Fine tuning brakes in VESC

How-Tos & Esk8 mechanics Esk8 Mechanics
#1

I am enjoying my newly built board but I am having trouble with just one thing, brakes.

I’m running a molicel 12s4p with LLT BMS and the guy who built my battery has made it clear that I shouldn’t push more than -40 amps of battery current overall. Sure this sounds fine to me but my problem is super weak brakes.

I’m comparing my current brakes to the extremely powerful Meepo Hurricane brakes which I cannot figure out how to replicate.

Other than the bat, I’m running 6384s 170kv and 2 SkyArtSolos and I have a 15:47 ratio belt drive. Is 15:47 or 170kv the problem here?

Settings: Keep in mind this is per ESC

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#2
  1. Is that P26A P28A P42A or P45B?
  2. Is the BMS wired for regulated discharge or bypass?
  3. Is there a limiting factor in the wiring/construction?
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#3

also, if you’re talking regen current per side, you could easily do -15 or -17 per side and still have plenty of brakes without reaching -40.

but most of us run discharge bypass on our BMSs so we’re only limited by the ESC and don’t have to worry about a bms tripping and losing our brakes.

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#4

P42A

I’m fairly sure it’s not bypass because I was told not to exceed -40 battery amps but I unfortunately don’t know more. It’s not my field of expertise.

There shouldn’t be any wiring limits other than all the power running through a single XT90s

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#5

Sure the brakes aren’t terrible, but I’ve bumped up to -44 overall and it makes a minor difference but not as much as I’m looking for.

Why would -30 do the same/better?

#6

What size tire are you running? 3:1 gearing is going to be just OK for acceleration and braking o 6 inch tires. Also, are you talking brakes that stop you dead on hill or braking from 30mph to 0?

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#7

The brakes that feel weak at what speed? Low speed or high speed?

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#8

If I were in your shoes, check your throttle curve in the VESC remote setting. If that’s where it needs to be, set both sides to -15 for battery regen and -90 to -100 for motors. The battery regen can be an issue but if the -15 isn’t enough, bump it up to -18 then -20. I’m willing to bet it’s because of your motor current. How much do you weight and what’s the battery/esc/motor/gearing and tire size setup?

Edit: just re read and saw you had some of the info I listed, if you can just fill in the gaps… that would be awesome.

#9

I forgot about this thread… Ooops, higher speeds like 25+ it almost feels like brakes are a suggestion.

#10

6" street pneumatic
I weigh ~150lbs and Im running -20 but for the motor Im still in the -75 range. Am I mistaken in thinking the motor amps are responsible for low end positive and negative acceleration?

#11

No, they play a big roll in low end. Try a little bit of a higher number though and see what you think. It shouldn’t hurt anything if you’re esc can handle it. I think you’ll be pleasantly surprised

#12

Also, your mosfet temps should be 80 and 90 respectively for the solos.

#13

Then lower the battery minimum from -22A to -30A