Whats the best motor?

[ianc]

Has anyone come up with an idea of what the best motor is for the Belt? I've been looking for a new motor for my belt, I've got a sonix ESC 30a + BEC, so do I go for a sonix 3550Kv or 3800Kv? Or is there a better one? When I saw a 3900Kv that really confused me! What do the numbers mean and which is going to be the best for my belt?

Thanks in advance,
Ian.

[Ian 777]

Don't know nuffin about dese numbas man... Grant Mika(another_finn) Dierwolf and Ber will be able to help you.... Pm them if they dont post anything:YeaBaby:

[another_finn]

I already had the edit window open, but a friend came to visit before I had a chance to complete the post :)

Those numbers don't really mean much - they just tell you how many revolutions per minute the motor makes per volt under no load. Useful for selecting the right pinion for your gear ratio when you want to make a certain headspeed, but meaningless if you want to compare power. You'd really need to know how many amps they pull, or how many watts they are rated for.

Generally speaking, the 3900s and above are full of sound and fury but somewhat lacking in torque. They're good for smaller models where you don't have a lot of mass to get spinning, but not so suitable for 450 size and above. On 600 class helicopters you start seeing some massive windings with kV ratings below 1500 but ten times the peak power output of our stock 3800 Eskys.

(Yes, Mark, I know the Scorpion HK-2221-6 is a 4400Kv. That's not the only reason I consider it exceptional ;) )

Out of those options, I'd go for the 3550 Sonix. Maximum 28 A / 320 W peak power at 55 grams and $19... I like those figures a lot. Especially the last one :D

[Ian 777]

Wow see what I mean??? the man is a Genius:YeaBaby::lol:

[Jonnyheli]

I only know about rc car motors. I don't see the point on a better motor for a helicopter?

I know it probably makes the helicopter perform better but I don't see the point if you cant do 3d :roll:

Maybe there is some who can change my opinion here... because I don't see why?

-Jonny

[mnwizard]

You're supposed to have a reason to modify helis? :thinking

[another_finn]

Well, it's only really important if you do 3D, but I do see the point if the original is in any way marginal... When you're learning and need to punch out of a bad move, the last thing you need is the motor bogging down. Having 300+ watts of "up" at your fingertips can be a real comfort when you find out you underestimated the gravity of your situation.

Of course the truth is we just like new shiny bits with bigger numbers, but I'll bet a lot of you bought that explanation. Making them up is one of the most useful skills this hobby teaches you :D

[Grant_beltcp]

I was just going to write what anotherfinn just put lol.
Basically unless your motor is more than 300w theres no use looking at it for a belt for 3d. I personally wouldnt go less than 350w. the more powerfull motor helps alot for getting out of sticky situations and learning manouvers and then perfecting your collective management later.
I use the 425w -8 scorpion motor, but i did find the 320w hk2213-14 scorpion VERY good for its specs. If i was to put one into my belt it would be that one unless you are doing hard 3d.

[ianc]

I already had the edit window open, but a friend came to visit before I had a chance to complete the post :)

Those numbers don't really mean much - they just tell you how many revolutions per second the motor makes per volt under no load. Useful for selecting the right pinion for your gear ratio when you want to make a certain headspeed, but meaningless if you want to compare power. You'd really need to know how many amps they pull, or how many watts they are rated for.

Generally speaking, the 3900s and above are full of sound and fury but somewhat lacking in torque. They're good for smaller models where you don't have a lot of mass to get spinning, but not so suitable for 450 size and above. On 600 class helicopters you start seeing some massive windings with kV ratings below 1500 but ten times the peak power output of our stock 3800 Eskys.

(Yes, Mark, I know the Scorpion HK-2221-6 is a 4400Kv. That's not the only reason I consider it exceptional ;) )

Out of those options, I'd go for the 3550 Sonix. Maximum 28 A / 320 W peak power at 55 grams and $19... I like those figures a lot. Especially the last one :D

Thanks alot, I only wish you lived next door to me! I was hoping somebodywas going to say that the sonix 5500 was a good motor. Mainly because of the cost! :):):)

[Jonnyheli]

How many Watts is the stock belt cp motor?

-Jonny

[Grant_beltcp]

Not entirely sure, but i would guess around the 250/280w mark. Its not a bad motor, just rubbish quality and will bog on punch outs.

[another_finn]

The 3800 kV (EK5-0006) is 20 A / 220 W.

... :shock:

I didn't even remember it was that bad. I guess it's finally time to upgrade...

[Grant_beltcp]

I didnt realise it was that bad either - i dont remember it being quite that rubbish but then again i didnt do much with that motor in apart from crash it:roll:
I have double that now and its awesome:clappp

[Ber60]

Max current = 20A
so Max power output = 11.1V *20A = 222W
Max efficiency: 80%
So 222W *80%= 177W

To compare you need 375W to drive a bike at 30Km/H (love these motors)and I am in the market for a Scorpion 2221-8 (more docile) to

[Jonnyheli]

Max current = 20A
so Max power output = 11.1V *20A = 222W
Max efficiency: 80%
So 222W *80%= 177W

To compare you need 375W to drive a bike at 30Km/H (love these motors)and I am in the market for a Scorpion 2221-8 (more docile) to

Oh so that how you work it out :P

375W to drive a bike at 30Km/h but is that with some1 sitting on it?

-Jonny

[Ber60]

You are the the 375W ( if you are on the bike)
At my age I am lucky to get 175W :happyd

[Grant_beltcp]

The current ratings on those vary. I believe that rating is its continous and is more at peak. 177w really is pants! No wonder i love this scorpion -8 so much, 3x the power!

[DierWolf]

LOL wow people calling me by my real name now thats cool :)

KV behind the numbers means Rotations per Volt..

so 3900kv on your belt cp running at 11.1 volts = 43290 rpm the motor CAN do with nothing attached to it.

Devide that number by your main gear and pinion ratio and take about 75-80% of that number for efficiency and thats your Headspeed you should expect.

Wattage of the motor comes in to play when you apply pitch, this adds the load to the motor and a low wattage motor can only handle so much load before it overheats itself and then on top of that the ESC and Battery.

Now just because the Belt CP motor is low wattage doesnt mean its junk, the RPM it can give you makes up for the lesser blade pitch.

Finn made reference to 600 size motors which all have low KV ratings and the reason for this is becuase 600 size heli's run double the voltage! 22.2. and they are much more efficient as well so it still equates to the same amount of rpm in the end with a good setup.

What you need to be looking for is a High Wattage High KV motor, which the scorpion motors are... The sonix motor is good but their recommended esc rating is way off, its a pretty powerful motor and it overheats the 30A ESC i would go with 35 or 40A.

Only reason i bought the 30A for it was i didnt believe the numbers of 350 Watts but it sure enough is... so if you do get the sonix and use it with that 30A esc make sure the ESC has good ventilation on it.


My suggestion to you as a beginner is to simply buy a 13 tooth pinion for your esky 3900kv motor and use it with that 30A esc you got... your headspeed will go way up and the heli will be Very Very Very stable and still have tons of OMMF for you to do climbouts with no bogging that i can see so far.

Hope to have helped everyone out on this KV Rating thing, its not just a number :)

[ianc]

The mud is becoming much clearer now thanks chaps. I think i'm going to go for the Sonix 3550Kv with a 13 tooth pinion gear.

I've got a Sonix 30A ESC, so I think I've come up with a way of keeping it cool!
They are heat sinks out of an old PC.

Thanks again for all your help on this subject
Ian.

[Ian 777]

Brilliant post wolffie, now the number start to make sense to me, thanks bro:)

You too Mika and Ber :thumbup:

[Ber60]

Come to think of it :thinking, I know the wattage and kv of the engine
How do I get the headspeed needed with X blades at Y pitch to do a hover/3D with a heli of Z weight.
Trial and error ?

[DierWolf]

The Sonix comes with a 13 tooth installed.

Using the PC Heatsink is a good idea to get the heat away quicker so long you have ventilation over the heatsinks.

Ber... suggest if you wantall that info you buy a tack LOL.

[tom dubya]

Hey guys i to am looking for a new motor as my second esky motor bit the dust and was thinking i'd get a scorpian. But i am still on the stock esc. should i upgrade that with the new motor also or would it be fine. I'm glad i came across this post because when i was looking at the scorpians online i couldn't make heads or tails out of all the selections of scorpians. This has helped quite a bit.

Good to see where all you ex-heliguy's have gone to and your still around. Was wondering what happened to ya. Is tahitiwibble here to?

[DierWolf]

Esky ESC can hardly handle the stock motor, it definately will fry to pieces with a Scorpion motor.

Suggest you upgrade both at the same time.

Wibble i havent seen in a while but yes he did sign up here as well.

[another_finn]

Ooh yeah, don't even show the Scorpion to the stock ESC. That's a recipe for an instant fireball :)

Let us know if you find one online, though... I've been looking all over, and everybody seems to be out of stock. Except one place in Europe that's charging enough to keep all but the most desperate buyers away.