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I can't help it...It's an illness I tell you...

Posted by James Cann on January 13, 2011 at 5:30pm
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I have clinical multi-projectitis.

It's incurable.

After seeing the GRASP lab video sof quads literally jumping through hoops, I HAD to make one of my own.

The beginnings: 

Although everyone else seems to be going open-rotor, I want zero collateral damage to people, pets, and the living 

room walls, so I decided on a ducted-fan design.

4 EDF combos from Hobby King

https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11166

Combined thrust of 4400g.

Combined mass of 424g.

 

The 5Ah 4S 40C LiPo from my currently grounded Swift Heli:

https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10307

Mass: 578g.

 

For testing, the initial fuselage is a chunk of extruded poly insulation.

5 Deans connectors and a new soldering iron later (the old 30Watt one couldn't make a decent joint for the wiring harness), this is the result:

I christen her "The Ugly Pink Quad."


3689385013?profile=original

 

At present, she's brainless.   I just did a test with a little solderless breadboard sending the throttle signal to all EDFs simultaneously and, not surprisingly, things were learned:

 

1) With 4400grams of max thrust pushing 1220grams of pinkness, it only took about 1/3rd throttle position to hand-hover.

2) It wants to rotate.

 

Next issues: Basic landing gear (The motors are outrunners), basic brains, and an IMU 

 

 

 

Tags: pink, quad, ugly
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Comments

  • James Cann January 18, 2011 at 4:34am

    Not certain why, but sadly, one of my four ESCs may be dead.Will verify Tuesday, and will decide on whether to continue the Quad, or get more pink stuff and go for a Tri-Copter version while the mailman brings a replacement...

  • Brad Smith January 15, 2011 at 12:10pm
    Iv,e thought about this too , but could,nt get by the inefficiency of lost thrust + drag for my purposes but i can see the advantages if you can get ccw fans without them your gonna waste more energy constanly correcting for ever changing torque loads (for every correction u,ll need a correction) you might can find ccw fans from other vendor and grind down and adapt to your motors &shrouds
  • Matthew Coleman January 15, 2011 at 9:15am

    If you make the landing gear from foam the whole thing would float and keep the electronics dry.

    Think of it, Water starts from your bath tub or garden pond.

    Best not be in the bath with it considering all those nasty rotating bits.

     

    Bring on "The Ugly Floaty Pink Quad"

  • Michael Colton January 15, 2011 at 1:24am
    Tilting two of the fans will work fine, they don't need to be adjustable because the brain will compensate for yaw issues. This is how many of the MicroQuads fly (Jose Julio's and my own included)
  • Lew Payne January 14, 2011 at 9:23pm
    I like it, I like it! If the project doesn't perform well, you can always retrofit the parts into four CPU coolers.
  • hamish January 14, 2011 at 5:13pm

    You'd be better off with bigger, slower props . .. . plus you'd be able to pick up some counter rotating ones

     

     

  • Hopper January 14, 2011 at 3:18pm

    I had a similar thought a couple years ago. Used foam poster board for the airframe. Initially tried two fans on paddles and quickly discovered the need for two more.

     

    3692152224?profile=original

     

    Added two more fans but they were only supported by whimpy axels and quickly broke off on power up.

     

    3692152241?profile=original

     

    Came up with a better design that supported the fans on both sides

     

    3692151800?profile=original

    Unfortunately, I used whimpy ducted fans. It couldn't even support its own weight using an external power supply! Didn't have the cash for brushless, so the whole project went on the shelf. I never even got far enough to discover the counter-rotating issue. But I still learned a lot.

     

    Keep plowing forward, James. Who knows what you might discover.

     

    Worst case, it's good free entertainment for the rest of us!  ;)

  • Matthew Dugal January 14, 2011 at 12:32pm
    Obviously, I did not think that through.
  • Moderator
    Sgt Ric January 14, 2011 at 12:10pm

    "think about it: make the motor spin backward and then turn it around -> spins in the same direction as before ;-"

     

    ..and since it spins in the same direction, isn't the moment of torque the same as before?

    Have we gained anything?

     

  • James Cann January 14, 2011 at 10:13am

    Yes, they are brushless (3 phase synchronous motors), so reversing any two lines will reverse direction.

    However, ducted fan blades are curved for aerodynamic efficency, and the stator blades would then be the wrong way as well.

     

This reply was deleted.