3D-Flyer Kevin

Can some one please do me a big favor and explain to me everything about brushless motors?

Kevin

bruce88123

I don't know anything about them but I do know there are "electric" forums on RCU that will give you GREAT info and RCU has a sister site www.wattflyer.com that is dedicated to all things electric.
Other than electric stuff, I'd be glad to help you though.

B.L.E.

Well, they don't have brushes. They really are small permanent magnet 3-phase synchronous motors and they need a brushless electronic speed control (brushless ESC) to convert the DC voltage from the battery into the 3-phase alternating current that the motor actually runs on. Even though the ESC is sold separately, it is an integral part of the motor and the motor will not run without one. The esc does not have to be the same brand as the motor but it does need to be large enough to handle the motor's maximum amps and voltage.
Premium brushless motors and lithium polymer batteries offer power that matches or exeeds that of glow engines. At least half ot the F3A pattern competitors have gone electric, I don't think it's because they are trying to be politically correct.

Mr67Stang

Brushless motors where created for people that just could not learn to tune a nitro engine...

KidVermin

My Feedback: (3)

http://www.diynetwork.com/diy/rc_pla...320834,00.html

This is just one of many sites if you simply do a Google search typing in electric brushless motors.
These pooter search engines are chock full of information if you type in your questions.

B.L.E.

Nah....they were created for those of us who are too lazy to clean glow engine mess off of our planes after flying and want to spend the day at the field flying, not fiddling with an engine that's giving problems. (air leak? I just replaced the lines, let's try a new plug, maybe it's bad fuel, maybe the fuel tank is foaming) An added bonus, after a day of flying, your clothes don't stink.

CGRetired

My Feedback: (1)

One thing I do know about them is that it's much easier to get 5 stiches on your finger with one than it is with a glow engine!

DS.

Iturnright

True the little propellers are sharp, but I've seen glow engine start procedures and they scare me, I'm a fan of having the propeller not turning! I'm actually a bit surprised there aren't more accidents from glow powered planes since the propellers always have to turn, and you physically have to start it by flicking the prop, as well as extensively tuning engines just inches behind a spinning prop. So, you might not get just 5 stiches.

Anyway, brushless motors are also different and better than brushed motors because there is no physical contact between the brushes as a brushed motor has. Therefore effieciency is increased as well as a reduction in wear and tear by not having two parts touch during the revolutions.

B.L.E.

The one thing that a glow engine will positively not do is start up by surprise and go to full power because someone accidently bumped the throttle on the transmitter while filling the tank with fuel or something similar. Most of the serious prop accidents that I have witnessed with glow engines happened while adjusting the needle valve, not during startup.
Most of us think of electric planes as one of those ready to fly toys with power systems equal to a Cox .049 glow engine. Big brushless motors take electric power to a level that matches large glow engines and the props on these planes are just as dangerous.

aeajr

My Feedback: (2)

You are right, of course.

Whether we fly glow or gas, electrics or gliders, there are proper safety procedures to be followed. Each type of power source calls for special handling. One is not better than the other, they are just different. Each has its own benefits and each has its own hazards.

I fly electrics and gliders because that is what is allowed at my field. If the landowner would allow glow, I would probably be flying those too. I like a wide variety of flying experiences.

However one caution is universal .... Keep your fingers out of the prop!

opjose

12 stitches on my forearm, thanks to a .30 equivalent brushless motor and a bumped throttle...

Ouch!

RVator

My Feedback: (1)

Suitcase and I have been using some E-Flight brushless motors lately. He has a Park 400 on a profile extra 300 and I have a Park 480 on a Mini Ultra Stick. The nice thing about Eflight motors is the numbering system they use, 400 for old brushed speed 400 planes. Park 15 for 15 glow size etc.. I have never tried to figue out AXi's or HiMax's numbering. E flight motors come with the motor mounts and prop adapters. Not a bad deal for the money. I have also been using Castle speed controllers also with good luck.
I like the conv of electrics but for me I like to keep them under 28 -30 ozs. Bigger than that for the money in batteries and speed contoller I would rather have another 100 fourstroke powered plane.

aeajr

My Feedback: (2)

Sounds like you might be wise to use an ESC with an arming switch or to install one yourself.

I have been flying electrics for 4 years. Nicked myself twice. Considering that is over 1500 electric flights, I would say that is a pretty low injury %. But a switch is not a bad idea. The rest of my flights, probably another 1500 are glider flights.

B.L.E.

In brushless motors, the losses of a commutator and brushes are replaced by losses in the ESC. If you think that there are no losses there, feel how warm your ESC gets during use.
Most brushed motors are cheap can motors with reletively weak ferrite field magnets. Most brushless motors use super strong neodymiun alloy field magnets. The high magnetic field strength means that fewer turns of wire are needed to arrive at a given kV rating. Fewer turns means that there is room for a larger wire in the armature (stator). A larger diameter and shorter wire means a dramatically lower winding resistance and this is where both the high power and motor efficiency comes from.
Before brushless technology was introduced, Astroflite made premium brushed motors with high strength field magnets. These had power and efficiencys that compare with today's better brushless motors.

opjose

Actually that brings up the question about doing this...

I've noticed that some of the Jeti ESC come with power/arming switches.

Which is it? Do these things merely arm the motor or do they enable power to the ESC?

If the latter any suggestions about dealing with ESC's that do not have switches?

I REALLY wanted a switch on the ESC of the plane that cut me up, but it's 60A ESC has no provision for this.

Hints, suggestions, and tips in this regard are welcome.... heck it probably merits a seperate thread on the subject.

Thanks!

B.L.E.

On my plane powered by a e-flite power 60 I have a Castle Creations HV85 ESC (yea I know it's sort of overkill). This ESC has no built in battery eliminator so I have to use a regular reciever battery to power the radio and servos along with a on/off switch for the reciever battery. If I leave that switch off, the ESC will get no signal from the reciever and will not arm.
I have since added a switching regulator BEC but I still use that on off switch. I plug in my main battery and the ESC makes the first part of the arming music. Then I turn on my Xmitter and when I turn on the reciever switch, the ESC finishes the arming music and it's ready to go.

On the smaller CC ESC's with BEC's, you could probably put a switch on the red wire that goes to the throttle channel of the reciever to prevent the reciever from getting power until you are ready to launch. The center red wire is +5 volt power wire that powers the reciever and all the servos. The white or yellow is the signal wire and the black is the ground.

opjose

How about an On/Off switch that controls ALL power on a setup where I am user the ESC's built in BEC?

e.g. I would like to be able to connect the battery pack and close the hatch up, but only flip the switch, powering up the plane when I am ready to go.

Also what do the ESC's with the built in switch do? Do they flip the power on to the ESC? Or do they merely prevent it from arming?

B.L.E.

I believe those switches merely prevent the esc from arming. The biggest problem with a main power switch is getting one that can handle all those amps and not be ridiculously heavy.
Some people rig up a Deans Ultra Plug in series with the power and mount it flush to the outside of the fusilage. To arm the plane, you stick a shorted Ultra Plug in the socket like a car key.

opjose

Excellent idea. I'll try that.

JLIN26

Electrifly has a great website to find out more about brushless in-runner & out-runner motors. I was able to convert my NexStar Select by using Electrifly's Electric Motor Configuration http://www.electrifly.com/config/. All I had to do was put in 5 different facts about my NexStar and in less than a minute I had all I needed in order to convert my glow trainer to a brushless electric trainer. I hear that Hobbico has come out with a brushless electric trainer. I think it's called the ElectriStar Select. Has anyone heard anything about this trainer?