fnp

Can anyone tell me how much power does a 0.46 and a 0.60 glow give in terms of thrust and prop speed. What motors and on how many cells would match this performance in terms of thrust and prop speed.
Thanks FNP

Henke Torphammar

tell us which plane you intend to convert and we´ll get you the numbers you need. you can not just say a Hacker B50 X equals a .60... it can be setup from everything between three times as fast as a .60 to 3 times the thrust, but not both at the same time, so we first need to decide on a plane for it.

Matt Kirsch

My Feedback: (21)

Yep. Rarely does an airplane need BOTH the thrust and speed produced by the recommended glow engine. It's generally most of one, some of the other. As much as half the power output of the engine is simply wasted "thrashing air." I'm sure you've run into a case or two in your travels of 3D/FunFly type planes that the pilot REALLY needs to be careful with as far as high speed passes due to flutter. These are textbook cases of the excess of which I speak.

Reproducing glow engine performance numbers in electric is both heavy and expensive. It's more advantageous to determine what the airplane needs, and provide that. Performance is just as good, if not better, and both cost and weight are optimized.

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My Feedback: (6)

Thanks for the info,

I was going to ask the same question but see it doesn't work that way. For my first conversion I want to start with something simple. I have a Piece-o-cake, two channel with a 72" w/s that runs on a 20 something 2 stroke, it has plenty of wing and would be perfect as a first conversion flyer.

If someone could suggest a brushless/NiCad combo for the motor/battery to start I would appreciate any help very much.

Many thanks

Mike

Henke Torphammar

we are happy to help!

do you have any pictures of the plane, estimated AUW on glow? what kind of performance do you want?

Henke Torphammar

http://www.dynaflite.com/airplanes/dyfa1009.html

this one?

thinking the AXI outrunenr series would fly this plane well, Perhaps the new 2814/XX on 8xGP2200 or simular. you hsould really go for nimh! handles like nicd but twice the flight time and more power

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Yes, that's the one only I plan on adding ailerons to improve handling a little and want it to fly with good power, not like a glider. My thinking is it would make for a great park flyer. If larger wheels were added it could handle grass with ease. I thought Li-poly's would be a better way to go but like everyone flight time is what I want.

Can you suggest a motor/battery combo that would work on other models in that range to save money.

Thanks again for your help.

Mike

Henke Torphammar

Hi

ofcaurse li-polys are the best, but as you asked for nicds I thought you wanted the cheaper route.

check aircraft-world.com for data on the 2814/XX AXI and a proper li-poly, say 3 series ~3-4000mAh. which brand does´t really matter.

Matt Kirsch

My Feedback: (21)

Just as an FYI, the power systems recommended aren't limited to just the plane being discussed. They will, of course, power planes of similar size, weight, and flying qualities.

The Piece-o-cake, if the 72" version, is the .049 powered version. I believe the Butterfly is the 100" .10-.20 glow powered version. So, this plane needs very little power to fly. Excessive power will not cause excessive speed, but may cause wing flutter. It'll definitely climb well.

Be careful with your modifications. Ailerons will have limited usefulness on the polyhedral wing. BTDT.

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My Feedback: (6)

Thanks Henke and Matt,

I'll check the 2814/xx and see what I can find out. I should go with Nicad's or NiMih as I don't have a charger for Li-Poli's yet and your suggestion of NiMH indurance sounds like the way to go.

Would anyone mind suggesting an ESC for the 2814/xx, I have a 10 amp and 20 amp with a used 35 amp on the way from auction.

Thanks guys again, it's people like you that really help make this a fun hobby.

Mike

Matt Kirsch

My Feedback: (21)

The AXI2814 is a brushless motor. You will need a brushless ESC to run it.

Henke Torphammar

as with batteries, any of the well know ESC bands would do such as Schulze, Jeti, CC or TMM. useing mostly TMMs for cruceing amongst the Vikings with our outrunners over here <g>

TMM 25 would do.

Matt Kirsch

My Feedback: (21)

TMM's a little tougher to get around the US. With CC (Castle Creations), you get made in the USA, and darned good customer support.

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My Feedback: (6)

O.K. Thanks, I was wondering about what size of ESC for the AXI 2814. Sounds like a 25amp would do well. Any thoughts on the cell size or count for the 2814/??.

Thanks

Mike

Matt Kirsch

My Feedback: (21)

AXi provides application charts for all their motors at www.modelmotors.cz. This information helps immensely with figuring out what prop/cell combination works without having to try a whole bunch of different combinations. Plus, the numbers are fairly accurate. It's one of the two main reasons I'm a big fan of AXi motors.

We've really been going about this whole conversion all wrong. Henke recommended a series of motors, left you hanging, and we've been concentrating on discussing motors ever since. You can't pick a motor until you know how much power you need. With electrics, you can dictate exactly how much power the plane has, and you must do that, or you're just poking in the dark. Electric power is measured in Watts, which is the metric equivalent of Horsepower. Electric Watts translates directly into mechanical Watts to spin the propeller, through the motor.

What's this plane weigh? Maybe two pounds at most? For normal glow sport plane conversions, I generally recommend 100 Watts per pound to get comparable glow sport plane performance, but this is an underpowered floater. I have a feeling that 50 Watts per pound will make it seem like a hotrod. Two pounds, 50 Watts per pound, 100 Watts total. 100 Watts spinning as large a propeller as possible will haul this plane around like a rag doll.

Let's look at the AXi 2814 series motors, and their suitability in a 100 Watt application. We'll start with the 2814/10. The lowest-power combination is 7 NiCd/NiMH cells (2S LiPoly) and an 8.5x6 prop. Current draw is 22.5 Amps for a power of 138 Watts. That ought to be plenty.

AXi's application charts allowed us to kind of skip a step, which is to manually size the battery, but that's okay. We've now got all the information we need. You'll need a 7 cell NiCd or NiMH, or a 2S LiPoly that can handle 22.5 Amps, a brushless ESC that can handle at least 22.5 Amps, the AXi 2814/10 motor, and an 8.5x6 prop (or something in that size range, from 8x6 to 9x5).

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My Feedback: (6)

Matt,

Thanks for the info. it's just the kind of help I can use trying to chose a prop for a motor. I wish there were more sites like that around. As things progress I'd like to ask more questions if you don't mind.

Thanks

Mike