Newbie needing help with questionable motor
 

Hi,

Over 15 years ago, I was in the hobby of RC Airplanes and then got married and things changed. This weekend the local club had an auction. I attended and got a couple of DX7 Spektrum raidos, a partial built kit and an airplane with an eletric motor. With this airplane, I had to get a receiver, charger for the transmitter battery and a new battery for the airplane. Once I got things figured out of how to plug things in correctly without frying things, I tried to run the motor. It would flip the prop back and forth and about 1/3 up on throttle, it would kick the motor in with very little power, like it was at fast idle, it would quit at 1/2 throttle. I don't know what the issue is, either the ECS isn't working or the motor isn't.

So the first question - is there a way to test th motor/ECS without having another one to swap?

Second - the model number on the motor is B3630/08-4000 - with a gold body and the label is pink. I really wish I could attach pictures, as that would make it clearer. The ESC only has the markings of 40amps on it, that is it. What motor/ECS would I need to purchase?

Third, the wires from the ECS to the motor, three wires, red/black/yellow - I matched them up - would that make a difference if swapped around?

I would attach pictures, but due to the fact that my actual account on this site I don't recall what the password is. I tried to do the reset password, but just gives me this error when clicking on the link.
The address that you have used to request a new password is not valid. Please request a new password be sent to you by using this form. (Link removed due to limit of site)
Now if someone knows how to take care of the password, please let me know, I'd love to get back to my other account and use it instead of this new one.

Thanks, Michael

PS: Hoping to get this figured out and maybe be able to get someone to trim this airplane out for me and maybe have a bit of training on it, but I think I'll be able to fly around with ease, given I was able to pickup the real flight at the Hobby Town, take off, fly around and land with not issues. Just like riding a bicycle...

Grab a beer and some crisps, you have some reading to do. Don't try to take it all in in one go.

Take it to the club, let them have a look at it, join the club.
Troubleshooting is much easier to do live, less questions because they can see a lot rightaway.

What plane/make/size/type/mass?

What happens when you connect servo instead of ESC on throttle channel? Does it move with the stick you expect it to, full throw?

What is the battery type/voltage/#cells/capacity?
Charged correctly, what charger?
Same question for controller, there should be some voltage indication.
Propsize and -diameter?
(Small changes, massive effects: current drawn is proportional to pitch, voltage², Kv³, and diameter⁴.)

Current and voltage-sag when running, rpm?

Other possible causes and solutions:
Motor stuttering? Won't run?

Vriendelijke groeten https://www.rcuniverse.com/forum/ima...ilies/wink.gif Ron
• Without a watt-meter you're in the dark ... until something starts to glow •
• E-flight calculators • watt-meters • diy motor tips&tricks • Cumulus MFC •

Some well-structured reading for rainy/windy days, including e-flight_101 & 102, and some handy e-tools.
Will save you, and us :D a lot of questions. Notably the 'what went wrong?' kind of questions :(
Will also prevent you from burning up several controllers and/or motors and/or battery:
E-flight primer and tools

And pleasepleaseplease, do your RC equipment, wallet, ego, battery, controller, motor, house/garage/car a big favour ... get a watt-meter.
It will more than pay for itself, will save you at least one fried motor and one fried controller. Will also help you finding the best setup and help you troubleshooting. A must have.

Vriendelijke groeten ;) Ron
• Without a watt-meter you're in the dark ... until something starts to glow •
• E-flight calculators • watt-meters • diy motor tips&tricks • Cumulus MFC •

Since the motor runs, there's probably nothing wrong with ESC and motor.

For future reference ...

• Mounting screws too long, delved into motorcoil(s)?
• Battery polarity okay on battery connector? (Something I would always check on a new battery, or a new wiring harnass.)
  Wrong polarity would ruin ESC, almost instantly.
• Bad connection somewhere between ESC FETS and/or in motor:
  Motor stuttering? Won't run? Read before asking.
• Several motor tests
  1. Drytesting brushless motors - WFF (RCG user vollrathd)
  2. Opening an outrunner for visual inspection
     • Innov8tivedesigns → resources → video classroom → shaft/bearing replacement
     • Outrunner Disassembly and Stripping - RCG
  3. Overheating magnets causes de-magnetizing (irreversible! :(), which in turn results in higher velocity konstant Kv. Motor wants to run faster, thus drawing more current and more power.
     Motorcurrent and -power drawn are proportional to velocity konstant Kv³ :eek::eek::eek: , resistance losses in the copperwire are proportional to current² :eek::eek:
     Therefore resistance losses are proportional to Kv⁶ :eek::eek::eek::eek::eek::eek:
  4. Higher current → hotter motor → weaker magnets → higher Kv → higher current → hotter motor → weaker magnets → higher Kv → higher current ⟲⟲⟲ etcetera etcetera.
     Temperature runaway, major conflagration :(
  5. Determining whether magnets still have original strength, by determining whether velocity konstant Kv (in rpm/volt) is still the same, three simple straightforward methods.
     www.bavaria-direct.co.za → motor constants
  6. Generator test, only using a power drill and a voltmeter
     (Re)winding and building motors - RCG (sticky) → opening post → #40 Generator test.
  7. If you don't trust your ESC: use another brushless motor as a generator:
     Three Phase Alternator - Three Phase Motor? - RCG

Vriendelijke groeten https://www.rcuniverse.com/forum/ima...ilies/wink.gif Ron
• Without a watt-meter you're in the dark ... until something starts to glow •
• E-flight calculators • watt-meters • diy motor tips&tricks • Cumulus MFC •

Safety
Remove prop when setting up or changing power system.


The three motor/ESC wires are equivalent, but not identical. They carry the same power signal albeit with a 120degree phase ('time') difference, switching between zero and full voltage. One complete voltage cycle corresponds with one magnet passing a stator pole.

You can connect the three motorwires anyway you want. If motor runs in the wrong direction, just swap any two of the three motorwires. But NEVER EVER swap battery wires to reverse rotation, reversing battery polarity will ruin you controller, bigly, in the blink of an eye :(
Different colours for motorwires are handy for remembering the ESC→ motor connections, that's all

See also these
brushless motor animations and simulations - RCG


Motorvoltages at full throttle, no chopping up voltage in pieces.
Attachment 2270984


Motorvoltages at partial throttle, PWM chopping ('grass') to reduce effective voltage.
Attachment 2270985


Zoomed in on above scope trace directly above.
V is chopped voltage, I is smoothed current.
Attachment 2270986
from www.consult-g2.com → course


Scope traces from www.aerodesign.de/peter, DIY brushless motor building (english&german)
162

/* Oops. Wrong planet. */

ron_van_sommeren Thanks SO much for all the information. It's going to be quite a learning curve for me. Almost enough that I'd rather stay with glow engines :-)

I really appreciate all the information, I'll have to slowly dig through the list of information.

No need to reply to this, but I was able to plug a servo into the throttle and found that the throttle responded as I expected. I did research the radio to see if there is any training of the ECS and didn't find anything, but I'm not 100% certain on this.

As for just going glow engines, I don't see that truely happening as I've started a very small investment. Electric motors and glow engines have pros/cons of both, I'll just have to decide if I will go all in on electric or do both.