Motors Eflight Power 15 Comparable Substitute

[Derek]

I have a project coming soon that has Eflight Power 15 brushless motors as the recommended motor. I believe it's a 950kv motor. I'm not really a fan of Eflight electronics (personal preference). I'm also not very good at choosing suitable motors. I still rely on Tony's input....Tony, are you there?

To my knowledge, the Power 15 can swing a 13" prop on 3S. I'm looking to do the same thing.

What are your suggestions?

 

[Smoggie]

Best way to match motors is to look for another motor with similar weight and similar Kv.

In this case that would mean 950Kv and 150g. Hobbyking make a range of eflight clone motors, so the Turnigy G15 would be a straight drop in replacement: Turnigy G15 Brushless Outrunner 950kv

Or pick your favourite brand as long as the Kv and weight are a close match.

 

[Tony]

Sounds like a good motor to me. The Tacon 15 was the first thing that popped into my head, but even though it has the right KV, it's a little heavier.

 

[Smoggie]

Doesn't have to be an exact match, I'm sure the Tacon would be just fine.
Depending on how tight the installation is, it's also worth looking at the physical dimensions. I've had a few planes where the length of the motor is critical to avoid the spinner sticking way out in front of the cowl. The eFlight motors are quite long anyway so probably wont be a problem if swapping brands.

 

[RandyDSok]

I'm not really a fan of Eflight electronics

I understand and agree myself... they seem to be heavier and bigger than I care for. Of course going with something I'd prefer... would end up making you rebalance everything ( ie CG )... I really like Motrofly motors. The DM2815-950 is only 125g but it's also much shorter ( and higher priced as well, which doesn't seem to go over well on this forum... but I like the quality vs the cheaper motors )

Motrolfly Motors

 

[Smoggie]

I'm a fan of the Motrolfly motors too. They aren't available over this side of the pond but when I flew mainly fixed wing i imported a few of their motors. They are about the only supplier i know of who will do custom winding to meet your specific requirements.

 

[Derek]

Originally, i thought of the Tacon 15. Its rated for up to 5S but the wattage on 3S isnt very impressive.

I'll have a look at the other suggestions. Thanks guys!

 

[Derek]

I'd like to bounce this project off you guys. Here is the project plane that I'll be building soon:


The designer, Spike, has used the Eflight Power 15 motors but I'm looking for an alternative, as I mentioned before.

Although still kinda pricey, I came across these Cobra motors

Cobra C-3520/10 Brushless Motor, Kv=980 | Brushless Motors | Products | Innov8tive Designs

With that motor, even on 3S and a 13x8E APC prop, the prop chart is saying 562 watts at 50 amps. Now, this plane is anticipated to be between 14 and 17 lbs AUW. Besides take offs, I don't anticipate flying this plane at full throttle. It's not gonna be used as a stunt plane, speedster, 3D (lol), etc. This plane is going to be flown, hopefully, steady.....smooth....deliberate....and just cruise around.

What do you guys think?

 

[RandyDSok]

What do you guys think?

For the size of the motor you linked too... it's not expensive

That motor is much heavier at 210g than the Power 15 at 152g ( which is already heavy for it's size ). It's also has a much larger diameter than the Power 15. Unless you are also scaling up the plane... the motor is too big based on the original motor it was designed to use.

If your "lol" by the 3D portion was meant to indicate your reluctance about believing that... then I'm with you. I think it'd sport around fine but seriously doubt it'll 3D even if the dihedral is reduced.

 

[Derek]

Oh no no no....i have no interest in any sort of 3D with this plane.

As for the motor...i thought the Power 15 was a 35mm motor...but you are right...that Cobra motor is much heavier compared to the Power 15. Ill keep looking.

 

[Derek]

Well, it's still obvious to me that I am no good at choosing motors. It's a good thing that I'm better at building and flying the models, lol.

Randy, I appreciate the suggestion of the DM2815-950 but I can't justify $83.00 for a motor, especially since I'll need two motors.

Smoggie, I've checked the pricing, availability, and specs of that G15 from HK and I'm thinking that the G15 is gonna be the motor I go with. At $30 each, I'll order 3....two to be mounted and one as a spare.

Although I didn't go with the Tacon and Motrofly suggestions, I do very much appreciate the suggestions. Now that I've got the motors picked out, I can choose esc's and probably place my parts order soon.

 

[Smoggie]

Here's another option I'll throw in the mix. I really like Sunnysky motors, they are in my experience really good quality for the price and have very high power rating for their size.

The Sunnysky X2820 920Kv would be a nice option on 3s or the 800Kv on 4s : Sunnysky X2820 2820 800KV 920KV Brushless Motor For RC Models

 

[Derek]

I like Sunnysky motors too. I have them on my mini quads.....tough lil motors. Although, that particular motor....i dont think thats gonna work. I have seven 3S 5000mah packs. Im trying to build this plane with 3S in mind. Unfortunately, those Sunnysky motors, at 11.1v, dont even show 400 watts in the specs. I'll have a look at some other Sunnysky's.

 

[Smoggie]

Derek, you must be reading the wrong spec. The 920Kv motor at 11.1V (3S) pulls 476W and 42A with a 13x8 APC prop, with a freshly charged battery it would be more than that.

You need to scroll down past the 800Kv spec to find the details for the 920Kv motor. The rating shows 52A max which is a fair bit more than the other motors listed so far, so it's potentially a more powerful motor if you prop it to it's limit.

 

[Smoggie]

Another point.. If this plane is going to be up to 17lb then you will be very marginal on power with Power 15 or equivalent motors. While it should fly ok, take off run would be long and climb rate slow. If operating from a slightly rough grass surface you would probably struggle to get off the ground at all. A 200g motor like the Cobra you found would be a better bet if you want a little bit more power. On a 17lb plane the added 3oz for larger motors inst significant, but the extra power certainly could be. You can always throttle back if you dont need the power but there is nothing worse than flying a badly underpowered plane.

You would of course need larger ESC if using a more powerful motor.

 

[Derek]

and this is where I get confused. You are saying that the Power 15 (and similar) probably won't be enough motor and yet the designer of the plane runs two of those Eflight Power 15 motors with 13" props on 3S. Now, I will absolutely agree with you when you said that there is nothing worse than flying an underpowered plane...been there...done that...and it's just no fun. Underpropped is one thing, but underpowered just sucks!

 

[Derek]

Smoggie...I was looking over that spec chart for the Sunnysky motor...i've attached a screenshot from what I saw.

Am I looking at the wrong spot because I'm not seeing what you are talking about?

 

[Smoggie]

That's the spec for the 800kv motor. Scroll down the page.

 

[Smoggie]

and this is where I get confused. You are saying that the Power 15 (and similar) probably won't be enough motor and yet the designer of the plane runs two of those Eflight Power 15 motors with 13" props

Yes but does his plane weigh 17lb and is he flying from rough fields at that weight?

 

[Derek]

That's the spec for the 800kv motor. Scroll down the page.

Oh, I see....I just didn't scroll down far enough. I see what you are saying now. Sorry about that!

Yes but does his plane weigh 17lb and is he flying from rough fields at that weight?

If I'm not mistaken, the designer has flown the plane with a max weight of 20 pounds. He took the empty airframe and taped pop cans to it...check this out.


It looks like the first flight, the plane weighs 8.355kg (18.41lbs). Smoggie, you also asked if he takes off from rough fields....I've watched all of his videos. Mostly, he takes off from paved runways (some are not smooth). There are some other Gemini v2 videos that show the plane taking off from grassy fields and they also appear to have the Power 15 motors......but, now that I'm looking at the same Sunnysky specs that you are, lol, I see that those motors are probably quite comparative to the Power 15 motors and less expensive.