Blogs

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

Posted by James Cann on January 13, 2011 at 5:30pm
3689384963?profile=original

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
E-mail me when people leave their comments –
Follow

You need to be a member of diydrones to add comments!

Join diydrones

Comments

  • Darren January 20, 2011 at 6:59pm

    picture the quad suspended in the middle of a hoberman sphere.. \in theroy any shock should be absorbed throughout the quad frame as it tries to collapse.

    Hoberman_Sphere.jpg?width=200

  • Squalish January 20, 2011 at 6:56pm
    My take on that Darren - Long-armed copters like you drew can be protected using a tensegrity (wire) guard for a decent weight savings, but IIRC I have seen several designs with foam or metal prop guards.
  • Darren January 20, 2011 at 6:36pm

    Dont take this too literally... but the concept is to encase the whole quad, not just the blades.

     

    3692155574?profile=original

  • Darren January 20, 2011 at 6:21pm
    as far as saftey is concerned, I think I have the best solution for that... (insert tease music here)
  • James Cann January 20, 2011 at 5:38pm

    Ducted fans are totally enclosed, with a set of stator blades beneath.   Essentially, if I were to dremel off the surrounding duct, and the stators, I would have a small, high speed propeller that had much less thrust.

    Mostly I choose the ducted fan route to have a built-in finger/furniture/pet safety margin.

  • James Cann January 20, 2011 at 4:08pm
    3692155522?profile=original
  • James Cann January 20, 2011 at 4:02pm

    Unfortunately, the speed controller is toast, and lost a screw at less than half-power the other day, so the Ugly Pink Quad is on-hold/no more.   The redesign will be a tri or bi-rotor, more robustly built.

    Info soon.

     

  • Choppy January 20, 2011 at 1:42pm
    I think he means kick off two diagonally opposed fans to couteract the torque of the motors. I've seen it done on hovering quads when all the props are of the same rotation. Actually, it wasnt a quad, more of a quin? Had a IC motor in the middle for main thrust and 4 brushless motors on the outside. Hovered nice. How is this project going? (I assume you have gone totally mad and have too many projects on the board like me...)
  • Darren January 20, 2011 at 10:47am

    @hamish, not quite sure I understand your post... but IYO what way is not wrong? ;)

  • Choppy January 19, 2011 at 3:22pm
    On another tangent, as quads use low KV motors for better control resolution, would longer arms (moment) be better for high KV ducted fans? That is put them out further?
This reply was deleted.