Save the weight of servos - don't have any!

Just steer your multi engine master piece by reducing the power to one of the motors. This control system has been used on 5 Aeronutz machines with great success.

We started with R/C and used a computer based Tx to mix the two speed controllers.

Now we are using the Z Tron TMREM Rx which is designed for this purpose.
Its not such an advantage these days as the latest servos are very light - lighter than the extra  motor and you have a huge load on the cells. BUT if you want to make a nice B25, Hampden or Catalina which has more than one motor anyway its great fun, and you don't have to fiddle about fitting the servos or hinges.

We use two Ni Cd cells and a DC/DC voltage booster to ensure the supply to the Rx does not go below 2.7v.

Andrew has been using the "bang bang" Twin Turbo system in one of his Catalinas but with bigger transistors for lager motor loads - see his sketch
.... and how long will it be before Barry wades in and has a go, what a lot of F/F electric planes !

Ray now has a twin steer flying with with added twin booms and elevator/rudders. Ray also has a twin steer D/F Cambera jet!! Both are made of 2mm wall foam and IR controlled with the TMREM Rx
Rays twin steer Mosquito needed a bit of dihedral !

Dave Ridgway's Vimy used R/C and was made of hot cut white foam.
Simon's twin thing used R/C and had retracting U/C !
Simon's Flying wings and Shorts Southampton used the TMREM system, Mark's Catalina does too.
The mighty Peter Smart has a TMREM  - see his electric F/F blue foamie Bombay adding the TMREM control system will add about 2g to the plane!!! Whoopee.

We do have a data sheet on wiring up a R/C Rx with Voltage booster and two Esc's - a paper copy.
Here is a quick sketch of how to wire up the Infra red TMREM Rx and it's two built in Esc's to a voltage booster and two flight motors.

Notes if you use the Z Tron TMREM Rx unit.
Don't go over 1 Amp per motor. If you do the motor will stay on full power until you disconnect the battery. Similar effect if you go below 2.7v supply.
 

If you are using three 50 mA cells:
    You can use two KP00’s with gears and a variable pitch prop
    You can use two Tru Flight UM-001 's
    You can use two Kenways
    You can use two Wes Technik 4.5 - 0.6 motors

You can't use two direct drive KP00’s with Union 80 mm props on full throttle

Using two 50 ma cells you can use any of the above motors without going over 1 Amp, KP00’s with direct drive are simple and quiet but do draw lots of current thus reducing the flight time.

Simon's flying wing uses two 50 mA cells with two direct drive KP00‘s, which is ideal as it requires very little thrust due to it's low drag and 25g weight. Two direct drive KP00’s produce about 12g of thrust at most, so a 50% power to weight = flying weight of 24g

Model Design
You really need a minimum of 50% power to weight as you need to reduce power to one motor to get the machine to turn.
We would prefer to see two 50 mA NiCd cell models, smaller models have smaller turning circles !
If you use two direct drive KP00’s and Union 80 mm props,  the props could be replaced by DIY 82 mm plastic cup ones, which are a little bit better.
You may need to use 0.5 mm carbon rods as extension shafts to keep the CG about right?
Blowing air over the wing is very helpful too, produces lift and stability.
The infra red control systems and DC/DC converter weigh about  = 2.5g and uses about 2 mA !
Simon's pure flying wing is 600 mm span, no vertical fins, two cells, two KP00’s. all 2 mm sheet foam construction.
Mark's Catalina is a little under powered but it is 29" span, 43g, with two 50 ma cells, IR control, DIY geared KP00's
Hide the enamel coated copper wires to the two sensors inside the wings, but allow a little slack for movement as they are a bit fragile. Have the sensors looking outward, they can pick up the light bouncing off the walls Ok. even in our Parklands venue, which is one of the larger halls.

So, make a super streamlined model that has the motors in front of the wings and weighs a total of 25g including two KP00's, two 50 mA Ni Cds, Infra red.

  more later ......