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

I used the beta software on my 150HV and had a ESC failure. Garret is looking into it with ZTW, but no word back yet. The throttle response was better and I am not going to say that the failure was directly the fault of the software. The update was for the HVs only as the others seem fine.
 

Aeroplayin

70cc twin V2
Can I ask what size and make prop you are using, the motor, and how many cells?

Commutation is all about the instant torque brushless motors produce on instant throttle up, especially in high inductance motors, like the 28 pole variety. Timing is determined by the ESC from reverse voltage coming back from the rotating motor during the off switching episodes because the motor is generating voltage. This is measured, and rotation is calculated, and the ESC attempts to sync the voltage-in with the voltage-out.

The problem with motor torque, is that it is inversely proportional to RPMs, and so the most torque is produced to get the motor rotating. Since volts is the EMF (electromotive force) or the pressure of the power supply, and Amps is the current, or the rate of power flow, when instant torque is applied, the flow is increased and the pressure is decreased -- so the Amps spike and voltage sags. As the voltage sags, it also means there is reduced voltage available to the ESC to match up to the reverse EMF.

When we went to 12S systems on 10S motors, adding more voltage adds more initial rotation speed requirement, and torque is increased proportionally. I did once put a CapPack on a system I was having timing issues with, since adding capacitance should help the instant voltage requirement. But I never really tested the system both ways so it's tough to know what really happened. CapPacks can't hurt, and are probably one of the best things you can do for your ESC. I've not had timing issues for a while since I stopped over-propping my systems, and started selecting the right motor instead, but I do wish I knew definitely if the capacitors actually helped.
 

zmonster97

Member
Motrolfly 4330-400kv, xoar 19x10 prop on 6s. Ive used this combo for almost two years now and its worked. I just switched to a ztw gecko due to the recent esc frying. (I think the caps broke off)
 

Aeroplayin

70cc twin V2
Yeah, that should not be a problem then. You're max Amps is no where near 125 with a 19x10 on 6S with a 400Kv. I keep wondering if the wrong, or bad, capacitors are the problem with some of these issues. Increasing the capacitance is one way to try to fix it, the other is to reduce the inductance, by putting the source wires (battery and ESC wires) as close together as possible and keeping them as short as possible. You don't have any extensions on the source side, right?
 

AKfreak

150cc
Did you set the endpoints correctly to arm the ESC? I know I had a,similar problem. It was something stupid that I figured out. Is yours the HV?,
 

zmonster97

Member
No extensions. And yes, I set the endpoints. I dont think I should have to add caps just to get it yo work when other esc will work without that.
 

Aeroplayin

70cc twin V2
I agree 100%, and there is nothing more frustrating than an ESC that can't handle timing when others can. I only two brands now and eliminated the problem using props that are recommended for the motor. If the connectors have a good solder joint, then I'd send the ESC back.
 

AKfreak

150cc
I know this is going to sound stupid, and you most likely already have it right, but you do have a RX battery pack powering your receiver right. You know there is no BEC in the ZTW HV ESC's. I will be honest, that got me when I first used one of these VS a Castle.
 
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