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Step 9 Main Rotor Head
Insert the metal center hub (2002-003 Bag #5) into the metal center yoke (2002-001 Bag #5). Add a M3x8 bolt on
each side of the yoke. Use blue Locktite on the two bolts. (2002-001, 2002-003) Smear some Vaseline on the two
rubber dampers (2002-011 Bag #5). Then insert one damper on each side of the yoke. Slide the feathering spindle
(2002-005 Bag #5) through the rubber damper and the yoke.
Find the two blade grips (2002-007 Bag #5) note that the four main blade bearings (2002-008 Bag #5) are pre-
installed in the blade grip. Add the metal pitch control arm (2002-009 Bag #5) onto the blade grip using a single M3x6
bolt. Add the steel pitch control ball stud (2002-231 Bag#1) to the pitch control arm (2002-009 Bag #5). Use Locktite
on the pitch are and pivot control ball.
Slide the completed blade grip onto the feathering spindle (2002-005 Bag #5). Insert a M3.5x12 bolt and a washer
through the blade grip to secure the hub to the spindle. Use Locktite on this bolt ! Do not over tighten as this will only
mushroom the shaft and make bearing removal difficult.
Slide the seesaw (2002-017 Bag #5) onto the center hub. Fit two flanged plastic bearings (2002-160 Bag #3) or the
flanged ball bearings (2002-022 OP) if you are building a Ninja pro master , into the center hole of the seesaw. Secure
the seesaw to the hub by using a M3x6 bolt through each flanged bearing. Tighten the two M3x8 bolts sufficiently to
remove all free play, but the seesaw should still be able to move smoothly ! Use Locktite on the bolts. On this and the
following steps it cannot be stressed enough the importance of the seesaw and mixing arms pivoting freely without
excessive play. The use of Locktite is mandatory during these steps.
Fit two flanged plastic bearings (2002-160) or non-flanged ball bearings (2002-022A Bag #4M) if building a Pro
Master onto each mixing arm (2002-019 Bag #5). Add the two mixing arms (2002-019) onto the seesaw. Use a
M3x10 bolt with Locktite to secure the mixing arm to the seesaw. Tighten the M3x10 bolts sufficiently to remove all
free play, but the arms should still be able to move smoothly. Fit steel ball (2002-239) onto mixing arm (2002-019) use
M2x8 screw with nut and Locktite.
Insert two plastic flanged bearing (2002-160) or (2002-022A) if building a Pro Master on the seesaw. Slide the flybar
(2002-015 Bag #10) through the flanged bearings and the seesaw ! Use a ruler to check to make sure equal length
sticks out on either side of the seesaw. Add a flybar control arm (2002-013 Bag #5) on either side of the seesaw. Coat
the threads of each M3x6 set screw with Locktite, then fit a set screw inside each control arm. Make sure both arms are
level ! Insert a 3mm locknut into the underside of each control paddle (2002-253 Bag #5) Then screw the paddles
onto the flybar. Wick some thin CA glue into the paddle hole after threading it onto the flybar ! Make sure the two
paddles are at same distance from the control arm and are level with the control arms. This is an extremely important
step you can follow the picture to cut a flybar jig template. Check the flybar balance by letting the seesaw pivot on its
bushings. Add tape to the light paddle until balance is achieved.
M3x8
M3x8
003
011
005
005
231
007A
008
007
008
009
043
001
3.5X12
WASHER(S)
M3 NUT
M3X25
M3X6
CN2135 HEAD BUTTON (PURPLE)OPTION
CN2136 HEAD BUTTON (GOLD)OPTION
CN2122 CARBON
STIFFENER FOR
FLY BARS
(OPTION)
M3 NUT
1 1
1 1
1 1
1 1
1 1