Remote Control Plane Engine Options
Three main types: petrol engine, electric engine and now a days jet engines. Yes legit actual jet engines. There is also a derivative of the propeller usually electric propeller engine that is a fan instead of a prop that fits in a jet fuselage but they are not real jets.
The petrol engines run on Nitromethanol – I think – and they have a reciprocating piston combustion engine. I asume they are two stroke. They dont have a spark plug, instead they have a ‘glow plug’ which is basically a very small coil of wire at the top of the cylinder. You start a petrol engine by attaching a battery pack via small alligator clamps to the glow plug’s outside protrusion and the body of the engine. That causes the glow plug to glow and then you spin the propeller and if the fuel air mixture is ok then the engine fires and your in business. Because the prop is a danger and tedious to finger flick, you can buy a device that spins the prop for starting – a kind of external hand held starter motor. These little petrol engines actually produce some serious power thrust and NOISE! They are measure in CC or cubic inch in figures like 0.40, 0.60 etc. Air cooled. Apparently according to science these glow engines shouldnt work but they do haha. The start process can be difficult and is similar to starting a petrol / gas powered lawn mower engine. They can fly for a long time.
Then theres electric engines, they have some pros and cons, namely they are less noisy than petrol engines, they can change battery packs and go again quickly they are easy to start and stop, they are not very hard to operate. BUT the batteries will last a few minutes only. And also as petrol burns, the plane gets lighter, but as a battery runs out of juice they electric plane remains at its takeoff weight – unless you have mice onboard trained to throw the battery overboard. lol. In any case both types of plane still require a separate battery system to run the transmitter receiver, and servo controllers. If you are using a drone style multicopter style config, you may prefer electric engines, because you can make minute and instant power adjustments which is perfect for computer controlled drone stabilisation.
Jets: Jets are relatively new and SO EXCITING!! The best known manufactuerers of RC Jets is Jetcat. There are also a plethora of small bespoke manufacturers and budding designer/builders. So far the state of the art of RC jets is they require a major overhaul every 50 hours. Also they are very innefficient compared to proper sized jets and same power piston engines. I reckon one of the inherent problems of RC jet engines is that their small internal circumference means an outsized boundary layer on the inner surface which will probably clog up the airflow and cause inneficiency. Only way to solve that would be to increae the size of the jet. We are starting to see some of the larger RC jets being utilised for small personal ultralight aircraft such as the 4 Jetcat jet engines on the Yves Rossi Red Bull wing suite. I believe they are in the order of 200 Newtons thrust each – 20KG of thrust per jet. Not bad. Another crossover success is to power the Cri Cri with two jets or to use a jet or two on a glider. As time progresses these RC jet engines will likely become more reliable, longer interval between overhaul and cheaper to acquire.
In summary RC planes can use electric petrol and jet engines.
And just finally I couldnt cover RC plane engines without mentioning Moki radials! Check out the sights and sounds of this sensational engine! Moki engines are amazing because they are true radial engines small enough for use on RC planes. Often RC planes in the past that needed to simulate the appearance of a radial engine, would kind of dress-up to look like a radial. But now that there are real radials, theres no need for that, and they produce some power too!
Actually let me add just one more engine type to the list: Pulse jets! Yes you can get RC plane pulse jet engines. I believe HobbyKing sells a plane that is powered by pulse jet. Pulse jets are extremely extremely extremely extremely loud…But apart from that, and their massive fuel consumption and their tendency to glow red hot, they are nice little engines with no moving parts!