Service Home How To Procedures 50 Taper - TSC - Compensating Union and Threadless Transfer Tube - Replacement - Mill - AD0412
Last updated: 12/16/2024

Mill 50 Taper - TSC - Compensating Union and Threadless Transfer Tube - Replacement

AD0412

Applies to machines built from August 2018

Prerequisites

This procedure explains how to replace the compensating coolant union and the threadless transfer tube  on the vertical 50 taper mill built after August 2018. This procedure can also be applied to the horizontal 50 taper mill built after August 2018. Skip the "50 Taper Mill - TSC - Threadless Transfer Tube - Replacement" if you only replacing the compensating coolant union.

For the Captive Stub Shaft Compensating TSC Union Replacement, refer to the: 50-Taper - Captive Stub Shaft - Compensating TSC Union and Transfer Tube  - Replacement - VMC
Note: If you are unsure which commpensating TSC union is installed on the machine, refer to the Compensating TSC Union - Identification Guide.

Note: For troubleshooting information, refer to the TSC Compensating Union Troubleshooting Guide.  

Machine Requirements:

  • Software Version 100.22.000.1000 or higher

Compensating Coolant Union - Removal

1

Note: You must remove the spindle head cover to gain access to the compensating coolant union [1]. The compensating coolant union is located on top of the tool release piston (TRP).

[ Power the machine OFF ]

Disconnect all hoses that connected to the compensating coolant union.

2

Remove four bolts [1] that secure the compensating coolant union to the TRP.

Remove the compensating coolant union [2].

Threadless Transfer Tube - Replacement

1

Remove the snap ring [1] that keeps the transfer tube [2] bearings in place.

Pull the transfer tube assembly [2] out of the TRP.

Important: Do not use the pliers to pull the transfer tube out. This will damage the transfer tube. If the transfer tube is stuck, insert Ø0.25"X 24.0" rod through the bottom of the spindle and gently tap the transfer tube out.

2

Inspect and clean the bore [1] of the transfer tube bearing retainer.

Make sure that the hex and the o-rings [2] on the bottom of the transfer tube are free of defects.

Apply Red-I grease to the o-rings and the hex [2].

Insert the transfer tube into the TRP until you feel that it contact the drawbar.

While gently pressing down, slowly rotate the transfer tube to align the hex on the transfer tube with the reciving hex on the drawbar and then firmly press the transfer tube down into the drawbar.

Important: Never use a mallet or any other excessive force to drive the transfer tube down. If the hand force is not enough to seat the transfer tube, remove the TRP and inspect the bore on top of the drawbar.

Install the replacement snap ring [3] over the transfer tube bearing. Make sure that the snap ring is fully seated in the groove on the bearing retainer.

Compensating Coolant Union - Installation

1

Inspect the top of the transfer tube for any debris or damage.

Apply Red-I grease to the rubber seal and the bore on the bottom of the coolant union [1].

Install the compensating coolant union over the transfer tube with the fittings pointed to the right.

Tighten the four mounting bolts [2] and back them off 1/4 turn.

While rotating the spindle by hand, gradually tighten and then torque the mounting bolts in the criss-cross pattern.

Note: Refer to the Haas Fastener Torque Specifications for the correct torque value.

Insert a screw driver [3] into the top JIC fitting [4] until you feel it contact the piston [5].

Note: The top cover has been removed in this image to illustrate the piston. Do not disassemble the coolant union.

Lightly press downwards until you feel the piston [5] contact the shaft [6] to eliminate the gap [7].

Reattach the hoses to the coolant union.

Run the spindle motor at 100 RPM and verify the union is not rubbing on the shaft. Gradually increase the spindle speed from 100 to the max RPM and check the coolant union for abnormal noise and vibration.