3M AT-DIS7_PROHD manual III. This section for SGV Exhaust machines, Motor Assembly, Testing

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into the mounting hole of the Swivel Exhaust Assembly and Housing until the end of the screw is flush with the inside surface of the Housing. Place the Nut into the cavity of the Housing and thread the Screw into the Nut until tight. Move onto the “Spindle, bearing shield and Shaft Balancer Assembly” Section.

III. This section for SGV Exhaust machines:

A)Install the Shroud or SGV Vacuum Skirt onto the Hous- ing by working the shroud or skirt over and around the bottom of the housing flanges. Make sure the line up slots (on the Housing) and tabs (on the Shroud or Skirt) are engaged.

B)Attach the SGV Skirt Adapter or SGV Shroud Adapter to the exhaust port of the Shroud or SGV Skirt.

C)Clean and lightly grease the two O-rings and place them in the two grooves in the SGV Retainer.

D)Put the SGV Retainer into the mounting hole of the Ø 1 in. (28 mm) Hose SGV Swivel Exhaust Assembly.

E)Push the Ø 1 in. (28 mm) Hose SGV Swivel Exhaust Assembly into the exhaust port of the SGV Skirt Adapter or SGV Shroud Adapter. Screw the SGV Retainer into the threaded exhaust port on the Housing with an 8 mm Hex Wrench. Torque to 45 in/lbs (5.08 Nm. ).

Spindle, Bearing Shield and Shaft Balancer Assembly:

1.Place the Washer and Shim on the Spindle shaft with the curve of the Washer facing up so that the outside diameter of the washer will contact the outer diameter of the Bearing. Place the Bearing on the Spindle with the seal side toward the Washer. Press onto Spindle using the T-1B Spindle Bearing Press Tool (see figure) until seated at bottom.

2.Insert Shim with tangs into the bottom of Spindle Bore

of the Shaft Balancer. (Do not use this shim if Shaft Balancer text shows a + symbol.)

3.When the Spindle Assembly is done correctly, the Bearing will rotate freely but not loosely.

4.Take the new Filter and center it on the small bore that the original Filter was in before removal. With a small diameter screwdriver or flat-ended rod, press the Filter into the bore until it is flat in the bottom of the bore.

Place the Valve into the bore so it is oriented correctly, then press the Retainer into the bore until it is flush with the bottom of the Bearing bore.

5.Apply a pin head size drop of 3M Rite-Loc TL71 or equivalent to the outside diameter of each of the bear- ings on the spindle assembly. Spread the drop of bear- ing locker around the bearing until distributed evenly. CAUTION: Only a very small amount of bearing locker is needed to prevent rotation of the bearing OD. Any ex- cess will make future removal difficult. Place the Spindle

Assembly into the bore of the Shaft Balancer and secure with the Retaining Ring. CAUTION: Make sure that the Retaining Ring is completely snapped into the groove in the Balancer Shaft. Allow the adhesive to cure.

Motor Assembly:

1.Use the larger end of the T-13 Bearing Press Sleeve to press the front Bearing (with 2 Shields) onto the shaft of the Shaft Balancer.

2.Slide the Front Endplate with the bearing pocket facing down onto the Motor Shaft. Gently press the Front End-

plate onto the Bearing using the larger end of the T-13 Bearing Press Sleeve until the Front Bearing is seated in the bearing pocket of the Endplate. CAUTION: Only press just enough to seat the bearing into the pocket. Over-pressing can damage the bearing.

3.Place the Key into the groove on the Shaft Balancer. Place the Rotor on the Shaft Balancer, making sure that it is a tight slip fit.

4.Oil the five Vanes with a quality pneumatic tool oil and place them in the slots of the Rotor. Place the Cylinder Assembly over the Rotor with the short end of the Spring Pin engaging the blind hole in the Front End- plate. NOTE: The Spring Pin must project .060 in. (1.5 mm) above the flanged side of the Cylinder.

5.Press fit the rear Bearing (2 shields) into the Rear

Endplate with the T-1B Bearing Press Tool. Make sure the T-1B Press Tool is centered on the O.D. of the outer race. Lightly press fit the Rear Endplate and Bearing

Assembly over the Shaft Balancer using the small end of the T-13 Bearing Press Sleeve. The sleeve should press only the inner race of the bearing. IMPORTANT: The Rear Endplate and Bearing Assembly is pressed correctly when the Cylinder is squeezed just enough between the Endplates to stop it from moving freely under its own weight when the shaft is held horizontal, but be able to slide between the Endplates with a very light force. If the assembly is pressed to tightly the motor will not run freely. If the pressed assembly is to loose, the motor will not turn freely after assembly in the Housing. Secure the assembly by placing the Retaining Ring in the groove of the Shaft Balancer. CAUTION: The Retaining Ring must be placed so that the middle and two ends of the hoop touch the Bearing first. Both raised center portions must be securely “snapped” into the groove in the Shaft Balancer by pushing on the curved portions with a small screwdriver.

6.Lightly grease the O-Ring and place in the air inlet of the Cylinder Assembly.

7.Lightly grease or oil the inside diameter of the Housing, line up the Spring Pin with the marking on the Housing and slide the Motor Assembly into the Housing. Make sure the Spring Pin engages the pocket in Housing.

8.Carefully screw the Lock Ring into the Housing with the T-6 Motor Lock Ring Wrench/Spindle Puller Tool. Torque to 60 in/lbs (6.77 Nm.) NOTE: A simple technique

to assure first thread engagement is to turn the lock ring counter clockwise with the T-6 Motor Lock Ring Wrench/Spindle Puller while applying light pressure. You will hear and feel a click when the lead thread of the lock ring drops into the lead thread of the housing.

9.Spin on a new Pad and hand tighten it using a 24 mm Pad Wrench.

Testing:

Place 3 drops of quality pneumatic air tool oil directly into the motor inlet and connect it to a 90 psig (6.2 bar) air supply. A 12,000 RPM tool should run between 11,500 to 12,000 RPM when the air pressure is 90 psig (6.2 bar) at the inlet of the tool while the tool is running at free speed. This free speed will be about 500 RPM to 1,000 RPM less when a Vacuum or Hook Face Pad is used because of wind resistance. This will not affect performance when sanding.

34-8700-5191-8

Revision 10/03/07

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Contents 3MA0021 3MB00053MA0010 3MA0041Motor Disassembly Shaft Balancer and Spindle DisassemblyHousing Disassembly Changing GripsII. This section from Section I for CV Ex- haust machines Housing AssemblyFor 5 and 6 in and 150 mm machines Spindle, Bearing Shield and Shaft Balancer Assembly Motor AssemblyTesting III. This section for SGV Exhaust machinesSymptom Possible Cause Solution Low Power and/or Low Free SpeedInternal air leakage in the Motor Housing Disassemble the Sander and clean