head speed

[anthony1]

i'm running my v2 pro with an ice lie 50 governed to 2900, 3000,and 3100, the heli flies better with 3100 and i was wondering if i should get rid of the governor and run a higher head speed, opinions please

[SeanM]

It all boils down to personal preference if you ask me.. Higher head speeds will always yield more stability and response.. but it will also impact your flight times quite a bit obviously. Whether the performance gain is worth it for your flying style is up to you.

As for the governor... I too am using the ICE lite 50, but on 6S with the 450MX 1700kV motor. I did have to do a little fiddling around in order to get the motor to maintain a fairly constant head speed during high load situations, but I eventually got it dialed in with the PWM frequency maxed out at 24 kHz and 7 for the timing. I ended up maxing out the gov with a head speed of 3200, which will be the same for the 3400kV motors on 3S.

I believe the tail behaves better when it can rely on a constant rotor speed. From my experience, bogging the motor can lead to a tail blow out.

[anthony1]

i think i have mine set as an outrunner and low timing, what changes do the pwm and timing make , what do i look for, i notice bogging in high stress manouvers

[SeanM]

I think that PWM frequency stands for Pulse Width Modulation. If so, then I believe that would be the rate at which the ESC sends pulses of power to the motor. The higher the rate, the shorter the time between each pulse. I decided to raise the frequency because I noticed that the ESC seemed to lag behind when the load was changing.. especially between positive to negative pitch maneuvers.

I'm afraid that I don't quite understand the motor timing aspect of it. I just raised the value, while keeping a close eye on the ESC's and motor's temps. Once I started getting noticing less head bogging during high load maneuvers, I stopped. I suggest changing one value at a time so that you can better understand how the changes impact the performance. I did notice an increase in the temp of the ESC after a flight, but it never got hot. Even with it under the batter tray, with a battery strap over it. Keep in mind that running on 6S makes the system run at fewer amps, so the ESC will get much warmer on 3S.

[anthony1]

thanks i will give that a try, how do you like 6s? what are the advantages and as i already have the ice lite 50 would that just mean a change in motor?(and batteries)

[twentyafter]

I have read several times on these forums that you should not have it set to outrunner mode, that is for planks only. I do not know the reason behind this.

[SeanM]

The power and efficiency of the 6S setup is impressive. After breaking in my 6S packs, I could really notice the difference in power. It just doesn't bog like it did on 3S. The headspeed still drops a tad sometimes, but that can be controlled with collective management for the most part.

The effeciency of 6S is most obvious when charging the packs after a 4 min flight. This same flight time used to consume over 1500 mah on 3S, but on 6S it only consumes about half that. This makes charging faster too. I can charge my 5C packs in 13 min if I'm in a rush.

[RedOctobyr]

Originally Posted by SeanM

The effeciency of 6S is most obvious when charging the packs after a 4 min flight. This same flight time used to consume over 1500 mah on 3S, but on 6S it only consumes about half that. This makes charging twice as fast too. I can charge my 5C packs in 13 min if I'm in a rush.

Yes, but I would expect the mAh used from a 6S to be around half that of a 3S, right? For the same total energy (in terms of something like watt-hours, or mAh * volts), the mAh will be cut by half when you double the voltage.

That doesn't mean you're using any less energy. If you want to look at *energy* use (vs just current), you need to look at mAh times the voltage.

In terms of charging faster, it's a smaller mAh you need to put back into the battery. But I'd imagine you're maybe using, say, 1100mAh 6S batteries, vs 2200mAh 3S batteries. So in terms of the C rating of the battery, a 1C charge for 6S is 1.1A, vs 2.2A for 3S. Charging at half the amps, but for a battery with half the capacity, is still the same in terms of C.

Don't get me wrong, I'm not saying 6S is bad (it sounds pretty cool, and the lower current draws will lose less voltage to resistance in the wires). Just that I'm not sure that the difference in mAh draw points to 6S being twice as efficient.

[SeanM]

I completely agree with what you're saying, except for the part about charge times. I should have probably mentioned that I'm charging 6 packs in parallel. So a 5C charge rate on 3S would be 11 amps per pack, and 66 amps total for my needs. My PL6 can't go above 40 amps, nor can any other charger for that matter. However, being that the capacity is almost half on 6S, I can charge my 1200mah packs at 5C.. Or 36 amps. That's all I was getting at...

As for the effeciency aspect of it, I know that you can't expect the 6S setup to be exactly twice as effecient. There are plenty of other factors involved that impact the theoretical calculations. I'm just trying to put it into perspective for those that don't know exactly what to expect.

[RedOctobyr]

Ahh, I see what you mean, sorry. I only have a 106B+, but the 10A limit that seemed so huge with 1S 300mAh mCP X batteries is now sounding a lot smaller, with 3S 2200mAh I will be current-limited at 10A, and will only be using around half of my 250W limit. 10A will get me (4) 3S 2200 batteries in parallel at 1C.

If this becomes a problem, I could go to a 206B (20A limit).

Or, I could buy a second parallel-charging board, and wire it kind of in series with my current board. Make/buy an adapter cable to let me go from the 6S balance plug on my charger, and split it out to 3S going to the first parallel board, and the "second" 3S going to the second parallel board. Each board would now only be wired to do 3S batteries, max, but since that's the biggest I have, that would be OK.

I believe the charger would now see the two boards, each with at least one 3S battery attached, as a 6S setup. Now I can basically max out both my 10A *and* my 250W limit at the same time. It's kind of a series-parallel setup.