Help with motor timing and PWM for KDE 450XF?

[kirby_]

I'm going to be using a HobbyWing 50A Platinum V3 with a KDE450XF. I'll be using the governor in my FBL.

For now, I'm looking for the longest flight times. I do some sport flying, and the occasional flip or roll. The specs for this motor say:
Timing: 5-15deg.
PWM: 8-32KHz

This ESC's timing range is 0-30deg, it's PWM range is 8-32KHz.

I've done a bit of reading and as I understand it, the lowest timing possible should give me the lowest current draw right? Given my goals, I think I should choose the lowest timing both the ESC and motor support, 5deg.

For PMW, I understand that a higher PWM can make the motor run smoother, at the expense of higher ESC temp. I don't know where I should set this. The HW ESC recommends 32KHz if using the built-in governor, I assume so it can react to changes more quickly, but I'm not sure if that's the right thing for my setup. I'm leaning towards setting the ESC to the lowest value the motor supports, 8KHz, but I'm not sure.

Any advice is appreciated!

[jmackey]

I recommend starting with the Hobbywing default values for timing and PWM. I've experimented a lot with this motor / ESC combo, and the default settings yielded the best balance of power, flight time and temps.

Great motor / ESC combo too. Enjoy!

[kirby_]

Thanks for the advice!

One question I have is more about understanding what various timing values do to a motor. If the motor specs say 5deg is the minimum possible timing, why isn't that the best value for longest life? As I said, I think there's some side effect of low timing that I don't understand.

[BP58]

I picked up the 1750kv version for my 360mm 450 and brought the laptop to the field. At the end of 15 hard sport/3d flights tweaking settings I went back to stock everything with 15 "low" for the Castle internal gov.

What I gather is that increasing gov gain and motor timing get you a small increase in peak performance at the cost of heat and amps. That mainly applies to timing.

I as well don't know if lowering timing has any negative tendencies. You can always try it at 5 because it is with in the specs.

I got a hunch that you are overthinking this as a new pilot. You won't notice much difference in flight times maybe 10 20 seconds after hours of tuning. Just go fly man.

[LoveToFly1]

a little over though here, yes, but good questions though! I will look for my email from Patrick explaining this, and I will post it.

timing being lower will give a tic less power, but with lower heat. probably will not even notice the power unless your flying hard 3D and a very experienced pilot.

gov gain is also a "feel" or "personal preference" thing. I like mine high as I can get it on my smaller helis, and a little lower on my larger ones. gov gain can shorten flight times also, using more power. most importantly though, too high of a gov gain can damage the heli.....so pic what feels good, and works well for your setup.

[LoveToFly1]

from Patrick to me about Timing.....

On Mon, Sep 22, 2014 at 6:07 PM, KDE Direct (Patrick) <patrick@kdedirect.com> wrote:
Hey Michael,

There’s a misconception in the market about timing and torque, and all of us have been confused by this (I was for years as well, until I collaborated with Castle Creations on some stuff). Basically, it’s just like car engines that dynamically change timing – higher timing increase HORSEPOWER, but not torque. Lower timing increases TORQUE, but reduces horsepower – it’s one of those fun dynamics.

So, if you want the most efficient RC Helicopter setup, it’s always best to lower-timing to generate more torque (and less heat), but gear it to have the governor-overhead you need to prevent bogging. It’s the opposite in Airplanes – as the RPM of the propeller is what creates thrust, and by increasing the timing – you increase the resultant RPM, so you make more power. It burns more energy in doing so (increasing timing ALWAYS reduces efficiency and makes more heat), but you can make more power and increase the RPM of the propeller. Increasing timing ALWAYS increasing motor RPM.

PWM is a whole different animal and would take me a chapter to explain, but essentially, 12kHz or 8kHz works great across the board.

Now, things are a bit different with YGE ESCs and each governor is different between brands. You can try increasing the timing to 18 degrees (the stock Outrunner setting) and see how you like it – it may or may not feel more powerful for you, but it will almost always make the motor run a bit hotter (and shorter flight time), and the generation of maybe more power. Try it – you may or may not find it makes much difference.

Timing is like the “fine-tune” dial on a radio – it changes about the last 5% of the performance of a motor.

Thanks,
Patrick
Owner, KDE Direct

[Xrayted]

Originally Posted by LoveToFly1

from Patrick to me about Timing.....

And is very point is demonstrated very well with my KDE 535G3 and my Castle ESC in my Goblin speed.

I started out using the default medium timing range in the ESC, and would pull 10-11,000 watt peaks in my speed runs governed.

I dropped the timing to low and got the exact same speed and performance, however my power dropped to 7-8,000 watts max due to the extra torque and being able to maintain RPM at high pitch values under load more efficiently.

The motor runs cool and all is great with the reduced power draws. Guys are always bragging about how many watts they are pulling as if more means better performance, but it doesn't if all that power is being wasted on poor governor management or heat.

Our helis need torque, and with the proper gearing (run the smallest pinion you can get away with for the governed rpm you want) and proper ESC settings, you can get a lot of performance with less power needed to do so.

High wattage draws alone does not mean you have a powerful setup, and might just mean you have a very inefficient setup instead

[LaDon]

That is exactly right. We run 2150 head speed on the fora 700. We use a castle 120 hv on it and only pull max amps of around 160 once in a while and max wattage of 5800 in a hard 3d flight. I have seen ppl bragging about pulling 10000 watts and the guy above is right. Horribly inefficient and pretty poor collective management also

[Xrayted]

This is also the core issue in the "gotta run crazy high HV setups for best performance" crowd.

It's always the same story......packs and ESC are hot, motor is hot, my X brand motor bogs, and on and on, but "I went HV and everything was so much better" therefore the assumption is its the higher voltage that cured it all. The classic causation equals correlation fallacy.

The real reason is because the higher voltage is just covering up a bad setup and poor collective management by reducing the amp draw and subsequent heat on everything that wouldnlt be there in the first place if geared and setup properly

I was warned the KDE is a powerhouse but runs hot by a few guys when I bought it. Powerhouse yes, not even close to hot. I'm 135-150F max in a fully enclosed speed canopy which is nothing. Packs come down barely warm as well, and it's un-boggable up to 16* pitch on 12S so far, holding within 50 RPM of set values using the lowly ESC governor even when pushed to the max on a speed run.

Anyone who claims you "need" 14S or more on a 700, or 6S on a 450 for a proper powerful and cool running sport or 3D machine otherwise doesn't understand gearing and ESC setup for the RPM they are running.

[LaDon]

Perfectly said. We still run 3s on the forza 450 and it will rip the sky up