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Old Feb 04, 2004, 06:17 AM
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Australia, SA, Murray Bridge
Joined Oct 2003
186 Posts
maiden b2 twin edf

hi i bought a gws B2 stealth bomber
looks good flys ****
can anyone help with setup
gws recomend 7 cell battery but it seems wayyyyyyyy under powered and doesnt fly at all
anyone else got/had one of these?
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Old Feb 05, 2004, 01:30 AM
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San Jose,CA
Joined Feb 2003
139 Posts
B2

Try A 2 cell lipo pack,the less weight will help alot.
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Old Feb 05, 2004, 01:38 AM
Watts your motivation
roccobro's Avatar
San Bernardino, CA
Joined Aug 2003
6,512 Posts
I flew on the 8 cell pack was almost OK, like most GWS birds. Moving the CG for better performance. I just soldered a 9 cell pack to see how it goes. Someone Down Under was flying with a 3s Lipo pack and said it was great, that was about 4 months ago. I have not heard from him to see if the motors are still intact

Justin
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Old Feb 05, 2004, 05:23 AM
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Australia, SA, Murray Bridge
Joined Oct 2003
186 Posts
dont realy a go lipo just yet the ots are o high in oz
ill try 9 or even 10 cell
if my speedy likes it
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Old Feb 05, 2004, 10:25 AM
Watts your motivation
roccobro's Avatar
San Bernardino, CA
Joined Aug 2003
6,512 Posts
I tested a nine cell pack last night using 800mah 5/4aaa cells.

cells---volts---amps---thrust---weight of packs
8 --- 6.7 --- 9 --- 125g --- 120g
9 --- 7.5 --- 10 -- 150g --- 134g

I stopped there as I have a vibration in one fan from an impact (oops!) that get REALLY loud at the high RPMs of the 9 cell. I will try it out in the field this weekend though. As far as balancing, without a steering servo in front, all my gear right on the CG mark balances just right for maiden flight. I'm moving it back some more still after this mornings flight.

Justin
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Last edited by roccobro; Feb 05, 2004 at 10:43 AM.
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Old Feb 05, 2004, 11:11 AM
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Ed Waldrep's Avatar
Las Vegas, NV
Joined Dec 1996
7,933 Posts
It's my understanding that the AAA packs are only good up to about 7 amps or so, then the voltage drops. Looking at your numbers, that seems to be the case. Get some Kan 1050 packs, they can handle 15 amps or so before the voltage drops.
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Old Feb 05, 2004, 01:14 PM
Watts your motivation
roccobro's Avatar
San Bernardino, CA
Joined Aug 2003
6,512 Posts
LOL! I have a pack already made up, I was just afraid to try it for fear of smoking the motors before I learn to fly it "underpowered". By going with another aaa cell, it ups the voltage closer to optimal without pushing the amps into the motor fatality zone.

Nominal voltage for max thrust according to GWS's site is 9.6V and 5.9amps, 10.8v and 6.6A is fatal. Does this mean I can theoretically put in 10V and 12A for the 2 motors? Or is there a rule of thumb when splitting power to multiple motors?

Justin
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Old Feb 05, 2004, 09:54 PM
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San Jose,CA
Joined Feb 2003
139 Posts
Frying motors

You will definitely fry those motors increasing the volts that much,let alone the added weight of another cell isn't going to help either.The key to getting as much as you can out of those motors is low voltage,unless your using the higher volt rated ones.You'll save yourself alot of headaches if you go buy A 2 cell lipo pack,unless you have the higher volt motors,then go 3 cells.The duration and weight of lipo packs will make fo better flights anyway.
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Old Feb 05, 2004, 10:07 PM
EDF rules... :)
AirX's Avatar
Joined Nov 1999
13,633 Posts
Roccobro,

I am using an 8cell Kan1050 on a pair of EDF 55 300's in tests so far no problem. The speed 300's need the amps, going to 9 cells might be a bad thing for these motors but 8 seems good so far.

Cheers,

Eric B.
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Old Feb 05, 2004, 11:44 PM
Watts your motivation
roccobro's Avatar
San Bernardino, CA
Joined Aug 2003
6,512 Posts
Mirageman- I see what your saying on increasing the voltage, but I'm kinda far from the 10-10.8V fatal threshold for these EM150 motors. By adding a ninth cell I increased thrust 25 grams while only adding 14 grams of batteries. The numbers I posted above are the under load amounts, just as it would be using a lab power supply in bench testing. The 10 amps *static* split to 2 motors are still 1-1.5amps from fatal there also. I do have some Lipos ready to go in, I just want to see how my bird stacks up to what GWS claims will work. Call me stubbord or stupid, but I enjoy the challenge.

I do know of one person using the 150 motors with 3s lipos with great results. I'd alread have fallen back to the lipos if I hadn't already flown it on the recommended 8 cell pack.
Thanks,
Justin
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Old Feb 06, 2004, 01:48 PM
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Ed Waldrep's Avatar
Las Vegas, NV
Joined Dec 1996
7,933 Posts
You know I forgot that the B2 comes with the 150 motors, I was thinking it was the 300s. Switching to the Kans will provide more juice and might smoke the motors, true. Darn brushed motors and fans just aren't the best combo, pull enough power and they melt!
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Old Feb 06, 2004, 02:25 PM
Nickel what?
Phreakish's Avatar
Prescott, Arizona, United States
Joined Jan 2003
2,365 Posts
twin himax 2015-5400's Now that'd give it new life, hehe.
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Old Feb 06, 2004, 05:23 PM
Watts your motivation
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San Bernardino, CA
Joined Aug 2003
6,512 Posts
E-flightline.com has tried all the 2015 series motors in their A-10. The 5400 needed serperate Lipo packs because of the 15 amp draw EACH. The 4100 are still on video on their site under "corn hog"- flies great, and they have settled on the 3600's as good all around (video on that also). I'll be doing my own check on the B2 using the 3600's and 4100's. AFTER I'm done with the "stock" testing.

Justin
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Old May 31, 2004, 01:51 PM
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Essex Junction, VT
Joined Oct 2003
7 Posts
Setting up new B2

I was going to try the stock arrangement (150 motors), but seeing that the EDF's are glued in, I decided on the brushless upgrade while I can get at the fans outside of the plane. Good thing, too, as it was wicked hard to get the fan off the motor plus the adapters for the 2015-4100 motor were oversized for the stock fan housings so they needed to be adjusted.

If I were to do it again, I'd probably get the fan parts from www.e-flightline.com

So, now I have the motors and fans ready to test for the thrust improvement and then install in the plane. Still waiting on the high current lipos, I'll probably try a KAN 1050 while I'm waiting.

Do you think I should reinforce the wings with carbon tubes or carbon fiber tape?
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Old May 31, 2004, 07:53 PM
Watts your motivation
roccobro's Avatar
San Bernardino, CA
Joined Aug 2003
6,512 Posts
My B-2 flew great with a 2S pack of 1300 (10C) Irate cells. Needed a dive for a loop but it flew at less than half throttle for almost 10 minutes. At its peak, the 150 motors pulled 12(!) amps. Did not burn a motor, but broke a housing on a crash. Winding up some CD parts still before she flies again. Report how the Himaxx's work out, as I never got to install mine (fron e-flightline.com).

Justin
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