Brakes failing at high speeds

Strawbs · December 20, 2017, 8:07pm

Hi all, hoping to get some help with my brakes

Setup - Enertion dual motor kit with VESC and PRO4 battery pack

My problem comes when I am braking at high speeds. The breaks completely shut off for about 2-3 seconds and the board wont respond to any input. Braking at low speeds seems to be fine.

I’m wondering if this can be a simple fix in my VESC settings? brake limit cut-off or something?

Any help would be appreciated. Thanks!

Battosaii · December 20, 2017, 8:39pm

What’s high speeds? 25mph 35Mph?

krloz · December 20, 2017, 9:29pm

does the vesc reset when this occurs?

onepunchboard · December 20, 2017, 10:01pm

prob too much stress on vesc.

u can increase abs current
increase regen current
increase gear ratio
make sure vesc is cool with air flow
get lower kv motor

Namasaki · December 20, 2017, 10:41pm

Post screen shots of your Vesc settings so we can have a look.

Achmed20 · December 20, 2017, 11:02pm

if you run it in FOC, disable that. doesnt run well on all VESCs out there. mine fails especialy with breaking.

dg798 · December 20, 2017, 11:06pm

Make sure you don’t limit your erpm with negative torque.

Strawbs · January 22, 2018, 2:36am

Here are my VESC settings. Seems pretty standard from what i’ve been searching.

Does anything on here jump out?

Martinsp · January 22, 2018, 2:40am

The problem is you changed the maximum input voltage, put it back to 57V and your brakes will work all the time.

Strawbs · January 22, 2018, 2:40am

I don’t think its the VESCs overheating. It happens immediately when starting the board cold. For example… (Turn on board, run motors, hit breaks… the breaks cut out even when not standing on the board)

Strawbs · January 22, 2018, 2:41am

Thanks, I’ll try this

Martinsp · January 22, 2018, 2:42am

Further explanation is that when you brake there is a voltage spike due to the motor generating power when braking, this triggers the VESCs protection and forces it to reset that explains the 2-3 seconds which the VESC does not respond to any input because it is going through a power cycle. After it boots up it works until you brake again.

EDIT: this does not happen at low speeds mostly due to the voltage not crossing the threshold for the VESC to reboot.

Strawbs · January 22, 2018, 2:43am

That’s it exactly. Simple fix. It looks like I’m up and running again.

Thanks friend!

Martinsp · January 22, 2018, 2:44am

No worries.

scepterr · January 22, 2018, 3:42am

Hey I was setting up a couple vescs the other day…and I was thinking; is there ever a reason to change max input voltage? I couldn’t think of one.

Martinsp · January 22, 2018, 8:16am

I dont think there is, at least for esk8 applications. Maybe it is there so that if someone wants to push the limits they can increase it or something.

I have never encountered a situation where I had to change it