Motor timing

[gearhd48]

I know that with more timing advance comes more rpm and heat, less timing , less rpm , less heat. I'm have not seen any timing charts like they used to have with real cars, nor have I seen any Mfg suggested timing on instruction sheets with the motors. So is there a balanced timing degree of Tq & Rpm to start from? I know you have the two different windings, but does the manufacturer or motor size vary settings? Any info/ opinions or motor tuning tips would be appreciated!

[Fluid]

There can't be a timing sheet with a motor because the optimum timing varies depending on voltage and load....and ESC. Be aware that if you set a timing on the majority of ESCs it does not stay there. Most ESC software uses motor feedback to constantly change the timing advance to match what each ESC believes is best. So 15 degrees on a Swordfish may have different results than 15 degrees on a Castle or MGM. You have to try different settings with your setup.

BTW timing which is set too low can increase heat substantially. It is always a balancing act.


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[zooma]

There can't be a timing sheet with a motor because the optimum timing varies depending on voltage and load....and ESC. Be aware that if you set a timing on the majority of ESCs it does not stay there. Most ESC software uses motor feedback to constantly change the timing advance to match what each ESC believes is best. So 15 degrees on a Swordfish may have different results than 15 degrees on a Castle or MGM. You have to try different settings with your setup.

BTW timing which is set too low can increase heat substantially. It is always a balancing act.


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Can you or anyone else explain how the ESC manages the timing? What is it measuring? What is it varying? How does it do this dynamically during a run?

[Fluid]

Below is a comment from a Castle engineer on another forum. I had a more detailed one by the owner but can't find it right now...

Castle Creations ESCS use dynamic timing. The actually timing advance varies with the speed of the motor to maximize power/efficiency at any speed the motor is running. The 15 degrees our normal timing shows is only the middle of the timing range the ESC will use to run the motor. This is one of primary advantages of a sensorless system over a sensored system which has fixed timing. With fixed timing the motor will only be running at its maximum performance/efficiency with a narrow speed range and will fall off quickly below and above that speed. Castle Creations ESCS also compensate for motor inductance when setting timing advance. A high inductance motor will pull our timing up. Castle Creations


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[zooma]

Below is a comment from a Castle engineer on another forum. I had a more detailed one by the owner but can't find it right now...

Castle Creations ESCS use dynamic timing. The actually timing advance varies with the speed of the motor to maximize power/efficiency at any speed the motor is running. The 15 degrees our normal timing shows is only the middle of the timing range the ESC will use to run the motor. This is one of primary advantages of a sensorless system over a sensored system which has fixed timing. With fixed timing the motor will only be running at its maximum performance/efficiency with a narrow speed range and will fall off quickly below and above that speed. Castle Creations ESCS also compensate for motor inductance when setting timing advance. A high inductance motor will pull our timing up. Castle Creations


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Thanks. If the detailed one shows up, please post that too.

[Fluid]

Found it. This is from the owner of Castle from another forum, this is the best official explanation I have. . (I still use Castle controllers almost exclusively in my FE boats - my remaining HydraICE models, my water cooled aircraft models, and my fan cooled aircraft models.)

"The Castle controllers use a different timing scheme from other controllers on the market. This is why Castle controllers run motors cooler and more efficiently at partial throttles than most controllers. We have found from testing, that even though other controller manufacturers list timing numbers (in degrees) on their controller software, the numbers they quote have nothing to do with reality. They are just arbitrarily assigned advance numbers, and they change from motor to motor by a significant amount. Locking timing advance to an arbitrary advance number is useless anyway -- a speed control that locks timing advance to a specific number of degrees would be horribly inefficient across the control envelope -- it might work OK at full throttle, but partial throttle would be inefficient, or it might work well at partial throttle, but full throttle would be inefficient. In the Castle controllers, we use an arbitrary advance number -- but it makes more sense. The low numbers run near neutral timing, which give excellent efficiency, but not optimum power. The middle numbers give good power, with a slight decrease in efficiency. The high numbers give maximum power, with a larger decrease in efficiency. We don't rate a bogus "timing" in degrees, because the timing changes depending on the motor type -- we dynamically adjust timing based on the running parameters of the motor. Thanx! Patrick Castillo"

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[gearhd48]

Many thanks for taking the time to share this info! In my mind I kinda saw this answer coming but was hoping it not to be, so in essence there's a trade off in timing but no real numbers due to variables, so it's all trial and error to tune a system in, kinda like props! LOL.

[zooma]

Thanks, Fluid. But Patrick hasn't really explained how it works. The one thing he hints at is that the advance might be RPM or throttle position dependent, which I guess the circuitry can determine dynamically. I don't know when he wrote this. Maybe at that time Castle controllers were the only ones with an "automatic" setting. My two Swordfish Pros have an automatic setting. I am not trying to design my own ESC, just trying to figure out if the automatic setting is best for all my boats.

[Fluid]

He wouldn't describe it in too much detail due to propriarory concerns. The post was from 2009 and he did qualify it by saying "most controllers". I believe he was referring mostly to the vast majority of Chinese controllers flooding the market then. I don't think any of my Castles have an "automatic" setting...but I've never used it anyway. Newer controllers like the top end Schulze do not allow easy user setting of the timing, auto is default.


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