HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Dec 13, 2014, 10:59 AM
Registered User
Joined Dec 2014
2 Posts
Question
Can I run a brushless motor without a reciver?

I have a motor I want to use for a project (a mini-prop powered car) before I put it in my plane. I have the right ESC and battery, but do not have time for shipping and don't want to waste money on something I won't ever use again. I only need for it to turn on and off ex. When I connect or disconnect two wires. Is it possible?
AlodiSnazzy is offline Find More Posts by AlodiSnazzy
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 13, 2014, 11:04 AM
Detroit 2-stroke junkie
1320fastback's Avatar
USA, CA, Oceanside
Joined Jul 2008
3,474 Posts
No.
1320fastback is offline Find More Posts by 1320fastback
Reply With Quote
Old Dec 13, 2014, 11:18 AM
Registered User
Staffs, UK
Joined Nov 2003
10,944 Posts
No, you need either a Tx/Rx or a servo tester to produce the same sort of signal. No signal, no motor running.

Steve
slipstick is online now Find More Posts by slipstick
Reply With Quote
Old Dec 14, 2014, 06:30 AM
Registered User
Joined May 2014
46 Posts
You can also build a little interface with a PIC or an attiny(arduino) that create the pulse signal as your RX .
pierrotm777 is online now Find More Posts by pierrotm777
Reply With Quote
Old Dec 14, 2014, 06:41 AM
Jack
USA, ME, Ellsworth
Joined May 2008
17,310 Posts
The easiest way is to use a servo tester as a throttle. That will generate the same PWM signal that the receiver does and you can run the motor with a variable throttle that goes from off the full throttle.

Servo testers can be a cheap and simple as these:

http://www.ebay.com/itm/like/131308449441?lpid=82

or you can get one with a display of the PWM rate and that will also handle more testing tasks and types of servos:

http://www.ebay.com/itm/like/131308449441?lpid=82

Also available from places like deal extreme and bang good and the like...

Jack
jackerbes is offline Find More Posts by jackerbes
Reply With Quote
Old Dec 16, 2014, 05:54 PM
Registered User
Joined Dec 2013
28 Posts
Simple : connect the wire for 2ms, disconnect for 50ms, reconnect for 2ms etc...
I don't remember for the 50ms, but i'm sure for the 2ms
camousse is offline Find More Posts by camousse
Reply With Quote
Old Dec 17, 2014, 03:39 PM
Registered User
United Kingdom
Joined Nov 2014
13 Posts
They use a circuit refered to as a timer in control line planes where there is no receiver.
It waits an amount of time after switch on, then runs the motor at a preset speed for a preset amount of time.
There are applications where you can run a bldc motor using a microcontroller, but your into some complex electronics for that.
Dr peppers is offline Find More Posts by Dr peppers
Reply With Quote
Old Jan 07, 2015, 02:51 AM
Registered User
Joined Dec 2014
2 Posts
thanks for all the help! i acctualy ended up not needing to use what i was making with the motor anyway.
AlodiSnazzy is offline Find More Posts by AlodiSnazzy
Reply With Quote
Old Jan 07, 2015, 09:15 AM
Registered User
earlwb's Avatar
USA, TX, Grapevine
Joined Dec 2008
13,790 Posts
Well although you didn't need to do it. eFlite makes a control line timer motor control device that you can use for this purpose. It has a timer that you can set in one minute increments, and a motor speed setting.

http://www.e-fliterc.com/Products/De...ProdID=EFLA172
earlwb is online now Find More Posts by earlwb
RCG Plus Member
Latest blog entry: My new Gaui X5 Rc Helicopter
Reply With Quote
Old Jan 13, 2015, 03:13 PM
Registered User
Joined Jan 2007
400 Posts
Quote:
Originally Posted by earlwb View Post
Well although you didn't need to do it. eFlite makes a control line timer motor control device that you can use for this purpose. It has a timer that you can set in one minute increments, and a motor speed setting.

http://www.e-fliterc.com/Products/De...ProdID=EFLA172
I made several of those a few years back using a MicroChip PicChip. Still have a few of them. Cost is a buck or two each.

Based on the work in doing the microcontroller software, now, I'd just buy that e-flite unit!
vollrathd is online now Find More Posts by vollrathd
Reply With Quote
Old Jan 13, 2015, 03:47 PM
Registered User
Staffs, UK
Joined Nov 2003
10,944 Posts
Quote:
Originally Posted by earlwb View Post
Well although you didn't need to do it. eFlite makes a control line timer motor control device that you can use for this purpose. It has a timer that you can set in one minute increments, and a motor speed setting.

http://www.e-fliterc.com/Products/De...ProdID=EFLA172
Unfortunately it has been discontinued....which is a shame because most of the C/L timers still available cost about 3 times more.

Steve
slipstick is online now Find More Posts by slipstick
Reply With Quote
Old Jan 23, 2015, 12:03 AM
Hobbyist, tinkerer
United States, CA, LA
Joined Jan 2015
2 Posts
Hey all - long time lurker, first time poster here.
I have a near identical problem, and I hope you smart people can point me towards the best solution.

I need a push-button solution for control of a brushless motor that is always in hand.

I am running a red brick 60A, driving a Turnigy Aerodrive SK3 - 5055-280kv brushless. (I don't know if it matters, but I am using a li-ion 6 cell 22.2V, 6600Mah)
When the motor is running at the ideal speed, it is pulling 20A (though I don't know what PWM signal is being sent to the ESC)

I am looking for an off the shelf solution - something premade, that is relatively available. I don't know if there is a MOSFET that would produce the correct signal, or what -
I saw someone suggest the following " build a 5V-powered 555 circuit with a 20ms 'off' and an adjustable 1-2ms 'on' period."
I wonder if anyone knows where to get a premade board with these characteristics?

Any and all help would be hugely appreciated! you guys are awesome
IDMill is offline Find More Posts by IDMill
Reply With Quote
Old Jan 23, 2015, 12:19 AM
"Unnecessary Necessity"
coriolan's Avatar
Canada
Joined Sep 2006
6,035 Posts
Ready made:
http://www.hobbyking.com/hobbyking/s...vo_Tester.html
DIY(not much work but more expensive if you have to buy parts!)
http://www.sentex.ca/~mec1995/gadgets/servo4.htm
coriolan is offline Find More Posts by coriolan
Reply With Quote
Old Jan 23, 2015, 12:23 AM
Hobbyist, tinkerer
United States, CA, LA
Joined Jan 2015
2 Posts
Haha, That is what I have sitting on my workbench.

It works well enough for testing (as is it's namesake) but I need something that I can seal up inside a case, with the only access being a power switch and a pushbutton trigger to drive the motor.

I really need a chip or board that can be activated by a momentary switch, and sends the appropriate PWM signal to the ESC.

Any more help would be appreciated
IDMill is offline Find More Posts by IDMill
Reply With Quote
Old Jan 23, 2015, 04:39 AM
Registered User
United States, ID
Joined Sep 2011
658 Posts
Just reprogram the ESC controller chip. Should be easy enough. No need for extra complications.
jakestew is offline Find More Posts by jakestew
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Can Brushless motors run on 2 wires? Can they work without an ESC? Nelatonin Power Systems 38 Jan 13, 2015 07:58 PM
Question Can I run a quad/APM2.6 without a Power Module? Adam1979 Batteries and Chargers 4 Sep 16, 2014 10:18 AM
Help! can you use a brushed or brushless motor on any reciver lightningzeus Beginner Training Area (Aircraft-Electric) 2 Nov 30, 2009 10:40 AM
Yippee! can anyone make a cd motor run without an ESC? curious Power Systems 7 Nov 07, 2004 12:55 AM
How can I run a brushless without radio? Yukonho Power Systems 9 Feb 07, 2004 10:45 AM