Changing Knives; Sharpening Knives - SEM 3000 Operation And Maintenance Manual

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5.1 Changing Knives:

1. Disconnect all power.

2. Unbolt and lower the screen cradle, exposing the knife chamber for access. The safety limit switch

is now open, preventing accidental start circuit continuity.

3. Prior to replacing or removing the rotor knives, cover the edge of each knife with heavy gauge tape,

such as Scotch filament or cloth tape. All rotor knife bolts should be loosened before removing any

one knife as this will keep the rotor in balance. Remove all knives prior to replacing any one knife.

4. Bed Knives: A clamp bar holds bed knives in place. Note that the rear bed knife cutting edge is

pointed downward. Take the spare bed knife with the original clamp bar and replace the bed knife.

Be sure that the clamp bar lip is in towards rotor cavity. Repeat this procedure for the front bed

knife, except the cutting edge should face up.

5. Rotor Knives: Remove the tape covering the edge of all rotor knives. Then, adjust the distance

between the rotor and bed knives by means of the bed knife adjusting screws, and by manually

rotating the rotor in reverse. Adjust to a minimum of .005-inch clearance using a feeler gauge.

6. Rotor knife hex head cap screws should be adjusted to 190 ft. lbs. for the rotor knives and 45 ft. lbs.

for the bed knives

Note: Before tightening bed knives to full torque, determine that knives are set properly by manually

rotating the rotor in the operating direction, ensuring that the bed knives do not touch.

Inspect knives weekly and sharpen after every 80-100 hours of use.

Knives may be sent to SEM or a capable machine shop in your area for sharpening. When sharpened, the rotor

knives must be sharpened as a set to maintain consistency in tolerances between the bed knives. If knives are

badly nicked or damaged, they will function after sharpening if 75% of the cutting surface is effective.

NOTE: The rotor and bed knives are subjected to severe work and it is recommended that they be inspected

periodically for sharpness. The sharper the knives are kept, the better the machine will operate and the better

the quality of the particle being produced. Waiting until the knives have been severely rounded, chipped, or

otherwise damaged will result in heavy shock loading during operation causing a subsequent reduction in knife

life.

For re-sharpening diagrams refer to page 13.

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