Service Home How To Procedures VMC - Ballscrew - 32mm - Horizontal Plane - Replacement
Last updated: 03/06/2025

VMC - Ballscrew - 32mm - Horizontal Plane - Replacement

Introduction

This procedure tells you how to replace a horizontal-plane ballscrew. This procedure shows a 32-mm ballscrew for the Y-Axis of a vertical machine.
[1] Support-bearing housing
[2] Ballnut
[3] Motor housing
 
Note: To let you see the inner parts, this procedure does not show the saddle assembly [4]. Do not remove the saddle assembly to do this procedure.
 
Prerequisites:
  1. Remove the Y-Axis waycovers.
  2. Lubricate the new ballscrew. Refer to Lubricant Table for Haas Machine Components. Use the values for "Linear Guide/Ballscrew".
  3. Torque the fasteners. Refer to Ballscrew - Installation Tools and Torque Specifications and Haas Fastener Torque Specifications.
  4. The machine may require spacers in the installation. Refer to Ballscrew Spacer - Installation.
Tools Required
  • T-1451 Coupler Installation "Pacman" Tool
  • T-1069 Bearing-Nut Wrench Tool
  • T-1601 Collar-Nut Lock Tool

Removal- Ballscrew Motor

1

Jog the Y Axis away from the motor housing.

Push [POWER OFF].

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 bracket-bumper assembly [1].

Note: The bracket-bumper assembly is different on some machines.

Disconnect the encoder and motor cables [2].

3

Record the position of the adapter [1] for the lubrication-fitting.

Remove the adapter for the lubrication-fitting.

Remove the (5) screws [2] from the ballnut.

Use your hand to turn the ballnut [3] counterclockwise.

Do this until the ballnut is 6" (15 cm) from the housing [4] for the support-bearing.

4

If necessary, remove the sheet-metal skirt and the air-lube panel to get access to the motor housing.

Install the coupler-installation tool [1] on the motor coupling.

Note: Turn the ballscrew so you can see the screw [4] for the motor-coupling clamp.

Remove the (4) motor screws [2].

Loosen the screw [4] on the motor-coupling clamp.

Remove the motor with the motor-coupling assembly.

Remove the ballscrew key [3].

Removal- Ballscrew

1

Loosen the locknut screw [1] on the support-bearing.

Note: If necessary, push the table to get access to the locknut screw.

Install the collar-nut lock tool [2] on the motor-housing locknut.

2

Use the bearing-nut wrench tool [1].

Turn the support-bearing locknut [2] counterclockwise, until it is flush [3] with the shaft of the ballscrew.

3

Tighten the support-bearing lock nut screw [1].

Remove the collar-nut lock tool [2] from the motor housing.

4

Loosen the screw [1] on the locknut for the motor-bearing.

Install the collar-nut lock tool [2] on the support-bearing housing.

 Note: Make sure the collar-nut wrench goes into the support-bearing housing slot and into the slots on the locknut.

Use the bearing-nut wrench tool [4] to loosen the locknut [3].

Remove the locknut.

5

Remove the collar-nut lock tool [1].

Loosen the locknut screw [2] and remove the support-bearing locknut [3].

Put a wood block [4] between the ballnut housing and the motor house. The wood block supports the ballscrew when the bearing pack is removed.

Remove the bearing pack [5] from the motor housing.

Note: If necessary, hold the bearing pack and turn the ballscrew counterclockwise to remove the bearing pack.

6

If you can easily remove the support bearing [1], it is a slip-fit bearing. Go to Step 7.

If you can not easily remove the support bearing, do not remove it. You cannot remove a press-fit bearing.

Push the housing [2] for the ballnut in the direction of the housing [3] for the motor.

Push the ballscrew in the direction of the housing for the motor.

Remove the ballscrew [4] diagonally.

7

If the support bearing [1] is a slip-fit bearing, remove it.

Pull the ballscrew through the support-bearing housing.

Remove the ballscrew [2] diagonally.

Installation- Ballscrew

Prerequisites

Make sure the size and pitch of the replacement ballscrew are the same as the removed ballscrew.

The ballscrew may need spacers. Refer to Ballscrew Spacer-Installation.

1

If the support bearing is press-fit, go to step 2.

If the support bearing is slip-fit, turn the ballnut [1] until it is near the center of the ballscrew [2].

Install the ballscrew diagonally .

Push the ballscrew through the support-bearing housing [3].

Put the wave washer [5] onto the ballscrew shaft.

Install the slip-fit support bearing [4] onto the ballscrew shaft.

Push the ballscrew through the nut housing [6] and into the housing [7] for the motor.

2

If the support bearing is press-fit bearing, install the ballscrew [1] diagonally.

Push the ballscrew through the ballnut housing [2] and into the motor housing [3].

Pull the ballscrew into the press-fit bearing [4].

Put a wood block [5] near the motor housing. This helps support the ballscrew.

3

Clean the ballnut flange and mating face of the nut housing fully.

Install the motor-housing bearing pack [1].

Torque the screws for the bearing pack. Refer to Haas Fastener Torque Specifications. Use the values for steel.

Turn the ballnut [2] until the lubrication-fitting port [3] is very near to the position you recorded during removal.

Push the table until the ballnut goes into the ballnut housing [4].

Turn the ballnut slightly to align the screw holes. Attach the ballnut to the ballnut housing.

Use your fingers to tighten the screws.

Install the lube-fitting adapter [5].

Use your hand to to tighten the lubrication-fitting adapter [2].

Remove the wood block.

4

Install the locknut [3] for the support bearing.

Make sure the locknut is flush with the ballscrew [4].

Tighten the clamp screw [2] for the locknut.

Attach the lock tool [1] for the collar nut.

Install the locknut [5] for the motor bearing.

Use the wrench tool [7] for the bearing nut to torque the locknut [5] to 15 ft-lb (20 Nm).

Torque the screw [6] on the locknut. Refer to Ballscrew - Installation Tools and Torque Specifications.

Remove the lock tool [1] for the collar-nut from the support-bearing casting.

Loosen the clamp screw [2] on the locknut for the bearing support.

5

Install the lock tool [1] for the collar nut onto the locknut for the motor bearing.

Use the wrench [2] for the bearing nut to torque the locknut [3] for the support bearing to 4 in-lb (0.5 Nm).

Remove the collar-nut lock tool [1] from the motor-bearing housing.

Torque the screw [4] on the locknut. Refer to Ballscrew - Installation Tools and Torque Specifications.

Install the bracket-bumper assembly on the housing for the support bearing.

Go to Top

 

Installation- Ballscrew Motor

1

Apply a thin layer of grease to the ballscrew key [1].

Install the ballscrew key.

Make sure the coupler-installation tool [2] is installed.

Install the motor [3] with the motor-coupling assembly [4] on the ballscrew shaft.

Torque the (4) motor screws. Refer to Haas Fastener Torque Specifications. Use the values for iron.

Remove the coupler-installation tool [2] from the motor coupling.

Make sure the slot in the motor-coupler [6] is not aligned with the slot [7] in the motor shaft.

Torque the screw [5] for the motor-coupling clamp. Refer to Ballscrew - Installation Tools and Torque Specifications.

Install the encoder cable [3] and the motor cable [3].

2

Push POWER ON.

Set Setting 53, Jog w/o Zero Return, to ON.

Jog the Y Axis in the positive (+) direction to the end of travel.

 Caution: Do not run the ballnut into the hard stop.

Push  [EMERGENCY STOP]

Torque the screws [1] that hold the ballnut. Refer to Haas Fastener Torque Specifications. Use the values for iron.

Release the  [EMERGENCY STOP]. Push [RESET] to stop the alarms.

Jog the Y Axis in the negative (-) direction to the end of travel.

Push  [EMERGENCY STOP]

Install the bracket-bumper assembly [2].

3

Use your hand to turn the ballscrew [1] in one direction. Turn the ballscrew until the table is at the end of travel.

Turn the ballscrew [1] the other direction until the table is at the end of travel.

If the ballscrew is correctly aligned to the ballnut housing [2], the ballscrew turns with constant tension.

If the tension changes while you turn the ballscrew, you must adjust the ballnut housing.

To adjust the ballnut housing, do these steps:

  • Loosen the (8) screws [3] that hold the ballnut housing to the saddle assembly. For Minimill reboot machines, these screws are difficult to access. Remove the cover [4] and turn the ball screw so that the ballnut housing screws are accessible from underneath the base [5] as shown.

  • Release the  [EMERGENCY STOP]. Push [RESET] to stop the alarms.

  • Jog the table in the negative (-) to the end of travel.

  • Jog the table in the positive (+) to the end of travel.

  • Push [EMERGENCY STOP].

  • Turn the ballscrew with your hand to make sure the table moves with constant tension. If the tension is not constant, go to step 4.
  • If the tension is constant, incrementally torque the (8) screws that hold the ballnut housing to the saddle assembly in a star pattern. Refer to Haas Fastener Torque Specifications. Use the values for iron.

4

Again turn the ballscrew in each direction to the end of travel.

If the tension continues to change while you turn the ballscrew, do these steps:

Loosen the (4) screws [1] on the bearing support. Keep the screws sufficiently tight to control the adjustment.

Remove and discard the alignment pins [2].

Note: Alignment pins are used only in production to decrease assembly time. They do not keep the ballscrew aligned.

When the table moves with constant tension, torque the (4) screws in a star pattern. Refer to Haas Fastener Torque Specifications. Use the value for iron.

Do Step 3 again.

Set Setting 53 to OFF.

5

Proceed to the following procedures: