mAINTENANCE
Checking Trowel Arm Straightness
Trowel arms can be damaged by rough handling, (such as dropping the trowel on the pad), or by striking exposed plumbing, forms, or rebar while in operation. A bent trowel arm will not allow the trowel to operate in a smooth fluid rotation. If bent trowel arms are suspect, check for flatness as follows, refer to Figure 40 and Figure 41:
Lever Mounting Slot
(Left Arm Shown)
Roll Pin Hole
Blade Attachment
Bolt Hole (1 of 3)
Flat of
(Top of Arm)
Trowel Arm
Round Shaft Section
Trowel Arm
Figure 40. Trowel Arm
1.Use a thick steel plate, granite slab or any surface which is true and flat, to check all six sides of each trowel arm for flatness.
2.Check each of the six sides of the trowel arm (hex section). A feeler gauge of .004" (0.10 mm) should not pass between the flat of the trowel arm and the test surface along its length on the test surface. (Figure 41) .
Trowel Arm
Flat Test
Surface
Feeler Gauge
(.005 in./0.127mm)
Feeler Gauge
(.004 in./0.10mm)
Figure 41. Checking Trowel Arm Flatness
3.Next, check the clearance between the round shaft and the test surface as one of the flat hex sections of the arm rests on the test surface. Rotate the arm to each of the flat hex sections and check the clearance of the round shaft. Use a feeler gauge of .005" (0.127 mm). Each section should have the same clearance between the round of the trowel arm shaft and the test surface.
4.If the trowel arm is found to be uneven or bent, replace the trowel arm.
Trowel Arm Adjustment
Shown in Figure 42 is the adjustment fixture with a trowel arm inserted. As each trowel arm is locked into the fixture, the arm bolt is adjusted to where it contacts a stop on the fixture. This will consistently adjust all of the trowel arms, keeping the finisher as flat and evenly pitched as possible.
1. Locate the trowel arm adjustment tool P/N 9177.
ADJUSTMENT
BOLT
LOCKING
NUT
DISTANCE
FIXTURE
ARM
SIDE-VIEW
Figure 42. Trowel Arm Adjustment Tool Side View
2.Ensure the fixture arm is in the proper setting (up or down) for your trowel arm rotation as shown in Figure 43.
Figure 43. Trowel Arm Adjustment Setup
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