What’s your acceleration? Is it really a beast?

General Discussion
1

So I was discussing acceleration on another thread with @rusins and I think this would be a cool way to compare how powerful your board really is once you are actually on it.

The easiest way to calculate your acceleration is to first use @Kug3lis’s calculator and enter your values to get your max wheel torque in Nm. (this feature may be added in later. Here’s the link https://calc.3dservisas.eu)

Once you have your rotational torque you can translate it into forward force by dividing by the radius of your wheel. In my case 0.0485, I have 97mm wheels. All measurements should be in meters or the same units.

This gives me 16.5Nm / 0.0485 = 340Nm of force

Finally we can use the formula acceleration = force / mass. A = 340/60 (I weight 60kg…Yes, I am a midget)

Therefore acceleration = 5.7m/s/s or 5.7m/s^2. This means for every second I travel I will gain 5.7m/s of speed. So theoretically it will take me about 3-4 seconds to reach top speed.

What’s your max acceleration? Would you beat me? Smoke me? Or get smoked by me?

3 Likes
2

Alternately, tape your phone to your board and use an accelerometer app on a fairly smooth path. Or plot speed vs time from VESC telemetry.

1 Like
3

Been awhile since physics 101 but…

image

18.432 Nm / 0.05 m = 368.64 Nm force

160 lbs x 0.454 kg = 72.64 kg

Accel = 368.64 / 72.64 = 5.075 m/s^2

5.7 - 5.075 = 0.625

Looks like you just smoked me by 0.625 m/s^2

4

Yea, I don’t buy that calculator. IT says I only get 2.36 Nm total between 4 motors, with 12kw of power, lol. That’s def not right. I get 0-20mph in 3 seconds. Seriously, good luck staying on at full throttle.

5

Well u doubt then forumala itself :wink:

Formula is simple 60 / (2 * PI * kV) * Motor current = Nm

I guess u use hub motors and 3kW ea so around 60A and 80kV and gear ratio is 1

((60/(2 * 3.14 * 80))*60)*4 = 28.6624203822 Nm

Any direct drive sucks at torque pretty badly

1 Like
6

Try it again, it was updated recently as it used to only count the single motor torque

7

Oooooh sounds like a close and race, this would be a fun way to race people in different countries haha

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8

Is your wheel diameter 97mm or just radius? Because radius is half diameter… So for e.g. 107mm is 53.5mm

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Ahhh bollocks I did entered diameter. Instead of radius. Thank you, it’s meant to be radius though right?

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Yes, when I will be back in hotel I will write down some more thoery on acceleration and etc stuff.

1 Like
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I’m not sure if radius is right though as that means I’m accelerating at about 20km/h which cannot be correct, can it?

12

I just entered your rough values and it says 25Nm, maybe you entered something wrong last time

13

Hell yeah we could get everyone’s acceleration numbers and start a ranked leaderboard thread lol

2 Likes
14

Sounds cool, great idea

15

He probably run quad hub motor setup which is around 80kV motors 1:1 gear ratio, 3kW motor power rating

16

Shit I wrote 60 but phone converted it to 6 for some reason

EDIT: nvm it suppose to be around 30 something he wrote incorrectly…

image

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Are you sure it’s not meant to be divided by diameter as I’m getting about 5.5m/s/s acceleration which seems a bit high

18

I really like this concept but I feel like there’s a big difference between theoretical acceleration and what you can put to the ground without belts slipping, rider falling off, etc. I think it’d be really cool for people to post their 150 foot drag times. And would be interesting to compare to production boards as well.

If anyone’s curious, I got 5.49 m/s/s acceleration using the calculator and my mass of 77 kg.

19

I’ve been actually thinking of making an Esk8 leaderboard app that would take data and show leaderboards (similar to the boosted showdown this past summer). There would be different leaderboards based on city, state, country, continent/region, Fraction (think NY Collective vs Baesk8) and Globally. Builds would also be ranked based on Theory Specs vs Real World Preformance and would be given classes and ranks. Based on the data put in one would be able to see were their board would stack theoretically next to production and other builds via theoretical drag race and charts like Skatemetric does.

Don’t know about how popular it would be and if the work towards starting it would be even worth it.

1 Like
20

Yeah I’m getting about 5.6m/s/s at 60kg but that seams far too high to me. That’s almost 20km/h every second, I’d be reach top speed in just under 3secs