I have been quite busy the last couple of days getting some testing done with the HobbyWing Platinum 40A ESC PRO I received a few days ago. I will warn you ahead of time, there are a lot of numbers being thrown around here and on the spreadsheet linked below, so towards the end I have tried to distill out what I think are the best settings for each ESC for the motor I tested today.
You can read more about my initial thoughts and initial testing with this ESC here at this blog post.
Yesterday, I decided to test several of the quad racing motors I have (a couple didn't get tested as they are in planes right now and I was a bit too lazy to pull them out 😳) I tested these motors with all the default settings just like I had tested the 2212/6 2200 Kv motor mentioned in the blog post above. I was quite surprised when the numbers were quite a bit lower than they were with the Turnigy Plush 40A ESC. Bit of a headscratcher, especially in the mid range power. You can read the numbers on my motor spreadsheet, click on the tab labelled Quad racing motors.
So I reached out to rcplanepirate to get some ideas why there might be this reduction in performance. He reminded me of a conversation we had awhile back that some experimentation would probably be required with this HobbyWing ESC as it has so many options for settings. He suggested trying different timing options and also switching the PWM frequency settings. So this morning I got some batteries charged, got out the thrust stand and away we went😊
The following texts are quoted from the HobbyWing ESC manual regarding timing and PWM frequency settings. As you can see, a lot of options for timing.
Timing: 0 degrees/3.75 degrees/7.5 degrees/11.25 degrees/15 degrees (factory default)/18.75 degrees/22.5 degrees/26.25 degrees.
Usually, low timing value 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.
PWM Frequency: 12KHz/8 KHz, default is 12KHz.
For some motors with high Kv (high speed) and many poles, the 12KHz PWM frequency may let them work more smoothly. But the higher PWM frequency will make the ESC hotter. Generally the 8KHz frequency is suitable for most motors.
Now, having read that, not to put my "whiney pants" on, but there are a lot of generalities there.😒 All the motors ran smoothly in the brief tests, so I'm not sure exactly what is supposed to happen when they don't run smoothly, might have to find that out in the air. Second, if the 8KHz frequency is suitable for most motors, why is it not the default PWM frequency?! Head scratching continues...you will see more what I mean later in this post😏
So to capture everything all together, I created a new page on the motor spreadsheet called ESC testing. I chose one motor, the Racerstar BR2406 2600 Kv as it is kind of in the middle of the pack of the quad racing motors I have tested thus far, bolted on a 6x4 APC prop and got to work.
I also decided to test this motor on the three ESC timing settings (low, medium, high) with the Turnigy Plush 40A ESC as I had not done that and was interested to see if there were any major differences. Interestingly enough, this is what it says in the Plush ESC manual about timing settings (nothing about PWM frequency, so I might have to try and research that a bit more).
Timing: Low/Medium/High (3.75 degrees/15 degrees/26.25 degrees), default is low.
Usually, low timing or medium timing is suitable for most motors. In order to get higher speed and bigger output power, please choose High timing.
Interesting, as you will see from my tests, no huge difference and in fact low timing is the best with this motor with the Plush ESC.
So with the HobbyWing ESC, I went through every timing setting initially with the default 12KHz PWM frequency.
Nothing really jumped out at me here, the mid range power was still significantly lower regardless of the timing setting with this PWM compared to the Plush 40A ESC on low timing. The Plush mid range thrust was still better than any setting by 12 grams or more. Full throttle settings were all relatively close, nothing that really stood out a whole lot as the timing setting rose, the full throttle thrust did increase until the top level of 26.25 degrees where it seemed to fall off a bit at both top and mid levels😐.
So then I started over, changing the PWM frequency to 8KHz. This is when I noticed a big change, especially at 50% throttle. Right away I noticed an increase in mid range power, even at the lowest timing setting. The lowest mid range power at 8KHz is still 10 gr higher than the highest result at 12KHz and it continued to climb steadily as the timing settings went up, peaking at 43 grams more than the highest mid range thrust at 12KHz. There wasn't as big an increase in full throttle power, 10 grams more thrust at full throttle at 8 KHz than at 12KHz at the maximum. Fortunately, at 8KHz, the best mid range and full throttle numbers are at 26.25 degrees timing.
Although there is not a huge difference at 8KHz between 22.5 degrees and 26.25 degrees of timing, at 26.25 degrees it produces a bit more top end thrust at 0.6 less amps drawn.
So looking at the Turnigy Plush numbers, at high timing it produced 3 gr more thrust at mid throttle, but less 10 gr less thrust and pulled 31.2A to do so. Looking at the numbers, I will stay with low timing for this ESC. In order to easily compare, here are the best numbers for the Plush ESC with timing at low compared to the HobbyWing ESC with it's best setup.
Plush
50% throttle - 11.5A/141.5W producing 487 gr/17.2 oz of thrust;
100% throttle - 29.8A/352.3W producing 935 gr/33.0 oz of thrust.
HobbyWing ESC with timing set at 26.25 degrees and PWM frequency set at 8KHz.
50% throttle - 12.3A/149.7W producing 508 gr/17.9 oz of thrust;
100% throttle - 31.6A/369.5W producing 948 gr/33.4 oz of thrust.
So while this process was a bit tedious programming the HobbyWing ESC using the transmitter between each test, I learned a lot and it was worth it to go through the process. Thanks again to RCPP for the tips and ideas.
The HobbyWing ESC does seem to allow the motor to wind up just a tiny bit faster than the Plush, although it is tougher to tell with the motor on the bench, field testing will be necessary to see if this converts into better acceleration. I have already put this motor in my "beater" RC Powers Su30 V4 and will do field tests comparing the Plush and HobbyWing ESCs on my next available flying day.
Park Jet noise...the "other" sound of freedom😎
Cheers,
Scott
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