Outrunner Motor Timing Q's

[jeeeeeeright]

Thanks a lot. Do you know if the Flighttech "New Range" ecs's will be a better match for my motor. The local shop is only selling Flighttech equipment.

[scalefreak]

	Quote: Originally Posted by jeeeeeeright
	Thanks a lot. Do you know if the Flighttech "New Range" ecs's will be a better match for my motor. The local shop is only selling Flighttech equipment.

According to the specs, the new mosfets they are using are of a higher quality and the resolution should be much higher than the previous generation. I can't say for sure, but I would bet that the new line will fix your problem. Looks like they have a program card, also. I would definitely get one of those. That will open a whole new window for flexibility in the firmware of the ESC and allow you to tweak on the timing a bit more accurately. The frequency (PWM) is adjustable on the "New Range" ESC's, your motor will like a 8-16khz setting. It also looks like they are using Power Caps now (they may have been using them already??). If there were no power caps before that could possibly explain the problems you were having. The high frequency operation of your ESC creates a voltage ripple on the input side and the PC's will filter that out, increase your rpm's slightly and drop operating temps by 10 or more degrees, giving you an all around higher efficiency.


If you try one of the new ESC's let us know how it goes

[jeeeeeeright]

Will do. The prices here in Norway are however horrible... About $230 for the 80amp version, so this will blow a big hole in my "fun and games"-buget this month.

[migerthepimp]

well you see i used to have the same issue with my plane.... i had a axi 41/20/13 and castle creations 80. and i also messed with the timming to try to fix this, and nothing seemed to work! with my case it happened at exactly halve throtle... so one day my plane had a glitch on the ground and it ran in to a pole(prop broke).... so i put a new prop on it(about 2 inches smaller) and it turns out that my motor problems were being caused by over proping my motor! i did some experiments with this and it was very consistent! big props messed up my motor and smaller props dint..... and dont think you will lose power because a smaller prop, keep on going smaller untill your motor wont do that... with evry prop try changing the timing from all three and see with one is best untill you get it rite!

[migerthepimp]

	Quote: Originally Posted by scalefreak
	According to the specs, the new mosfets they are using are of a higher quality and the resolution should be much higher than the previous generation. I can't say for sure, but I would bet that the new line will fix your problem. Looks like they have a program card, also. I would definitely get one of those. That will open a whole new window for flexibility in the firmware of the ESC and allow you to tweak on the timing a bit more accurately. The frequency (PWM) is adjustable on the "New Range" ESC's, your motor will like a 8-16khz setting. It also looks like they are using Power Caps now (they may have been using them already??). If there were no power caps before that could possibly explain the problems you were having. The high frequency operation of your ESC creates a voltage ripple on the input side and the PC's will filter that out, increase your rpm's slightly and drop operating temps by 10 or more degrees, giving you an all around higher efficiency. If you try one of the new ESC's let us know how it goes

could you please elaborate more on the frequency of the esc...?
thanks

[scalefreak]

	Quote: Originally Posted by migerthepimp
	well you see i used to have the same issue with my plane.... i had a axi 41/20/13 and castle creations 80. and i also messed with the timming to try to fix this, and nothing seemed to work! with my case it happened at exactly halve throtle... so one day my plane had a glitch on the ground and it ran in to a pole(prop broke).... so i put a new prop on it(about 2 inches smaller) and it turns out that my motor problems were being caused by over proping my motor! i did some experiments with this and it was very consistent! big props messed up my motor and smaller props dint..... and dont think you will lose power because a smaller prop, keep on going smaller untill your motor wont do that... with evry prop try changing the timing from all three and see with one is best untill you get it rite!

The problem you were having may have been from over propping. Jeeeeeeright's proplem is from a latency issue with timing the motor.

You will lose power dropping prop size and you will lose power using to large of a prop. There are many ways to determine the correct prop size to use, the first being to follow the manufacturers suggestions. Slapping a random prop on a motor usually ends badly. I have burned up several 53 Series AXi's testing props static. Testing a motor static for long periods of time is also unhealthy for the motor. The problem you were having is because the high load of the large prop created an inability in the ESC to time the motor and you probably heard a screachin sound, or sounded like something was scraping. The noise is actually the motor and esc being way out of sync. A motor has the same to basic components as a speaker....a magnet and coil. The beeps you hear when arming your power system aren't coming from the ESC...the motor literally becomes a speaker when 2500hz pulses are applied to the motor.

[scalefreak]

	Quote: Originally Posted by migerthepimp
	could you please elaborate more on the frequency of the esc...? thanks

Not all esc's are programmable at this level, but the frequency (PWM or Pulse-Width Modulation) ultimately what makes your motor spin. ESCs pulse current to your motor in a binary (ON-OFF) manner. Changing the ratio of the ON time to the OFF time changes the speed of the motor. For example, at 80% speed, the current pulse is on 80% of the time and off 20% of the time. This cycle happens 60 times-per-second for low-frequency ESCs (60hz), approximately 3,500 times-per-second in high-frequency ESCs or through the spectrum on programmable models. The sounds heard from ( high pitch whining) a motor are always there, but the rotational noise at higher rpms makes the sound considerably less audible.

[tailwheelteacher]

i havent heard this question answered yet, what do i set my PWM to? 8 or 16? scorpion 3014-18

[scalefreak]

	Quote: Originally Posted by tailwheelteacher
	i havent heard this question answered yet, what do i set my PWM to? 8 or 16? scorpion 3014-18

16khz will be good. You'll get about 5% more power and a reliable startup. If you can adjust the timing advance with your esc, try the 15 degree setting (if you are using scorpions esc) or a setting close to that, but not over. Some motors will burp with a 15 degree advance and 16khz pwm on startup, but AXi's, XTRM's, Scorpions and a few others don't typically have that problem. Depending on your esc, you may get hesitation at startup. If you do, set your acceleration advance to .2 or .3 seconds.

[tailwheelteacher]

	Quote: Originally Posted by scalefreak
	16khz will be good. You'll get about 5% more power and a reliable startup. If you can adjust the timing advance with your esc, try the 15 degree setting (if you are using scorpions esc) or a setting close to that, but not over. Some motors will burp with a 15 degree advance and 16khz pwm on startup, but AXi's, XTRM's, Scorpions and a few others don't typically have that problem. Depending on your esc, you may get hesitation at startup. If you do, set your acceleration advance to .2 or .3 seconds.

right on, i set it to 16khz and 15 degrees and she runs smooth, the only problem i have now is that there is a dead band for about four or five clicks before the motor even powers up. i tried adjusting the endpoints the subtrim and all that but the esc just resets the dead band every time i hook it up.

[migerthepimp]

	Quote: Originally Posted by scalefreak
	Not all esc's are programmable at this level, but the frequency (PWM or Pulse-Width Modulation) ultimately what makes your motor spin. ESCs pulse current to your motor in a binary (ON-OFF) manner. Changing the ratio of the ON time to the OFF time changes the speed of the motor. For example, at 80% speed, the current pulse is on 80% of the time and off 20% of the time. This cycle happens 60 times-per-second for low-frequency ESCs (60hz), approximately 3,500 times-per-second in high-frequency ESCs or through the spectrum on programmable models. The sounds heard from ( high pitch whining) a motor are always there, but the rotational noise at higher rpms makes the sound considerably less audible.

thanks alot!

[scalefreak]

	Quote: Originally Posted by tailwheelteacher
	right on, i set it to 16khz and 15 degrees and she runs smooth, the only problem i have now is that there is a dead band for about four or five clicks before the motor even powers up. i tried adjusting the endpoints the subtrim and all that but the esc just resets the dead band every time i hook it up.

What are your options for timing advance?