plane powered by a servo moter

[Andrew C.]

you could use a bicycle pedal like mechanism so it provides power one way but not the other

 

[menachg]

you could do even better maneuvers and hard turns with two motors if the motor goes both ways and what do you mean by bicycle pedal

 

[xuzme720]

I'm guessing he means the freewheel on some bikes where power is applied in one direction but only freewheels in the other, like a ratchet.

 

[rcspaceflight]

If any ever does make a plane that is powered by servos, may I suggest a micro four engine plane? Like a micro B-17 or B-29. That would be epic. A Zippy 500mah 2S battery. A BEC. Rx. The four servos for the motors. Two micro servos for a bank and yank. It might be light enough to work.

Edit: Correction, it would be a full four channel because of the differential thrust.

 

[menachg]

what will happen if you use just differential thrust and connect it to the rudder/elevator in the receiver. hypothetically you could use two channel with elovon mix and you can use the original circuit board within the servo as esc and save a lot of weight

 

[rcspaceflight]

what will happen if you use just differential thrust and connect it to the rudder/elevator in the receiver. hypothetically you could use two channel with elovon mix and you can use the original circuit board within the servo as esc and save a lot of weight

I think a lot of cheap, I mean super cheap, kids toys are two channel planes. The throttle works as the elevator. So you'd really only need two motors and no control surfaces. The thrust angle is off so full throttle makes the plane climb and when you cut the throttle the plane drops. Then differential thrust would be for rudder. Of course dihedral for self leveling. I used to have one of those cheap two channels. I flew it when it was too windy out and it didn't last long. But it was fun while it lasted.

Actually, for a while NASA started to make a system that could control a plane, like a Boeing 747, using only the engines. There are a few emergency landings of the big buses where the pilots landed only using throttle. But the program was cut due to the high cost of the system and the rarity of a plane having full engine power and no control surfaces.

 

[menachg]

there is something that seem strange to me. everyone that explain how to modify regular servo to continuous rotation says to glue the potentiometer in position of where it stops to turn because that is the 0 degree of turning [natural and needs no turn]but that is the position that the potentiometer supply the most low of power wouldn't it will be better to glue it in 180 degree that the motor will move faster?

 

[Epitaph]

There is a cheap and nasty solution to the differential thrust idea with no control surfaces, which would be to use one of those cheap $20 coaxial helicopters. They come with the controller, and the cheap ones use a system where the 2 motors change power togeather with the throttle control, and when you want to turn all it does is speed up one motor and slow the other down, which is differential thrust at it's very essence. You might even be able to make some kind of elevator invention with the tail motor circuit which usually controls forwards and backwards. Then there are a lot of them that have lights enabled and disabled from the controller. Another good thing is that they usually work off a 1S battery, and can fly for 10 minutes off a full charge and just 150mAh, which makes for a very light battery. This option on the other hand might only be good for indoor, as the electronics lead to it being a very light plane, and that most of these cheap and nasties use IR control. The only thing I am not sure about in all this is as to the gyro onboard and if it will help or hinder, because the stablization outputs it gives base on the main motors controlling horizontal rotors...

There are some slightly more expensive ones with larger motors which usually work on 27mhz that would do for outdoors, but the whole idea of this thread was to use servo motors, and the micro IR are more or less servo motor powered.

In fact I might try it out as my S929 refuses to resolve the TBE no matter what I do (I must have dismantled the flybar 50 times already), and as for building materials, how about this crazy idea?: I don't know if you use the same in the States, but here when you buy for example mince meat or such from the butchers or the supermarket, and some pastry items too, they come on styrofoam like trays that are really molded 3mm depron... Use a few of those and yiu have a free (as it was only going to end up in the bin anyway once you've eaten your napolitana) very light weight building material in small scale... They say recycling is good, well, aeromodelists protecting the planet!!

 

[rcspaceflight]

there is something that seem strange to me. everyone that explain how to modify regular servo to continuous rotation says to glue the potentiometer in position of where it stops to turn because that is the 0 degree of turning [natural and needs no turn]but that is the position that the potentiometer supply the most low of power wouldn't it will be better to glue it in 180 degree that the motor will move faster?

Generally when someone modifies a servo into a continuous servo they want the motor to go forwards and backwards. If you're using the motor to turn a prop, then you would probably want to turn the potentiometer all the way in one direction. That way the motor doesn't spin when you have the throttle at zero. I'm unsure if the motor would spin any faster. So you may end up with full speed being at half throttle, but that's better than accidentally reversing the prop during flight.

 

[rcspaceflight]

This option on the other hand might only be good for indoor,

I was thinking that a servo powered plane would be an indoor flyer. It couldn't fly with enough weight to do well outside.

Mostly I was thinking that using servos to turn props is great for an RC blimp. I know that Flite Test / David made one in the Blimp episode. Well, they customized / altered one. But I know that Toys-R-Us and Target sells tanks of helium. It shouldn't be that difficult to make an indoor RC blimp. Three servos converted into continuous servos and keep the reverse on the motors. Two would be used to turn props with differential thrust and the third would be to move a weight forward and back to angle the blimp/motors up or down. Simple

Epitaph, I love your idea of converting a cheap indoor heli into a cheap indoor plane. Helis are much easier to find than planes. If it has a built in gyro, I think it would just screw everything up because it's trying to go into a hoover while you're trying to fly. But it's probably built into the Rx and you'd want to use that Rx for the weight savings. I'm not sure how well it would work, but $20 and some work for an indoor plane is really cheap.

 

[Epitaph]

The cheap cheap chinese ones that are on the corner store are probably the best... They usually fly pretty bad precisely because they lack a gyro. If I can remember what model it was, there was one on the internet a los that was very popular and came with a gyro in the "-1" model (dash one) and no gyro in the model without the dash one. The whole control is usually off of one all-in-one board with just 3 connections for the motors, one for the battery and a few for LEDs. The idea I got from my WLToys S929 that is giving problems, and just thought of the idea rather than having it getting dust on a shelf. If the rear rotor motor can be changed with a brushed actuator, then you can have elevator control, although it's not variable speed, it's more like a 1-0-1 switch, but couldwork... I think I have a miniproject on my hands!! The interesting thing also is that the trim adjusts the motor speeds in relation to each other, so it would have yaw trim, the lights can be turned on and off so that can be used for the same or to power another actuator for something, it has yaw "dual rates" by varying how much the 2 motors diferentiate (they also are not gradual, rather 1-0-1 fashion) and it has a pattern memory that remembers the inputs made and repeats them at a touch of a button. Maybe there is a way to remove the gyro or make it work to advantage...

 

[Epitaph]

Actually, now I think about it, this particular model doesn't have gyro control on the main rotors, as there are no linkages to adjust... It doesn't have a roll axis to stabilize, all it has is forwards and backwards that can be stabalized, meaning that the gyro would only affect the rear rotor... If that rear rotor was replaced with an actuator for elevator control, then the gyro would be controlling that!! If so, then you would make an input on the elevator and it would obey, and when you release, the elevator would be gyro controlled to return back to level flight automatically!! You would just have to make sure the polarity of the actuator is correct. Pushing forwards on the stck as a heli makes lean forward, and down elevator as a plane would be the same, as in pushing forwards would dip the nose, but the gyro would feel the same effect!! The only thing is the main board would have to be installed the same way it was as a helicopter... Which is in this cade pretty easy: flat horizontal.

 

[menachg]

if you just connect them to a receiver and do elovon mixing wouldn't it work [and you can still power it with 1s]