Alltrax Throttle Curve Question

yurtle

I have tried all the stock throttle curves and notice a distinct difference between them, even when all I do is put it to the floor. I assumed the curves were simply throttle on the "x" axis, vs. power on the "y". Is there a description somewhere that tells what they do?

1998 Series, 48 volt, 4855 controller.

Also noticed that unchecking the 1/2 speed reverse actually kills pulling power in reverse. I can't climb a steep hill with this unchecked, but can with it checked, contrary to what the .pdf says.

BGW

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LATrvlr

Good questions! I have the same controller and will be interested in the replies.

Also on mine with the 1/2 speed reverse box checked and when pin 4 has voltage (when the FNR is in reverse) the controller actually limits motor voltage to about 14 volts which is not even close to half of the pack voltage. My ITS is set correctly and produces the "full throttle" diagnostic light on the 4855 when the pedal is all the way down.

Alltraxdude

The throttle curves affect how the controller outputs power (y axis) as you progress through the throttle (x axis). So for any given throttle value there is an output power value. The curves give us the ability to create different performances for various circumstances. The linear is very much like your car, where half throttle is about half power. The S Curve has a lot of power increase at low throttle values, this is good for hauling or towing. Progressive feels more like a motorcycle, where the first half the throttle is a lot of throttle change for little power increase, but the last half fogs on the power. Inductive was created to linearize the ITS throttle, but we found it doesn't really make much difference.

1/2 speed reverse limits the amount of PWM (voltage) going to the motor to about 50% of the pack voltage when you are full throttle. It also takes into account the throttle map. So if 50% throttle on that is only about 30% power, then you'll see less than 1/2 pack voltage.

Its kind of odd that you don't get the same climging power when you are going in reverse than you do forward. Some motors have a prefered direction of spin and there can be as much as 20% difference in torque. Yours might be favored to spin the "forward" position. Or, the F/R is starting to go south. I think its just the motor.

Rich Csuk
Alltrax Inc
www.alltraxinc.com

rocknrone

Welcome, Rich!

yurtle

Thanks. That's what I assumed. If I punch it from a dead stop, I'd expect them all to work the same, yet they don't. Some are punchier than others. I'm on S curve now, and it seems to jump more than others from a dead stop to full pedal.

Was I right to assume if the 1/2 speed reverse is not enabled I should get full speed reverse? Mine seems to climb just fine with 1/2 speed enabled, but can't climb very much with it disabled. I may try disconnecting the reverse wire, to see how that behaves.

My FNR, Batteries, cables 4855, controller, solenoid, etc. are all new and the motor is 2004, but I just opened it and the brushes are fine, so I cleaned it up and replaced the bearing.

LATrvlr

Thanks Rich for your reply and welcome!

yurtle

OK to recap:

1/2 speed reverse checked, reverse seems about half throttle
1/2 speed throttle unchecked, reverse nearly unusable climbing hills

reverse wire disconnected from controller, squeals the tires and feels like full power

It appears that with Alltrax ControllerPRO, version 2.2 (build 39), the 1/2 speed reverse checkbox works when checked, but reduces power when unchecked. Is this the latest version?

I've tried all of the curves and when I stomp the pedal to the floor, they behave differently, which I don't understand. Perhaps I can datalog each run and compare the results. I confirmed that the different curves don't change the throttle up and/or down rate. Perhaps with the throttle up and downrates maxed out to ten, all the curves will behave the same. They were set to 5.

LATrvlr

Yurtle, did you ever learn more on this subject? On my 4855 with the check box off or on along with the orange wire connected, the reverse speed seems about 10% of forward. It's not really usable like that.

yurtle

No additional info.