Service Home How To Procedures 40-Taper - Inline - Non-Contact Encoder (NCE) Ring - Replacement - VMC - AD0305
Last updated: 03/03/2026

40-Taper - Inline - Non-Contact Encoder (NCE) Ring - Replacement - VMC

AD0305

Revision B - 3/2026

Introduction

This procedure will show you how to replace the 2" Non Contact Encoder(NCE) ring in inline spindle motors.

 Important: When replacing a non-contact encoder under warranty, make sure the old part is returned in the replacement part packaging or the warranty may be voided.

1.NCE Ring

2.NCE Read Head

3.NCE Read-Head Mount

4.T-0058 (Encoder-Ring Removal Tool 2")

5.T-0059 (Encoder-Plate Removal Tool 2")

This document applies to the following service kits :

  • 93-3199A NCE 2" GEN 2 SVC KIT
  • 93-5714 NCE 2" GEN 2 P&F SVC KIT (TM and MM only)

Tools Required :

  • T-1635 SPINDLE ORENTATION TOOL
  • T-0060 ENCODER REMOVAL TOOL ASSY 2"
  • Anti-Seize Compound

T-0060 has the following parts:

  • T-0058 ENCODER RING REMOVAL TOOL 2"
  • T-0059 ENCODER PLATE REMOVAL TOOL 2"
  • 40-1610 SHCS 1/4-20 X 1
  • 40-1614 SHCS 1/4-20 X 1 1/4
  • 40-0003 SSS 1/4-20 X 1 HALF DOG

Machine Compatibility :

  • All Haas VMCs

Non-Contact Encoder - Identification

Generation 1 and Generation 2 non-contact encoders are not compatible, and will not communicate with each other. If you are upgrading from a Generation 1 NCE to a Generation 2 NCE, the read head and encoder ring will both need to be replaced. 

Generation 2 non-contact encoders can be identified by the pigtail cable attached to the side of the read head [1]. Generation 1 encoders do not have this cable. 

Replacement

1

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.

Remove the spindle head covers.

Install the spindle lock tool (T-1635) onto the spindle.

For machines without TSC, remove the spindle air-tube assembly [1].

For machines with TSC, remove the bearingless TSC rotary union assembly [2].

2

Remove these parts from the top of the spindle:

  • NCE read head [1]
  • NCE read-head mount [2]

 IMPORTANT: Do not dispose of the read head mount [2]. It will be re-installed.

Put T-0059 [5] on top of the NCE hub.

Use the (2) 1/4 x 20" socket-head cap screws (SHCS) [3] to loosely install the (2) parts of the encoder-ring removal tool assembly [4].

Apply the anti-seize compound [6] to the (4) 1/4 x 20" stud-set screws (SSS) [7]. Put the (4) SSS [7] into the threaded holes on the encoder-ring removal tool assembly [8].

 Note: You will tighten these screws in step 5.

3

Make sure the encoder-plate removal tool fits correctly on the spindle-motor hub.

4

In 1 turn increments, tighten the (4) 1/4 - 20 x 1" SSS [1] in a star pattern until the encoder ring [3] is removed from the spindle-motor hub.

Remove the encoder-ring removal tool assembly [2].

 Note: Do not damage the spindle-motor hub when you remove the assembly [2].

Remove the encoder-plate removal tool [4].

Remove these parts from the assembly [2]:

  • (4) 1/4 - 20 x 1" SSS [5]
  • (2) 1/4 x 20" SHCS [6]
  • NCE ring [3].

5

Turn the encoder-ring removal tool assembly [2] upside down.

Put the replacement NCE ring [3] on the spindle-motor hub.

Use the (2) 1/4 x 20" SHCS [1] to install the (2) parts of the assembly [2].

Apply the anti-seize compound [4] to the (4) 1/4 - 20 x 1 1/4" SHCS [5]. Install the SHCS [5]. Tighten the SHCS [5] in a star pattern.

 Note: Make sure you gradually tighten the screws until the lip inside the NCE ring [3] touches the top of the spindle-motor hub.

6

Remove the (4) 1/4 x 20" SHCS [1] and the encoder-ring removal tool assembly [2].

Inspect the NCE ring [3] for any damage.

 Note: When you are working on a machine with the spindle encoder disconnected it is necessary to jump the encoder cable to move the spindle. Refer to the Spindle Encoder Jumper - Installation procedure.

Remove the spindle lock tool. 

Check the runout of the outer diameter of the encoder ring NTE 0.002" TIR.

7

Mark the high spot of the encoder ring [1]. 

Install these parts on top of the spindle motor:

  • NCE read-head mount [4]
  • (2) WASHER FLAT 0.170ID X 0.400OD [7]
  • NCE read head [3]
  • (2) 8-32" SHCS [2] (Do not tighten the SHCS [2]).
  • (4) 10-32" SHCS [5]

8

For RLS type encoders perform the steps that follow:

Put a 0.3 mm plastic shim [2] between the encoder read-head [1] and the high spot marked on the encoder ring [3].

Push the encoder read-head [1] toward the encoder ring [2].

Tighten the (2) screws [4] for the encoder read-head. Remove the shim [2].

 

Mill Encoder Ring to Read Head Alignment

Generation 2 Alignment: Proper alignment of the read head to the encoder ring is critical.  Check that the axial alignment and running gap of the encoder ring are correct.

[A] 0.000 +/- 0.045

[B] 0.012 + 0.008 - 0.004

 

 Note: If the read head and encoder cannot be aligned, the alignment bracket may need to be replaced. See Replace Alignment Bracket below. 

Note: For Generation 1 encoders, use the chart below. 

Generation 1 Alignment: Proper alignment of the read head to the encoder ring is critical. The alignment will vary based on the brand of encoder.  Use the chart provided to make sure the encoder ring and read head are properly aligned.

VENDOR                               RLS                                    BAUMER

A                              0.020" +0.020 / -0.039                 0.0453" +/- 0.019

B                              0.0118" +0.0079 / -0.0039           0.0118" +/- 0.0039

C                                           0.362"                                     0.360"

Incorrect installation of the spindle may axially misalign the motor shaft.  Measure the distance from the top of the motor shaft to the top of the motor TSC mounting hole surfaces.  It should be 1.291 ± .005.

If the shaft is axially misaligned the spindle motor must be replaced.

Test

1

For machines without TSC, install the spindle air-tube assembly.

For machines with TSC, install the bearingless TSC rotary union assembly.

Remove the spindle lock tool.

2

Push [ZERO RETURN]. Push [ALL].

Push [MDI].

Push [ORIENT SPINDLE].

For machines with the side-mount tool changer and the Classic Haas Control, refer to the VMC - Side-Mount Tool Changer - Spindle Orientation Offset - Parameter 257 procedure.

For machines with the side-mount tool changer and the Next Generation Control, refer to the Next Generation Control - Side-Mount Tool Changer - Spindle Orientation Offset procedure.

Look at the position of the spindle dogs [1].

Push [ORIENT SPINDLE].

Make sure the spindle dogs stop at the same position [3].

Repeat this step twice to make sure the spindle always orients in the same position.

If the spindle does not orient correctly, the gap between the encoder ring and the read head is not correct. Repeat Step 8 of the replacement procedure.

3

This step applies to  machines that have the Classic Haas Control or the Next Generation Control. The illustrations in this step show the Classic Haas Control.

Operate the spindle at 25% [1], 50% [2], and 100% [3] of the maximum speed.

 Note: In this example the maximum speed is 7500 RPM.

Make sure the spindle speed in the code is the same as the spindle speed on the display.

If these spindle speeds are not the same, make sure the encoder parameters are correct.