change motors

[Smoggie]

Nice cheating on the motor diameter measurement!..

Quantum motors are slighly 'barrel' shaped. The ends are smaller diameter than the main rotor part. You conveniently measured the smaller end part where the fan is. the main rotor body is 50mm diameter, the same as the Align 750MX:


So lets see the calliper around the main body of the Quantum.....

I'll repeat, they are to all practical intents and purposes the same size and weight of motor. Any differences there are (a millimetre here, a few grams there) would certainly not justify calling one "super light" and the other " beastly... big heavy".

How they perform in flight relative to one-another I cant say but to do that you would have to try both back to back on the same heli... no point comparing them on totally different helis that wont tell you anything.


PS.. i never said that you couldn't draw the power that Align claim, my only point is that each manufacturer has their own limits when they come to rating motors. Align might give a rating that is bordering on self destruction, others might give a rating that has a healthy safety factor. Neither is 'wrong' because there is no recognised standard for rating these motors. The thing with electric motors is they just keep drawing more power as you increase the load, until they self destruct.

[peptod]

Good night . Thank you for your help. I Just Want to get more flight time só think to use a 600 class motor but the align advice me to maintain my 750 .the 600 wont give me more flight time but use untill 80% throtle will do. My combination 14/118 only fit with h60219A. now I do not want to change That 750mx. I will use this Money to get a neurôn.

[RC/DC_5000]

One motor stator is a 4035. The other motor is a 4236. I will say that the caliper pinch was off. They are 2mm difference at the same pinch. Which makes sense that they are 2mm off at the stator. As measured by the manufacturers specs- not mine.

Of course we are only talking about a few mm. That's all we are ever talking about with these motors. The 4530 motors on 700-800 helicopters are only 3 more millimeters away. They make upwards of 10 kilowatts of power. At the sacrifice of more gyroscopic "weight".

There's videos online of motor shootouts with the Scorpion 45_ _ motor offerings. They recommend to use the smallest of the motors as possible to do the the job so as not to make the helicopter "feel" heavy.

I will agree that you'd have to fly them to know the difference.. and fly them hard at that. Because I've flown them hard... and feel how much heavier the 750mx feels and yet it clearly destroys the Quantum with 2000+ more peak watts- warrants the beastly title of it. It's definitely heavier and more gyroscopic.. but it pulls its own weight-

[RC/DC_5000]

"The thing with electric motors is they just keep drawing more power as you increase the load, until they self destruct."

If the motor is overloaded it will slow down. This will decrease the amount of Back EMF being generated, and so the current will increase dramatically but it will be useless/unused current.. NOT making more power. This will cause overheating. Align rated the motor to make X amount of power before this happens. You don't understand what the power rating is and you're not using the right terms. That rating is not a measure of consumption- it's a measure of output. The motor consumes current and makes power in watts convertible to HORSEPOWER- Torque X Speed. I can peddle by bicycle and measure a power rating in watts. Europe does it with cars.

You're implying Align can just keep the 750mx cranking and it will continue to make more and more power that they can then boast their rating with. NOT. The motor will not continue to make power indefinitely until it melts. It will slow down first, then stop making more power, then draw excess current, then it will melt. The rating is the breaking point before this occurs.

No load motor spins at peak voltage- add load- measure current...repeat. When the load slows motor down and temperature begins to rise....There is the rating. The motor can't do any more work. It's a physical limit. The choo choo train can only carry so much weight. Rating the motors is not conspiracy nor mystery. The stator size will very strongly hint what the motor can do. Like displacement in a combustion engine. Want me to prove it? I like to prove things, source things.. instead of just arguing senselessly.

Xnova 4530 = 5000 continuous watts rated consuming 120A
Scorpion 4530= 4800 continuous watts rated consuming 115A
Quantum 4530= 5000 continuous watts rated consuming 125A
Align 800mx 4530= 5100 continuous watts rated consuming 115A

Ya see... these motors not only have the same stator size, relative power OUTPUT and current consumption.. they also have a remarkably standardized method of measuring this power. Feel free to ever substantiate all your wild theories and claims.

A continuous rating means that you can leave it run like that all day. It will not be bogging down, drawing useless/excess current and changing its temperature. It can sustain the load indefinitely. Sure looks like they all do about the same amount of work to me and are rated about identical. Considering these motors draw somewhat different current and have somewhat different Kv values- they are remarkably similar in power OUTPUT... are they not? Power=Torque X Speed. They are not exactly the same speed. But they sure are close in power.

So with these identical motor sizes being nearly identical in power OUTPUT-what separates them? The current they draw to make the power (also known as efficiency) and the torque they can produce while making the power. HINT: The Scorpion might make more torque. It is often called the "Stump Puller". Torque affects RPM and thus throws off the power rating- perhaps misrepresenting how the motor actually performs in your helicopter. Which is why you hear people say... its only better on paper.