Baserunner + Grin All-Axle Motor settings

[HughP]

Hi All,

I've been happily ripping around on my bike w' a Phaserunner & Grin All-Axle front hub motor for a couple years. I recently bought a Baserunner because I like the cleaner install. However I'm not getting as smooth a ride as I did w' the Phaserunner so I'd like some help figuring it out.

With the Baserunner I'm noticing:

1) A high-frequency vibration from about 18km's/h through to 28km's/h when accelerating. Above ~28km's/h the vibration stops. It is very mild but I don't remember feeling it w' the Phaserunner. Seems greater when using throttle but also happens when I have assist set to 250W and I'm just pedalling w' PAS.

2) On my commute home yesterday I started feeling a 'knocking' from the motor. I thought it might be mechanical but it stops when I stop pedaling or don't use the throttle. It seems to be at about the same frequency as the wheel is rotating. I hooked up the diagnostic software last night and all three hall sensors are working. The knock is fairly inconsistent - it is happening about 50/60% of the time but varies in intensity from barely noticeable to quite noticeable.

3) Really inconsistent regenerative braking performance. It turns on and off (even with the CA indicating the brake is activated) and 'studders' a lot during braking.

I messaged Grin and Justin said : "we've also had a few cases of motor vibration that went away when the motors winding resistance value in the Software suite was manually reduced by 10-15% lower than what was provided in the autotune routine, so it would be worth trying that out too."

So I lowered the Resistant value from 74.00 mOhms (autotune) to 62.00 mOhms and that helped with vibration. Still some 'knocking' during acceleration and lots of 'knocking' during braking.

Anyone else have this setup and can tell me what parameters you're using and how the performance is?

 

[xmtx]

I know it's way late.
I stumbled upon your message.
I have the same vibration problem with a phaserunner and a Grin All-Axle motor. But no problem for regen.
Turns out, I did autonune on the engine instead of loading Grin premade settings.
However, after loading Grin settings for the engine, the vibration were way less potent, but still present, and on 2 different range of speed.

I contacted Grin about all that.

Here is their response:
"I would begin by confirming the correct motor parameter file for your winding speed is loaded to the phaserunner. If unresolved, I would then proceed to make subtle adjustments in phaserunner software. The relevant terms are PLL Damping, PLL Bandwidth, Current Regulator Bandwidth. I cannot cite values which will perform optimally. My approach would be to first increase the PLL damping in 10% increments, saving and testing. If no improvement was noted I would return the bandwidth to the stock value, and make 10% reductions to CRB and PLLB, saving and testing. In the past, vibration in direct drive hubs have been mitigated with reductions in these terms, but it's not impossible they may need to be increased to avoid the vibration."

I have fiddled a little bit about those values, but didn't find significant improvement.
I'll get into it more thoroughly later, before calling it quit.

I have a 10YO rewired nine continent of unknown model, that run way more smoothly on a phaserunner. With autotune, the vibrations occurs on a very short range of speed, it's way less inconvenient. Meaning, I know the phaserunner can do way better with a motor.

 

[micpha]

Hello,

I had the same issue previously with a Phaserunner and a RH212 from Nine Continent. Grin response was similar about the PLL and co. Since I was in a hurry I decided to go in extremes and cut in half the values in order to see a real difference. It paid out when I went on the low side.

My CRB went down from 1500 to 350. PLL down to 80 and damping to 0.5. The setting turned out ok. I didn't bother to find the finest adjustment but I guess I should take the time this winter.

 

[Knoot]

I've had the exactly same issues described by HughP initially with my MXUS XF40. So I connected my computer and was ready to play with the resistance and inductance values and first carried out an autotune procedure.
To my surprise I got an error message saying basically "The motor can not be detected". Therefore I checked the connection between the motor extension cable and the motor cable. Long story short: There was a non-working soldering connection between the motor cable and the motor connector. I should have known better, but I tried to squeeze a 10AWG cable into an XT60 connector and thought I had done everything right, but after 7500 km the connection was broken. Now I have Anderson connectors which fit fine.
Any noise, vibration and shaking of the motor is gone with the new motor cables.