Hobbyking Donkey ST4010-820

I have a Hobbyking Donkey ST4010-820 motor lying around from a plane I built (and subsequently destroyed) earlier this year. Now I'm interested in buying an Extreme Flight 48" Edge 540T EXP and I want to know if this motor will work in this plane. The statistics seem close enough to the Torque 2814T-820, the motor that Extreme Flight lists as the recommended motor for this plane.

I probably wouldn't use it, based solely on the name. Donkey? Who thought THAT one up? Lol

I have no idea. I know the motor works, and has plenty of power (the previous model it was in was an 8 foot scratch built flying wing), I just don't know whether it would work with this airframe.

On paper, it looks like the motor has the right stats. But it's super duper mega ultra hyper cheap! "Self oiling bushings" tells me that it doesn't even have proper bearings. Keep in mind that 3D puts more strain on the motor than anything else.

Bottom line: It may very well work, but do you want to risk a top notch airframe on a low budget motor?

NJSwede said:

On paper, it looks like the motor has the right stats. But it's super duper mega ultra hyper cheap! "Self oiling bushings" tells me that it doesn't even have proper bearings. Keep in mind that 3D puts more strain on the motor than anything else.

Bottom line: It may very well work, but do you want to risk a top notch airframe on a low budget motor?

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Well there's no low notch airframes to risk with it

I don't want to risk a top notch airframe, but i don't want to spend nearly $100 on a motor which could easily be replaced with one I already have

Don't use it. 3D is tough on equipment. Back a few weeks ago I had an omega130 blow up on me in a torque roll in my 47shp, and that omega is known to be a near indestructible motor and is one of the best motors for this size airfarme. You don't want to loose a nice air frame because you decided to skimp on something, spend a little bit more and do it right, in the long run you'll be happier.

3DMad5 said:

Well there's no low notch airframes to risk with it

I don't want to risk a top notch airframe, but i don't want to spend nearly $100 on a motor which could easily be replaced with one I already have

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I understand your way of thinking because I used to think like you. But I've had way too many mishaps caused by sub-par equipment that I'm now trying to use high-end components only. Replacing broken motors and ESCs and possibly repairing/replacing air frames gets a lot more expensive long term.

To give you something more tangible: The bearings (or in this case lack of bearings) in cheap motors are typically very poor. When they wear out, the bell starts to move from side to side and will hit the magnets when you pull a high-G maneuver. Since the glue holding the magnets in place is also inadequate (ask me how I know), you'll eventually rip out a magnet that will lodge itself between the stator and rotor. This will obviously cause a deadstick, which kind of sucks if you're in a hover without enough altitude to recover (again, ask me how I know). Furthermore, a seized motor is very likely to send hundreds of amps through your speed controller and burn it to charcoal (ask me how... Whatever, this is getting old ).

Now, if I had a cheap little foamie warbird or something like that, it would be a whole different story. Those planes don't put half the strain on the gear compared to 3D. Cheaper motors will probably work very well there.

Specs wise it would work, but I would avoid it for a number of reasons:

1. As Pontus said, it does not have bearings. It has bushings. This is pretty ridiculous IMO. These will wear out in short order, especially in 3D.
2. Collet adapter instead of bolt-on adapter. These are prone to flying off in hard maneuvers. Usually more of a concern in larger sizes but still not a good thing here.
3. All-steel bell is not as good at cooling as on a good motor, and adds weight. This means less weight in copper and magnets which means less power and hotter running.
4. We are pushing these motors pretty hard in our 48's for good performance. The lower quality and efficiency means to get that level of performance out of a cheap motor like this means a lot more heat and probably a burnt motor.

Invest a bit more money in a good motor and you will be much happier.

This motor, on the other hand, looks like a great candidate for being put in a beater plane for use in full-contact combat or something.

buy cheap, buy twice

As others have said, it would not be up to the stress that 3D puts on motors.. But there is a more immediate problem too. it's far to large in diameter meaning that there is no way that you could bolt it to the motor mount plate. You couldn't even re-drill the plane because the plate is only just big enough to take the standard motor. it's also rather on the heavy side as it will be well over 200g once you add a prop adapter.

Bottom line is it's not suitable.

if you want a HK motor that will fit the Edge and be a pretty close match to the Torque then the SK3 3542-800kv is a drop in replacement. The SK3's are actually pretty nice motors, maybe not quite as structurally strong as some of the premium brands, but if you don't do constant KE spins at WOT you should be fine.