.

Slowly jog the Z Axis in the negative (-) direction over the spindle.

When the spindle is fully into the spindle housing:

  • Turn the spindle to align it with the tapped holes in the casting.
  • Install the (6) spindle screws [2].
  • Torque the screws. Refer to Haas Fastener Torque Specifications.Use the value for iron.
  • Remove the 1/8" NPT plugs [3] from the oil fitting port on the spindle.
  • Install the spindle lubrication fittings [4] as shown.
  • Connect the spindle lubrication tubes.
  • Install the non-contact encoder assembly. Refer to the "VMC - 50-Taper - Non-Contact Encoder - Replacement" step from the 50-Taper - Non-Contact Encoder - Replacement.

  • Connect the encoder cable [5] to the encoder read-head [6].

3

Install the mid belt shield [2], if applicable.

Jog the Z Axis to the middle of travel.

Perform the spindle sweep procedure. Refer to VMC - Spindle - Spindle Sweep.

Insert and hand-tighten the motor-mount screws [3].

Tension the belt. Refer to VMC - Drive Belt Tension - Gates Sonic Meter - Instructions.

Torque the motor-mount screws. Refer to Haas Fastener Torque Specifications. Use the value for iron.

Refer to the "VMC - 50-Taper - Non-Contact Encoder - Test" step from the 50-Taper - Non-Contact Encoder - Replacement.

Install the tool release piston (TRP) assembly [1]. Hand-tighten the screws.

If the machine has through-spindle coolant (TSC), install the bearingless union. Connect the TSC hose.

4