Is somebody riding in duty cycle mode?

#41

but with his gearing, the no load speed is where the red line crosses above the yellow line in the top left chart

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#42

With no load at 9% duty cycle the board accelerates to 100% max speed. That’s kind of annoying.

#43

Huh. You’re right. I don’t get it either then.

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#44

recomendation: the vesc 300/75 should allow 100a motor and 100a battery, giving consistent max torque across the full speed range (if you must retain the 100a motor current setting, and want consistent throttle range)

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#45

Our VESC allows 200A that’s not the problem. We use 120A per VESC ATM. But never pulled more than 114A bar total.

#46

the problem is i suspect the 6.6 only allows 60a from the battery, so you’re only getting the 100a motor current at the low end of the speed range (look at the motor current - blue line, top left chart), but not the higher speeds, even though your 100% throttle corresponds to 100a at all speeds, you aren’t getting it at all speeds

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#47

Why is that an issue? There’s no load? A car can get to top speed with 10% throttle while sitting on jack stands. Doesn’t seem relevant no offense. In the history of motorized things, throttle has always controlled power, not absolute speed. To me it makes less sense for x throttle to match x speed, that means the ESC has to constantly adjust power by itself based on terrain and conditions. To me it sounds like there is less user control that way.

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#48

You might be right. Like I said, maybe it’s just me, but I prefer how the other remotes work that I’m used to. It is intuitive to get 50% power while using 50% throttle for me.

#49

Correct, but 50% power does not mean 50% speed. 50% power could mean 10mph or 50mph depending on whether you’re going up or down hill.

Edit also I think you keep crossing “power” with “speed”. Power is only really refering to how many Volts x Amps the motor sees, no relation to how fast it spins

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#50

I think it has nothing to do with max provided current or whatsoever.

#51

current control mode throttle controls torque and motor current… but when the battery current setting is less than the motor current setting (in this case you can’t go higher than 60a bat even if you want to), then you won’t get the same amount of motor current or torque at the higher speeds that you can get at the lower speeds (because it would exceed the 60a battery setting), even though at all speeds the throttle corresponds to whatever the motor current limit setting is set to… if you want consistent throttle (torque) at all speeds, then you need to lower your motor current limit setting to 60a while retaining the 60a battery setting, because you can’t raise the battery setting higher than this. or switch to a different controller that allows a higher battery setting such as the vesc 75v/300a

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#52

I’m getting the jist that what he wants is 100% throttle = 100% speed, 50% throttle = 50% speed. Regardless of terrain or conditions, so basically he wants the throttle to be more like variable adaptive cruise control than current control.

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#53

duty cycle mode would only approximate that if the load was constant, but the power would be more like an on off switch to full power (according to the motor current limit setting) during acceleration rather than anything smooth and controllable

if you want a mathematical explanation for this, suppose in duty control mode, you were to do full throttle (100% duty) from standstill (with no failsafe current limits), we get:

((100% * 50v battery) - 0v bemf) / 0.05ohm motor resistance = 1000a motor current and battery current (explosion)

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#54

I don’t need a new VESC I can go higher than 60A up to 120A. That’s not the problem. @BluPenguin get it absolutely right. This type of control is the opposite of an on off switch it’s the smoothest I experienced so fat.

#55

yes 60a battery per vesc, 120a battery total with 2 vescs… i suspect you won’t exceed 60a battery on one 6.6 vesc because of the firmware limits, even if you try to input a higher value.

if we’re talking motor current, then you can do 120a motor current on a single vesc, but not at the higher speeds which is why you don’t have full throttle range with your settings in current control mode – because current control mode controls motor current not battery current, and you can’t have consistent motor current at all speeds if the battery current limit setting is less than the motor current limit setting, after considering the firmware limits (120a motor, 60a battery).

#56

I suspect you will never get exactly the control mode you want on VESC no matter how you change throttle curves. It never had that option, ERPM was never a consideration in the throttle curve chart. If it is that important to you, you might have to switch to proprietary RC type ESC or grab something like an Evolve ESC/BMS/controller combo to get that feel.

#57

I’ve set it to 120A per VESC. That’s the VESC tool limit in this mode.
Above you can you the No limit mode, if you like. But like I said, we didn’t pull more than 114A bat in total so far.

#58

you can set the battery current limit setting to 120a per vesc, but this will be overridden and changed to 60a battery by the firmware, I strongly suspect. When you add up the 2 vescs, you can pull 120a max from your battery, because the most each will do is 60a, I suspect.

#59

I pulled a request to Benjamin. I have 2 Evolves, they pull 20A per VESC max. I would just like to have the same feeling like in HW or similar ESCs.

#60

why don’t you try 60a battery / 60a motor limit settings (in current control mode) and tell me if it fixes the throttle range issue, then at least you’ll have narrowed down the cause.