Metal Main Rotor Hub Subassembly - THUNDER TIGER Raptor 90 3D Assembly And Maintenance Manual

2-1-2 Metal Main Rotor Hub Subassembly

No. Material No. Description
1 HMC4-10B Socket Screw M4x10
2 HMJ2-12N Self-Tapping Screw M2x12
3 HMV1680 BRG d8xD16x5
4 HMX0816 Thrust Bearing d8xD16x5
5 BK0330 Main Rotor Hub Pin
6 BK0325 Thrust Washer
7 BK0326 Spindle
8 BK0435 Washer
Insert the aluminum Main Rotor Hub Pin and the Flap Dampers. (might need to apply silicone grease for easy installation). Push
the No.7 Feathering Spindle into the dampers and the rotor hub. Add No. 14 Flybar Control Rod. Slide both finished Main Rotor
Grip onto the feathering spindle and the secure with two M4x10 bolts and washers according to the drawing. Use two Allen
wrenches to tighten the two M4x10 bolts simultaneously.
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(1)
Add Loctite
Important Note:
The Raptor 90 3D kits come with non-linear flap damper for aggressive 3D flying. You may choose to experiment adding from
one up to three 0.4mm thick shim (No.10) washers between the washer (No.8) and bearing to further stiffen the main rotor flapping.
Stiffing the main rotor head will speed up the cyclic transient response, but may cause the helicopter fuselage to oscillate at around
1600 RPM. This oscillation characteristic exists for all helicopters with hard 3D flap dampers. The inner dampers should be
replaced periodically if a lot of 3D flying has been done. When the dampers are worn, the main rotor blades can flap excessively
during some 3D maneuvers and risk touching the tail boom.
Qty.
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No. Material No. Description
2 9 BK0477 Washer
2 10 BK0703 Flap Damper Washer 0.4mm
4 11 BK0874 Inner Damper
2 12 BK0875 Outer Dampper
1 13 BK0075 Ling Ball
2 14 BK0664 Flybar Control Rod
1 15 BK0319 Main Rotor Pitch Housing
2 16 BV0548-1 Metal Main Rutor Hub
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(2)
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The thrust bearing washer with the BIGGER
inner hole should be closer to the main rotor
shaft.
The thrust bearing washer with the
SMALLER inner hole should be closer to
the rotor blade.
24
φ
4.8
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Qty.
2
6
2
2
2
2
2
1