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-   -   Brushless motor direct to battery without reciever??? (http://www.rcuniverse.com/forum/rc-radios-transmitters-receivers-servos-gyros-157/11175443-brushless-motor-direct-battery-without-reciever.html)

amv101 07-30-2012 08:12 PM

Brushless motor direct to battery without reciever???
 
I am working on a project and want to hook up a brushless motor direct to a battery, without a receiver.

I simply need the brushless motor to turn off and on by a switch, and powered by a battery. It does not need any speed controlling. The servos will be powered by a seperate RX and battery.

Has anyone tried this before? Is it possible with stock RC parts? Would I still need an ESC?

Thanks!

BarracudaHockey 07-31-2012 04:34 AM

RE: Brushless motor direct to battery without reciever???
 
You may be able to control an ESC with a device that Hobby King sells that simulates a servo signal, but you will need an ESC to run a BL motor AFAIK.

Brushless motors aren't pos/neg, they are 3 phases that an esc acts as a high speed switch to power the magnets in sequence to get the shaft to spin.

proline8000 07-31-2012 04:39 AM

RE: Brushless motor direct to battery without reciever???
 
you can not run a brushless motor directly from a battery. The speed control times when the magnets of the motor come on and turn off to rotate.

dirtybird 07-31-2012 05:29 AM

RE: Brushless motor direct to battery without reciever???
 
You will need the ESC to provide the timed pulses to run the motor, then you will need a servo pulse generator to turn the ESC on if you are not using a receiver.
Why not use a brushed motor? Much simpler.

Lazer 07-31-2012 10:32 AM

RE: Brushless motor direct to battery without reciever???
 
One other point to make is that the ESC converts the Battery DC current to AC for the 3 phase brushless motor. ;)

pilotpete2 07-31-2012 11:24 AM

RE: Brushless motor direct to battery without reciever???
 
Good luck trying to get 3 phase AC outta an ESC, and good luck trying to run a BLDC motor on 3 phase AC.
The ESC simply sequentially switches the DC current though the 3 winding phases of the motor with the timing being controlled by back EMF from the motor.
Pete

Rafael23cc 07-31-2012 11:59 AM

RE: Brushless motor direct to battery without reciever???
 

Quote:

ORIGINAL: amv101

I am working on a project and want to hook up a brushless motor direct to a battery, without a receiver.

I simply need the brushless motor to turn off and on by a switch, and powered by a battery. It does not need any speed controlling. The servos will be powered by a seperate RX and battery.
Does it have to be brushless? You can do it with a brushed motor, I do not know how many times you will be able to do it, but it can be done. Talk to the electric Dragster type of guys and they will show you how. When I was getting bit by the RC bug I visited a lot of RC car tracks.

Rafael

rmh 07-31-2012 02:36 PM

RE: Brushless motor direct to battery without reciever???
 
Why not get a servo controller - JR makes a tiny box called called a matchmaker - you can plug in any modern servo -and turning a small disc - run full travel- I would expect it would also run an ESC

dirtybird 07-31-2012 08:19 PM

RE: Brushless motor direct to battery without reciever???
 
The ESC runs off a servo output from the receiver so any device that simulates that will work
The brushless motor is in fact a three phase motor and will run as a motor if connected to three phase power. The ESC does not operate it as a three phase motor, however. Its operated as a two phase DC motor with the other line supplying the timing

pilotpete2 08-02-2012 08:16 AM

RE: Brushless motor direct to battery without reciever???
 
To get the BLDC motor to run on 3 phase AC at 50-60Hz, you'll need a starter motor. A simple permanent magnet motor on AC would have to accelerate to synchronous speed in one revolution, which is impossible, so it will just sit there humming at the line frequency, unless you spin it up close the the sync speed, which is 1800rpm with a 12 stator pole 3 phase motor on 60Hz.
Pete

dirtybird 08-02-2012 09:21 AM

RE: Brushless motor direct to battery without reciever???
 
With todays electronics you can generate three phase current from DC where you have complete control over the synchronous speed. You can then start from zero RPM and run it up to the speed you want. Just why anyone would want to do that escapes me. But then you never know.

pilotpete2 08-02-2012 04:13 PM

RE: Brushless motor direct to battery without reciever???
 
Yes, that's called a variable frequency AC drive. In the late 80's the railroad loco manufacturers switched to VFD drive running 3 phase induction motors which result in lower maintenance costs and longer running time between overhauls than the series wound traction motors pioneered by Sprauge.
Pete

TFF 08-02-2012 07:39 PM

RE: Brushless motor direct to battery without reciever???
 
The control line electric guys have speed controls made up for motor only runs. You will have to google it.

AndyKunz 08-03-2012 07:41 AM

RE: Brushless motor direct to battery without reciever???
 
They still use an ESC, the device they use is a timer that generates the signal as if it came from a receiver. I designed the one Bob Hunt flew at the Worlds several years ago.

Andy

henryh73 08-15-2012 04:47 PM

RE: Brushless motor direct to battery without reciever???
 
Hello,
How would I connect these?

http://www.hobbyking.com/hobbyking/s...vo_Tester.html
http://www.hobbyking.com/hobbyking/s...ESC_Opto_.html

I jsut started getting into this type of stuff, so I barely know what I am doing, but I need to for a project

The black and red wire on the servo tester connect to DC power souce of 4.8-7.2V, and the thing wire from the esc connects to the 6 copper prongs on the servo tester?


The thick red/black wires on esc connects to 2s lipo battery, and three black wires connect to brushless motor

Is that correct?

Where can I put in a simple on/off switch?

thanks for helping


amv101 08-16-2012 08:03 PM

RE: Brushless motor direct to battery without reciever???
 

Quote:

ORIGINAL: AndyKunz

They still use an ESC, the device they use is a timer that generates the signal as if it came from a receiver. I designed the one Bob Hunt flew at the Worlds several years ago.

Andy
Hello Andy

Do you or know any that does, sell something like this? I just need to run a brushless motor with a simple on and off switch.

Thanks!

AndyKunz 08-17-2012 05:57 AM

RE: Brushless motor direct to battery without reciever???
 
The timer the C/L guys seem to like now is the "Will Hubin timer" as I understand it.

See post #2 here: http://www.rcuniverse.com/forum/m_91...tm.htm#9115273

Andy

chuckk2 08-18-2012 04:02 PM

RE: Brushless motor direct to battery without reciever???
 
Once you have the Motor, speed control, and battery, the next thing to look at is
http://www.hansenhobbies.com/products/rcelkits/sckit/

$10.95


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