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SECTION 5 - MAST COMPONENTS
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5-25
e. Holding complete sheave wheel assembly, slide
assembly into top of mast section-4 and align
threaded holes in sheave pin support bars with
holes in mast rails.
f. Attach to top of mast section-4 using two (2) 3/8”-
16UNC x 1/2” long socket head-countersunk-flat
-
head capscrews, each side. Coat threads with
Medium strength Threadlocking Compound and
tighten.
51.
Carefully slide mast section-4 into section-3 until ends
are even. Check to make sure chain assembly
(narrow
chains)
are seating properly in chain anchor block chain
sheave wheels attached to mast section-3.
Mast Section 5 - Assembly
52.
Locate the remaining mast section-5
(platform mounting
- mast section).
Lay mast section on a flat stable surface.
53.
Attach the remaining chain bottom anchor plate
(one
with threaded holes aligned at the outside of bracket)
.
Attach through set of holes in bottom of mast section-5
with four (4) 1/4”-20UNC x 3/4” long bolts, place a flat
-
washer under head of each bolt.
NOTE:
The platform mounting section slide pads, are assembled
differently than the slide pads for the other mast sections.
Mast section-5 slide pads may need to be assembled/disas
-
sembled several times in order to determine the correct
shim stock required for proper fit.
54.
Complete the following steps to determine shim stock
thickness required for section-5;
NOTE:
Always use the an even amount of shim material behind
slide pads on both sides of the mast rails. This will keep
mast sections centered in rail channels and prevent any
distortion of the section.
a. Use two shim pieces per slide pad, a thick one and a
thin one.
b. Start with a total thickness of approximately.035”
and.075” thick shim stock.
c. Attach shim stock and slide pads to both sides of
mast section-5 using five (5) 1/4”-20UNC x 1-1/4”
long, hex head capscrews per side, with flatwasher
under each bolt head.
(Assemble shim stock and slide
pad to mast section rail with shim stock against rail
and slide pad with beveled side out)
.
d. Carefully thread the slide pad mounting bolts with
flat washers through slide pads and shim stock into
threads in mast section-5. Be certain there are no air
gaps between shims, shim and mast or shim and
slide pad when tightened.
NOTE:
Mast section-5 into section-4 fit should be very snug but
still be able to be pushed together by hand. If too tight,
remove section-5, disassemble slide pad and reduce thick
-
ness of shim stock.
e. Begin sliding top of mast section-5 with closed rail
down engaging the slide pads into slide pad chan
-
nels at bottom of mast section-4’s open rail. Con
-
tinue to push section-5 into section-4 until BOTTOM
ends of mast sections are even.
f. Check mast section for side play. If play exists use
thicker shims dividing thickness equally between
both sides of mast.
g. When mast slide pads are shimmed properly, there
should be no side to side movement of slide pad in
rail channel. Mast sections should be very snug in
channels but still be able to slide in channel by
hand.
55.
Slide mast section-5 out even with top of section-4.
56.
Insert threaded ends of chain assembly
(attached to top
of mast section-3)
into the opening between mast sec
-
tion-4 and mast section-5. Slide the threaded ends
through the holes in bottom chain anchor plate located
on bottom of mast section-5. Loosely thread two (2) 3/
8”-16UNC nuts onto stud threads on each chain. Chains
will be adjusted later in assembly.
Figure 5-26. Mast Section 4 - Sheave Wheel Assembly
1.
Support Bar Screws (a)
5.
Wide Spacer
2.
Pin Support Bars
6.
Sheave Pin
3.
Narrow Washers
7.
Square Keys
4.
Sheave Wheel Assys.
NOTE:
(a) Apply Medium strength Threadlocking Compound
to threads.
1
1
2
2
3
3
5
6
7
4
4
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