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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Mark Mc on December 30, 2016, 12:33:25 AM

Title: Prop for Brodak Electric Ringmaster
Post by: Mark Mc on December 30, 2016, 12:33:25 AM

I built a Brodak Electric Ringmaster using the recommended package with the 9 x 4.5 prop.  The plane just seems to have no authority.  Line pull on 60' lines felt too light.  I put two flights on it and didn't want to try anything more than a wingover and a loop.  The plane barely pulled through the loop.  I'll give it a couple more flights, maybe max out the RPM, but I'm wondering about an alternate prop to the 9 x 4.5.  Looks like my only APC alternatives are a 9 x 6 or a 10 x 5 prop.  Seems a 6" prop would be too fast, and a 10" prop might be too much current draw.

What do Y'all think?  Try a different prop?  Or is it just me and I need to learn to fly the recommended setup?

Mark

Title: Re: Prop for Brodak Electric Ringmaster
Post by: CircuitFlyer on December 30, 2016, 08:30:38 AM

I use an APC 9x6 EP on mine.  Works great, no complaints.  Mind you, its a scratch built S-1 and not a Brodak package either.  Give it a try, as long as you keep an eye on temps & current it can't hurt.

Paul

Title: Re: Prop for Brodak Electric Ringmaster
Post by: Motorman on December 30, 2016, 05:20:07 PM

Use the 9-6 and lower the rpm and you'll get the speed you want and use less battery power. I do 2 minute trim flights so you can get 2 rpm adjustment trys out of one battery. Set it real low with any new prop. Try 8500 and see how close to 5.2 sec a lap it is.


MM

Title: Re: Prop for Brodak Electric Ringmaster
Post by: Tim Wescott on December 30, 2016, 06:04:08 PM

Quote from: Mark Mc on December 30, 2016, 12:33:25 AM

I built a Brodak Electric Ringmaster using the recommended package with the 9 x 4.5 prop.

Are you using the recommended motor & battery?  If not you'll need to do matching tweaks to the prop.

Title: Re: Prop for Brodak Electric Ringmaster
Post by: Mark Mc on December 30, 2016, 07:46:39 PM

Quote from: Tim Wescott on December 30, 2016, 06:04:08 PM

Are you using the recommended motor & battery?  If not you'll need to do matching tweaks to the prop.

Yes.  I usually pick and choose components when building, but this time I decided to just buy the whole electric package minus charger from Brodak.

Mark

Title: Re: Prop for Brodak Electric Ringmaster
Post by: Motorman on December 31, 2016, 08:30:49 AM

A 9x4.5 is something you would use on a glow engine. Electric uses higher pitch. Although if the 9x4.5 is a MAS with way too much under camber it might almost work except that those are terrible design props. Just get an APC 9x6 E tractor. Tower has free shipping right now. http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXZK94&P=ML

MM