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Old Mar 18, 2011, 06:52 AM
Thailand
Joined Aug 2010
506 Posts
Discussion
How do I know what timing to set the ESC to?

I know you can alter the timing on the ESC but how do you find out what to set it at?
Is it the motor that determines the timing?
Is there any way to find out what the timing should be set to?
I wish the motor manufacturers would say what the timing should be.
I'm a bit confused and need to learn about it.
Jim
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Old Mar 18, 2011, 07:05 AM
John Foltz
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Woodstock, GA
Joined Jan 2011
390 Posts
For a brushless motor, the number of poles (magnets) determines the optimum timing. Less timing advance is more efficient and higher timing advance is more powerful but uses more juice, within the range that a particular motor can use.

I set my 14-pole motors at 20 degrees. Fewer poles need a lower timing advance. Some ESC's give you a guide in their instructions. Here's the one from E-flite:

Quote:

E-flite Pro ESC timing recommendations:

Low Timing Advance
Timing Degrees – 5 & 10
Motor Poles – 2 to 4
Expected Performance – Good balance of power and efficiency
Motor Poles – 6 or more
Expected Performance – Best efficiency and run time (lowest power)

Standard Timing Advance
Timing Degrees – 15 & 20
Motor Poles – 6 to 12
Expected Performance – Good balance of power and efficiency
Motor Poles – 14 or more
Expected Performance – Best efficiency and run time (lowest power)

High Timing Advance
Timing Degrees – 25
Motor Poles – 12
Expected Performance – Highest power, less efficiency
Motor Poles – 14 or more
Expected Performance – Good balance of power and efficiency


Don't confuse stator arms with poles, poles is number of magnets on the outer rotating part of a brushless outrunner. Inrunners on the other hand (magnets in the center) are almost always 2 pole.

You might find more help for your motor here:
http://www.rcgroups.com/forums/showthread.php?t=1105695
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Last edited by jfflyer; Mar 18, 2011 at 07:13 AM.
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Old Mar 18, 2011, 07:26 AM
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Ken Myers's Avatar
Commerce Township, MI
Joined Aug 2001
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Here is a link to a timing test that I did on outrunners.

http://homepage.mac.com/kmyersefo/timing/timing.htm
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Old Mar 18, 2011, 07:52 AM
Thailand
Joined Aug 2010
506 Posts
Thanks guy, all very useful stuff.
I have Turnigy 4030 880 kv that runs great if not a little hot.
I will reduce the timing to the low setting.
8 pole with 12 windings.
Thanks again.
Jim
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Old Mar 18, 2011, 11:13 AM
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As Ken found out... in most cases, if a motor runs well on low, don't bother to change it.
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Old Mar 18, 2011, 12:38 PM
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meshyx's Avatar
Norway
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Yeah, start on low, and if the motor screeches (means the esc is loosing sync with the motor), or other weird things, try going higher.
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Old Mar 18, 2011, 08:45 PM
Thailand
Joined Aug 2010
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Meshyx, there was a guy at our flying field with a smallish motor in a sport model. It screeched at full throttle.
This other guy had a programme card and put the timing to the high setting and it stopped the screeching.
Not sure what other problems it may cause, overheating or whatever?
This is all useful stuff. Thanks again to everyone.
Jim
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Old Mar 18, 2011, 09:33 PM
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Jim,

Certain motors seem to need high, certain motors seem to need low... but predicting which and why is beyond me!

My first experience with screeching was a Nippy Black 1812/100... horrible noise until I lowered the timing.... perfect after that.
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Old Mar 18, 2011, 09:54 PM
Jack
USA, ME, Ellsworth
Joined May 2008
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The ESC that have user changeable timing will usually have like a low, medium, and high and use the medium as the default.

Generally higher timing will increase RPM and motor temp and lower timing will drop the RPM and the motor will run cooler. So most of the time you can just leave it on medium. But if it stops a screeching problem, then it makes sense unless the motor gets too hot.

Too hot is also a result of the throttle use, if it is getting too hot you can prop down or back off on the throttle some to drop the temp.

This is no free lunch, if you get more power out of a motor there is always a price somewheres else, motor temp, battery duration, etc.

Jack
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Old Mar 19, 2011, 09:16 PM
Thailand
Joined Aug 2010
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Thanks again for all the advice.
I guess it is all a learning process and each motor ESC combination is different?.
Start with low and advance at your peril then? lol
My new Turnigy motor that I thought was really good appears to have a noisy bearing after only 2 flights. Looks like it has been fitted rather roughly.
Down the SKF shop on Monday again then. lol
Jim
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Old Mar 19, 2011, 09:30 PM
John Foltz
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Woodstock, GA
Joined Jan 2011
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Low is not the best setting for high pole count motors, and may not even work well on some of them, depending on the degree of automatic timing advance your ESC has for varying motor speeds.
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Old Mar 19, 2011, 09:50 PM
Thailand
Joined Aug 2010
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Ok. I will need to get my watt/amp meter, temp gauge out and do some serious testing.
Who including me thought going electric would be easy? lol
Jim
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Old Mar 19, 2011, 09:56 PM
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Chattanooga, Tennessee, United States
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Quote:
Originally Posted by jfflyer View Post
Low is not the best setting for high pole count motors, and may not even work well on some of them, depending on the degree of automatic timing advance your ESC has for varying motor speeds.
I run virtually every 14-pole motor I test on "low"... and even Steve Neu's Neutrino (26-pole), which I reviewed for him, ran well on "low".
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Old Mar 19, 2011, 11:35 PM
John Foltz
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Woodstock, GA
Joined Jan 2011
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Quote:
Originally Posted by Dr Kiwi View Post
I run virtually every 14-pole motor I test on "low"... and even Steve Neu's Neutrino (26-pole), which I reviewed for him, ran well on "low".
Then you probably use an ESC with dynamic timing that detects the optimal setting for the motor and adjusts it according to motor speed. A fixed 5 degree advance isn't going to work well with such a motor.
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Old Mar 20, 2011, 12:09 PM
Jack
USA, ME, Ellsworth
Joined May 2008
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I'm told that the Castle Creations ESCs will not normally show major changes when you changed the timing because of the "quality of their algorithms" or something like that. You can see that, at least to some extent, in the timing testing I did on a motor here using a Phoenix 80 ESC:

http://www.rcgroups.com/forums/showp...&postcount=984

The link has the full details and images from the eLogger, the summary was:

Low (0) timing - 10 second full throttle averages:

6,775 RPM, 10.8V, 16.9A, 183 Watts - temp 68F to 75F

Medium (5) timing - 10 second full throttle averages:

6,904 RPM, 10.8V, 17.4A, 188 Watts - temp 81F to 86F

High (10) timing - 10 second full throttle averages:

6,885 RPM, 10.8V, 17.7A, 192 Watts - temp 71F to 78F

On the Phoenix ESC the default is Medium or 5 degrees of advance. But I don't see much incentive to fool around with changing the timing much...

Jack
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