How to Choose Components For an RC Plane - Gas Engine to Electric Conversion

What you should consider before converting your RC- Engine Size: converting a standard.40 size RC gas
airplane gas engine to an electric motor system. Withengine to an RC electric motor.
the changes in RC electric motor technology it isNow you need to determine what type of batteries
possible to fly ANY size model using RC plane electricyou will need. This is based mostly on your budget and
motors. The biggest leap in making this possible hastime till land variable. In other words, how long do you
been two fold. First we have model airplane electricwant to fly for and still get performance.
engines that are powerful enough, not to mention muchThe most obvious choice is going to be a Lithium
more efficient, that they rival or even surpass gasPolymer battery, this is the most advanced battery
slimers/smokers/nitro hogs, or whatever else you maytechnology available for RC model airplanes. They are
call RC airplane gas engines.also the most expensive. Other older battery
In fact you can expect to see an increase in thetechnologies are available, such as, lithium ion and nickel
performance of a model airplane in several areas.metal hydride. They can do the job, but at a weight
Your take-off is shorter, climb rate will increase andcost and flying time consideration. So choose carefully.
you can now fly in areas that have noise restrictions.In the Arrow Example: We will use a 4200 mAh 11.1V
The debate between the benefits of RC plane electricLi-Poly Pack. This was determined based on the flight
and gas motors are as controversial as thoseperformance we were after, some aerobatics, but
between PC and Mac users. It will continue for as longmainly stable easy going flying. Nothing too extreme.
as they are both in existence.As with any gas RC plane conversion to electric (or
Some questions you might be asking before youany electric radio controlled airplane for that matter),
convert your RC model airplane's gas engine to an RCyou will have to consider an ESC (electronic speed
electric motor...control). This hooks up to the motor, battery, and
How long will the battery allow me to fly? With today'sreceiver. You will need to pick one that can handle the
Lithium Battery technology, you can easily expect 10required number of battery packs, servos and have
minute flights, even in bigger aircraft. The days ofprogrammable features. This will make life easier for
overheating the batteries and fire hazards are almostyou if you pick one that is feature rich. Of all the
non-existent. There are many add on features thatcomponents, this is one to spend a little more on. You
you can now purchase that all but eliminate batterywill be glad you did.
hazards. Such as temperature monitors and voltageFor this example, we used a 40 Amp Brushless
indicators.Controller with Program features. There are lots of
Here are some questions to ask before you startmanufacturers of ESC's so take the time to
buying any components. These questions will helpreseaRCh them.
determine what components to buy.Prop Selection is an important consideration. You need
1. What is the radio control plane that you are wantingto be aware that with an electric conversion there is a
to convert? Is it a trainer, sport plane, 3D etc.. This ispossibility that your model plane will not have enough
important because you will need to determine theclearance when using an electric motor prop. It may
electric motor based on your models capabilities, andneed modifications to the landing gear (making them
what you want it to do.longer) so that the prop has clearance.
Example: Hangar 9 Arrow with a.40 size gas engine.For the Arrow example we used an APC 13x10
Would require an electric RC motor equivalent to apropeller. Most electric motors now have a table that
AXI 2826/12 External Rotor Brushless. This motoryou can find on their website that will recommend the
would allow this model to perform basic aerobaticspropeller range to stay within.
with its semi-symmetrical wing.One final consideration with RC gas planes converted
Specs of the Hangar 9 Arrowto electric. You always need to factor in cooling of the
You will need these numbers to help determine thebattery pack and esc. In fact many modelers, including
motor, battery, and prop requirements.myself, put the ESC on the outside of the plane, usually
- Wingspan: 63 inI mount it under the engine on the firewall. You also
- Overall Length: 52.5 inneed to make air vents to cool the battery inside the
- Wing Area: 710 sq inmodel. Without this, you run the risk of overheating
- Flying Weight: 5.7 lb (as a radio controlled gas plane)batteries and ESC's.