Turnigy AE-45A ESC - testing timing and PWM combinations

Hi Everyone -

I have been catching up on some testing with the Turnigy AE-45A ESC the last couple days😊  You can read more about my initial impressions and testing with factory defaults and the 2212/6 2200 Kv motor at this blog post.  That motor performed very well with the factory defaults, however, as you can see in the discussion below, it took a little more research to find the right setting for a higher Kv motor.

Like I did with the HobbyWing Platinum PRO 40A ESC, I decided to run through the entire series of combinations of timing (8 different settings) and PWM (pulse width modulation) frequency (2 of those), so a total of 16 different runs to find the best combination.  I had wanted to use the Racerstar BR2406S 2600 Kv motor like I did with the HobbyWing test, but it wasn't running that great (problem now fixed and will be the subject of another article😏)  If you want to read about the advanced testing on the HobbyWing ESC, please go to this blog article.  For this series of testing, I used the Racerstar BR2306S 2700 Kv motor as it is quite similar in performance to the BR2406 2600 and is the same brand.

So here is what the manual says about timing.

Timing: 0/3.75/7.5/11.25/15/18.75/22.5/26.25 degrees, default is 15 degrees.  Usually, low timing is suitable for most motors.  But there are many difference among structures and parameters of different motors so please try and select the most suitable timing value according to the motor you are just using.  The correct timing value makes the motor run smoothly.  And generally, higher timing value brings out higher output power and higher speed.

So similar to the HobbyWing which also has 15 degrees as default timing, if low timing is suitable for most motors, why did they choose a setting almost in the middle as default?!😕  Also, if you don't have a thrust test setup, how are you going to know what timing will work best with the "motor you are just using"?!

Here is what the manual says about PWM timing.  Note that this ESC has 12 and 24 KHz as options, the HobbyWing has 8 and 12 KHz.

PWM frequency:  12 KHz/24 KHz, default is 12 HKz.  For motors with high Kv (high speed) and many poles, the 24 KHz PWM frequency may let them work more smoothly.  But the higher PWM frequency will make the ESC to be hotter.

Again, almost word for word to what the HobbyWing manual says😏

All the details are available here on my motor test spreadsheet.

For the sake of discussion, let's look at a few of the numbers.  Here is the performance with the Racerstar BR2306S 2700 Kv motor, 6x4 APC gas prop using the Gens Ace 2200 3S 45C battery.  Links to these can be found on the spreadsheet.  This motor based on the specs on the Banggood website is supposedly a 35A max load current motor, but that is based on their test charts, perhaps the motor can be pushed harder, but I used this number in decisions I discuss later.

Factory default (15 degrees timing/12 KHz PWM frequency)

50% throttle - 10.7A/133.6W producing 480 gr/16.9 oz of thrust;

100% throttle - 34.7A/399.4W producing 955 gr/33.7 oz of thrust.

Compared to the Turnigy Plush (factory default settings) and HobbyWing (with the custom settings), the 50% throttle power is about 25 gr lower.

As you will note on the spreadsheet, at times the high end thrust was up and down, but mostly in the neighborhood of about 955 gr or so regardless of timing or PWM.  One thing you can see with the 50% throttle thrust is that as soon as the PWM is changed to 24 Khz, the mid range power is much better until the timing gets to the two highest settings then it falls off considerably.  So interestingly for a higher Kv motor, I would not go with default PWM setting right away because of the increase in mid range power.  Although I do like to rip around at full throttle pretty regularly, I spend about 80% of my time at about 60% throttle, so best mid range power is important to me.

So after switching the PWM to 24 Khz, here are a couple of timing settings that stood out for comparison. 

Timing 3.75 degrees

50% throttle - 14.6A/176.5W producing 510 gr/18 oz of thrust;

100% throttle - 33.9A/397.6W producing 960 gr/33.9 oz of thrust.

Timing 15 degrees (factory default timing)

50% throttle - 11.3A/138.6W producing 510 gr/18 oz of thrust;

100% throttle - 35.7A/424.8W producing 955 gr/33.7 oz of thrust.

So keeping in mind what I mentioned earlier about my flying style, even though I would be drawing more amps for a little less (5 gr) thrust with the timing at 15 degrees, I would select that as my timing with 24 KHz as the PWM.  The reason being is that when I look at the 50% throttle setting, even though the thrust produced is the same, with 3.75 degrees as the timing setting, it pulls close to 30% more amps to produce this power!😲  Given that I spend about 80% of my time close to this throttle setting, the amp draw at mid range would be too high for my liking with 3.75 degrees timing.  I may experiment with this at the field, but will start off with the 15 degrees timing/24 Khz PWM combo.

Of note I think is that this custom setting I discovered produces almost identical numbers to the Turnigy Plush default settings.  The HobbyWing 40A ESC with the custom settings I found for that for high Kv motors produces more top end thrust, but about the same mid range as the AE and Plush ESCs.

So again, it was interesting testing.  I guess what makes me scratch my head again is that without a thrust test setup and watt meter, how is your average person going to find out these optimal custom settings that they encourage you to experiment with in the manual?😕

Field testing to start very soon😀

Park Jet noise...the "other" sound of freedom😎

Cheers,

Scott