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Electric Stunt => Gettin all AMP'ed up! => Topic started by: jim gilmore on September 30, 2009, 10:19:43 AM

Title: 1/2A start up at low cost ??? just how low ?
Post by: jim gilmore on September 30, 2009, 10:19:43 AM
Ok, I'm building an .10 powered 1/2A pathfinder.
I'm interested in electric at some point and cost is always going to be an issue.
So lets say I wanted to try test stand engine set-up. What all would I need and what would be a low cost setup.
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: Alan Hahn on September 30, 2009, 10:36:41 AM
Check out Dennis Adamisin's  post just below.

http://stunthanger.com/smf/index.php?topic=14109.0
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: jim gilmore on September 30, 2009, 12:50:10 PM
At this point there is incomplete info there to decide what one needs.
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: Alan Hahn on September 30, 2009, 01:03:41 PM
At this point there is incomplete info there to decide what one needs.

I am sure he will fill it in!
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: Dennis Adamisin on September 30, 2009, 07:50:36 PM
At this point there is incomplete info there to decide what one needs.

...and for that I apologize.  I expect to post the complete set-up BUT if I do that now it will be missleading - it ain't right yet!

I have only had the bird out one time, results are promising but inconclusive.  Propellor effectiveness was WAY lower than predicted, upsizing the prop pushes me up TWO sizes in battery.
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: jim gilmore on October 01, 2009, 08:23:03 AM
how about more blades?
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: Archie Adamisin on October 01, 2009, 01:32:47 PM
Jim,

What do you want to fly and how do you want to fly it?  I have several different options and just need specific info to guide you to what you will need.  I flew the X-Wing on a $5 Emax 2805 2800KV using a $8 Tower Pro ESC and $8 Zippy 1300 20C 2S pack.  It turns a 5 x 3 Cox 3-blade @ 12-13,000 rpm @ 13 amps.  I charge the 2S packs 2 at a time on a Hextronic 8080 charger that cost $27.  All this is available through Hobby City.

Now if you put 3S 1100's on this motor, it will turn a 4.7 x 4.7 @ 18-19,000 rpm @ 19 amps.  This would make screamin setup for a 1/2 A combat model on either 35' or 42' lines.

Another option is to use a 2040 inrunner with whatever Kv suits your specific needs.  They offer them in 2080, 3500, and 4850.  I have a 2040 2080 Kv & a 2040 4850Kv.  I use the 2080 Kv in a Speed 400 racer on 3S and fly on a 5.5 x 4.5 prop @ 13,000 rpm pulling 12 amps static.  I use the 2040 4850Kv motor in a EDF on 3S and it absolutely screams at close to 50,000 rpm.  I ran it up on a 4.1 x 4.1 on 3S and it was screaming and pulling 25 amps.  Not sure of the rpm but it was around 30,000 by sound.

In-runner by nature will be more efficient, but are a bit heavier in an oz/watt out comparison.  The Emax 2805 2800Kv weighs around an oz and complete with battery and ESC you are looking @ 5.5 ozs total ready to put in an airplane.

Archie Adamisin
Muncie, Indiana
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: Archie Adamisin on October 01, 2009, 03:01:47 PM
Here are some test numbers and some pictures of the Emax that was tested.

Emax 2805 2800Kv

3S 1050 20C Rhino Li-Poly
APC 5.25 x 4.75 Prop @ 17,500 pulling 17 amps

3S 1050 20C Rhino Li-Poly
Cox 5 x 3 (3) blade prop @ 16,500 pulling 18.5 amps

2S 1300 20C Zippy Li-Poly
Cox 5 x 3 (3) blade prop @ 13,250 pulling 13 amps

Picture shows set-up as pulled from the X-Wing Fighter.  It has a Will Hublin FM-0 timer and Tower Pro 18 amp controller.

Archie Adamisin
Muncie, Indiana
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: Archie Adamisin on October 01, 2009, 03:10:09 PM
Here are some number for the Turnigy 2040 2080Kv motor on 3S Rhino 1050's

Archie Adamisin
Muncie, Indiana
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: jim gilmore on October 01, 2009, 05:08:38 PM
Not sure what exactly an X-wing is except for star wars ? Size weight line length ? how about a photo ?
Title: Re: 1/2A start up at low cost ??? just how low ?
Post by: Archie Adamisin on October 01, 2009, 05:20:37 PM
See this thread.

http://stunthanger.com/smf/index.php?topic=14264.0

Archie Adamisin
Muncie, Indiana