To drill all the holes accurately I made some 'wrap' templates. Thes are stuck on to the tail boom with spraymount and wrap around the circumference of the boom.

The holes are then drilled out completely accurately.

I applied this principal to the junction piece as well.

A slot is cut to accept the end of the tailboom support within the tailboom, the support has a lug that locates into this and locks it in position, this can be seen in the drawing.

I am using an alloy tail motor mount, a suitable piece of copper tube was epoxied in position at the end of the tail boom, the tail motor mount uses hex head screws to lock on to this.

The completed tail with the alloy tail motor mount.

I am using the short version of the Fiegao brushless tail motor which is very powerful for its size.

This picture shows how the tail boom is joined to the rear of the main chasis.

The lower section of the main chassis extends 25 mm to allow the junction piece, which has a slot filed half way down its length at a tangent to its diameter, to slide the 'C' section. This is then bolted in place.

The completed tail assembly.

This forms the central core of the Helicopter for the main mechanicals.