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Electric power harness maiden flight

Posted: Sun Jan 21, 2018 6:53 pm
by Odakyu-sen
After 18 months of planning and development, Brendan enjoys the maiden flight of his electric powered harness. The first flight was a cliff launch, to confirm the thrust and handling characteristics.
In future, he plans to make a conventional takeoff from the ground.


Re: Electric power harness maiden flight

Posted: Sun Jan 21, 2018 9:44 pm
by Toomb
Well done! Thanks for sharing. Please keep us updated. Does he have a blog or website we can check out?

Re: Electric power harness maiden flight

Posted: Sun Jan 21, 2018 9:50 pm
by Odakyu-sen
Brendan has a YouTube channel. Here is one of his videos showing stages of work on the electric harness.


Re: Electric power harness maiden flight

Posted: Mon Jan 22, 2018 8:18 am
by Toomb
Awesome! Thanks.

Re: Electric power harness maiden flight

Posted: Sun Feb 04, 2018 5:37 pm
by RidgeRider
Hi Toomb

Flying my rendition of an electric HG propulsion unit was a blast :) It gave me the ability to gain height on demand to fly over obstacles (cliff rotor in the maiden vid) and also to extend out my glide (to get to LZ in the vid). For testing I am only flying on half the battery's that the design is spec'd for, with all the battery's onboard I hope to do a flatland powered launch - like a Mozzie.

Without power the rig did not feel at all cumbersome (when flying!), although it surely had some effect on glide just through the extra weight. This is important to me, as I want to eventually use it for thermal hunting when flying inland.

The inspiration and design concept was from Reidar Berntsen's "E-Help" (he has a YouTube channel), although I took a different path with the chassis and componentry.

The build was slow as I built it as a hobby project, not letting it interfere with my normal flying and trying not to let it get in the way of all the other things needing to be done. Plus, there were some costly items I needed to buy and these needed to be carefully managed with the beloved :wink:

If you would like some specs here ya go:
.
  • Static thrust: 28kg (62lbs)
  • Weight (not including normal harness): 13kg (29lbs)
  • Prop: Falcon Propeller Beechwood 34" x 10"
  • Voltage: 54V
  • Current (at wide-open-throttle): 122A
  • Time @ WOT: ~6minutes (although I'm running on a half-battery-pack for testing, so double).
I have project documented most things via the App "Slack". This is not a public collaboration as otherwise you get too many silly comments about impending doom, etc. Happy to invite anybody into this Slack project if they are interested :)

Cheers.

Re: Electric power harness maiden flight

Posted: Mon Feb 05, 2018 7:45 am
by Toomb
Thanks. You guys are making great progress. I hope to be able to build something like that someday with off the shelf components to allow a flat land launch. Thanks for leading the way......

Re: Electric power harness maiden flight

Posted: Tue Feb 06, 2018 12:03 pm
by DMarley
Excellent project and execution!
What motor and controller are you using?
Thanks

Re: Electric power harness maiden flight

Posted: Mon Feb 26, 2018 2:01 pm
by RidgeRider
Thanks DMarley, thanks Toomb :)

Motor (non-sensored 80KV): http://www.freerchobby.cc/e_productshow ... ar-39.html

ESC: https://www.aliexpress.com/item/Flier-n ... 0.0.uYr1Wz

Since buying both these items I now have a good relationship with the companies direct. If anybody wants an intro to buy or for more info, please let me know.

Re: Electric power harness maiden flight

Posted: Mon Feb 26, 2018 2:08 pm
by RidgeRider
Second flight - very little wind:



SeeYou flight graphs attached :)
#1: metres altitude, by time
#2: m/s climb rate, by time

Re: Electric power harness maiden flight

Posted: Mon Feb 26, 2018 5:25 pm
by Lucky_Chevy
Congratulations on the successful flight. A demountable power would really open up flying in some areas, especially if weight and cost are kept to a minimum.

The unit seems to be a bit under powered. Given the torque available from the electric motor I wonder if a larger diameter prop or a slightly greater pitch would improve the climb performance. Alternately, I suppose you could increase the output voltage if your components could handle it.

Good luck with your development and thank you for sharing the videos. I can't wait to see your continued progress.

:thumbsup:

Re: Electric power harness maiden flight

Posted: Tue Feb 27, 2018 2:55 am
by RidgeRider
Thanks Lucky :)

You are spot on, I am holding the performance back with only the half-pack of (test) battery's. Its limiting full-power current. Now I'm impatiently waiting for more battery's to come back into stock.

With more ergs, the next step is to try a 34" x 14" (currently using 34 x 10). Then perhaps a 36 x 12. The awesome thing is that these excellent Falcon Beech Props are only US$75 a piece, so not too expensive to experiment with :thumbsup:

I actually think its the lack of prop pitch that's catching me out. With my current prop, at 0 airspeed I'm getting 28kg/62lbs thrust (good). With a pitch of 10 though this goes down 17kg/37lbs at an airspeed of 17kts/20mph (not good). A pitch of 14" would bring this back to 23kg/50lbs. Fun times and much chasing of the ultimate tweak :shark:

Re: Electric power harness maiden flight

Posted: Tue Feb 27, 2018 10:02 pm
by Lucky_Chevy
Keep up the good work. This is the coolest thing I've seen in a while.

Dan