Service Home How To Procedures 40-Taper - Inline - Captive Stub Shaft - Compensating TSC Union - Replacement - VMC - AD0774
Last updated: 12/12/2024

40-Taper - Inline - Captive Stub Shaft - Compensating TSC Union - Replacement - VMC

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Introduction

This procedure shows how to replace the Compensating TSC Union with a Captive Stub Shaft.

Note: This image shows the two types of Captive Stub Shaft TSC Union out in the field, the functionality is the same for both.

For the Non-Captive Stub Shaft Compensating TSC Union Replacement, refer to the: 40-Taper - Inline - Compensating TSC Union - Replacement - VMC

For 50T Compensating Union Replacement, refer to 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.  

 

Tools Required:

  • Spindle Lock Tool (T-1635)
  • MobilGrease XHP 222 (99-1686)
  • Extra-long 5mm Allen Wrench

Machine Requirements:

  • Software Version 100.22.000.1000 or higher

40T - Inline - Captive Stub Shaft - Compensating TSC Union - 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.

2

Remove the TSC hose [1], union air pressure [2], and drain line [3] from the union.

Remove the bolts and washers holding down the union [4].

Use a 5mm hex T-Handle or Allen Wrench to un-thread the union stub shaft from the motor [5].
 Note: The TSC shaft has left-hand threads.

Once the stub shaft is un-threaded from the motor mount, remove the union [6].

3

IMPORTANT: DO NOT DISASSEMBLE THE TSC UNION.

Check that the orientation of the elbow fitting [1] is set to 45 degrees.

Check the orientation of the Vacuum Generator. It should be oriented as shown in the image [2].

Note: DC-1 machines will NOT have a hose barbed fiting [3] and will instead have a push-to-connect fitting [4].

4

Clean and inspect both Motor and Stub Shaft for any burrs or imperfections.

Apply a thin coat of Blue Tacky Grease [1] (P/N: 99-1686) to the Stub Shaft.

Add 1 drop of BLUE thread locker [2] applied to the threads of the Stub Shaft.

5

Make sure spindle is still locked using T-1635.

Verify that all standoffs [4] are of EQUAL LENGTHS.

Place the Union on top of the motor with 4 standoffs [4].

Thread the Stub Shaft [2] onto the Motor Shaft[3] using a 5mm hex T-Handle or Allen Wrench.
 Note: The TSC shaft has left-hand threads.

Important: Keep magnets away from encoder read head and encoder ring (> 6 inches). This includes magnetic indicator bases. 

Note: If TSC union mounts to a sheet metal bracket on the motor, break loose bolts on bracket so it has freedom of movement. (Encoder gap spacing is lost by doing this)

6

Torque [1] Stub Shaft to 20 ft-lbs (27 Nm) - CCW.

Hand thread the Union's (4) Screws [4] all the way down through the standoffs [3].

Align the TSC Union by floating it in:

  • Turn the motor by hand to make sure the shaft is not rubbing as you tighten the union bolts.
  • Rotate the motor by hand while with the other hand, feel if the union is rubbing with the shaft.
  • If no rubbing is present torque the bolts to 13 ft-lbs (17 Nm) in the star pattern.
  • Run the spindle motor at 100 RPM and slowly ramp up speed to verify the union is not rubbing on the shaft.

Install the replacement TSC hose from the check valve to the union [5]. Install the new 5/32 clear hose from the spindle solenoid to the union [6]. Connect the drain hose to the union [7].

7

Note: A flat ended dowel pin or other cylindrical part that is 0.275 inches in diameter and at least 2.6 inches long is needed for this step.

Insert your dowel pin [1] into the top JIC fitting [2] until you feel it contact the piston [3].

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

Press downwards until you feel the piston [3] bottom out or contact the shaft [4] to eliminate the gap [5]. The piston will move about 0.040".

Compensating TSC Union - Test

1

With no tool in the spindle, command TSC.

Check that a steady stream [1] of coolant comes out of the spindle.

Check the amount of coolant coming out of the drain tube. There should be no coolant draining but a steady drip [2] is acceptable.

2

Run TSC with the spindle at 1000 RPM. Slowly ramp the speeds up to the maximum spindle RPM.

The union may make ringing noises as the carbide wears in. This noise should diminish within minutes of running for the first time. The noise may return briefly each time the speed or pressure is increased.

Check that a steady stream [1] of coolant comes out of the spindle.

Check the amount of coolant coming out of the drain tube. There should be no coolant draining but a steady drip [2] is acceptable.

3

Insert a TSC tool with a small orifice [1] in the spindle, run TSC with the spindle at 1000 RPM. Slowly ramp the spindle speeds up to the maximum RPM.

Check that the amount of coolant coming out of the drain tube is not more than a steady drip [2].