Acemodel Omega build
By John Holloway

The components arrived safely in a sturdy box and the components were laid out to inspect that they were in good condition, these comprised of:-
Fuselage (pushrods for the rudder and elevator are pre-fitted).
Two tail plane surfaces including joiner and bell crank pivot pin.
Two wing panels.
Carbon wing joiner with built in dihedral.
Supplied bag of finishing components.

The finish of the parts was excellent

I started by using the supplied motor mount to fix the Hacker A20 6XL gearbox and motor combination.I made a support ring from carbon fibre and balsa sandwich to fit onto the gear box which will be epoxied to the inside of the fuselage to support the motor mount, this could be made out of a variety of materials.

The assembled motor and supports were epoxied into the fuselage making sure that the thrust angles build into the models interior moulding was butted up securely to the front motor mount.I used 30 minute epoxy and micro fibres.

The esc and cables were “hot glued” in place to keep them clear of revolving motor.

I used a 16x10 Aeronaut prop with a 32mm spinner for 4mm shafts +3º twist and a red 32mm spinner to complete; these were purchased from another dealer. The esc is 40 Amp BEC.

Picture of the red spinner fitted.

The tail was the next to receive attention, not much to do here other than epoxy the provided threaded ball link to the rudder at the reinforced area, after drilling the correct sized hole making sure not to drill too far through the rudder. An area adjacent to the link will need to be relieved so that the push rod and ball link can clear the fuselage.

The supplied nylon ball link can now be screwed to the fitted pushrod and movements checked.

There is nothing to do with the elevator other than slide the connecting pivot and bell crank pin surfaces through the vertical tail making sure that the bell crank pin is located in the pre installed bell crank.

I then made a carbon/Kevlar balsa sandwich plate and installed the two Hitec HS 65mg servos to this and then screwed this to two hardwood side rails epoxied to the fuselage sides.

I soldered the clevis linkage to the elevator pushrod so that adjustment can be made and made a “Z” bend on the rudder servo because adjustment can be carried out at the ball link end.

In hindsight I should have staggered the servos so that the linkages are moved away from the fuselage sides.

Make sure that the servos do not bind on the supplied hatch cover.

I then moved to the wings, these require the two aileron servos and two flap servos’s to be installed in the servo bays, I used Hitec HS 125mg wing servo’s, these may be a little over the top but I had these spare so used them.

A certain amount of trial and cutting will be necessary so that the linkages fitted without binding on any part of the wing, also the clevises will need a certain amount of grinding away so that they also fit without binding.

The supplied threaded clevis connectors were screwed into the moulded points on the moving surfaces after grinding to a suitable shape and length.

You can see from the pictures the shape required of the clevis.

To allow the pushrod to exit the top of the wing you need to remove a small area of the top skin as you can see in the image below. A hole will also need to be made through the rear spar allowing the pushrod clearance. this does not affect the structure in any way.

 

Aileron connection at the top of the wing.

Aileron connection from the servo.

The servos were mounted to hardwood strips epoxied to the wing surface.

There are mountings for a variety of servos on the Acemodel website which can be used with better effect. The wiring harnesses were made from twisted wire from Maplins in the appropriate colours and connected to multiplex connectors. The wires were epoxied so that damage to them does not occur when plugging and unplugging. These were then epoxied in place on the fuselage only, and left loose in the wings. Wiring harness are available from Acemodel if you prefer less work.

Image below shows detail of the wiring harness after connection to the wings.

Fitting the Canopy
So that the hatch cover can be easily mounted and removed, I epoxy a carbon fibre rod to the inside of the cover so that it protrudes a small amount at both ends, this is then used to locate it onto the fuselage and slid towards the front and latches in place.

I use packing tape and stick this to a piece of glass or carbon fibre cloth then spread 30 minute epoxy onto the cloth and firmly bind this to the inside of the canopy trapping the carbon rod so as attach it to the inside, this can then be filed so that a good fit is made.

After the epoxy has cured you can peal off the packing tape to reveal a nice shiny surface.

Top tip...........do not used colourd packaging tape!

Finished Canopy.

 
Battery and esc in place.

Control Throws and setup.
These setting were from Acemodel and used as a rough starting point that can be changed to suit your flying style.

CG should be 84mm from leading edge
Ailerons up 15mm down 7
Elevator Up 9mm down 9mm
Rudder 15mm both ways
Crow braking
Flaps down 75/80 degrees
Ailerons up 5-8mm
Elevator down 4mm (adjust in flight)
Thermal flaps and ailerons down 1.5-3mm
Speed ailerons and flaps up 2-3mm

I have not had enough flight time due to an “electrical glitch” which I have to cure, but initial thoughts are very positive, the model is very stable and indicated lift well. I will report any changes to the above setup after further flying and testing.

John Holloway.