Battery side lower than controller side when riding switch

Hi. First time poster, long time lurker. Thank you so much for this repository of knowledge. I appreciate all you have contributed to my favorite hobby.

My build:
Makers PEV - Little FOCer 3.1, flowglider enclosure
Flipsky BLE
84v 20sP2 battery by Mario Contino
Fungineers - Battery box
Superflux Motor
TFL - Varails, regular straight setup
TFL - Enduro

My build is functioning great. Almost no hiccups, so far.

My issue:
My stance is regular. My board rides just fine, controller side forward. However, when I do a 180 and ride out switch (battery side forward), the nose (battery side forward now) is lower to the ground than when riding controller side forward. I sometimes even scrape the ground. It’s as if the board is setting the set-point lower when I’m battery side forward? I’m not sure what’s going on.

My query:
Is this a feature of the Vesc software? If so, where can I adjust the settings to control this? Why doesn’t the board behave the same as when it’s controller side forward? What parameters change when it’s battery side forward?

Thanks!

If its especially prevalent coming out of a 180, I would say its very likely to be your accelerometer calibration. Watch Dado’s video on accelerometer calibration or follow that part of the IMU guide here on PEV.dev

Thanks, Nico. I’ll check it out later today, and see if that’s the issue. And, yes, it’s more noticeable coming out of a 180. I’ll reply back here with my findings.

Cheers!

So…

I reset my IMU, and paid special attention to the accelerometer. The issue persists.

Let me add some clarity and nuance to my ‘issue’. The board maintains the set-point (level riding position) when riding controller side forward. However, when I ride switch (battery side forward) it feels as if the set-point is changed. The nose (battery side forward) is now lower than level, and it remains that way, indefinitely. So, to clarify… It’s not just coming out of a 180, riding switch, it’s constant when riding battery side forward. The board rides one way, controller side forward, and a different way, battery side forward.

Any thoughts on what parameters may be affecting this?

BTW, it’s rideable. I’ve gotten used to it. We are talking about 2.5 to 3 degrees. I just want to dial it in.

Thanks, and I appreciate any/all the help.

Cheers!

Hmm, hard to say if you’re confident Accelerometer is solid. First, if you have anyone that can observe from the outside or setup a camera, I’d see if you can get any confirmation that that’s what’s actually going on, and not just placebo from the battery side being heavier and taking less effort to push into.

Second thing I’d do is observe the AppUI tab, specifically the Setpoint and the individual setpoints that make it up. See if there’s any feature that seems to be affecting the setpoint when riding battery side front in a way that matches up with what you’re feeling. You can also observe the True Pitch reading and see if the behavior can be noticed through that. Those details might help clue into what’s going on.

It’s confirmed that battery side forward sits lower. I had my gf film me while riding (battery side forward sits lower than controller side forward) + I scrape the grass/street on my transition to that side, and can easily nose drag (when riding battery side forward) and cannot do the same riding controller side forward.

I took several screenshots of the AppUI tab, both when riding controller and battery side forward. However, I don’t know what to make of the numbers. They fluctuate rather quickly, and cannot figure out what’s affecting what. I’ll post some pics now, but am not sure if that will help.

Static, board engaged, hold on flat ground:

Moving, controller side forward, fast pace:

Moving, battery side forward, fast pace:

I’ll keep exploring after it stops raining.

Again, thanks for the help.

Cheers!

Hard to exactly tell without a screen recording for each scenario, but from the screenshots it looks fine. Im not sure if youve done anything with the tune or meased with ATR settings, but i would backup (make sure AppUI tab has loaded up before you back up, otherwise your tune wont be backed up), then go to AppUI → Tunes, refresh the tune archive, and load the default tune to test. If the problem is still present, feel free to restore your backup.

At that point, honestly all i can suspect is that you’re doing IMU wrong somewhere, likely accelerometer. When you say you reset your IMU, did you load defaults? This is done by going to App CFG, tapping the “…” in bottom right, read defaults, then write. From there, you can do IMU from scratch to make sure it isnt confusing itself if its already configured poorly. I would consider doing this and skipping accelerometer at first. Its preferred to calibrate accelerometer at some point, but you can skip it at first and test, even without calibrating it shouldn’t be bad enough to cause an issue like this. The only other thing i can recommend is maybe recording your screen as you calibrate your IMU from scratch so we can verify its being done correctly.

Thanks, Nico.

I haven’t messed with any ATR settings. I’ll try the default tune to see if the issue is due to that. However, it’s been like that throughout all the tunes I’ve tried (the ones in the ‘Tunes’ section of AppUI). Easy test to do. I’ll start there.

I reset the IMU through the IMU wizard. I didn’t load defaults in App CFG. I’ll try it as you have it written here and record it as I go.

I’ll work on this later and post my results here.

Thanks, again!!

Have you been able to see if Nico’s suggestions have helped you with your issues? I have the same issue, but have been too shy to ask, but would LOVE to see a fix for it. It feels like the board will just drop the nose when I do a quick stop and go battery side forward, and it does seem to just stay that way, but could just be my mind playing tricks on me

Hey, bud!

I haven’t messed around with my Vesc tune for some time. I’ve. been spending some time adding LEDs and riding my GT. I’m going to get back to dialing it in this weekend.

Before I put it down, I had gotten used to the ride (lower, riding battery side forward). It got to the point that I was unsure if it was mental or physical. I’m going to start from scratch to see if it’s still there afterwards. If I solve it (either by realizing it’s in my head, or by determining it’s actually lower) I’ll make sure to post it here.

I’m still tweaking the ride, which is pretty much why I built the Vesc to begin with… gives me something to tinker with.

Cheers!

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