deli_conker

Okay. So I bought my very first plane that uses elevons. I'm moving to it from my aileron trainer (that didn't take long). Anyways, the plane is small and came with an unbrand brushed motor. I put the plane together yesterday and maidened it about 1 hour ago (that didn't take long). I was severely unimpressed. Every other plane I've flown has been non-stock. I've always put a brushless setup in instead of the brushed motor it comes with. Until yesterday, that is. I had to go full throttle just to stay airborne. Definitely not what I'm used to.

So now I need some advice on what motor to put in this puppy...

Here is the plane...
http://hobby-lobby.com/shockflyer-su27.htm

Here are the replacements I'm thinking/unsure of...
http://www.aeromicro.com/Catalog/fei...or_3963184.htm
http://www.aeromicro.com/Catalog/fei...or_3962671.htm
http://www.aeromicro.com/Catalog/fei...or_3564314.htm

I'm running a 2s 910mAh lipo and the stock 3x3 pusher prop.
I have no idea what the stats for the stock motor are.

davideboracay

look at hobby lobby brushless AXI motors.
they are really powerful.
if your plane weighs around 5-12 oz. get the 2208/34. then you can get a castle creations thunderbird 18. then it will need a 10x5 prop
if your plane weighs a little bit more you should consider the AXI 2212/34
these brushless motors are outrunners so they don't need a gearbox.
the torque is amazing with these setups.
you can still use the same battery and have 4-5 minute flights


DAVIDE

deli_conker

Well, the plane has an AUW of around 4 ounces. The size of the stock motor is around the same diameter of a helicopter tail motor but is about as long as a GWS 300 motor.

That size prop will be a problem as it is situated inside the main wing (there's a cutout for it). I may be able to go up to a 4 or 5 inch prop, but anything larger won't work unless I change where the motor is mounted.

I played around with the demo of motocalc, and it couldn't come up with anything that would work with a 2S lipo and a 3x3 prop (brushed or brushless). Makes me wonder why it shipped like that. I did a few other calculations with it, and it suggested a GWS 300 and a 4x2 prop. Any other suggestions?

Hatty

That's a pretty small space to stick a motor and prop. It almost looks like you would need a ducted fan system so that you can modify it to fit the plane. But, I don't know of any stand alone motor that will work.

Fliprob17

This motor may work http://www2.towerhobbies.com/cgi-bin...?&I=LXLWW2&P=0

deli_conker

The outer dimensions and weight of the one listed above are about the same size as the stock motor. I did some more playing around with motocalc, and it suggested a 4x1 prop with a brushless motor running at 6200 Kv or a 4x2 prop running at 4800 kv. Right now I'm looking at some Feigao motors that might fit the bill. Can anybody think of anything I might be missing?

Fliprob17

That is a lot ov KV to be running direct drive. You may be better off going with something closer to 4000 KV and the 4x2 or 3 prop........just a thought.

Glacier Girl

My Feedback: (4)

Deli,
First two on your list would probably be over amped with the load on a 3x3, 5 and 5.5 amps max.

Take a look at the Eflite Park 400 4200kv inrunner, similar in dimension specs, but can handle 18 amps. With a 3x3, on 2s power 5 amp draw, 2.6 thrust, 72 mph.
Want a little more thrust and a little lower speed, go to a 3.5 x2. Will spec out around 5.6 amps, 3.9 thrust and about 47 mph.
Either will fit the bill with the stock esc and battery pack specs.
If you go with a bigger esc and pack, you could prop it to rip the wings off if you want.

deli_conker

I think I'd go with the lower speed at this point. This is my first elevon plane and first plane after aileron trainer. I'm willing to cut out a little space for a bigger prop if necessary. Up to a 4 inch, that is.

The eflight motor is actually a little bigger than the stock motor. Stock is 12mm by 30mm and less than 20g. the eflite is 20mm by 40mm and 68g. Is the weight difference taken into account?

Also, I'm assuming that the speeds you are giving are at full throttle. Am I correct in this? I usually fly at half throttle or less. I typically overpower the crap out of my planes. It helped a lot when I was starting out to get out of sticky situations. It was weird having to go full throttle with the stock setup. It sank like a rock as soon as I gave any aileron input (yes, I gave elevator as well).

Matt Kirsch

My Feedback: (21)

Guys, keep in mind here that the entire plane is only supposed to weigh 4 ounces. It's the little ShockFlyer Sukhoi 27. A Park 400 weighs nearly as much as the entire plane should, so that's not an option.

The little Feiago motors are going to be your best bet for brushless. Choose the motor based on the propeller you can get; for example, I don't think there is such a thing as a 4x1 prop. 3x2 or 4x2 GWS orange props would be your closest options.

May I ask what battery you're using now?

deli_conker

Thunder Power 2s 910mAh. The box says the plane is supposed to weigh 85 grams. I weighed mine and it came out to 121 AUW. That's a quite a bit (50%) higher than what's on the box, so that may explain the poor performance. I still want to go brushless though.

Which Feigao motor do you think would work? Which prop to go with it?

deli_conker

Okay. Now that I've had a night to sleep on it, I've got some questions. I'm still grasping some of the aspects of electric flight, so bear with me. I usually trial and error things out, but I'm trying to increase my understanding.

Is this to say that the the motor is pulling too much current from the battery if it spins a 3x3? If so, I am looking at motor stats wrong. I was thinking that "max amps" was the most current that you could put to the motor. But in this case, it looks more like it means that "max amps" is what it draws by itself at full throttle. Am I wrong on this? If this is the case, then I'm limited to my battery's output, right? My TP s2 910mAh that can discharge at 16C continuous should be able to handle a draw of 14.5 amps.

How about medusa? I found some here...
http://radicalrc.secure-mall.com/sho...=1&cart=462600
But their max amps are higher than the Feigao motors.

I guess it comes down to choosing parts in order. Does it make more sense to choose the prop first and then the motor? If so, I'll stick with the 3x3 prop that it came with (one less thing to buy). What do I need to know to choose the motor from this point? If I switch my prop to a 4x2.5, how will that affect my motor choice? I usually don't go above half throttle, should this be a consideration in my choice? Sorry if these are dumb questions, but I'm trying to get out of the "I'll just buy it and see how it goes" mindset and actually learn a thing or two about this hobby. I can't help but feel like I am missing some of the proper tools though.

Thanks for your continuing patience...

Oh yeah, the recommended battery is a full ounce less than the one I'm using. If I used the recommended battery, my AUW would be around 93 grams. So that's my oversight as far as the stock setup is concerned. Still want to go brushless though...

shindin

My Feedback: (5)

I have my eye on that plane as well, I have watched the video on the HL site, and doesn't look anything like the performance you are describing..... are you sure it doesn't need more battery? for some reason I was thinking it needed a 3 cell
I'd email HL and ask them what setup is being used in the video on their site.......

Kiiski

On H-L's website under the "here's everything you need" section, they list a 1320 3 cell.
Kiiski

shindin

My Feedback: (5)

3 cell 13xx mah was what I thought, I have one of those that I figured I could try in it..... does anyone know if that would fly it anything like the video on the hobby-lobby site? I am new to electrics, but when I watch the video, it doesn't sound like a brushless motor to me, heck, it almost sounds like a glow d/f system.... if a 3 cell pack will fly it like the video I want one, but if it's going to take a whole new power system to get what they're showing, I would think there should be mention of it....... anybody care to venture a guess??
L

airraptor

My Feedback: (66)

the feiago brushless motors are weak. go with a medusa 12x30mm 4000 kv motor and a 4x2 gws/hobby lobby push on prop and get the heat sink for it. that motor and a 480 thunder power or evo batt will be real good. a plane like that with little thrust and high drag isnt going to be a speed demon. try to keep weight down and try to clean up the plane as far as drag goes. like rounding of all leading edges, use bits of foam to make ramps (streamlined) around servos,recievers, and batterys. anything to make it cut through the ait better will help alot. the next motor down will be the aon 12x30mm it is slightly less power than the medusa.

now for the best and fastest motor go with a E FLIGHT park 250 motor and a 4x4 -5x5 prop and a two cell 480. this will geive the best climb and speed and still is same weight as 12x30mm motors but since is a out runner and a kv of 2200 will give better power to drag, you can even run this motor on 3 cells if prop for a 4x4 prop. if you plan to use the park 250 let me know and i will help you mod it so it can be set up to handle the smaller props better since it has a prop saver instead of a prop holder

jooNorway

The original motor is a brushed motor! The original battery is a 2S400 20C LiPo. The controller have a rate of 6A max...

If you want to upgrade to brushless keep two things in mind: The weight is important, and you need an inrunner with a kV at 3000 appr. This plane is meant for a small fast rotating propeller with 3-4 inch diameter. Also remember the original motor is delivered with a efficient CAM-propeller designed for the system.
You should get a tiny brushless inrunner with the same diameter as the original motor, and I know Feigao have motors which suit. Maybe some of the other mentioned would do the job too, but I don`t know those brands.

Run the gadtet on 3S, but the amperes should be no more than 6-9Amp. Then a battery like a 3S400 20C is the obvious choice, remember weight! A 1200mAh battery is madness and the plane is destroyed when addding that much weight.
Get a lightweight controller like CC Phoenix-10 or Thunderbird 9. The Thunderbird 18 weights 10 gram more and is a large weight-penalty on such a small plane.

Upgrading from 6Amp brushed on 2S to a brushless on 3S and only 6A gives nearly the double of power. Anything larger/heavier have made you a heavy bad flying gadget instead of a fast manouverable nice indoor Sukhoi...

And of course: small servoes, and a really lightweight receiver without the casing on.

Just my 2C.