I had a Twinstar back in the days of Nicad batteries and Brushed motors. It flew beautifully but the foam was very weak and even with my perfect landings the fuselage was always breaking.
The Twinstar 2 has Elapore foam which is said to be strong and light so thought I would give it a go.
The parts
MUST have a straight fuselage
Embedded components
It had better be straight!
Same goes for the wings and their fuselage fixing.
The electrics consists of two Opto ESCs in parallel, with the two signal leads in parallel into the throttle port of the Rx. Rx and servo power supplied by 5A Ubec.
Opto ESCs were chosen because they are lighter and smaller than BEC ESCs. They are also cheaper and run cooler. The Ubec had been lying around the workshop for years.
Fuselage underside and wings centre-section fibreglassed as it will be a belly-lander.
When applied to foam the enamel paint took 3-days to dry!
Motors were installed in the supplied mountings with the motor leads extending back to the ESCs, close to the Rx.
Colour scheme is based (loosely) on Canadian firefighting aircraft.
Final assembly, note the ESCs mounted on the fuselage under the leading edge of the wings. Being outside they are exposed to the full cooling effect of the airstream, hence can be safely operated at their full rated current. Because of the high wing and the location of the door they are quite inconspicuous.
All the decals on, ready to go.
She flies a treat. On a 3-cell LiPo she is fairly sedate, but becomes fully aerobatic on 4-cells. The motors were a bit noisy on full throttle so I decided to stiffen up the mountings.
Moved the mounting plate back and chopped off a bit of the nacelle.
Flies quieter now. Tried unidirectional and contra-rotating props but made no noticeable difference to the flying characteristics, so left them as unidirectional.
At the end of the season I decided to retro-fit an undercarriage. Just cut out the foam and glued-in a couple of balsa blocks.
Made no difference to the flying characteristics but the landings look better.
All-in-all, delighted with the project.
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