maintenance
Blade Pitch Adjustment Procedure
Maintenance adjustment of blade pitch is made by adjusting a bolt (Figure 25) on the arm of the trowel blade finger. This bolt is the contact point of the trowel arm to the lower wear plate on the thrust collar. The goal of adjustment is to promote consistent blade pitch and finishing quality.
Look for the following indications if blades are wearing unevenly. If so, adjustment may be necessary.
Is one blade is completely worn out while the others look new?
Does the machine have a perceptible rolling or bouncing motion when in use?
Look at the machine while it is running, does the trowel guard ring “rock up and down” relative to the ground?
Do the pitch control towers rock back and forth?
Spider Plate
Trowel Lever
(Finger)
Trowel Arm
Blade Pitch
Adjustment Bolt
Figure 25. Blade Pitch Adjustment Bolt
The easiest and most consistent way to make adjustments on the trowel arm fingers is to use the Trowel Arm Adjustment Fixture (P/N 9177). It comes with all the hardware necessary to properly accomplish this maintenance and instructions on how to utilize this tool.
If a trowel arm adjustment fixture is not available and immediate adjustment is necessary, temporary field adjustment can be made if you can see or feel which blade is pulling harder by adjusting the bolt that corresponds to that blade.
A better way to determine which blades need adjustment is to place the machine on a known FLAT surface (steel metal plate) and pitch the blades as flat as possible. Look at the adjustment bolts.They should all barely make contact with the lower wear plate on the spider. If you can see that one of them is not making contact, some adjustment will be necessary.
Adjust the “high” bolts down to the level of the one that is not touching, or adjust the “low” bolt up to the level of the higher ones. If possible, adjust the low bolt up to the level of the rest of the bolts. This is the fastest way, but may not always work. Verify after adjustment the blades pitch correctly.
Blades that are incorrectly adjusted often will not be able to pitch flat. This can occur if the adjusting bolts are raised too high. Conversely, adjusting bolts that are too low will not allow the blades to be pitched high enough for finishing operations.
If, after making Blade Pitch adjustments the machine is still finishing poorly, blades, trowel arms, and trowel arm bushings may be suspect and should be looked at for adjustment, wear, or damage. See the following sections.
Changing Blades
It is recommended that ALL the blades on the entire machine are changed at the same time. If only one or some of the blades are changed, the machine will not finish concrete consistently and the machine may wobble or bounce.
1.Place the machine on a flat, level surface. Adjust the blade pitch control to make the blades as flat as possible. Note the blade orientation on the trowel arm. This is important for
2.Remove the bolts and lock washers on the trowel arm, and then remove the blade.
3.Scrape all concrete and debris from the trowel arm. This is important to properly seat the new blade.
4.Install the new blade, maintaining the proper orientation for direction of rotation.
5.Reinstall the bolts and lock washers.
6.Repeat steps
page 30 —
