Assembling the Sceadu Evo 50 tail gearbox
| Author: | Rob Turnbull |
|---|---|
| Article Date: | 8th May 2007 |
Fit the belt through the tailboom.
Refitting the belt down the boom is made much easier by wrapping some tape around one pinched together end of the belt and then simply feeding it through the boom.
With the belt fitted through the boom, slide it over the rear pully in the tail gearbox and position the boom so that it sits neatly inline with the slot and is pushed as far back into the gearbox housing as it can go (there is a moulded stop point which the boom should be pushed up against).
It is important to get the twist of the tail belt through the boom correct. A twist the wrong way will make the tail rotor blades spin backwards, and an overly twisted or unusually twisted belt can cause major problems, so be careful.
The correct way to twist the belt is to put a 90° clockwise twist in the belt at the heli end of the boom.
You can check you have the twist correct by working the belt. The main rotor blades spin clockwise, this in turn spins the front tail rotor pully anticlockwise, which then transfers down the belt to the rear pully to drive the tail blades in an anticlockwise direction, as viewed from the right side of the heli (the tail blade assembly is on the near side of the boom to you).
Be careful to not un-twist the belt, so as to not confuse the twist issue (any further!).
Tailboom in place
Fit the other half of the tail gearbox housing into place, making sure everything sits in place correctly (the end of the tail output shaft should fit into the hole in the bearing of the outer housing you have just fitted, for example). Tighten up the screws and nuts to clamp the housing down on to the boom and close the tail gearbox. Check everything moves freely.
Refitted tail housing
Now refit the tail rotor blades ensuring correct blade orientation. Also, refit the vertical fin.
Tail rotor blades and vertical fin refitted
The next task is to fit the tailboom assembly into the heli.