Custom torque curves- What's the theory?

SEHunter

I have a Club Car DS with a new SR-48600 control but this question applies to all carts with DC motors. About to start playing around with making custom torque curves. The SR control has one default that gradually arches up. While the old AXE had one throttle map, the SR separates the speed and torque curves into two charts, both relative to actual throttle position.

My primary question is if a straight linear "curve" (regardless of what throttle position you set %100 torque/speed at) is more suitable than the upward arching curves for a golf cart motor?

Talking with Vic at D&D, he never cared for all the "curves" but prefers a linear throttle map. Granted, he was referencing the factory curves in the older Alltrax controls as his example, like the "S" curve.

BGW

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SEHunter

Been messing around some more with creating custom torque curves. I make one then test ride, make another then test ride, etc. The most noticeable change I can feel is simply adjusting the throttle response which to my knowledge is not a power adjustment but rather the delay or sensitivity between my foot and when the motor responds. %100 is unpleasant and the cart is way to sensitive and jerky. I've settled on 75% and it is responsive but not over sensitive.

As for the speed and torque curves, I went with Vic's preference of linear curves. I set speed at 0-100 with a straight line. I set torque at 0-75% with a straight line. No dots in between on either. Makes it simpler to adjust. And it feels pretty good to me. I'd still like anyone's input on advantages or disadvantages between a linear torque curve vs a curved torque curve...

The more I messed around with it I noticed there isn't much change in feel with small increments. At this point I only wonder if the torque curve can be set in a way that's not healthy for the motor or if there's really no distinction in regard to motor protection/health....

scottyb

I prefer something more like this. Electric motors make the most torque at low speed and you need the most torque when starting hard off the line of out of a mud hole. So I want the torque to maximize quickly and I want the throttle to come on gradually. I can stop the pedal and increase acceleration if I want but, that is not how I usually drive

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SEHunter

Thanks scottyb, i was hoping to see examples as you provided. The second graph you provided shows an aggressive torque curve (compared to the Alltrax preprogrammed curve that I have used as my base line).

Trying to have the correct understanding of what's going on inside the motor in relation to the torque curve adjustment. Is there anything wrong with or damaging to the motor if you didn't taper off as much and maxed out torque as soon as say 30-40 percent throttle? Likewise, is it worse or harder on batteries or just all depending on my foot?

SEHunter

Emailed Alltrax with those questions also. Curious to hear their thoughts.

SEHunter

Alltrax said there’s no negatives to a linear torque curve but that for the most part it’s just personal preference. I’ve done a lot of adjustment and it takes drastic changes to feel a difference. The stock adjustment was as good as any.