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EXI 450 Tail Shaft Replacement:
Video of inspecting a tailshaft
This
page will describe the steps to replace a tail shaft. Very often
the tail shaft is bent in a crash. It is often hard to detect if
the shaft is bent. You will at least need to remove the tail
blade assembly to inspect.
(Click on Photos to enlarge)
1) Remove the grub screw on the tail blade hub. You will use a 1.5mm Hex wrench.
If it is stuck, heat up with a soldering iron tip to loosen the loctite.
2) Remove the control arm by disconnecting the ball link then unscrewing the control arm screw.
Make sure you do not lose the spacer that is between the control arm and extension comming off of the tail box.
Note:
At this point you can inspect the tail shaft by placing the heli on a
table. Spin the main rotors so that the tail shaft rotates. Look at the
tip of the shaft for any wobble. If it wobbles, continue to replace it.
3)
Remove the 6 screws holding the tail box together. Note that on a metal
tail, there is a screw behind the extension that does not go all the
way to the other end. You do not need to remove that screw.
4)
Slowly pull the tail assembly apart. The tail shaft MAY stick to the
left side. If so, tap it out but do not force it. You can head up
w/ a hair dryer but do not heat up any plastic or it may melt. Take
care not to twist the belt and if needed, put a pencil in place of the
tail shaft until you can re-assemble it.
5) Replace the tail shaft making sure the belt did not twist out of position.
Note: Turning the main blades CW from overhead makes the tail shaft rotate CCW looking from the right of the helicopter.
Note: as you replace the screws, put a drop of blue loctite onto the tips of the threads before inserting.
7)
Move the right side plate onto the shaft adn then negociate the 3
spacers as well at tail belt pully and small spacers back onto the
assembly. Replace the screws noting that the longer of them will
go up front on the bottom where the extension was.
8) Replace
the blade hub assembly onto the shaft. Pull the grub screw out and dab
a small amount of loctite on it. Align the grub screw w/ the slotted
area on the tip of the tail shaft and tighten.
9) Replace the control arm and make sure spacer is in the correct location.
10) Verify blade rotation direction is CCW looking from the right when you rotate the main blades CW looking from the top.
11) Lubiricate the tail shaft so that the tail slider moves across it freely.