2wd acceleration 4wd braking

How-Tos & Esk8 mechanics
#1

While riding yesterday I got in a situation where I could have used harder braking, since riding on Thanes it would cause drift instead of brake.

So what came to my mind since I don’t want a bigger battery nor shorter range, better acceleration or higher top speed, but just harder braking, did someone actually tried this?

Could you use 4 motors but only 2 for pulling while all 4 for braking? Can vesc be programmed that way? Could it be only 1 more single vesc linked in parallel for the 2 “breaking” motors?

2 Likes
#2

Expensive brakes :joy: just turn your braking amps up

1 Like
#3

Amps are not an issue, I can lock 2 wheels at current setup, problem is grip while braking, you can brake as hard as your wheels can grip to the surface.

With 4wheels braking you practically double the grip you have while braking…

Is it expensive? Yes. Is it worth it? I think so.

3 Likes
#4

Subscribed, want to do this as well

2 Likes
#5

You can definitely do this by turning your motor amps to zero on the positive side.

But the real question here I think, is

Is there a more efficient way to do this that doesn’t involve a full-fledged 4WD setup?

3 Likes
#6

I wonder if using DC motors (instead of BLDC) on the front, you could use a single VESC to control each motor’s braking, like one “common” phase wire and a “hot” for each motor

A) motor 1 hot
B) motor 1, 2 return
C) motor 2 hot

Of course this would require a firmware feature addition

1 Like
#7

Servo controlled disc brake?

2 Likes
#8

That came to my mind as well. The problem I see is how to control it with remote and make it simple.

That way I guess you would need another rocker on the remote, or maybe it can use the same signal from remote while braking.

#9

Definitely same signal.

Multiple receivers always works for me.

#10

Would this be cheaper, and easier to implement?

#11

How would you mount the disc brake? On rear wheels you have pulleys and idk if it’s best idea to put strong brakes on front wheels. How would it be controlled?

#12

Most servors are pwm controlled, dunno exactly how, but if the servo would engage in the lowest end of the throttly only, you could have normal electrical brakes until you hit that part of the throttle and then the disc would engage.
If you use uart control dunno at all.

#13

Isn’t more grip entirely to do with the wheels rather than the brakes as you’ve indicated that you can lock them up? Either that or perhaps some type of ABS tamping down of the brake intensity may help with the skid-causing lock ups.

#14

Well, amount of grip one have is based on wheel and surface material, and of course the downforce you apply to the wheel.

PU wheels have far inferior grip comparing to pneumatics (that’s what I have noticed riding both), PUs i am currently riding are evolve abec 107s and I find those quite grippy for pu standards.

The other issue with pu wheels and rear only breaking is that it is counter intuitive to transfer all your weight on rear leg while heavy breaking, and rear wheels start to do small bounces thus loosing grip even more.

It is much easier to transfer weight on front leg while breaking, increasing downforce and with it the grip itself, so my thoughts that front brakes would be way more effective than rear ones.

ABS sounds good, there is a reason all new cars have abs implemented.

#15

Time to get Brembo on the forum lol

1 Like
#16

Just a sanity check please… I would like to test rear wheel brakIng vs front wheel braking today or tomorrow…

So I could just reverse motor direction in vesc tool and ride it as a front wheel drive deck? Right?

#17

If you run unsensored you can even just swap phase wires. Else like you say.

1 Like
#18

That wouldn’t work without new motor config run. Better to just change the motor direction in the vesc tool.

1 Like
#19

Sure that works, without new motor config. why shouldn’t it? i’ve done this many times

#20

You might wanna give TB110s 74a/72a a try.

2 Likes