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Electric Motor Effciency (Density / Watt / Losses)

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Patrick

Tue Oct 29 2013, 08:03PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Big Bad and Ash Small, you guys are describing the UAI's flying wing drone for Canadian police perfectly. it has a folding prop too. it orbits the officers location and has a camera turret which turns 360 degrees to keep the location constantly visible.

I need to find the 2012 pic of me holding it up...

edit: here we go.

Me holding UAI's machine in August 2012 Grand Forks, North Dakota. As a part of the IARC mission 6 competition.

BigBad

Tue Oct 29 2013, 10:13PM

Registered Member #2529 Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600

Ash Small wrote ...

Now you're talking. A VTOL 'glider' could have a lot of potential (but not for Patrick's competition). Use the motors for take0off and landing, and maybe for some propulsion in 'glider mode', and just glide and use thermals as much as possible.

It wouldn't take a lot of expanded polystyrene/balsa wood/ carbon to modify Patrick's design to glide as well.

You'd do better to just lob it into the air somehow/anyhow and land horizontally; you don't want the bigger motor, propeller and battery that VTOL needs.

Patrick

Tue Oct 29 2013, 11:09PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

There is a kick start group that developed a flying wing that takes off and lands vertically but transitions horzontally...

BigBad

Wed Oct 30 2013, 01:01AM

Registered Member #2529 Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600

Oh sure, but they'll get rather less flying around time.

Patrick

Wed Oct 30 2013, 03:27AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

It flies really well with a 5.9 x 6 prop on the rear fan... I've had it well above 50 inches AGL, and out of ground effect. I'm going to time the next flight.

EDIT: it flies fully loaded for 5:10, while mass =1.6 kg, on a 3000mah 3 cell lipo, which weighs 240g.

Ash Small

Thu Oct 31 2013, 11:43AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

BigBad wrote ...

You'd do better to just lob it into the air somehow/anyhow and land horizontally; you don't want the bigger motor, propeller and battery that VTOL needs.

Yes, that would give the longest flight time, at the cost of manouverability.

I still can't believe we scrapped all our Harrier jump jets.

Patrick

Thu Oct 31 2013, 01:41PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

If you foreigners keep your harriers, how will we Americans trick you into buying the F-35 for 3 times as much?

Ash Small

Fri Nov 01 2013, 02:15AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Patrick wrote ...

If you foreigners keep your harriers, how will we Americans trick you into buying the F-35 for 3 times as much?

Well, we seem to be relying on tornadoes and typhoons, and 'in flight re-fueling', apparently we can hit anywhere in the world.....We've even got rid of our aircraft carriers.

There's no reason why 'in flight re-fueling' can't be adapted to LiPo's.....I believe I mentioned this before in one of the threads on this topic. Just drop one and pick up another.

Patrick

Sat Nov 02 2013, 01:50AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

ive just got new epoxy and electronic goodies... and i have a lot of FG and CF fabric already. i also tuned the CoG and CoT such that it hovers easier now.

this newer flight board includes a GPS ability and antenna, so i should be able to fly waypoints now. even though my academic competiton forbids GPS, it still useful for other endeavors.

on Thrusday, 10-31-2013, i flew several minutes on the Shasta College campus for the math, physics and chemistry professors, they were all super impressed and encouraged me to talk to the Cal Fire training site on our campus... (there have been several large wild fires here in northern California, and several firefighters have been killed nationally this summer.) i think forest fire fighting may be the better place to start the whole "drone roll-out" to see if first responders of any kind, can even make use of drones at all.

Ash, as per your previous in flight refueling comment. The Saturn car company had a paddle type plug for their electric car, so people wouldnt get killed when it rained, and they wanted to drive somewhere. It split the transformer in half, a primary in the fully encapsulated paddle, and the secondary in each car. so the "plug-paddle" didnt even need to be anything precise just in close proximity, this method could be used to drop and pickup each battery i guess?

In flight re-battering...

From left to right, the Flight Board, the GPS unit, and the Orange RX reciever.

BigBad

Sat Nov 02 2013, 11:21PM

Registered Member #2529 Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600

In-flight 'refueling' is not, in principle, all that hard, it's just a dish or yagi pointed at an aerial on the aircraft.

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