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Noin
09-16-2005, 08:23 PM
My father has the plane mentioned above. It comes with a 550 brushed motor. We were wondering if anyone has tried using a 3S lipo pack with this plane and motor combo. The battery that came with the plane is a 8.4V Ni pack.

Matt Kirsch
09-19-2005, 04:22 PM
Unless you compensate for the additional voltage with a smaller prop, the motor will burn up from too much current.

I believe this is a direct-drive motor, though. The prop will have to be so small that any power improvements gained from the higher-voltage battery will be lost on the inefficient prop turning nearly fast enough to cause a time distortion... It really needs a gearbox.

FinnFlyer
09-19-2005, 05:10 PM
It is on a 2:1 gearbox.:D
With a 12x10 prop.

rcAirTycoon
09-26-2005, 03:22 AM
It's not an insignificant investment but if you can afford to spring for a brushless motor and LiPoly set up, that ship will soar..

I converted my GP Sportster EP to brushless with an AXI 2814-12, 30 Amp ESC, and a ThunderPower 4200 maH 11.1V LiPoly and 10x6 prop. Unimited vertical baby!

Unfortunately the ship met its demise shortly after the conversion (run-in with a powerpole), but it was fun while it lasted...

J

Scratch
09-28-2005, 08:43 PM
rcAir, how much did your sportster weigh? I have the Ryan STA EP and I believe it's just about the same weight. I'm thinking of upgrading, currently it has the 600 brushed in it, it's a dog.

rcAirTycoon
09-29-2005, 04:21 AM
Just over 3.5 lbs...

Matt Kirsch
09-30-2005, 01:13 PM
Wow how time flies...

It'll still be smoking pretty bad with a 2:1 gearbox and a 12x10 prop, but at least we can work with it now that it has a gearbox. Limit prop size to 11x7.

Noin
09-30-2005, 03:14 PM
I will try the 11x7 prop with the higher voltage battery. But first I am going to find out how much a new/replacement motor is, I don't want to ground my father for my experiment...lol.

Any other thoughts guys?

eflyer3
10-01-2005, 10:45 PM
I converted my GP Sportster EP to brushless with an AXI 2814-12, 30 Amp ESC, and a ThunderPower 4200 maH 11.1V LiPoly and 10x6 prop. Unimited vertical baby!

I am considering using a similar setup. How did you mount your AXI and did you maintain the same right thrust/downthrust angles?

Thanks

Dan

Neil Bussard
02-08-2006, 08:06 AM
I have been flying the stock Sportster 48" on a 3200 mah 11.1V Wattage pack, with an Electra Fly 55 amp ESC. This is the 2:1 stock gear box, prop adapter and stock 12x10 prop which is very light. I am sure that it is pulling high amps but I have been flying most of the time at half throttle except when I want to hot dog it a little. I burnt out one set of brushes on the first motor after many flights, replaced the motor with another stock one and have 125 minutes on the second, still flying. Pretty cheap fun. Was thinking of reducing prop size, but it just keeps running. Just bought an AXI 282010 for it when it quits.

jimw1956
05-01-2007, 02:47 PM
I will try the 11x7 prop with the higher voltage battery. But first I am going to find out how much a new/replacement motor is, I don't want to ground my father for my experiment...lol.

Any other thoughts guys?

I read this post where a guy mentions frying his ESC with a 3S Lipo...might want to ask him about it.

http://www.rcgroups.com/forums/showthread.php?t=474047