Pre-Order Focbox Unity $249 | R-SPEC Drive Kit $579USD

Mongrol A.B.C. Warrior, MBS Comp 95, idea drive 20mm belts, stewii Escape's, 10s lipo, dual 190kv

mountainboard

#43

Even if you lower your max values in the vesc you will reach your geared top speed. It just will take longer.
If you want to limit your top speed you need to limit your max erpm or use an app with which you can setup your max speed.


#44

By the way, how you like the motor mounts?
I‘m thinking of getting one set of them too.
But not sure yet if the clearance is enough on the back.
Could you check something for me if you have a minute?
Imagine you would make a wheelie, how high you can lift the nose till the motors touch the ground?


#45

Just like Andy says, and for what you could set alf your batt max possible.
I have never run split signal yet sorry … but did you well set the ESCape (detection motor works fine etc ?)

Hope it help a little bit :wink:
Good DIY mate ! You’re riding your new board soon !!!


#46

just put my wheels back on the nose points 2 o’clock, its a solid mount its a bit heavy for the trucks i have i think but hay ho… anyways

so your saying i cant restrict the speed within my speed controllers…
So im now a bit more confused! :blush:


#47

I haven’t run anything yet just powered up and connected two receivers to my remote.


#48

Thx!

You can, but not by settings the max amp values to the half.
It’s like a car with 100HP which you restrict to 60HP. You still reach the 120km/h just once it’s faster with more torque and once it takes longer.
Sure if you set the values so low that it would take like 5km till reach your top speed you als will not ever drive that fast.

To half your theoretical top speed you need to calculate the max erpm you would reach with your actual gearing and than set your max erpm limit to half of it in both vescs.
You can use this calculator to get your numbers

https://calc.3dservisas.eu/?Pc8xD8IgEAXg_8JsDBRo1RVNpxoSE7srQ00kJelo_O-997Bu3z2O4_ioR5jUSb1fZVY7Ka5S2H0nXsJNbCwZhY4KaNBaszijMr4aPU3NOdMIC2a0ADp9vVci0oaKmzjKehJhS_4HPSeeUxfRQZN3XHdwDr9JmWt3zOIMOxI_qO_nwBjNaVy4NeLUD9tvUj9iBSye8NpRq-8K


#49

Doesnt motor detection give those max erpm figures?


#50

The max erpm is defined by your max voltage and your motor kV rating.


#51

Great build! I’m in East Sussex and keen to build an emtb - nice to see someone straying away from the usual tramps and bling builds!


#52

Thanks, i wish i had built a Trampa but timing on having the money when a good secondhand one was for sale was bad, i actually don’t like the overall look of my board at the mo (kinda looks like its from the 80’s) thinking about taking the red anodising off the spare set of hubs i have to cut down on the color overload… :blush:

I suppose i should i say its not turning out how i thought it would, i still love it its just not what i would do if i had a second go at it, which would be get the MBS birds and upgrade the back hanger to a metal one, best advice i can give is if you do start a build is…

Don’t have a budget :smile:


#53

I think il just go easy on the throttle (trigger) then and set it up as standard…
See anything wrong with my calcs???


#54

That’s retro man :stuck_out_tongue_winking_eye::ok_hand:
I like what you made out of it!
There always things to improve or change, but one by one. It doesn’t need to be perfect from the beginning.


#55

As far as I can see the values look right.
What you plan to set for your motor max/min and battery max/min values?


#56

i have no idea… my plan is to read more because i have no understanding of what effect the max/min motor battery settings have, or what is best for what i have… :worried:


#57

It’s not that difficult as soon as you understand the logic behind.
Basically you have three parts you need to look at first and find there max and min values.
That’s

  1. your battery max constant current for charge and discharge
  2. the max constant current your vesc can handle
  3. the max constant current your motor can handle

With the first two points you set your battery max and min values according to the weakest point.
So let’s say your escapes can handle 60-80A constant and your battery can handle 80-100A constant, I would set the batt max value to 40A in each esc. Why 40 and not 80A? Because your escs are connected parallel so you need to half the max value of your battery output.
For the motor max value, you have sk3 motors, look up the specs, they should be rated to 60-80A something like this. So a good staring point would be to set the motor max at 60A.

Let’s jump to the motor and bat min values.
What you need to know
In general they regulate how strong your breaks are.
Motor min is dominant at low speed.
Batt min is dominant at high speed.
The more far the values from 0 the stronger the breaks (-40a is stronger break than -20).
If you look at your battery with 8Ah you can charge them with 1C so 8A that would make a batt min of -4A per vesc. As you don’t break a full charge cycle, but usually only like 10-20sec max I think (and that’s only my opinion) it’s ok to set the batt min value to -10 to -12A per esc.
For the motor min I would start with -55A.
Take your board for a spin and look how it feels and in case you not happy just adjust the values.
Let the batt min values how they are and adjust the motor min values to -60 till -80A if the breaks too weak, or to -50 to -40 if they to strong.

Long text but I hope it’s understandable and helps you out :sweat_smile:


#58

I love you, not as much as i love myself but i still love you… :smiling_face_with_three_hearts:

i will have more questions no doubt and unfortunately :blush: but il leave you be for now, take the rest of the day off you hansom bastard…

Im off to do some motor detection… and software revision…
while :pray: for no blue smoke.

To be continued…


#59

:joy: good luck :+1:


#60

Some more precise/full system details…

each Escape 80a -120a burst.

each Motor max load 70a, max power 2400w.

Batteries 8000ah 15c/30c with a max charge of 5c (not 1c ,does this make a difference?also what amps is best to charge them at?)
bat pack combined 120a - peak 240a i think!!

so, settings in order would be

BLDC.

MOTOR.
Motor current max. 60a
Motor current max break. -60a

BATTERY
Battery current max.30a < unsure on this one
Battery max regen. -10a

then click next :blush:


#61

Looks good!
Start with it, there is still some head room on your bat max value but I would change it only if you not happy or want more power :sweat_smile:
The settings you chose are save :ok_hand:

Charging current, the lower the better (if the lipos rated 5c than theoretically 40a :joy::man_facepalming:)
4-8a should be fine.


#62

Done, i’ve set bat max on 40a, so the (set soft voltage limits) section now,
Currently reads…

Battery voltage cut off start 40.80 v

Battery voltage cut off end 37.2 v

What if any changes are required?