moving the industry forward - "E" Prize

[AZ ChopperCam]

with some recent events happening at another forum I got this crazy idea.

there was a standing offer, the X-Prize, for the first private company to make a reusable ship that could carry 3 people into space. Mr. Rutan and his gang at Scaled Composites won with Spaceship One.

So.. how about an E-Prize??

how can we get some companies, private individuals to pony up some funds for a prize to the person who can make an electric helicopter fly for 30 minutes?

maybe with requirements like this

12-15lb RTF weight
4lb must be set aside for payload
30 minutes from take-off to touchdown
10% reserve left in pack
must be charged and flown 3 times with 30min flight cycle 20 minute cooling cycle and 30 minute charge cycle.

Yes it seems unrealistic but that's the point.

If say $50-75K was at stake wouldn't that do nothing but help push the envelope?

[Art-Tistic]

If say $50-75K was at stake wouldn't that do nothing but help push the envelope?

Yeah....but only if I could land her upside-down in a puddle. :badair: :badair: :badair: ....then we'd have a contest :twisted: :twisted:

[R Hudson]

Good one, Ant!!!

[askman]

20% payload with 30 min flight using electric is possible. the key is really efficient blade and lightweight setup. (flat bottom blade is a must)

for comparison, I have a stretched corona AP setup with 8oz camera and I can get close to 30 min flight with 4S4400 pack. (at 1800gm auw with 450gm pack and 500gm for mount/camera) rest of the airframe is 850gm. it would have been easy for me to go 30 min with right lipo pack setup. corona is fixed pitch, so it has undercambered blade. very efficient lifters. I have flown it over 2200gm without issues.




btw the record duration is over 1 hour with eco 8.

[Tonystott]

I believe the duration has already been done (I seem to recall they were going for 60 minutes, having already passed 45. But the payload is a different story!

[AZ ChopperCam]

yes but I am looking for a ship that carries 4lb of gear that can do it.

[askman]

the key is the blade technology. RC heli has been overtaken by 3d flying, so that we can't get efficient blade anymore. (tough enough time finding semisym, much less flat bottom) I know that like90 has made some flat bottomed blade for trex, and they saw a hugh improvement in duration.

if you can get about 40watt/lb average, you can hit your goal. with efficient motor. maxi joker at 16lb all up weight with 12S7400 pack (5lb pack) will give you about 30min flight. (this is also 100oz/m^2 disc loading, which is good for the large heli) it should be close to 4lb payload. (don't know what maxi joker weight is empty, but should be about 7lb)

[Art-Tistic]

I'm sure the blade design has a lot to do with it. My Vario runs 25mins eating up 6 amps on my Tanic 7350's that's with a Tango 45-07 motor and the Jazz 55-10-32 esc. The blades are the 675mm Vario Reflex blades. They are flat bottoms with swept back tips part #403 $132 clams and when I ran flybarless it was the weighted tip version part # 407 @ $141. FYI the reflex are only available for CCW rotation. Also the 675mm blades in the vario heads gives a total disc diameter of 1500mm.
The AUW is 14lbs complete and thats mostly the 2 5S3P packs, if I went to an ESC that could handle a higher cell count I wonder what times I could get with a 12S2P evo?????

No time for me to play, I got to go make money with her now........but I will say this she's a lot more efficient than my Maxi. :dontknow

Regards,
Ant

[askman]

oh yes, going flybarless using Vstabi will result in about 15% more flight time. Anthony, sounds like you are already capable of hitting 30min with your setup.

CCW/CW is no big deal. almost any heli that has tail belt driven can be changed back and forth easily. so vario 675mm is available. perfect for the stretched raptor. run it down as low an rpm as prudent, and you will have really efficient setup. throw in Vstabi, and you are set.

edit. actually, if you are running ap2000i, you may not even need vstabi.

[AZ ChopperCam]

hmmm what is the blade grip thickness and bolt hole on those 675's???

[askman]

shoot, all varios are 14mm root. :( shoot. still, may be worth investigating.


http://us.vario-helicopter.biz/shop/index.php?cPath=25_51&sort=3a&page=4&osCsid=7f8898e0c5e26c7ad9ae3c571c0900ab

[AZ ChopperCam]

sounds like some custom grips are in order!

[Art-Tistic]

sounds like some custom grips are in order!

Why, what is the diameter of the raptor's main shaft? The vario is 10mm....in fact DJ (barter time) I've got the Flybarless head sitting here for you to try if you want, I was waiting to see what you come up with for the joker before I buy a gimbal? Maybe a gimbal for the head......I can even drive up to MJP to pick one up after you get the head....let me know bro.
Ant

[Art-Tistic]

CCW/CW is no big deal. almost any heli that has tail belt driven can be changed back and forth easily.


But how would you get the main rotor going the other way? Can ou just flip the oneway bearing on the raptor and reverse the polarity on the motor or in the ESC? :dontknow

On another note, Askman I placed a web order for a small gimbal and the IR switch, can you give me an update. I'm hoping to get the Trex in the air and making some jing by the end of the week.

Thanks
Ant

[askman]

your order should ship out monday next. which optio do you have? I forgot to ask. I have version for video out port on the top or bottom. (pentax keep changing it in its versions. 4 is on the bottom, 5 is on the top)

raptor is 10mm shaft, as is most of heli in this size class.

one way bearing needs to be flipped. in worst case, it can be pressed out and re- pressed in in opposite direction, but overall, it is easy. just need access to a press in worst case.

Motor is even easier. on brushless, you two lead being swapped will reverse direction. :)

vario has silence head for good price. very tempting with swash driver.

[Art-Tistic]

I just picked up an Optio S5i (hasn't arrived yet)
I have the flybarless head and swash driver here.....if DJ wants it, I could use a gimbal for the maxi. :wink: :wink:

[AZ ChopperCam]

how hard is it to fly one of those heads? stable?

[Art-Tistic]

Floaty.....but graceful in FF.
I did go back to the skyfox head and the non-weighted (403) blades. I wanted her to be able to just sit there in a hover. Not sure how it (FBL head) would handle with the spartan or a vstabi

[askman]

looks like vario must uses very soft damper to make flybarless flyable. probably very mellow flying only with heavier blade most flybarless setups are notorious for being hard to fly with some unwanted tendensies like ballooning in forward flight.

Vstabi is used by people running flybarless 3d setup, and basically a Fly by wire system with 3 gyros for stabilization. so, you can make any head into flybarless setup and make it work. it is very flexible but expensive system. it will have no problem with vario head, but bit of overkill. might be cool to run it with stiffer damping though and I see no issue with spartan setup on vario head. it should help stabilize it and make it easier to hover.

this is very intriguing thought. 15% gain in flight time is definitely a plus. (15%is number quoted by vstabi)

[GGoodrum]

Mikado is actually going to be selling a version of the V-Stabi system. Their test pilots have been playing with Logo 10 and Logo 14 variants, and getting about a 15% improvement in the max wats they-ve been able to pull (something over 3000W in a Logo 14 with 580 blades....). I don't know if that also means a 15% improvement in efficiency and/or flight times in an AP setup, but it does sound like it would make a significant improvement. It also comes with a PC application that lets you "dial in" whatever performance characteristics you want, so you can easily setup a very stable flight configuration. It comes in either a 2-axis version, where you use yor existing tail gyro, or a full 3-axis version, with no tail gyro.

-- Gary

[theLane]

If I could build a Corona that would stay in the air for 30 minutes, I would be in heaven!

Is it really possible? I am building one right now and I have the Astro 20 w/45 esc. It's all stock. What battery would give me the most flight time?

[askman]

it is possible to do corona that flies 30min. I know people that runs 3S6000 getting almost 30min on corona. I run 4S4400 and get 25min. . astro will run hot though.

[theLane]

3S6000!!! Wow... I didn't think they went up that high. Would my 45amp esc and setup handle that? 4S4400... hmm.... I'm gonna go look for that battery - thanks!