7.6— REEL TO BEDKNIFE
ADJUSTMENT
The reel is adjusted to a fixed position bedknife. This makes a more rugged and stable frame retaining adjustment longer.
To adjust the reel to bedknife contact, turn the hex adjuster on each side of the reel down. Proceed slowly and do not over adjust - about 1/8th of a turn on each side. Do not over tighten. A too tight reel will wear much faster. The reel should “wipe” or lightly touch the bedknife. By using paper strips held between reel and bedknife, check to see that blades are cutting the paper all the way across.
Use heavy gloves and be careful— blades are sharp!
7.7—REEL END PLAY ADJUSTMENT
As the reel is used, normal wear of the reel bearings will cause end play. This condition could cause uneven wear to moving parts and uneven cutting of turf.
Test for end play periodically by trying to move the reel from side to side in the frame. If there is any movement, adjust by loosening the locknut on the adjustment body, which is located on the inside right end of the reels and turn adjustment bolt in a half turn or less. Do not overtighten as it would cause excessive bearing wear. Test again for end play, if reel is rotating freely and end play can not be detected, retighten the locking nut on adjustment bolt.
LOCKNUT & SCREW
NATIONAL® HYDRO 70" TRIPLEX
7.8— BACKLAPPING PROCEDURE
Back lapping is a very important step in maintaining sharp reel blades on the rear and wing mowers.
Many types of compounds are available for lapping. However, we recommend a good pre- mixed water soluble compound such as Pinhigh. Prices, grit ranges and ordering information are available by calling a toll free phone number
This procedure should be performed when the reel blades and bed knife become slightly rounded and the grass is not cut cleanly with only a slight bed- knife adjustment. After grinding the bedknife and reels, backlapping should be done to establish a perfect match between the bedknife and reel blades.
1.Clean cutting units of any foreign debris and disengage reel clutch.
2.Make sure to adjust the bedknife to the reel so that the bedknife is level with the reel and light contact is maintained.
3.Reels must be run in a reverse direction to be lapped. Remove exterior guards as needed. Attach a back lapping machine (not supplied by National Mower) to one of the outside reel stub shafts of the front two cutting units, following the instructions furnished by the backlapping machine manufacturer.
NOTE
Some back lapping machines may not rotate all three cutting units simultaneously. If this occurs back the reel adjustment off or disconnect the remaining two cutting units and concentrate on one cutting unit at a time.
4.With reels running, and concentrating on one reel, apply the lapping compound using a 2" or 3" wide brush. Apply the compound evenly to the mowing blades. Adjustment of the reel to bedknife may be required, relap as necessary.
Be extremely careful not to let the brush, your fingers or your clothing get caught in the reels. Use approved safety glasses to protect eyes from flying particles and abrasives.
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