Electric to electric conversion.

I have an old GP Spectra glider that runs on a seven cell NiMH 8.4 volt pack. The motor is a GP GoldFire 550 that is brushed. I am
looking for the most inexpensive way to convert to an equivalent motor that runs off a LiPo 3S 2200 MAH rated at 15C. I don't know much about electrics and since this is a glider I don't want to invest a lot into it. You can reach me at snipped-for-privacy@msn.com
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On Sun, 11 Oct 2009 10:04:32 -0700, Ted wrote:

Find out the power rating for the GoldFire, then find an outrunner brushless that matches it's power rating and works on a three cell pack. There are a bunch of (relatively) inexpensive outrunners out there -- Tower Hobby and Hobby Lobby both carry them if you want to mail order, your LHS may be of help if they know electrics (if you live around Portland Oregon I highly recommend Coyote Hobby in Oregon City).
You'll need a speed controller and charger, of course.
--
www.wescottdesign.com

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wrote:

I converted a Kyosho 2m Stratus Sports (the old, foam-wing variant) glider to brushless.
It originally used a HUGE brushed motor and a 7-cell NI-CD battery. Typically, a pack would last for some three climbs (about 1-1/2 minute each) wich would give me, each, about 5 minute of gliding time (unless I found an unusually strong thermal). That equaled just under 20min flying time for a NI-CD pack.
The same glider can now reach altitude in only 30 seconds of motor time and can float around from there for some 10 minutes on a zero-thermal flight. A LIPO pack lasts countless flights, so on a typical, mixed good/bad thermal day, I can fly a whole afternoon on a single LIPO charge.
I use an inexpensive "Waypoint" 2215-18 outrunner motor on a 3S, 20C 2100mAh LIPO battery. The HUGE weight saving combined with the greater power efficiency turned the glider into a whole new machine.
Note that you wll probably need to move things around in the glider in order to keep its CG within limits.
Definitely worth it.
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I have a Goldberg Electra with a master airscrew geared 500 brushed. I simply swapped to a LiPo ESC and I use 2 2cell 2500mAh in parallel. Gives me 7+ volts @5 amps. Both packs together weigh about the same as the NiCad packs I used to use so it balanced out the same. Flies great.
Dan

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I have a Goldberg Electra with a master airscrew geared 500 brushed. I simply swapped to a LiPo ESC and I use 2 2cell 2500mAh in parallel. Gives me 7+ volts @5 amps. Both packs together weigh about the same as the NiCad packs I used to use so it balanced out the same. Flies great.
Dan

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I have a Goldberg Electra with a master airscrew geared 500 brushed. I simply swapped to a LiPo ESC and I use 2 2cell 2500mAh in parallel. Gives me 7+ volts @5 amps. Both packs together weigh about the same as the NiCad packs I used to use so it balanced out the same. Flies great.
Dan

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I have a Goldberg Electra with a master airscrew geared 500 brushed. I simply swapped to a LiPo ESC and I use 2 2cell 2500mAh in parallel. Gives me 7+ volts @5 amps. Both packs together weigh about the same as the NiCad packs I used to use so it balanced out the same. Flies great.
Dan

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On Tue, 13 Oct 2009 09:07:53 -0700, Fubar of the HillPeople wrote:

Whazzup? Is your ISP confused?
--
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Thanks for all the great advice but when I costed out what would be required it would be more expensive than buying an entire new ARF. Since I got this for nothing, its not worth the expense. I will try to fly it just with a hi start and forget the motor. Seems similar to a Gentle Lady.
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I guess so. I only hit send once. I dunno what the deal is.
Dan

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On 10/11/2009 10:04 AM, Ted wrote:

It's the Electronic Speed Control (ESC) that's important here. Get on Tower's or GP's site and look for the specs for your ESC, see if your ESC will handle the LiPo. If not, see if they have a brushed ESC for the 550 that will handle a 3s1p LiPo.
CR
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