Grin eZee front CA3 kit, with a Fischer AG torque sensing BB and a 48V battery.
The CA3 documentation suggests setting FastRampRate relatively high in order to eliminate time lag for a ramped throttle output to catch up with the bike when you apply the throttle and are already moving, and setting RampUpRate and PASRampUpRate more slowly to smooth out harshness. But it seems to me that having a high ramp rate as the system goes through lash would maximize harshness: you’d want to have a slow rate as the motor transitions from coast to drive and then speed it up afterwards.
I spent the last few days playing with the settings to see if I could locate the lash transition by feel:
I was hoping that I’d be able to find a setting that would let me separately identify the lash crossing event and the increase in ramp rate afterwards, but that didn’t pan out: it ended up just being harsh or not. But I did end up being pretty happy with
I'm not sure about the FastThresh setting and how it relates to the Amps signal that I'm getting from the CA3 serial data over PuTTY. That signal reads a limited number of values, and it never reads between 0.94 and 3.18 amps.
It seems to me that if there was another breakpoint (or two) to set intermediate ramp rates in the middle of the range we could get a faster power delivery without sacrificing smoothness. And why is FastThresh in amps? It seems to me that it should be in volts, something like 0.2 VPS below W volts, then 0.5 VPS up to X volts, then 4 VPS up to Y volts, then 8 VPS above that. You'd get a nice soft takeup through lash, then a progressively increasing rate rather than a sudden jump.
What are y’all’s thought on this topic?
The CA3 documentation suggests setting FastRampRate relatively high in order to eliminate time lag for a ramped throttle output to catch up with the bike when you apply the throttle and are already moving, and setting RampUpRate and PASRampUpRate more slowly to smooth out harshness. But it seems to me that having a high ramp rate as the system goes through lash would maximize harshness: you’d want to have a slow rate as the motor transitions from coast to drive and then speed it up afterwards.
I spent the last few days playing with the settings to see if I could locate the lash transition by feel:
FastRamp set at 0.2. 0.5, 2, and 4 VPS (I tried 0.1 and 0.15 but got no power at all with those settings)
FastThresh at 0.2, 0.5, 1, 2, 3 and 4 amps
RampUpRate/PASRampUpRate at 2, 3, 4, and 8 VPS
and doing WOT step inputs at a variety of speeds.FastThresh at 0.2, 0.5, 1, 2, 3 and 4 amps
RampUpRate/PASRampUpRate at 2, 3, 4, and 8 VPS
I was hoping that I’d be able to find a setting that would let me separately identify the lash crossing event and the increase in ramp rate afterwards, but that didn’t pan out: it ended up just being harsh or not. But I did end up being pretty happy with
FastRamp = 0.5 VPS
FastThresh = 2 amps
RampUpRate = 4 VPS
PASRampUpRate = 3 VPS
This gives an unobtrusive power engagement when pedaling and a somewhat faster but still smooth feel on throttle, with not much lag. Setting FastRamp to 2 VPS makes both PAS and throttle noticeably harsher. I’ll probably try RampUpRate at 5 or 6 to see how they feel.FastThresh = 2 amps
RampUpRate = 4 VPS
PASRampUpRate = 3 VPS
I'm not sure about the FastThresh setting and how it relates to the Amps signal that I'm getting from the CA3 serial data over PuTTY. That signal reads a limited number of values, and it never reads between 0.94 and 3.18 amps.
It seems to me that if there was another breakpoint (or two) to set intermediate ramp rates in the middle of the range we could get a faster power delivery without sacrificing smoothness. And why is FastThresh in amps? It seems to me that it should be in volts, something like 0.2 VPS below W volts, then 0.5 VPS up to X volts, then 4 VPS up to Y volts, then 8 VPS above that. You'd get a nice soft takeup through lash, then a progressively increasing rate rather than a sudden jump.
What are y’all’s thought on this topic?
