Problem while trying to accelerate

Hi guys. Having an issue I’m not sure what to do about.

On my Haya build with dual Flipsky 6.6 singles and 6354 BKB 190kv motors, using a Hoyt St. puck for control. When moving slowly (<5mph) and I try to accelerate slowly, there is oftentimes some points where my board tries to slow down instead of speed up.

I checked for faults, but I’m not kicking any up on the VESCs, and I’m running FOC sensorless mode on both right now.

I remember reading about possibly making the deadzone larger on the input, but I’m not really sure if this is related to what I’m experiencing. Also, the issue is not bad enough that I’m worried about riding the board since we’re talking about <5mph when this is an issue,

Any tips/advise?

You sure you’re in mode 3?

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I would troubleshoot if there’s nothing obvious. Try running BLDC for a bit and see if you have the issue. Plug the sensors in if you have any and try both.

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Did you set the deadband/throttle response in the VESC tool?

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@Kellag Definitely in mode 3

@Brenternet Going to be doing this, but I was hoping it was something obvious for someone else that I just didn’t know about. Going to give sensored a try first, then give BLDC a shot after that and see how it behaves.

@Itsmedant TBH I’m not sure what to adjust. I’ve gone thru the setup and checked the midpoint/max/min and they are all within acceptable ranges and the remote works perfectly. This is just what I consider a strange behavior from when you have the thumbwheel free, and the board is moving “freewheel” to what I would think should be the point in the throttle range where its literally breaking even with the speed at which you’re travelling. From that point on, it always behaves how I would expect. Could you expand on what I should be doing different with regards to deadband/throttle response other than going with the defaults VESC tool recommends during the wizard setup?

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Is it juddery or smooth when it happens? Not the most experienced here but could be a loose phase wire?

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Its kinda jittery, but I’d expect that with it being in sensorless mode. I’ll check the phase wires, but I doubt this is it given the issue only occurs during a very specific range of input, not randomly throughout the ride, and there are no faults kicked up on the VESCs.

If you plug the VESC to a PC dose the signal bar move up smoothly on the PC

(Quick way to rule out the remote)

Is it as you push the remot forwards or is it when you snap the remote at 30% let the board acelarate.

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I can test with 2 remotes to see if its a possible remote issue, good suggestion.

When I’m cruising, mind you at slow speed around 5mph, I have my thumb on the remote but its mid stick. When I start to move it forward, there is some space (I imagine the deadzone) during which nothing happens. Then at some point as I continue to move the thumbwheel more forward, the board starts to jitter/slow down illustrating the behavior I find annoying. Then as I continue to move the thumbwheel more forward, I get to a point where the motors are actually keeping up with the current speed I am travelling at, and so if I held the remote at this point, I would continue to travel at the same speed indefinitely, no jitters. Then if I continue to push the thumbwheel more forward, the board accelerates. no jitters.

You want to engage the equivalent to a clutch in a car with out the added resistance slowing you down.

Double check


Control Type

I’d start there

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