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STUDENT HELP
- Thread starter khoifish17
- Start date
yes and no I am currently looking for props. I want to try bigger prop yet I want to test if smaller one will get the most power out of the gearbox. Idk any recommend on prop. We use a 7inch 4.7 sf which we test with a thrust measure tool. We test with some prop like different pitch and inch but that was the best one. We never test the smaller one and slightly bigger one.
This is how the challenge work. No battery is being attach to the plane due to "too complex for some student"(i didnt write that). This challenge the power source is being attach to the plane by some alligator clip(to control, you add the voltage for more power or reduce for less power). The plane is being tension by the electrical wire from the power pole. The team will then have 8 minutes to fly and carry as much weight as possible. The minimum is 20 cm above the ground (count from the landing gear down to the ground)
*i will try to find some pics
*i will try to find some pics
So you are flying in a circle, like this guy. That is similar to what we call that control line. The handle he is holding has 2 wires, they are used to control the elevator. By changing the angle of his wrist. In theory these wires could be used to supply electricity to the plane. Not sure if anyone has done this, I’ve never seen it done.
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yes, the power source is frok 9volt to 12volt. The idea is the same but I cant not use any surbo. The only "mechanic" part is motor and prop. I will try to get a video up here just isnt the best quality. The idea of flying in the circle is exactly the same just smaller scale and a pole instead of a human.
I’m thinking you need to max out the amp draw on the motor. It would be helpful if you have any specifications on your motor, how may amps can it putt without burning it up. If you don’t have any specs on the motor we will need to sneak up on it. Test a prop for a minute or two to see if the motor gets hot, if not hot try a larger prop. You are looking for the motor to get hot enough you can comfortably hold for while but not so hot you have to immediately let go.
He's limited to an eighty's style dc motor rated at 6 volts DC. He's got twelve volts DC available. The airframe doesn't even have to be an airplane. It has just has to haul a heavy load through the air and last for eight minutes. No control surfaces, just throttle and tethered to a post.
A frackin' blimp! Holy cow, build a blimp with some down thrust.
A frackin' blimp! Holy cow, build a blimp with some down thrust.
I don’t have enough experience to say for sure. I think a gearbox would be beneficial. I also think you could have too much gear reduction. I'm thinking something in the 2-4:1 ratio, I don't think the answer will be 10:1. Others with more experience may have different advice.
I'm not sure if the limiting factor will be wing area or power from the motor. Here is my thinking for the plane, more air speed = more lift. So the question is how much airspeed will you need to achieve maximum lift with the wing area restrictions given. Can the motor supply enough thrust to achieve that airspeed. OR Will the motor wimp out before we reach the maximum potential of the wing area.
I'm not sure if the limiting factor will be wing area or power from the motor. Here is my thinking for the plane, more air speed = more lift. So the question is how much airspeed will you need to achieve maximum lift with the wing area restrictions given. Can the motor supply enough thrust to achieve that airspeed. OR Will the motor wimp out before we reach the maximum potential of the wing area.
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Here is a PDF of the rules for the Lindbergh Electric Aircraft (LEAF) Challenge
http://www.leafchallenge.com/
the power supply is 0-16 volts at 1.5 amps.
Teams must use an electric motor (Kelvin #850647, #851950 or TeacherGeek #1821-70)
Anyone have ideas?
http://www.leafchallenge.com/
the power supply is 0-16 volts at 1.5 amps.
Teams must use an electric motor (Kelvin #850647, #851950 or TeacherGeek #1821-70)
Anyone have ideas?
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Nah. From what I've read, pushers use more power to do the same thing. I don't know why.
I wanted to mention that you handled my initial outburst like a pro, though. I misunderstood what I was seeing and reading and you managed to push me aside with respect. That was very well done.
My next idea was helium bladders. Nope. I read the pdf. dang.
Keep in mind, my knowledge of aerodynamics is from my own schooling, and that was a long time ago. I get confused with RC because of what the power to weight ratio is capable of and the fact that my aerodynamics knowledge is so very basic.
You need lots of lift. Lifting surfaces cause drag, and that drag means you need more power. You were looking to the gearbox to get that extra thrust. OK.
Ratio. Back in my motorcycling days, I swapped out the rear sprocket for one with one more tooth. That little change meant I had less torque, but I pulled fewer RPM's at speed, got better gas mileage (I commuted on the thing, it was important) and generally stressed the drive train less.
I can kind of see it, but not quite. Does that give anyone any ideas?
I wanted to mention that you handled my initial outburst like a pro, though. I misunderstood what I was seeing and reading and you managed to push me aside with respect. That was very well done.
My next idea was helium bladders. Nope. I read the pdf. dang.
Keep in mind, my knowledge of aerodynamics is from my own schooling, and that was a long time ago. I get confused with RC because of what the power to weight ratio is capable of and the fact that my aerodynamics knowledge is so very basic.
You need lots of lift. Lifting surfaces cause drag, and that drag means you need more power. You were looking to the gearbox to get that extra thrust. OK.
Ratio. Back in my motorcycling days, I swapped out the rear sprocket for one with one more tooth. That little change meant I had less torque, but I pulled fewer RPM's at speed, got better gas mileage (I commuted on the thing, it was important) and generally stressed the drive train less.
I can kind of see it, but not quite. Does that give anyone any ideas?
