Help With Motor Timing and Poor Throttle Response (Gecko 120HV)

[gyro]

I changed all that I know, fixed end point, down graded fw to 3.27, response fast, no bake, auto lipo 3.2. I didn't adjust the timing.

Are you saying I can squeeze more power with ESC settings?

Castle ESC deliver less power to the motor.
I've come to this conclusion based on my tests and observations of others.

You'll never get as much power with the same prop/batts on castle when compared to a ZTW.

But, you may get better response it seems

 

[Aeroplayin]

You may know this already, but for the benefit of others reading this that may not understand what's going on....

The timing on Castle Ice2 ESC’s is automatically determined by the ESC. The setting choices on Castle Link are for a dynamic range for the advance and retard settings according to RPM. Expanding the range too much will produce more heat than performance gains. It is possible to get a complete shutdown on motors that inherently run hot. So for 3D applications, and especially Hacker motors in 3D applications, the low setting are recommended by Castle, and I'm sure Steve at Castle would agree because he's the one that told me this.

Motrolfly motors do run a bit cooler so this is not a concern to us, even here in Florida with those motors.

Another thing about the Ice2 as far as acceleration and timing is that the older firmware versions work better. Many of the guys I talk to about ESC performance agree that 3.27 works better with 28 pole motors, which I have confirmed, and 4.02 works better with 14 pole, which I have not confirmed just yet. I'm actually running 3.27 on a DM4330-206 with a 21x8 and getting 3110W peak, so I have no plan to change anything.

Also, I watched the video, and you may want to try putting your throttle at the mid-point before connecting power. When you hear all the cell count beeps, advance to full until you get the signal that the ESC has recognized WOT, then pull all the way back until you get the signal that the ESC has recognized off, and is armed. Now there is no question that the ESC knows where off and WOT are.

As far as programming a throttle curve, we usually start with point [1] 32%, [2] 42%, [3] 49%, [4] 61%, [5] 75%, [6] 100% or something like that, to get the mid-range a little flatter for hovers and harriers, which is like having a little more exponential right around the middle. My Tx is an older 9303 so I'm not sure how you'd do that with Futaba.

 

[gyro]

Jim, any idea why some ESC tend to put more power to the prop than others?

 

[Aeroplayin]

I don't know enough about how each are programmed, and can only speculate. What makes it worse is that it seems to be a mystery to anyone I ask, regardless of their involvement with ESCs.

But, from all the testing we've done, I can't use measured Watts as a measure of power. First of all, it not measured. It is calculated from the measured voltage and current. Second, it only addresses power into the system, and not the power needed to rotate the prop. That's Watts-out, which can be calculated using the RPMs and the prop specifications and load constants.

So if I say I'm getting 3100W peak off the log data, and someone says they are getting only 2500W off their meter, then this is really not comparing apple to apples. What we need to do is compare RPMs in a static test, and as long as we compare results at a comparable air density, on the same motor, with the same batteries, and know the real time voltage, the ESC that swings the same prop faster with all these factors being relative, wins.

With a 216Kv on 12S, a 59g 20x8 PJN will do 2900 to 3140 Watts-in at between 7800 and 7990 RPMs in static testing (not flight data). I'm peaking at 7969 RPMs on the Castle log, but most of the early readings are in the 7850 range. I've testing this with the tach at the same time and the readings are close enough for me. Some guys are reporting seeing just over 8000 RPMs on their tach with the Ice2 and Ice Lite, and I've seen 7990 off my Mezon 95 OPTO.

This also happens to be between 21.4 and 21.7 pounds of thrust at this RPM level (and I'm at an air density of about 1.1 Kg/m3)

 

[Aeroplayin]

BTW - that 3000 Watts-in really calculates to about 2550 Watts-out, which is about 3.4 HP. Pe Reiver's thrust calculator will say 20.4 pounds of thrust because it uses a function of 6 pounds per HP, but I use a formula that adds a prop spec variable that brings it more in line. So the same HP on two different props could actually produce different thrust measurements. I've also found that RPMs will change load constants too, so I adjust for that. My prop constant for a 20x8 PJN is 1.023 at 7840 RPMs, so a 20x8 PJN will need 2546 Watts-out, or 3.4 HP at the shaft, to spin that fast.

 

[AKfreak]

When you say, "Watts out", you mean Watts that I would read on my watt meter?

 

[gyro]

I think he means watts to the prop, as measured by calculating rpm and efficiency. It's not something you can measure on a meter IIRC.

 

[FlyMike1]

I read this from the beginning and I had seen what you were talking about in you video. I have two planes with the 125A. In St George I will show you how mine spools up fast with 20X8 Xoar props. My planes seem to have more power but its hard to tell that just from the vid. Someone will have a RPM meter and I would like to see what mine are pulling. Motor is Motrofly 4325, See you there

 

[AKfreak]

I read this from the beginning and I had seen what you were talking about in you video. I have two planes with the 125A. In St George I will show you how mine spools up fast with 20X8 Xoar props. My planes seem to have more power but its hard to tell that just from the vid. Someone will have a RPM meter and I would like to see what mine are pulling. Motor is Motrofly 4325, See you there

I will be there Saturday for sure. I can't wait to see your setup. I am sure my current setup is going to fly great. It flew ok with terrible throttle response, but now all of that is history.

 

[Enterprise]

I noticed on the bench yesterday with no prop on, that there was a lag in the spool up power given to the motor. With no load, it should be pretty quick and it was not. I will have to see how it work in the air. I tried changing the start power, but that just changed the initial power boost, and not the throttle response. My guess is it is a "feature" to prevent commutation. Since I am using a Hacker A60-8S, Castle controllers are not a viable option. I would have to get a Mezon or another Scorpion Commander.