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Home the rotary axis and mark the front of the platter [1]. 

Disable the A-Axis scale.

For CHC: Parameter 269:0 A-Axis Linear Scale Enabled to 0.

For NGC: 5.083 A-Axis Linear Scale Enabled to False.

NOTE: It is important to mark the front before removing the platter to make the re-installation process easier. 

Disengage the brake and unplug the hydraulic booster line [1] before removing the platter.

NOTE: If this step is not done before removing the platter the brake can be damaged.

Place an indicator on the face of a gauge block and do a push and pull test to measure backlash.

Do a push pull test every 90 degree's and take the values at each location. 

Keep these values as the rotary will need to be brought back to these values later in the procedure. 

Once complete home the machine, making sure the arrow is facing the front of the machine, and turn the machine OFF.

Mark the harmonic drive mount and casting in the position it is in before backing off the drive from the ring gear [1].

NOTE: Marking the mount will make it easier to adjust backlash later in the procedure.

Loosen the (3x) HHB 3/4-10 [2] on the drive mount. Back the harmonic drive off the ring gear by loosening the adjustment bolts [3] in the opposite direction the harmonic drive is in.

The drive mount pivots off the shoulder bolt [4], do not loosen this bolt.  

Remove the center bore plug [1] by removing bolts [2]. 

Remove the plugs [3] to access the 3/8-16 SHCS [4]

Remove the platter bolts [4] and safely lift the platter using the proper lifting equipment. 

Unplug the encoder cable [1] from the encoder and remove the interpolation box. The cable [1] is routed through the center bore and beneath the ballnut housing. 

Disconnect the output cable [1] from the interpolation box this cable routes through the machine to the control cabinet as shown in the image. 

Disconnect cable 12VDC power cable [1] from P34A / B on the PSUP and [2]  Scale Feedback cable [2] from P5A on the Maincon Expansion PCB.

With cables disconnect, carefully remove the cables from the electrical cabinet and conduit.

NOTE: If the machine does not have an expansion board the cable will be plugged into channel 12A on the maincon board.

Remove the encoder and encoder bracket from the center mount.

If your machine has the elbow fitting into the bearing [1], the brake must be removed to remove the oil line.

If your machine has a lube line directly going into the bearing [2] pull the lube line out before removing the bearing.

If the machine that has no oil line to the bearing [3] proceed to step 12.

To remove the brake remove the 3/8 bolts that hold the brake to the casting

Remove the bearing and encoder mount assembly lifting from the table assembly. 

NOTE: Make sure there are bolts that attach the bearing and encoder mount plate.  

Replace the old encoder mount plate and install the new encoder mount plate [1].

NOTE: Remove and install the encoder mount plate you must install 2 bolts [2] through the bearing into the encoder mount plate. This will lift both components together during the replacement. 

Re-install the bearing and new encoder mount plate assembly.

Incrementally torque the 3/8-16 bolts in three stages and in a star pattern.

HAAS TORQUE SPECIFICATION

Indicate the bearing flat NTE 0.0005 in (0.013mm) on the outer race of the bearing [1]. 

Place the indicator on the inner race [2] to be able to rotate the indicator.

Re-install the elbow fitting [1] or lube line [2] back into the bearing.

Install the brake and tighten the bolts down. 

Indicate the outer diameter runout [1]. 

Outer diameter runout is NTE 0.0005 in (0.013 mm) to 0.002 in (0.051 mm)

NOTE: We advise indicating the OD runout to 0.0005 in (0.013 mm) to improve machine alignment.

Torque the 3/8-16 bolts to the recommended value 

HAAS TORQUE SPECIFICATION

NOTE: Place the indicator on the inner bearing race [2], this is the portion that can rotate. 

Apply a thin film layer of 5% Molly Mobil Grease PN 99-1792 to the outer diameter of the brake assembly. 

NOTE: As soon as the grease is applied to the brake install the platter. DO NOT let it sit out. 

Find the z-pulse on the encoder, mark the bolt hole [2] that lines up with the z-pulse usually indicated by a dot [1]. 

NOTE: The dot should be on the top side of the ring [1]. 

Install the ring onto the encoder mount using the hardware [1]. The ring should be mounted on the bolt patter [2] that is directly under the larger hole on the encoder mount. 

NOTE: Place the ring in the position with the Z-pulse located as it is in the image.  The encoder dot/Z-pulse [3] must be placed under the centerline of the platter [4]. 

Install the platter back on the table, making sure the side with the mark that was previously made is facing towards the front [1].

Plug the brake hose back into the break booster, with the hose connected actuate the brake a few times to center the platter. 

After the platter is centered install the bolts that attach the platter to the casting. Do not torque the bolts down yet. 

Verify the concentricity of the platter off the center bore [2], this is NTE 0.002" in (0.051 mm) 

Torque the 3/8-16 bolts to the recommended value and verify the concentricity. 

HAAS TORQUE SPECIFICATION

 NOTE: A jack screw can be used to bring the platter into concentricity. 

Bring the harmonic drive back to its previous position by matching the mark [1] previously made during the removal process.

Tighten the set screw previously loosened to back off the drive [2]. This will bring the backlash close to what it originally was but additional adjustments may be needed.

Once in position tighten the (3x) HHB 3/4-10  [3]. The drive mount pivots off the shoulder bolt [4], do not loosen this bolt.  

Turn the machine ON. 

Place an indicator on the face of a gauge block and do a push and pull test to measure backlash.

Do a push pull test every 90 degree's to find the "tight" spot. This will be the location with the smallest amount of backlash.

The backlash should be brought back to the original value taken at the beginning of the procedure. 

After adjusting backlash, torque the (3x) HHB 3/4-10 nuts loosened in the previous step to 200 ft-lbs. 

Place the indicator on the face of the spindle and set the indicator [1] on the inner diameter on the ring [2]. This is NTE 0.0005 in (0.013 mm) TIR. 

Mount the encoder and encoder mount bracket to the center mount. The image is taken as if facing from the front of the machine.  

NOTE: The platter is shown off in the image, but should be assembled back on the table during this step.

Route the cable [1] through the main body and follow the routing shown in the image.

NOTE: There is a junction under the table where the portion of the cable going to the control cabinet meets with the portion going to the encoder. 

Plug the cable in channel P5A on the expansion board attached to the back of the Maincon board where the old cable was originally removed from.

 NOTE: If the machine does not have an expansion board the cable will be plugged into channel 12A on the maincon board. 

Set the encoder gap using the mylar shim [1] provided with the encoder. 

Turn on the machine and make sure there are no alarms present at power up.

Re-enable the scale parameter.

For CHC: Parameter 269:0 A-Axis Linear Scale Enabled to 1

For NGC: 5.083 A-Axis Linear Scale Enabled to True

Plug the center bore back up and torque the platter bolts following the Haas torque chart linked below. 

HAAS TORQUE SPECIFICATION

NOTE: After the rotary encoder has been replaced the rotary compensations must be redone, please contact Haas Service for further instructions. 

Run the platter to confirm the scale is working properly.