Hello everyone, I am new to this forum so my name is Gabriel. How come an RC airplane's propeller is backwards compared to a real life propeller. An RC propeller turns counter-clockwise but a real life one turns clockwise. I wonder why they designed an RC one like that. Thanks for any input!

From the pilot's point of view (i.e. from the cockpit looking forward) an R/C prop runs clockwise.

Last winter our club had an indoor rubber event, so a bunch of us built penny planes. (To anybody who hasn't done this yet, I'd highly recommend it. It's educational, rewarding, ... and humbling.) Anyway, I wanted to make a good propeller, so I soakedthe blades, formed their curves and outlines and put it all together for he event....

Trouble was, I was thinking that when the winder attaches at the propeller end, it's turning the same way that I'd flip the prop if it were an IC engine, so my propellers were made backwards. Everybody gets the prop going the wrong way sometimes? Maybe not, but I sure did!

Just guessing but I believe that most engines rotate the same way even in full size aircraft but the props are often gear driven for reduction purposes?. But then again the double Wasp used planetary gearing IIRC so there goes that argument.....

For our model engines can you imagine trying to flip the prop "under"? The fields would be littered with bits of fingers........ Also it has a lot to do with the single prop nuts being threaded right handed. The way the shafts turn now they tend to tighten the nut and prop. If they turned the other way they'd tend to loosen. So there would be lot of props and nuts along with the bits of fingers on the fields........

Shall I go on..... :stupid:

Hi Gabriel; Almost all aircraft propellers turn clockwise, from the pilot's point of view, whether they're models or full size. Twins almost always have counter-rotating propellers, one turning each way. This requires two different props.

Another different propellor is the "pusher" type. These are not just regular props installed backwards. They have to turn the same direction, but force air away from the engine, instead of towards it. They're like a mirror image of a regular prop.

I installed a pusher prop backwards, once. It sort of worked, but it wouldn't fly the plane. Installed backwards, the thin trailing edge became the leading edge, so it was still "blowing" in the right direction, but not very efficiently.

Gabriel, I'm gonna take a stab here and guess that you're a full scale pilot. My guess is based on the fact that you included your "N" number underneath your name. Model engines and full scale engines both rotate counter clockwise. You're used to seeing the propellor from the perspective of being in the cockpit. When you're messing around with an RC aircraft, you're seeing the propellor from the outside. The engine has not changed direction only your perspective has changed.....give a few moments of thought, you'll see what I"m saying.

Yes -I think its the common screw thread that determines the normal direction of prop rotation on a model.

On full size, the props are mounted, er better ( to say at least, and dont shed props every new moon! ). Hence rotation can be either way, as on some multi-engined aircraft prop rotation is reversed on the other wings ( not all !).

Cheers...

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RC Propeller Question (post # 1)

Hello everyone, I am new to this forum so my name is Gabriel. How come an RC airplane's propeller is backwards compared to a real life propeller. An RC propeller turns counter-clockwise but a real life one turns clockwise. I wonder why they designed an RC one like that. Thanks for any input!

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Methinks they all turn same way. The Cub does. MY PW R-2800 did. Hey, Gabe. I bet you been flying a Griffon powered Spitfire, haven't you? Son-of-a-Gun, bet that's fun.

Or at least a 1966 Cherokee 140! Fun plane! What particular RC engine did you see turning left?

Gabriel:

The older British engines, Bristol radials and deHavilland in-lines for example, turned "Backwards." The French also had a lot of CCW engines, for this example the Salmson radials. But in every case the engines could be made in a reverse rotaton for a special installation.

The rest of the world has taken over the Limeys and Frogs now, all standard engines turn the same way.

And,as stated in an earlier post, many twins have the right engine reversed to decrease the yaw with the left engine out. This is due to torque effects - with the top of the prop turning toward the fuse torque tries to turn the plane to the running engine, minimizing the turn tendency of the engine's thrust. Doesn't eliminate it, but it helps.

Twin flying on one, try that for fun.

Bill.

PS: My ancestry includes Limeys and Frogs, so don't fuss at me about racial "Pejoratives." wr

Throughout history props have turned both ways. Just depends on the engine.
When buying a prop for an ultralight, you must know which way your particular application turns, as this depends on if you use a belt reduction, or gearbox.
Some twins have the same type engine, but on turns one way, one turns the other.
Just depends.

Jetts

I don't know about the engine, but the prop on a Sukoi or Yak rotate the opposite of other aerobatic planes. In a torque roll they rotate to the right.

Tracy Hill

Tracy:

While the world has overtaken the Europeans, the Russians continue to hold out.

And thank you for pointing it out, I had completely forgotten the Polikarpov's, the Kutsnutsoff's, etc. built in the Ukraine and Russia.

As a historic note, back in '38 or '39, the Russians attempted to copy the R-R series of V-12 engines, they had those turning backwards (British manner) also. Don't remember for sure, but I think the Yak-3 used that engine, the one I'm thinking of was used as a tank buster.

Never a single, always a twin. Keeps the tingle, keeps you thin.

Bill.