Originally Posted by bobepine

Would these calculations not also point to imminent smoke running 20 amps ESCs with 2208s/1800kv motors? So why they work?

When I first started building quads, I was using F20 amps ESCs from Hobby King with RCX 2822/1800kv and even 2822/2600kv.

Back then people were complaining about high KV and amps draw making these setups not really flyable... People posting links of ecalc and rolling eyes were common. But many of them still fly fine today with this setup. And nowadays, fast setups usually have high kv motors.

In any case, I am sure that with the right ESCs, these motors would outperform the 1400kv motors you use, even if you run them on 6s... I could be wrong, though.





These were developed by TMotors for Armattan but it is actually something our reseller on Amazon is working on. And yes, the techs at TMotors were giving me strange looks when I asked for 2212 running 2212kv. (They are actually 2200s with 20kv + or - tolerance) but we named them the 2212/2212 for cool marketing purposes.

I only have 4 samples in my possession. Not what I will use these guys on yet.

Best,
Chris

They look like awesome motors Chris.

What size props and batteries were you using on the 2600 KV motors?

A lot of these calculations and numbers are theoretical because they are based on full throttle and static loads.

In real life nobody flies at 100% throttle all the time and the props unload significantly when the quad is allowed to climb rapidly during a full power application. (i.e. less force required to rotate props means less power required from the motor, esc and battery)

A set up that might cook on the bench in 60 seconds at 100% throttle could be fine for years when flown normally on a quad.

A perfect example is the 350 QX - if you hold this thing in your hand and apply full throttle for 30 seconds you can smell the motors and they are so hot they will burn you. In flight, flying it hard for 10 minutes the motors come down cool.

Rob, thanks for the explanation, this is very useful.

I agree, all this math, at the end of day, does not really matter, what matters is how the quad flies.

Originally Posted by Rob2160

They look like awesome motors Chris.

What size props and batteries were you using on the 2600 KV motors?

A lot of these calculations and numbers are theoretical because they are based on full throttle and static loads.

In real life nobody flies at 100% throttle all the time and the props unload significantly when the quad is allowed to climb rapidly during a full power application. (i.e. less force required to rotate props means less power required from the motor, esc and battery)

A set up that might cook on the bench in 60 seconds at 100% throttle could be fine for years when flown normally on a quad.

A perfect example is the 350 QX - if you hold this thing in your hand and apply full throttle for 30 seconds you can smell the motors and they are so hot they will burn you. In flight, flying it hard for 10 minutes the motors come down cool.

Back then I was using 2250s 3s, 40c, on CNC and M models with 8 inch props. 2822-2600Kv. Ecalc screams at you for doing this to 20 amps ESCs. But it works. Look at skull flying his tricopter with 8 inch on 2600KV. Ecalc not liking that, either.

Armattan 355 Tricopter Acrobatics (6 min 6 sec)

I'm not saying anyone is wrong. But I had the very same conversation with my US re-seller about this. TMotors found it a very unusual list of requested specs for this motor. But our reseller insisted equipment is pushed to the limit on many setups such as 1306 motors on 4s. On paper, it's not recommended. But when tested it performs awesome.

He has a niche market in mind, obviously, so I look forward to hear from him when he runs his own tests. I think he will shed much light on the motors performance and perhaps, limitations, too.

Best,
Chris

Originally Posted by bobepine

Back then I was using 2250s 3s, 40c, on CNC and M models with 8 inch props. 2822-2600Kv. Ecalc screams at you for doing this to 20 amps ESCs. But it works. Look at skull flying his tricopter with 8 inch on 2600KV. Ecalc not liking that, either.

https://www.youtube.com/watch?v=6CSOq1RPupE


I'm not saying anyone is wrong. But I had the very same conversation with my US re-seller about this. TMotors found it a very unusual list of requested specs for this motor. But our reseller insisted equipment is pushed to the limit on many setups such as 1306 motors on 4s. On paper, it's not recommended. But when tested it performs awesome.

He has a niche market in mind, obviously, so I look forward to hear from him when he runs his own tests. I think he will shed much light on the motors performance and perhaps, limitations, too.

Best,
Chris

That is a great demonstration Chris and it proves that calculations and stationary bench tests don't always paint the full picture.

At full throttle in flight these machines move incredibly fast and that unloads the props big time and also keeps things cool.

Look forward to hearing more about these motors. I can already see an upgrade for the 355 V-tail on the horizon....

Wow, I would have never thought that would fly so well.
You totally convinced me, I am dying to try it now.

Here is a flight log from today.
Taranis records up to one data point every 0.1s (10Hz) so it is missing the current peak sometimes during reversal.
With my current setup:
Motor: Sunnysky 2212 1400kV
ESC: Afro 30A OPTO
Propeller: LEAP 450 3D
Battery: 4S 1800mah
(Benchtop static trust is 26A)

Vertical Punch out pulls up to 75A
Horizontal Punch out pulls up to 65A
Reversal pulls up to 50A

Originally Posted by codepox

Vertical Punch out pulls up to 75A
Horizontal Punch out pulls up to 65A
Reversal pulls up to 50A

Attachment 8179666

It isn't that much really, 250 mini quads are often pulling more.

Originally Posted by QuadsD

It isn't that much really, 250 mini quads are often pulling more.

Yes, you are correct, but this is still a decent load.
My lower C batteries are hot after a flight, not alarming or burning hot but definitively hot.
Actually, this is probably too much for my Glacier 4S 1800mah 30C because after about 20 charges they feel now soft after every flight, they are like a little bit puffed but it goes away when they cool down.
The Pulse 4S 1800mah 35C seem to hold better.
I started to use some Tattu 4S 1800mah, they have more performance, especially at the end of the flight, and they are just warm after the flight.

Also it is interesting to notice that with a power system pulling ~26A on the bench doing a static trust test which should translate into 26x4 = 104A total.
I only measure ~75A max in flight, this confirm what Rob was saying before about the propellers unloading in flight.

Originally Posted by codepox

Here is a flight log from today.
Taranis records up to one data point every 0.1s (10Hz) so it is missing the current peak sometimes during reversal.
With my current setup:
Motor: Sunnysky 2212 1400kV
ESC: Afro 30A OPTO
Propeller: LEAP 450 3D
Battery: 4S 1800mah
(Benchtop static trust is 26A)

Vertical Punch out pulls up to 75A
Horizontal Punch out pulls up to 65A
Reversal pulls up to 50A

Attachment 8179666

Hey codepox - are you sending accelerometer data as well? I'm curious as there are no plateaus in the data you are graphing..

Originally Posted by SystemsGuy

Hey codepox - are you sending accelerometer data as well? I'm curious as there are no plateaus in the data you are graphing..

Yes, I do, I added the graph in my previous post.
What do you mean by there is no plateau?

Originally Posted by codepox

Yes, I do, I added the graph in my previous post.
What do you mean by there is no plateau?

I would have expected to see you hit a plateau / flat line on current on a punch out - eg motors at 100% draw of battery capacity, and that it would have lasted more than .1s?

I'm going to go capture some blackbox just out of curiosity now - well, that and as an excuse to fly ;-)

Originally Posted by SystemsGuy

I would have expected to see you hit a plateau / flat line on current on a punch out - eg motors at 100% draw of battery capacity, and that it would have lasted more than .1s?

I'm going to go capture some blackbox just out of curiosity now - well, that and as an excuse to fly ;-)

The logs miss sometimes the peak of the motor reversal when I flip the quad because the motor reversal is very fast ~0.2S.
But they don't miss the punch out which last more like 2 seconds, my punch out are pretty small, I could do longer ones, but the quad gets so small so fast and my eyesight is not what it use to be.
You don't see the plateau because the logs are zoomed out and you see the all flight, I attached a zoom on a couple of punch out where you can see the plateau with the throttle pegged.

On the log, it nice to see the initial current peak, then the current decrease as the quad pick up speed and the propellers unload.

The Autoquad team is just releasing the new ESC32V3.
The ESC has talking capability, pretty cool, check the video.
I like the realtime telemetry over CAN feature too, I am looking forward when Cleanflight will have support for CAN, much faster and low latency than SmartPort.
But it does not look like the ESC32V3 supports 3D mode.

00055 (0 min 33 sec)

Originally Posted by codepox

The Autoquad team is just releasing the new ESC32V3.
The ESC has talking capability, pretty cool, check the video.
I like the realtime telemetry over CAN feature too, I am looking forward when Cleanflight will have support for CAN, much faster and low latency than SmartPort.
But it does not look like the ESC32V3 supports 3D mode.

https://www.youtube.com/watch?v=pxS4nKm0ha4

I go flying to get away from the nagging! Between my Pixhawk and Taranis and now talking ESCs I'm beginning to think I may not bother!

Originally Posted by chris jones

I go flying to get away from the nagging! Between my Pixhawk and Taranis and now talking ESCs I'm beginning to think I may not bother!

Good point.