Complete Stop Downhill/Uphill on a Mountainboard (VESC6) is it possible?

#31

I think it would be best to apply the full brake only when the throttle is below 10%, as in more than 80% brake power, and of course low erpm. That way it’s dynamically controllable with the throttle input only.
I’d assume that no one uses more than 80% of the braking power below 5 km/h or so anyways.

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#32

Agreed. I have plenty of throw on my brake trigger to spare.

#33

So when can I expect the new firmware? Does Sunday work for y’all?

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#34

I haven’t tried it yet, but if you use the setting that has reverse and set a really low max reverse ERPM it should brake you, it’s what @rey8801 is using to overcome the low braking force of DD

In my board uphill is no problem, I just accelerate enough to keep the board stopped, it would be the same in downhill, you brake enough to keep it stopped

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#35

Yes I think I will try that just in case the “real firmware” takes longer than sunday :smiley:

#36

I can do exactly that. Hold my position on an incline or a decline.

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#37

I can’t find where I can set the maximum reverse speed in the Metr App ?
Any ideas ?

#38

Nevermind… I just set it up with VESC Tool… I now run “Current Hyst Reverse with Brake” and have the Reverse Speed Limit set to 4km/h and the maximum direction switch ERPM around 1000.

Lets see how this goes…

Only strange thing is with the speed limits on VESC Tool that it will first spin faster until the speed limit kicks in but thats only on the bench I guess - have to test it on the road

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#39

I don’t think that’s the mode you want. You want current mode. But give it a try and if it doesn’t work then try current.

#40

When I tried it in current mode it will directly go into Reverse without braking first. Thats why I choose the Hyst mode.
I tried it only on the bench but I was not able to just brake (even with setting the Max ERPM very low) it would go from forward directly to reverse.

the Current Hyst Reverse with Brake did work and braked first and then would go reverse on the second reverse tap

#41

That’s why you limit the reverse speed under profiles. So that it doesn’t go back at high speed. A lot of us are using it.

There are 2 types of braking possible when near 0 speed. Active and passive. Passive just shorts all three phases, active pushes current in opposite direction.

#42

But shouldn’t it stop the motor in current mode first and not directly jump from Forward to Reverse with only hitting the reverse once ???

#43

No. It will go into reverse directly after it has braked, but barely because of the reverse speed limit. So the effect is that it brakes, and crawls back in reverse direction if you don’t reduce the brake. If you reduce the brake a little bit, you don’t go back at all.

#44

Strange… I always thought that hitting the brake two times makes it go reverse… (or maybe that was Ackmaniacs Firmware that I have on my longboard?).

Anyways - I will try both modes tomorrow and see which one suits better for everyday use… Thanks for the recommendations

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#45

Yep I have been using it but was an idea of @Winfly or @mishrasubhransu. It’s called active braking. Once you get the right values for your setup and style or works pretty good

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#46

Keep us posted please. I wouldn’t mind being able to hold a stop and have reverse :heart_eyes:

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#47

I had observed that on my robots first, that deceleration close to 0 speed was significantly more if I just used the current mode. Noticed that the motor current were higher. Makes sense because the backemf is very small at low velocities hence the braking current is also pretty small. However in current mode it can apply much larger voltage in opposite direction giving it higher braking current.

Decided to implement on eLofty and Bam it worked really well. But of course it goes back in opposite direction after coming to rest or limiting the reverse speed was very important.

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#48

So I just did a quick test.

With CURRENT Mode:

I will go downhill - brake and the wheels will lock shortly and then instantly go into reverse (not to my liking)

With CURRENT HYST Mode:

I will go downhill - brake - the board will slow down but still roll a little bit - I hit the brake again and then it wil stand still (or go reverse depending on the amount of brake I apply).

So the normal Current mode that will go reverse directly just doesn’t feel right in most situations for me

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#49

Yes, that’s why it is very very important that you restrict the reverse speed to a crawl. Have you done that? You can do that under profiles in the vesc_tool app.

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#50

Yes I did that… Set to 4km/h like recommended earlier…