NEED A FEW TESTERS WITH FOCBOX UNITY BUILDS - Low-speed Braking Fix Needs Testing

I went through the guided setup if that is what you mean.

yeah double check this. this is what happend to me at first.

OHHHHHH thank you so much! Ill go outside and test now.

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Two videos where you can hear the vibration. It’s definitely not belt skipping or anything like that. https://photos.app.goo.gl/s5p4nnfNptV4DKnDA

Stronger braking at low speed in a good way. Though I didn’t really test immediately back to back with the firmware so that could be my imagination.

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Thank you Jeff!

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@Deodand Sorry I jumped the gun, tested fix on my non-unity build. Works great, although you can hear cogging at the very end as you will see… sound most evident in second vid:

Thank you for this fix!!!

If anyone else out there is currently running Ackmaniac’s 3.102 with standard ( NON-UNITY ) 410, 411, 412 vesc hardware, i’ve forked ack’s FW with the fix applied for you to download and build for yourself, currently only forked to make change, but builds locally just fine for those interested.

Alternatively, here’s Ackmaniac’s FW 3.102 build files with the brake fix applied for vescs other than unity: Link

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This is exactly the same sound I get in my videos.

p.s. How the HELL do you accelerate at 160A like that?

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It’s motor current not battery current :slight_smile:

160A battery max… JEEBERS I could only imagine…

That’s what I mean, 160A motor current = a heap of torque. Unless you have a high KV motor I suppose and much higher gearing than me. I can only just get to 30A+30A motor current, that is with 140kV motors geared to 40km/h top speed. (70Kg)

dual 190kv motors with 20/36 gearing on 107mm flywheels, 10S4P 25R, 80A motor max 40A battery max per focbox. I think it’s the gearing… i’ve always geared for speed, so the torque is never anything too crazy.

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Ahh ok that makes some sense, you have almost twice the gearing (top speed) that I do, giving me double the torque-per-amp.

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Not sure if these will be of any use, but here’s some data from my vescs.

Brake%20Fix%20Vesc%20Log1 Brake%20Fix%20Vesc%20Log2

Ooo, how are you getting the data out? I couldn’t get ackmaniac to work…

Just to be clear, you should not run Ackmaniac’s firmware on the Unity.

I used this fix applied to Ackmaniac’s FW on the standard FOCBOX with a bluetooth adapter and ESC Monitor.

Are you running a Unity?

BTW, I watched your videos with the braking sound… same exact thing, you’re right!

Ahh sorry, my mistake. I meant running Ackmaniac’s Android app and getting it to speak via a BT module to the unity. Totally missed that you were testing on VESCs and not a Unity.

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Nice guys, I’ll see if I can do anything about the low speed chatter. To be clear, do you find it to be a small nuisance or is it prohibitive to your riding experience in some way?

Personally, a small nuisance on my setup, if that.

Relatively speaking, having the ‘chatter’ is maybe only 10% worse than what I imagine it would be like if it were not being there at all… but it’s 110% better than locking up completely.

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For me it is a nuisance to the extent that I thought my belt was skipping. I think the sensible assumption though is that these boards are not the worst possible case of it. Any ideas as to what is causing it?

That’s a good point… it can sound like a belt skipping. Does it feel like belt skipping when that happens, or do you just get that impression from the sound?

I didn’t get that impression personally, from the feel… and I know my belts don’t skip, but when they did, it does make a similar sound.

It sounds and feels like a belt skipping at very high speed, ie fast skips. I know I’m going low speed, and so I know its not a belt skipping. It’s also completely repeatable. I bet its a hysteresis problem. Definitely interesting!

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