Motor/ESC experts please chime in: Motor vs ESC Timing, which is better?
 

I searched and didn't come up with an answer to my question in the onroad and offroad threads. I've always wondered, if you wanted 20 degrees of timing (or whatever), is it better to do it in the motor itself or do it through the ESC?

What I'm wondering is if one is more efficient than the other, if one way yields more rpm or torque than the other, etc. Or do they provide EXACTLY the same results?

Thanks in advance for your comments.

If the 20 deg was a true 20 deg then they would be the same but in practice ESC timing is better, as you loose can timing as rpm increases.

Wow, I didn't know that the motor loses timing with rpm...this is great info! Are there any articles, per chance, that you can point me out to this? I've been searching and although I've come across great motor OR ESC articles, I haven't really found anything talking about timing.

By the way, I found this Novak article, but it doesn't really answer my question... :(

http://teamnovak.com/tech_info/view_article/20

It doesn't. Fixed timing on the endbell is exactly that: fixed.

ESCs have the advantage that they can vary the timing with motor speed; the faster the speed, the more the timing is advanced. That's called, depending on the manufacturer, "dynamic timing", "boost timing", or "ramping". The result is a wider motor powerband than fixed timing gives.

Senor delay results in loss of timing as rpm increases;).

Yes, if it were substantial it would. The delay is too short to affect operation.

You can't separate the two for a sensored motor in sensored operation mode.

1) Mechanical Endbell" timing" is always present (be it zero or wherever).
2) For a sensored motor ESC "timing" is always present (be it at zero, or wherever) and triggered from the sensors. (unless the ESC switches to sensorles).

I'd have to go with esc.

So no one's really answered my question... If I just want fixed timing across all RPMs, is ESC or can timing better AND WHY?

If the ESC timing and motor timing are both fixed, then by definition they will have the same behavior; neither is "better". So do whatever you prefer, or is most convenient.

To make ESC timing react the exact same way as motor can timing, you would have to set the ESC timing to all happen at once, at the very bottom of the RPM range.

There is an ideal point when each motor phase is fired in relation to the rotor position. This ideal moment changes as RPM increases, so dynamic ESC timing is more efficient than static timing.

If you set your ESC to apply all the timing at 0 RPM, as if it was static timing like it would be if it was set from the endbell, they should, in theory, perform the same, but only can timing is allowed for spec class racing.

if you only want 20 d then go with the motor timing as the brakes will be better,tbf 20d isnt a lot unless your running a low wind mod motor

Consider this quote from the Novak website:

"The time required to attain the rotor position from the Hall Effect sensor is on the order of a few micro seconds. If a motor's rotor is turning at 80,000 RPM, that would be 1333 revolutions per second, or 1.33mS per revolution. Compared to a microprocessor running at 20MHz (or 26,600 clock cycles @ 50 nanoseconds per cycle), that is a very long time, which means that the microprocessor is capable of executing many instructions during that time frame."
Source: http://teamnovak.com/tech_info/view_article/24

Theoretically there should be no loss in timing with RPM increases. The example provided by Novak considers a motor at 80,000rpm, which in North America is very uncommon since we mostly all run some type of stock motor . A 17.5t spins about 17,000rpm +/- 2000.

So does that mean motor can timing is better assuming I want the same timing throughout the rpm range?