stunthanger.com
General control line discussion => Open Forum => Topic started by: bob whitney on April 28, 2014, 06:28:05 PM
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is there any rule against the prop free wheeling on landing on an E-Stunt Ship
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Not in the USA.
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Yup
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First I heard of this. So whats the rule outside the USA?
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Bob,
Although there is no rule one thing you find with a free wheeling prop is "aero braking" in the wind. When I first started they didn't have the CL brake set up in the Castle 45 ESP. I was getting comfortable with the electric power and was flying in a bit of wind and when the motor quite I came around into the wind, was still about 2' off the ground and the ship hit the wind, STOPPED and fell out of the air. It really is not a good thing to have the prop free wheel if you have a choice.
Best, DennisT
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They are programed to land on reduced power from what I have seen,they are not free wheeling.
Juan
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I know from experience that a freewheeling prop makes an excellent airbrake. you really want to have a dead stop on the prop to ensure a decent glide.
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FAI rules the engine must be stopped on landing therefore prop must not be spinning . I am not familiar with AMA rules.
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Ooh, that's a long bow to draw. How do you determine whether an engine is off or not, in terms of an electric motor?
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Hit the ground with the prop turning and it's a crash and a DQ
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In the FAI rules it does say that the prop has to be stopped........
HOWEVER, their definition of stopped say that the blades can turn slowly so that an observer can see the rotating blades.
Here is the rule;
4.2.15.17 Landing Manoeuvre
Recommended entry procedure: The manoeuvre is entered from normal upright level flight at the
height of the base.
a) Start of manoeuvre:
As the model aircraft leaves level flight at the height of the base (+/- 30 cm) and with the
motor/s and propeller/s stopped.
Note: For the purpose of this rule, the word “stopped” describes a situation where the blades
of the propeller(s) are actually at a standstill or are rotating so slowly that the individual blades
can clearly be seen by an observer.
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Ooh, that's a long bow to draw. How do you determine whether an engine is off or not, in terms of an electric motor?
Electric flyers use the brake feature in the ESC.
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Seems to me that a IC motor's prop is not really stopped unless it ran lean and seezed the motor up. This rule book lawyering needs to stop and lets have fun
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Seems to me that a IC motor's prop is not really stopped unless it ran lean and seezed the motor up. This rule book lawyering needs to stop and lets have fun
In this case, it's worse than rule book lawyering, since this isn't in the rule book and there's no restriction about landing with the engine running, the prop rotating, or anything else like that! So (putting aside FAI which doesn't apply to the vast majority), the argument is about the relative merits of something that doesn't exist. Gotta love the internet.
There is a real, possibly legitimate, rule book question here but I can't bring myself to point it out.
Brett
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If you have ever flown RC you learn that a dead engine on a plane will let it land at a faster speed. With the engine on idle and not enough pulling power it will slow down very fast. This I know from experience. Also one of the reasons you land an RC plane with just a little power to keep it moving.
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If you have ever flown RC you learn that a dead engine on a plane will let it land at a faster speed. With the engine on idle and not enough pulling power it will slow down very fast. This I know from experience. Also one of the reasons you land an RC plane with just a little power to keep it moving.
It works the same with stunt planes, the same effect is the essence of how you avoid wind-up and generally have speed regulation even if the RPM is constant (like electric).
Why you have more drag when freewheeling VS stopped is an interesting thought experiment left to the reader.
Brett
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I'll throw this into the discussion. There are a bazzillion free flight rubber designs that use plastic store bought props. They have a built in free wheeling device. In competition P-30 rubber, it is usually desired that a precisely place wheel collar on the prop shaft take the load on the bearing while the prop is being driven by the rubber, and as it unwinds, there is plenty of room for the prop to move back from the hook or latch, and easily free wheel. If you have ever seem a free flight model with the prop hung up and not turning it is almost like a dethermalizer! It's another one of those things that you can stay up all night and drink a lot of beer while arguing about it! I got to see one of Windy's flight with his Typhoon (?) that had the Z-Tron system in it at the NATS one year, and he landed that with some power on, and killed it when wheels contacted the ground. I think this actually hurt him as his landing took several laps and wasn't as is described in the rule book for the landing maneuver. All things considered, I like my I/C engines and having the prop come to a nice, horizontal position for landing.
Type at you later,
Dan McEntee
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I'll throw this into the discussion. There are a bazzillion free flight rubber designs that use plastic store bought props. They have a built in free wheeling device. In competition P-30 rubber, it is usually desired that a precisely place wheel collar on the prop shaft take the load on the bearing while the prop is being driven by the rubber, and as it unwinds, there is plenty of room for the prop to move back from the hook or latch, and easily free wheel. If you have ever seem a free flight model with the prop hung up and not turning it is almost like a dethermalizer!
The difference between the freewheeling rubber prop and the freewheeling prop on a motor is that the rubber prop isn't delivering any power to the shaft, while the idling IC engined or electric motored prop (usually) is. I have this really nifty-looking Comet Gull II with a geared electric motor in it, and an ESC without brake. When you shut it down the prop stops, then starts to freewheel -- and man, you can see the thing stop dead in the air when that prop really catches.
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I like my I/C engines and having the prop come to a nice, horizontal position for landing.
Type at you later,
Dan McEntee
How do you get a 3-blade "prop come to a nice, horizontal position for landing"?
Just wondering.
Keith
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How do you get a 3-blade "prop come to a nice, horizontal position for landing"?
Just wondering.
Keith
That's when the three way Kanuton valve gets stuck in the two way position.
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That's when the three way Kanuton valve gets stuck in the two way position.
OK, how does one deactivate the Kanuton valve once it is stuck? Can we use the 2.4 gHz systems to clear it? I do not think I will install that valve ever again.
Keith
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All is well, went to my main man today and we programmed the brake back into the system , thanks for everyones responce
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Forgive me for asking, but what about folding props? ???
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When flying electric launch gliders with folding props, making the prop just spin at lowest throttle makes it a huge brake. A good way to help exit a flight that was getting too high, and to help slow for landing. Rather eye opening to see the glider almost fall when the prop went from folded to just over freewheel.