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Old Mar 06, 2008, 09:57 AM
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methos's Avatar
Canada
Joined Jun 2006
384 Posts
Help!
Power system for a Super Sportster 40 MkII

This could have been posted in the Glow to Electric Conversions forum, but I thought I'd post it here as it pertains to the power system mainly.

I'm going to be doing a Great Planes Super Sportster 40 MkII conversion to electric, and I need some help with the power system.

I'm a power freak. Just about everything I fly is overpowered... and that's the way I like it.
I also love speed. If it's not capable of 100mph, then it really doesn't thrill me much. The exception is of course indoor planes and highly aerobatic planes.

I want to know if it is realistic to want an electric power system for this plane that will push it close to or even beyond 100mph and still have good vertical performance without costing some rediculas ammount of money?

If possible I'd like to stick with Scorpion outrunners because I believe that by far they are the "best bang for the buck" but otherwise I am completely open to suggestions.
Also if someone thinks this plane is not a good plane for this conversion, and have a better plane in mind that is approx the same style and in the .40 - .46 size bracket, then please let me know.

This was my first idea for this plane, but I am not sure how it would perform on a 4.5 - 5lb plane:

Scorpion 3026-10
10x8 Graupner CAM Prop
ZIPPY 5000mAh 5S1P 20-30C Lipoly Pack
Lightflight Suppo 80 Amp HV ESC and a Medusa 6v external BEC

What do you guys think?

Thanks

Ed
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Old Mar 06, 2008, 11:46 AM
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methos's Avatar
Canada
Joined Jun 2006
384 Posts
Or how about this setup?

Scorpion 4020-12 (equivalent to an AXI 4120/14)
APC 11 x 10E
ZIPPY-H 5000 or 4000mAh 6S1P 20-30C Lipoly Pack
Lightflight Suppo 80 Amp HV ESC and a Medusa 6v external BEC

I'm not sure on the numbers, but by my (possibly wrong) calculations I should get close to my 100mph.

Anyone think this power system may be overkill?

Thanks

Ed
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Old Mar 06, 2008, 05:12 PM
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Dr Kiwi's Avatar
Chattanooga, Tennessee, United States
Joined May 2003
27,205 Posts
If the specs are right and Motocalc computes them correctly you get 100mph from your nearly 1000W.

Motor: Scorpion 4020-12; 542rpm/V; 1.92A no-load; 0.02 Ohms.
Battery: FlightPower 3700 (20C); 6 series x 2 parallel cells; 3700mAh @ 3.7V; 0.0037 Ohms/cell.
Speed Control: Castle Creations Phoenix 80; 0.001 Ohms; High rate.
Drive System: 11x10 (Pconst=1.16; Tconst=1) direct drive.
Airframe: Anything you want.
Motor Amps = 45.6
Motor Volts = 21.6
Input (W) = 986.9
Loss (W) = 93.3
MGbOut (W) = 893.7
MotGb Ef(%) = 90.6
Shaft Ef(%) = 88.3
Prop RPM = 11091
Thrust (oz) = 100.8
PSpd (mph) = 105.0
Time (m:s) = 9:44
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Old Mar 06, 2008, 05:25 PM
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methos's Avatar
Canada
Joined Jun 2006
384 Posts
Thanks Dr Kiwi, it's much appreciated.
Is this a power system you would suggest? In other words do you think it's the right choice?

Thanks again.

Ed
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Old Mar 08, 2008, 08:59 PM
I see the future.
Yukonho's Avatar
Halfmoon Bay, BC, Canada
Joined Feb 2002
2,136 Posts
I found a cool comparison chart at innov8ive designs
http://www.innov8tivedesigns.com/Sco...ison%20Web.htm
Lists many options
There are a couple other motors listed on my thread here http://www.rcgroups.com/forums/showthread.php?t=830480
I am doing a similar conversion, but don't need or want 100MPH. Honestly I think you will be hard pressed to push the SS to 100 with that fat wing it has, but I look forward to the video.
Colin
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Old Mar 09, 2008, 07:44 AM
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methos's Avatar
Canada
Joined Jun 2006
384 Posts
Quote:
Originally Posted by methos
if someone thinks this plane is not a good plane for this conversion, and have a better plane in mind that is approx the same style and in the .40 - .46 size bracket, then please let me know.
See that's the thing is, It doesn't have to be the SS... I have not bought the plane yet.

Maybe what I want is not realistic... I dunno. I want a traditional plane that actually looks like a plane like the SS or the the Pulse XT that will make a good sport aerobatic plane and at the same time will outperform most .40 - .46 glow planes in top speed.

I really don't know how fast a strong .46 will pull a SS or a Pulse, but I was lead to believe that it was aprox. 100mph.

Anyway, this is going to be put off for a little while now as I just bought my first slimer

Ed
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Old Mar 09, 2008, 08:12 AM
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Ken Myers's Avatar
Commerce Township, MI
Joined Aug 2001
4,460 Posts
A really strong 2-stroke .46 using a "typical" 10x6 prop might have a pitch speed of 80 mph.

Actual level flight speed would be less than that with a typical "sport" plane.
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Last edited by Ken Myers; Mar 09, 2008 at 08:18 AM. Reason: Added thought
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