Disassembly Instructions - 1 Hp Cut-Off Extension Tool
Important: Manufacturer’s warranty is void if tool is disassembled before warranty expires.
Disconnect tool from power source before tool repair.
Motor Disassembly:
1. Remove first 50296 Cut-Off Flange and abrasive, then remove the second 50296 Cut-Off Flange.
2. Remove Guard Assembly.
3. Secure housing using 51989 Repair Collar (
see back cover for Optional Accessories
).
4. Apply wrench at wrench flats on 51952 Extension Handle to remove 51952 Extension Handle from housing.
5. Slide 51982 Bearing Spacer and Spindle Assembly through rear of 51952 Extension Handle.
6. Remove 96512 Retaining Ring from front of Extension Handle and remove 51956 Felt Seal.
7. Secure 51955 Spindle at wrench flats, and remove 51950 Spindle Adapter and 51935 Coupler.
8. Secure 01007 Bearing and press 51955 Spindle through both 01007 Bearings.
9. Secure 54520 Bearing and press 51955 Spindle through 54520 Bearing.
10. Remove 96498 Wave Spring.
11. Pull motor assembly, and remove 53620 Motor Adapter with 95438 O-Ring.
12. Remove governor assembly by using a slotted screw driver. (LEFT HAND thread)
13. Secure 51925 Cylinder using 96209 Motor Repair Clamp (
order separately
) and place a 1/8” (3mm) drift pin to the base of the internal thread and
press the 51921 Rotor from the 02057 Rear Bearing.
14. Slide 02057 Rear Bearing from 51923 Rear Bearing Plate.
15. Remove 51925 Cylinder and 51926 Blades.
16. Secure 51921 Rotor in a padded vise and remove 51935 Extension Coupler (twist counterclockwise).
17. Slide 51922 Front Bearing Plate and 51927 Rotor Spacer from 51921 Rotor.
18. Slide 54520 Bearing and shims from 51922 Front Bearing Plate.
Motor Disassembly Complete.
Housing Disassembly:
1. Secure housing using 51989 Repair Collar (
see back cover for Optional Accessories
).
2. Remove inlet bushing (twist counterclockwise).
3. Remove 53682 Gasket, 51943 Spring, 96442 O-Ring, 51940 Spacer, 94528 Felt Silencer, 53686 Muffler Cap,
94924 Wave Spring and 53683 Spacer from 53681 Inlet Bushing.
4. Remove 51944 Tip Valve and 51945 Valve Seat.
5. Remove housing and 51989 Repair Collar and lay repair collar on bench with flange facing down so the collar is supported by throttle lever. Place a
3/32" (2.4mm) drift pin on 96444 Pin and tap pin thru housing.
6. Remove 51946 Valve Stem Assembly. Remove 96443 O-Ring from 51946 Valve Stem Assembly.
Housing Disassembly Complete.
Assembly Instructions - 1 Hp Cut-Off Extension Tool
Motor Assembly:
Important: Be sure parts are clean and in good repair before assembling. Follow grease, oil and torque specifications.
1. Place 51921 Rotor into padded vise with male thread facing upwards.
2. Slip 51927 Rotor Spacer over rotor shaft and down against rotor body face.
3. Press 96441 Coiled Pin into 51922 Front Bearing Plate. Make certain, coiled pin does not protrude beyond internal bearing surface.
4. Place a .002" shim into the base of 51922 Front Bearing Plate as an initial spacing and slide 54520 Bearing to the front plate base.
Note: 51951 Shim Pack contains .001" and .002" shims.
5. Slip bearing/bearing plate assembly onto rotor. Add one drop of Loctite
®
#243 (or equiv.) to 51921 Rotor 3/8"-24 male thread, and screw, torque 51935
Extension Coupler onto rotor shaft. Torque to 17 N•m (150 lbs.-in.).
6. Check clearance between rotor and front bearing plate by using a .001" feeler gauge. Clarence should be between .001" – .0015". Adjust clarence by
repeating steps 4 and 5 with different shims if necessary.
7. Once proper rotor gap clarence is achieved, install well lubricated 51926 Blades (4) into rotor slots. Dynabrade recommends lubricating blades with
95842 Air Lube.
8. Install 51925 Cylinder over rotor and front plate raised boss. Align coiled pin on front to cylinder slot.
9. Press 96441 Coiled Pin into blind hole on 51923 Rear Bearing Plate. Press (2) 96445 Coiled Pins into the back side of rear bearing plate.
10. Peel backing off 51924 Gasket and align it firmly in place onto 51923 Rear Bearing Plate.
11. Place 51923 Rear Bearing Plate over rotor mandrel and insert raised boss on rear bearing plate into cylinder diameter, while inserting short coiled pin
into cylinder slot. Be sure inlet slot on rear bearing plate line up with inlet slot on cylinder. To correct alignment flip cylinder end to end and repeat
steps 8 & 9 for correct assembly.
(continued on next page)
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