The next part of the build is the tail assembly, tail boom and supports. There are quite a number of small parts to this section of the build but it is not difficult. The main point is that care needs to be taken in this part of the build to make sure that the tail pitch slider is silky smooth when changing the pitch on the tail blades. Any binding or stiffness will cause tail wag problems in flight.

The parts for this build step are found as follows, bag HT7 contains the pitch slider, HT4 the tail gearbox, HT2 the boom and belt, HT5 the tail shaft, HT6 tails blades and hub, HT3 horizontal and vertical stabiliser and HT9 the tail pushrod and antenna tube.

OK, first job is to assemble the tail gearbox.

Firstly press the bearings into the tail case, one each side as shown below. Screw in the central hub for the belt tensioner pulley and then insert the tail drive shaft and pulley and locate the belt on the pulley. All shown below.
The two gearbox halves can now be brought together, don't forget to include the belt tensioner pulley. Screw in the three rear tail case screws, be careful not to overtighten and strip the plastic threads.

Now build up the pitch slider by inserting the two small screws through the pitch slider back plate and screwing the small ball links down. Care needs to be taken here !!

The ball links must NOT be screwed down tight to the back plate but must have about a 0.5mm gap so they can rotate freely but not to the extent that they are sloppy. Now slide the pitch slider onto the tail shaft ready for the control horn to be installed.

Next we install the control horn for the pitch slider. The horn installation is shown very clearly in the manual and all washers and bearings should be placed exactly as shown. Don't overtighten as you want the horn to move freely, again this must be silky smooth and rotate at the slightest touch.
Having done this the tail belt can be threaded through the boom and the tail gearbox mounted and secured onto the boom. I use a piece of string to pull the belt through the boom as shown below. One side of the gearbox has a peg that locates into a little hole on the boom, make sure this is in place before inserting the two screws to tighten the gearbox onto the boom, otherwise the gearbox will be able to rotate in flight. Don't forget that the two screws that go into the gearbox also hold the vertical stabilizer onto the gearbox!
We are now ready to build up the tail rotor hub.

Firstly install the balls onto the tail blade grips. Then using blue loctite (243) install the blade grips onto the center hub using the provided screws. Be careful not to get too much loctite on the screws as you don't want it getting into the bearings.

Then install the tail blades as shown with the balls leading the blades (bottom right picture).
The tail rotor can then be installed onto the tail rotor shaft and secured in place with the supplied grub screw. Again use blue loctite (243) to secure the grub screw. The tail hub should be flush with the end of the tail rotor shaft. Clip the ball links onto the blade grips, again with ball links leading the blades as shown. Tail rotor rotation should be anti-clockwise.
Now we can install the horizontal stabiliser and insert the boom into the main frames and connect up the tail drive belt. Belt tension should be not too tight, once installed and tightened you should be able to push the belt over until it will nearly touch the opposite side of the belt. If you make the belt too tight it will sap power and give short flight times. There is a good picture of belt tension in the middle of page 10 of the manual.

Take care to install the servo holder for the tail servo before installing the boom into the main frames. During this step the tail pitch control rod is installed and clipped into the holder under the horizontal stabiliser, make sure that the control rod slides freely in the clip and if not work on the clip to free it up with some light sandpaper.

After installing the belt and before you tighten up all the screws to clamp the tail boom check that when you rotate the main blades clockwise the tail blades rotate anti-clockwise. If not you have twisted the belt the wrong direction.
At this stage some light PTFE oil should be applied to the tail rotor shaft to allow the pitch slider to move as freely as possible. Also check all the ball links on the tail grips and the tail control rod to make sure that they are nice and free and not causing any stiffness or binding.
That completes the basic build excluding servos.
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