Hot 850Mx, 170f!

[Heli$]

Flew my 700 L Top kinda hard today practicing aileron tic tocs and other power demanding maneuvers. After the flight, I could smell a faint electric scent. I temped the top of the motor and it was around 170 F. Yikes! I always work on collective management but learning new maneuvers I'm not efficient till I get them down. Also, the esc was warmer than normal, max at 120 F.

I set the castle edge 160 esc to the appropriate timing and frequency but I'll double check tomorrow.

What are you guys getting good results with settings of the 850 mx?

Temp of the engine before flight 80 F
Flying at 5500 ft
2000 rpm
7 min flight, packs at 25%.

[RC/DC_5000]

That is warm but its actually not out of specs. IMO, 12 pwm is where the Align motors work best and you could try reducing your timing slowly to bring your motor temps down. If you're governed- make sure your govenor gain is high as possible.

I know everyone wants to advance the timing to get more and more power.. but if you compare two logs back to back. One log at 0 timing and one log at 10 timing- you'll have a better idea of how the motor is actually hitting. You want big, broad peaks of power. Compare the peaks and valleys between the two logs and make your own adjustments from there.

FWIW, Align has posted in manuals that their motors have the most torque at low or normal timing. After comparing my logs... I'd agree with them.

[Heli$]

Thanks RC/DC! I checked the timing tonight and it's 5 which is where I'll leave it. The PWM was at 12 and I'll leave it there to.

I'll crank up the gain on my Vbar and see how it goes next time.

[RC/DC_5000]

I'll also say that advancing the timing does not make any "more" power... it just changes the RPM at which it hits. So it may feel like you're making more power because you moved the peak into your range of operation.

Our task as hobbyists, is to find out where to move the power delivery to our utmost advantage.

[Heli$]

Good info RC/DC. If I do anything with the timing it would be bringing it to 0. Motor has lots of power.

Thanks

[Thestructured]

What's your max pitch?

[Heli$]

Pretty sure it's 13 degrees in the vbar software

[K2Freak]

Pretty sure it's 13 degrees in the vbar software

But set properly on cyclic tab to get 8 degrees, right? (Just checking.)

[Thestructured]

I'd check it with a gauge if you haven't to make sure it's not something much higher. That could be your elevated temps, but maybe not. If you didn't change anything and are getting higher temps out of nowhere then I have no idea.

[Heli$]

Pretty sure it's at 13. I use a digital pitch gauge. I'll double check though

8 degrees on the cyclic

[isogloss3d]

Originally Posted by Heli$

Flew my 700 L Top kinda hard today practicing aileron tic tocs and other power demanding maneuvers. After the flight, I could smell a faint electric scent. I temped the top of the motor and it was around 170 F. Yikes! I always work on collective management but learning new maneuvers I'm not efficient till I get them down. Also, the esc was warmer than normal, max at 120 F.

I set the castle edge 160 esc to the appropriate timing and frequency but I'll double check tomorrow.

What are you guys getting good results with settings of the 850 mx?

Temp of the engine before flight 80 F
Flying at 5500 ft
2000 rpm
7 min flight, packs at 25%.

Yeah 160 deg F feels really hot but it's still within acceptable range, especially with ambient temps in the 80's. I'm basing this off conversations with reps from KDE and Scorpion. My KDE 600XF 530kv regularly comes down at 160-170 F. I'm also running it on a castle esc with low timing and 12khz pwm. My flying is nothing extreme, just moderate 3D (at best) with 13 deg on collective, 10 on cyclic at 1950 rpm.

[Heli$]

Great, I'm glad nothing is wrong I hope. My only other big heli's (x5) motor always comes down warm so that's what I'm used to.

I also checked the castle esc logs and didn't see anything extreme. Amps sometimes spiked to 120 ish and esc temp around 130. Voltages looked good to.

I also took off the main blades to see if the drivetrain turnes smooth and it does.

Thanks

[KSHeli]

According to CC as long as your temps are below 220F they are within specs, so at 170F you're still good.

[Heli$]

Great!

[JohnC1988]

My 850mx comes down so hot you cant touch it , every time I fly .
I bought a little handheld fan from Walmart and I cool the motor down in between flights on hot days now . But even if I didn't use the fan I still have too many flights on the motor that every flight it was HOTT !! So I wouldn't worry . My 160 CC always comes down pretty cool or slightly warm . My settings are the align ones only with my choice of head speeds.

Thanks JohnC

[Excalibur3]

I was told to run 10 degrees instead of 8

Trex700Pro/Trex700LTop/Trex500L/14sgh T$3D

[semperfib400]

I've got about a dozen or so really easy flights on my 700L and the motor comes down hot no matter how easy the flight is. I've got my timing set according to the settings from aling. 12 Khz.

I tried reducing the gov. gain in my IKON since I'm using the IKON gov.. but that didn't help.

I saw one post above that increasing the gain would help make it run cooler?

From the other posts I'm starting to think these hot temps are just normal for this motor? Everything else comes down cool.

[Heli$]

Lower head speeds usually run things hotter but I'm at 2000 rpm which isn't all that low. The engine just runs warm I guess.

Maybe 2300 rpm it would run cooler? Not gonna try it though since I'm having a good time at 2000.

[RC/DC_5000]

Higher governor gain will absolutely run cooler as the ESC will be more aggressive to add throttle instead of letting the motor load up, bog down and draw excessive current. Its the excess current that gets the motor hot. Motors will draw more current under load especially when you can't add any more voltage.

When you add "throttle" you are really opening the gate to allow a more continuous flow of the max voltage into the motor. There really is no such thing as "throttle" in our application. Its just an informal name for controlling the power and speed of the motor. The ESC takes 50.4 volts, breaks it up and zaps the motor in variably delayed sequence along three wires. The more "throttle" you add, the closer you get to zapping the motor with all 50 volts. At 100 percent "throttle" the gate is wide open and max voltage flows in. Max speed, but also max power and torque.

When you leave the motor to deal with helicopter pitch loads without adding throttle- you are due for higher temperatures. A low governor gains acts more like a flat throttle curve- not adding throttle when required. So under a load the motor will draw more current.

As Heli$ said, the lower headspeeds heat up more- using less "throttle" and thus, a more pulsed and broken up flow of 50 volts. You want to use as much of the available voltage as possible to do work- because- voltage is an electromotive force.

Which is better to do work... using 70 percent of your max electromotive force... or using 100 percent? Thats what the ESC is pulsing out. And a higher governor gain is more aggressive to pulse out that force when needed.

[semperfib400]

Originally Posted by RC/DC_5000

Higher governor gain will absolutely run cooler as the ESC will be more aggressive to add throttle instead of letting the motor load up, bog down and draw excessive current.

When you add "throttle" you are really opening the gate to allow a stronger flow of the max voltage into the motor. There really is no such thing as "throttle" in our application. Its just an informal name for controlling the power and speed of the motor.

When you leave the motor to deal with helicopter loads without adding throttle- you are due for some high temperatures. Turn you governor gain way down and fly it hard to find out if you'd like.

I think I try increasing the gain and see what happens!