Propeller with propellers

[navillus5]

Jason -

I just saw you video - I followed the link from the Parallax page. Very nice work. I had a couple of quick questions...
MOTORS - are you using motors designed for electric RC planes (i.e brushless) or are you using cheaper motors that can be controlled with and H-bridge type motor controller.
REMOTE - I see that you are using a radio to control the Spyder. Is this necessary - meaning could you program the device to take-off, fly a set pattern and then land?

Dan (aka navillus5)

[JasonDorie]

Dan,

The motors are indeed brushless motors bought from a hobby store that supplies them for model airplane use, and the motor controllers are as well - they're interfaced using a modified version of the Servo_32 object that outputs 8 channels at ~200Hz (instead of 32 channels at 50Hz).

The Spyder does require a radio transmitter/receiver to fly it. In its current form, the Spyder is not self-stable. I fly model helicopters and set up the Spyder to control the same way, so I probably make it look easier to fly than it actually is. With clever programming and some good accelerometers it should be possible to make it self-levelling, but I haven't gotten there yet. I'd like to achieve that to see if I can do it, but my goal in building the Spyder was to make something that flew like my helis, not something that flew itself.

There are a number of other quad-copter projects out there, including Paparazzi (http://paparazzi.enac.fr/wiki/Main_Page), MikroCopter (http://www.mikrokopter.de), and others. Those are significantly more stable, but also more expensive. Most use a combination of GPS, altimeter, accelerometers, gyros, and thermal horizon sensors to get enough data for stable flight. I've seen video of a couple of those where the pilot sets down the remote, walks over and shoves it, and the copter recovers like nothing happened.

Jason

[noobmuncher]

Jason,

I have read through your forum and I must say it is an amazing project, even prior to seeing your project featured I had been planning on working on a simular project anyhow, so when I saw your project I was incredibly pleased. I must ask though, how did you prevent it from spinning? With the gyro I am able to KNOW when it is spinning, but I don't quite understand your system that prevents your from spinning. Would you mind clarifying please?

Thank you!

[JasonDorie]

The simple answer is torque.

The complicated answer is that the props are counter-rotating in horizontal or vertical pairs, but rotate in the same direction as their diagonal counterpart. The front right and rear left props spin one way, and the front left and rear right spin the other way. If I speed up a diagonal pair of props, they don't tilt the machine, but they'll torque it in the direction opposite the direction they're spinning. Slowing down the other pair of props keeps the amount of lift the same, and also increases the torque effect.

Jason

[noobmuncher]

Oh okay i understand how this works then, I was just always under the impression that propellers were built to only work in one direction of rotation. I assume I was incorrect then?

[Lab Rat]

flying inverted now that just plane awsome DO IT lol

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Parallax posesses power beyond belief.

Believe in it.
Visit me at
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[JasonDorie]

NoobMuncher - I buy the props in matched pairs where one made to rotate clockwise, and the counter-clockwise. It limits the selection somewhat, since it's harder to find props that are available as both 'normal' and 'counter-rotating'.

That's the key though - if the four props spun the same direction, their torque would sum, not cancel, and the thing would start to spin the moment it left the ground, like a helicopter without a tail rotor.

Jason

[noobmuncher]

Where can I purchase propellers like these online? What should I be looking for. If possible could you send a link? : )

Thank you!

[noobmuncher]

Any help with this would be appreciated, up until this post I had never really heard of this type of propeller, even though I understand the physics behind it.

[jeff2.0]

I found this today. It's way cool.

http://www.wimp.com/thehexacopter/

[Cluso99]

Jason: Are you still here?
If so, could you answer a few questions please...

What motors are you using?
Are you using ESC or are you driving MOSFETs and if so, what is your configuration.

I have a TowerPro 2908GS-18T motor with 30A ESC that I was going to use for a flying wing. Do you think these would be suitable or do you have a better recommendation?

I was thinking it would be nicer to control the motor directly (via Mosfets) than to use an ESC, although this is more complex. Your thoughts?

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Links to other interesting threads:

· Home of the MultiBladeProps: TriBlade,·RamBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: CPUs Z80 etc; Micros Altair etc;· Terminals·VT100 etc; (Index) ZiCog (Z80) , MoCog (6809)·
· Prop OS: SphinxOS·, PropDos , PropCmd··· Search the Propeller forums·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz·· MultiBlade Props: www.cluso.bluemagic.biz

[Szabi]

Woow Jeff, thats awesome but quite expensive and unfortunately only commercial FW without free source

let's put together our brains and start to build one like that with autopilot etc. and of course with free source.
Since this is a thread for completed projects we will need to open a new one, where we can continue to develop the 8cogHexaProp

Anybody seriously interested?

[Cluso99]

As noted, I have already opened a new thread on the Propeller Forum as I will be using a prop

A QuadCopter or HexaCopter using Propeller(s) and Gyros, Accelerometers, Compass, Pressure & GPS

http://forums.parallax.com/showthread.php?p=890157



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Links to other interesting threads:

· Home of the MultiBladeProps: TriBlade,·RamBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: CPUs Z80 etc; Micros Altair etc;· Terminals·VT100 etc; (Index) ZiCog (Z80) , MoCog (6809)·
· Prop OS: SphinxOS·, PropDos , PropCmd··· Search the Propeller forums·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz·· MultiBlade Props: www.cluso.bluemagic.biz