Saturday, 19 April 2014

Pusher trainer and test body

I made this plane so that my brother and his kids could have a go at flying RC planes, and as a test body for comparing different wings.

Actually this is the rebuild of that original plane which served it's purpose well, for one very windy but fun day.

It's a "pusher", meaning the motor is not on the nose but pushes from behind the wing. That means nose-in crashes won't end the flying session.

The tail boom is a 7.5 mm woven carbon fibre tube and the main body a 100mm x 60mm box.

The box needs to be tall enough so the prop clears the boom.

The rudder must be tall enough to get some of the airflow coming across the top of the wing. With a shorter rudder I experienced significant adverse yaw and poor directional tracking. Might be better with a tapered fuselage.
Motor mount is aluminium flat, bent up just past 90ยบ and stuck on to a glued down ID card on top of the box.

Aileron servo lead extensions are taped to the rear sides of the box so wings can be easily swapped.








Multiple wing tie-down posts allow for different chord size wings to be mounted. The tie-down points are reinforced with pieces of ID card.

The tail boom is hot glued to the bottom of the body then depron strips glued either side of the tube for extra strength.






Tail servos are mounted on the tail.

I initially had the tail servos forward in the body with Gold-n-Rod push rods but these were chopped by the prop in a boom flexing hard landing.







The nose is soft parcel packing EPP covered in clear gaffer tape for impact absorbtion. It has an EPP tongue extending into the body to hold the battery. The battery can be moved right up into the nose or further back for balance.

I use this nose design in all my pusher and slope soarers now. Velcro tabs hold it in place.

Turnigy 2622/14 1450kV motor, 7x4.5 prop
500g without battery
Flying weight 610g with 1300mAh 3S

This video shows the maiden using a symmetrical 1.4m Armin wing








2 comments:

  1. Really wonderful blog Sir.
    Which plane do you recommend for beginners(haven't flown even once) this or twin boom pusher? or peace drone?

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    1. Thanks anurag. I would recommend this style for your first. Pusher motor and dihedral wing. You could start without ailerons then add them later for a simpler build. Then the twin boom is a great second plane, much more agile. The peace drone would be difficult to learn on because it has some odd handling tendencies. It's great for flying in a straight line but resists turning sometimes. Good luck

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