Gwan Homies | Samsung 30Q - 10s4p w/ bms | Dual SK3 - 6354-260kv | Dual Vesc-x

ESK8 Electronics
1

Fuck Everyone | Including Myself.

This is my First thread so please be patient with me.

…Hi? So this is my first thread and i would like some information and help if you’re willing to give it. I’d like to build as fast of a longboard as i can, something that goes up to 30mph+.

So far i have purchased a few things, i’ll list the most important.

  • Longboard Deck.
  • Caliber II Longboard Trucks, 50 Degrees.
  • Orangatang Kegel 80mm Wheels.
  • 30 Teeth HDT 5mm Pitch 11mm wide wheel pulley, 20 Teeth HDT 5mm Pitch 11mm wide motor pulley. The pulleys have already been drilled and connected to the wheels.
  • Aluminium for my motor mount build, Which i plan to build myself.
  • Transmitter and reciever. However i would like to build my own transmitter, so if you can like me a thread that teaches how to do that, that would be great.

I plan to create a 10S4P Samsung 30Q battery pack. Thus this will provide: 12,000mah | 60Amps. I want to use this with dual Turnigy Aerodrive SK3 - 6354-260kv motors. Which will provide: a total of 4720w of max power, each motor will has a max load of 70a and can run between 8-10s. Dual Vesc-X ESC

What do you think about this setup and can you recommend me a bms that would be suitable for this setup and why it is.

Thank you.

2

If you use VESC, be careful with the 260 kv and 10s. You’d need to set your ERPM limit to 60.000 in the VESC settings. (Don’t know if the VESC-X can go higher). I’d take some 6354 with 190kv. There are a lot of places where you can buy them. Also the gearing seams a bit too low especially with that kv rating. 20:30 would give you a vmax of about 94 km/h according to http://www.elektro-skateboard.de/wiki/wissenswertes/strom-spannung-reichweite-vii

Most people use 36, 34 or 32 teeth on kegels and from 12 to 16 teeth on the motor pulley. You can play a bit in the tool i linked you to get the best gearing for your needs.

1 Like
3

That motor KV is too high for the VESC…

10 x 4.2 = 42v
42v x 260kv = 10,920 RPM
10,920 RPM x7 = 76,440  ERPM

The VESCy has an ERPM limit of 60k. Check out this thread.

Thats a strange gear setup, I dont think Ive ever seen it before. Look at this calculator for more info.

Use this BMS, its the best available and you can get it with an e-switch installed. Battery Protection Circuit Board (BMS/PCB/PCM) for 10S Cells 37V Li-ion and Li-Polymer Battery Packs Part number: HCX-D223V1

1 Like
4

42V at 60A is 2520W - that is the max Power your system can have (without adding in voltage sag). Not 4720W. Still plenty - just don’t fall in that marketing trap

1 Like
5

Thanks for the reply, i guess i have no choice but to either reduce my battery voltage or go for that 190kv motor, which i will probably get from torqueboards.

6

Could you tell me how you got that calculation and why its like that, does that also mean that the top speed wont be as high?

7

yeah i’ve seen that BMS quite a lot on other threads, thanks for the recommendation, for the e-switch does that mean i can add a led push button, two the two wires without it getting damaged.

do you think if i went down to 190kv with the same gearing that it would be okay, as its under 60k erpm.

8

You could probably use a push button, but its a 2 pole switch so no LED unless you use a step down converter to drive the LED.

You should be OK with the gearing you have, I’d try it out and see what you think before I spent more money, especially since its already installed. If you decide you don’t like it buy new motor pulleys and print (or get printed) new wheel pulleys. Pulleys are pretty inexpensive.

1 Like
9

The limiting factor is your battery. It can safely output 60A. The maximum voltage it can have at 10S is 42V. The current times the voltage is your power.

In real life you won’t be using 42V because the battery will sag quite a lot to maybe 3.8 or 3.9 in the beginning. this will reduce the actual power quite a bit. However: 2000W on a skateboard is no joke and will simply cause you to street your face if not handled carefully. Topspeed is mainly limited by voltage - not power. If you want to go faster you need to up the voltage to 12S but that will also increase your ERPM. In your case you need to find a way to get to 60000erpm and then gear your system according to the speed you want.

1 Like
10

With a 20/30 ratio you don’t need a super high ERPM to hit 30mph. A 190kV motor on 10S with that setup would easily get you to 30mph. Check out this calculator: http://calc.esk8.it/#{“batt-type-lipo”:1,“batt-cells”:10,“motor-kv”:190,“system-efficiency”:80,“motor-pulley-teeth”:20,“wheel-pulley-teeth”:30,“wheel-size”:83}|

1 Like
11

I laughed…

1 Like
12

thats cute baby

13

So i have a total of 4 batterys that i could potentially use, initially i was going for samsung 30q but there is a lot of conflicting information. so i would like one final review by anyone thats willing to help

US18650 VTC5 2600mAh 30A : http://www.gearbest.com/batteries/pp_399867.html INR18650 - 25R 2500mAh 20A : http://www.gearbest.com/batteries/pp_399862.html HG2 3000mAh 20A : http://www.gearbest.com/batteries/pp_399870.html INR18650 - 30Q 3000mAh 15A : http://www.gearbest.com/batteries/pp_399866.html

which is the best out of these, regardless of the price, and is there a better battery that i havent listed?

14

30Q is the way to go here :wink:

1 Like
15

I’m curious as well…

1 Like
16

This is my first build and I’m interested in using dual SK3s as well. Would 2 190kv motors work well? I’m looking for a high top speed along will lots of torque to propel me up hills.