Super Stearman
 

Has anyone looked at converting this big Bi-Plane? What kind of power system would it take and would it be possible to convert something this large to electric now with the advent of big brushless motors and Lipo batteries?

clarock

RE: Super Stearman
 

The calculations are the same no matter how big the plane gets. You still need X Watts per pound of final airplane weight to get Y performance out of the plane.

When this model came out, I figured it needed about 1500 Watts: 30 "round" cells at 50 Amps. or 9S?P LiPoly at 50 Amps. Hacker, AXi, Aveox, Actro, and many other manufacturers make 1500-Watt motors.

RE: Super Stearman
 

which stearman is this? by big I assume you mean larger then the Kyosho .40s... ?!

RE: Super Stearman
 

BTW I got the small kyosho one, I choose the Stearman before the Super, as the expectations on the super would have been lot´s higher as it looks way faster... even though the kyosho one are the same plane with diffrent color ;) hehe

http://www.vaxjorc.com/Models/ModelP...s/277_1025.JPG

RE: Super Stearman
 

I'm putting my money on the big Super Stearman from Great Planes, as the word "big" was mentioned. It was on my "must do" list until I overheard that someone else in the area had one and was going to do the same thing :D

Then again, for someone who has only flown park fliers to this point, "big" might be .40-size...

RE: Super Stearman
 

Your right, I was referring to the Great Planes Super Stearman with a 71" top wing and weighing in at 14-16 lbs.

clarock

RE: Super Stearman
 

if you want real power I would suggest the motor system used in the H9 80" P51. a C50 13XL 6.7:1 swinging a 21x15 (if I remember right) on 10s4p TP8000

it was clocked at 125 :)

it would also fly on a cheaper outrunner setup such as the AXI 4130, but moke like an ordinary PT-17, not like a super stearman ;)

RE: Super Stearman
 

We've just returned from our 4 and 5th flight of our Great Planes Super Stearman which we converted to electric power using this setup:
Axi 5330-24
Jeti 90 ESC
two, Thunderpower 5300 mAh 5s 18.5 volt lipolys in series
Mejlik 21" carbon prop
Performance? The plane is fully aerobatic but not 3d. Straight up vertical is probably 100 feet which is more than scale I'd bet. I took some video and I'll try to post it.

RE: Super Stearman
 

Great job, Can you tell us what your watts, amps and volts were?
whats the total weight ready to fly?
Also what mejlik prop are you using gas, or the new electric version.?

RE: Super Stearman
 

Ready to fly weight is 17 pounds with batteries tucked in a tray we built aft of the firewall, above the lower wing. Balance on the CG was perfect with no additional weight needed.
A quick preflight test showed 2100 watts at 55 amps
The prop is a Mejlik 21x8 which is a gas prop not one of their new electrics

RE: Super Stearman
 

My battery recharge data postflight is in now too. After three 5 minute flights characterized by aerobatics, touch and go's and minimal concern for throttle management, I replaced 4020 mAh into each TP 5s 18.5volt 5300 mAh packs. After the flight the packs registered a voltage of 18.6

RE: Super Stearman
 

I electrified the PT-17 variant this past winter/spring. As you can see, I made a few modifications to the ARF to suit my tastes.

I used a Feigao 5408411XL with a 5.2:1 planetary gearbox, a Jeti 77 Opto ESC, and 8S2P 8000 mah LiPos, turning a 16-10 APC-E. I am pulling about 1200 watts and amps in the mid 40's. The plane weighs just 12.9 lb. with batteries installed and RTF, and it needed NO additional ballast , thanks to the big 8000 mah packs.

It flies well--not underpowered, but not what I'd call full out aerobatic power either--just sport aero power levels. This might not be enough for the full-tilt aerobatic/3D types out there who like everything they fly to be able to hover ( :eek: ), but it's very usable for sport flying. Best of all, it's LIGHT.

Rick

RE: Super Stearman
 

Here is a link to view the video of our last flight.

http://media.putfile.com/GP-Super-Stearman

What a beautiful airplane!

RE: Super Stearman
 

Nice job Warren on the video,Thanks. It is always good to see other large electrics out there. We can always learn more about the electrics. Myself, I like the large electric too. I will throw in a couple pictures of my daily flyers for you guys to check out. I am glad I found this forum to see your planes.
Don Hofeldt out in California

RE: Super Stearman
 

Don those are some great planes you've got, all electric? Awesome! Is that a Boeing Fb4 Goshawk? One of my favorites. And these don't look like any ARF's I know, are they scratch built or kits? I've got a giant scale TopFlite P-51d on the bench. It was someone else's build; really detailed scale and I'm putting a big geared Hacker in it. All of yours are Axi powered? Post some detail on each plane and its setup.

RE: Super Stearman
 

Thanks for checking out the fleet of electrics. I only fly electrics as the town I live in has an electric field right by my house. I used the 5330 low count AXI on all of these but the Tri-Pacer. The Tri-pacer uses a 4130 and a 14.8, 4 cell and an 11.1 3 cell for power, and it swings an 18/12 E prop. The P-51, ME 109 run the same set up wiith the 5330 low count on 2, 14.8 4 cell packs, The ME 109 uses 8ooo mah not the 6000 like the others. The Boeing F42B uses the same power system, 5330 low count and same 6000 mah packs as the P-51 but I am using an 22/8 wood prop to get some wind over the tail and wings. I had a 18/12 on it but not enough wind was reaching the flying serfaces and it was not fun on the ground and slow to get off the ground. The amps stayed the same at about 54,
The pitts is going to have the 5330 F3a in it with 9 cells. Maybe 3 packs of 11.1 8000 mah packs???? I need some prop clearance on the Pitts too.

RE: Super Stearman
 

Very thoughtful of the mayor to put a flying field next to your house. I'm jealous. And are these kit built or scratch built--details, details, please!

RE: Super Stearman
 

Here are some pics of our Super Stearman

http://img1.putfile.com/thumb/9/24621423396.jpg

http://img1.putfile.com/thumb/9/24621423210.jpg

http://img1.putfile.com/thumb/9/24621421129.jpg

and here is some video of a recent flight (NB the engine noises are from a 40% Extra nearby the Stearman is all electric see above post for setup detail)

[link=http://media.putfile.com/GP-Super-Stearman]Great Planes Super Stearman[/link]

RE: Super Stearman
 

Hi Rick,
where do you have placed the LiPos?
I'm currently convert my Stearman to electric and I don't know how to install the battery...

Best regards
Robert