Not so Ultimate BiPlane

It has been over 40 years since I last scratch built a plane and then it was balsa and tissue, and it crashed… So this time not wanting to make life easy, I printed a A4 version of a foam plane, scaled the general proportions and used a flight test method of construction. The general specification:

Wing span: 840mm
Target weight: 1400gm
Wing area circa: 35dm2
Motor: 3536/1100/7 – 470watts
ESC: 60A

To give you an idea of the current build state, I have (I think) attached a couple of photos. During the ongoing build, I will provide updates, but do not intend to maiden it until the weather is better and I have mastered the RIOT!!!

Wing construction
Wing construction

Main components

Partial painted components

Hi all, now for a quick update; as can be seen from the pictures, the BiPlane is basically finished, however I do want to replace the wheels as I’m not happy with the current foam board version. I am trying a bit of an experiment with the sprung under carriage to help with landings on rougher ground (not that I would miss the landing strip).

At the start of this project, I had some target design figures with the key target being weight which has come in at 1.29kg fully loaded with battery. The result of this shows in its ability to not only lift itself vertically, but also pulls my arm up… All we need now is better weather so I can practice with the Riot before risking this plane.

BiPlane front quarter view
BiPlane front quarter view




OK… The first maiden flight lasted a couple of seconds… the last maiden flight was a few seconds longer as shown in this clip

All is not lost, the parts have evolved into the FlighTest Spitfire, a little over powered, but still within the FT design weight at 830 grams including battery

The evolution of the not so Ultimate Bi-Plane - Reborn
The evolution of the not so Ultimate Bi-Plane – Reborn

12 thoughts on “Not so Ultimate BiPlane”

    1. Its not a switch, but I do agree the photo looks like one. Its an aluminium bulkhead which is an easier material to work with than ply, particularly with air vent holes for cooling the motor and ESC.

  1. That is looking very fine Mr Barry. Top paint job.
    I was wondering the same as Scott, what spray paint did you use?
    Also you have a lot of servos there, I assume another 1 each for the elevators and rudder? Is the BEC on your ESC at least 3A? Although I tend to assume about 500mA per servo, I’ve never had a brownout problem, the others may have more experience of how many servos you can run off you BEC?

    1. The Overlander ESC includes a 5A BEC, with them all connected they all seem very crisp. I have not run the motor up to full power yet, but will do a full load test with the Watt meter to validate total loads including servos once the model is assembled.

      1. Chris has a point with the servo count, it`s looks like you will end up with 6, I think that’s pushing it a bit, but if the ESC has a 5amp BEC then it should be ok.

  2. Fantastic Job Mr Barry. That looks really good. I am looking forward to seeing that at the field.
    With that much power and those control surfaces it should be pretty trixy. 🙂

    1. Hi Chris, I have turned the throws down and set the expo the right way this time (not like the Riot…). The CoG was a challenge, hence the battery hanging out the front and the under carriage well forward so I didn’t need to add any ballast.

      I’m not planning to fly it until, I’m happy with the Riot