What equations or formulas do you use when building your plane? (Need help for a school project)

modbob

New member
Hello,

for a school project I am currently trying to build an RC Plane by myself. To do this I went to my local electronics store and bought a Pichler Boost 18S Brushless motor, a 25A ESC, a 4 channel receiver, a propellor, 2 servos and a LiPo battery. However, when I try to control the motor after I have connected it to the ESC, battery, and radio receiver, it doesn't work. All it does is go full speed, doesn't allow me to stop the motor with the controls on the controller, and forces me to unplug the battery from the ESC. Could anyone help me?

Thanks :)
 
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FDS

Elite member
Get a picture of the whole lot, plugged in. You may just have something set up wrong.
What radio transmitter are you using?
 

modbob

New member
I am using a REELY 4 channel transmitter. Could it be that the motor is damaged?
 

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Seahunter

Active member
Check the spec sheet on your receiver, the photo looks like your ESC is plugged into CH 4 on one photo, CH3 on the other, is that marked throttle? The lead (BEC) from the Esc must be plugged into the throttle slot. I am not familiar with that receiver, anyone have one?
 

modbob

New member
Thank you for all your input guys. I took Merv's advice and reversed the throttle channel and it worked :)
One last thing: do you have any formulas or equations you use when calculating say the wingspan (other than the WCL equation) or the angle at which the wings are positioned? It would be really helpful since my project is about the physics behind the flight of an RC plane and I am having difficulties finding information on that.

Thanks in advance!
 
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Chuppster

Well-known member
Thank you for all your input guys. I took Merv's advice and reversed the throttle channel and it worked :)
One last thing: do you have any formulas or equations you use when calculating say the wingspan (other than the WCL equation) or the angle at which the wings are positioned? It would be really helpful since my project is about the physics behind the flight of an RC plane and I am having difficulties finding information on that.

Thanks in advance!

Wingspan: What are your parameters? What are you designing for? Speed? Efficiency? Lifting?

"Angle at which the wings are positioned": Could you be more clear? Is this wing incidence? Wing sweep?
 

modbob

New member
Sorry for the ambiguity. I plan on using a wingspan of 100cm and a wing area of 1500cm^2. I am aiming to design a glider since I am a complete beginner and am trying to build something easy to control. For the "angle at which the wings are positioned" I mean the wing sweep since I had seen some examples (namely the Air Hogs Titan foam plane) where the wing sweep was greater than 0 and some examples where the wing sweep angle was 0, ie. a straight wing.

Thank you :)
 

Merv

Site Moderator
Staff member
You should look at the Tiny Trainer. Starting with a known design has many advantages for a noob. After you learn to build and fly, you will have plenty of time to do create your own design.
 

poor boy 101

Active member
Wow your school is picky. All I did last year on my project it ask the school to buy a guinea pig with all the electronics and I built it and got to keep it. And just flew it at the end of the year.
 

modbob

New member
Yeah I know. It's also a pretty huge project worth a lot of my final grade :(
Since I am interested in Physics I decided that I wanted to examine the laws of flight and aerodynamics but I hadn't anticipated that it would be this complicated.