Looking to build a Dual Motor Longboard, Newbie!

[aired_e39]

Hi All,
My office is moving with in a mile of me and I have been looking at electric skateboards, looked at marbel, boosted and more (ridden the e-go, its ok but lots of room for improvement)...but I am also a self taught mechanic and have more hours fixing, modifying and customizing cars then I care to think about. So in saying that I have decided that I want to explore looking at how to build a electric skateboard.

here are my goals and questions:

- spend limit of $800-1000 on everything except the deck.
- Dual Motor with dual esc
- torqueboard motor mounts
- caliber trucks
- anti spark switch from diyelectricskateboard
- the wii reciever and remote from diy electricskateboard

a) 25+ mph top speed with good acceleration
a1) what gear rations will i need, how do i balance the two?
a2) where can i find the motor and wheel pulley assemblies?
a3) with dual motors i was thinking the turnigy sk3 motors with 290kv, is this enough or should i be looking at different motors?

b) dual motors and dual esc's...
b1) should i be looking at esc's that are programmable? if so which ones?
b2) how do wire up two esc's to a single receiver?
b3) do i need to worry about adding capacitors to the circuits?

c) batteries and more
c1) what size of batteries do i need? I was thinking more towards the 10s lipo side of things, how many mAh's?
c2) battery management system? Where do i find these and how do determine what i need?

I have read through a couple of build threads but i have yet to see anyone explain how to run two esc's, are there wiring diagrams?

Thank you all in advance, I am quite excited about a build like this if i can keep it reasonable...

 

[astilwell611]

Hello,

Not sure if this is how everyone else does it but this is how I was planning on doing it.

https://www.youtube.com/watch?v=aADN7iCx9E4

I'm sure some of the others will chime in soon.

 

[sl33py]

Welcome to ES aired!

Sounds pretty doable if you are selective on components.

Let's break it down for you:

Motors - i'd recommend one of 3:
1 - Tacon bigfoot (63mm 245kv) - 55ea - $110.
2 - DIYes 5065 Sensored motor - (50mm 170kv sensored) - 85ea - $170
3 - Enertion R-Spec 6355 - (63mm 190kv) - 113ea - $226

ESC's -
XERun/FVT - ~$100 ea / $200
VESC (if you can find one) - 120ea - $240
DIYes 12s Opto ESC (non-sensored) adding as an option. Hopefully he'll have his sensored ESC up soon to add to the mix. 145ea - $270 discounted for pair.

The biggest difference on ESC's is the voltage (# series) it will support. Most hobby ESC's support 2-6s. Higher voltage is usually better for us, more efficient, more power, and faster (can be a negative and require more re-gearing). Hobby ESC's that support >6s like the Mamba XL2 (2-8s) is about $200ea.
A solution that Vedder has developed is the VESC. It takes a couple extra steps to configure, but is mostly copy/paste and pretty straight forward. With the new Windows ports of the BLDC tool to configure the motor/ESC it's even easier. Just follow the steps and ask questions if uncertain.

Caliber or Paris - $55-60 set. I'd also recommend getting better bushings for your weight ~$20.

Anti-spark switch. Nice, but i'd just run an XT-90 antispark loop key instead. $7 instead of $60.

Wiiceiver is really nice, but i'd opt for the GT2B as it's more reliable. You *can* make the wiiceiver more reliable by direct soldering the wires, or direct connect it to the VESC.

25mph is easily doable - it's all in the gearing and how you ride. Hills or flats? And of course your weight. I'm a big guy (265-275 geared up) and my dual 5065mm was geared for 25mph. I got one run w/ a tailwind to 30mph - but almost every other run i topped out 24-25mph consistently. I was on 8s and VESC's.

The important factors - Wheel size, Motor KV, Voltage(# Series), Motor gear, Wheel gear (# Teeth).

Example - this is my current build:

Gearing initially setup is pretty straight forward. You will get a set of gears with a belt setup for your motor w/ your motor mount kit. If you get Torque/DIYes's v1 full kit it has a 36t wheel gear. not sure which belt or motor gear comes with it currently. I know he was doing some 15mm belts (which are great for single motor setups).

Dual motors - do you want dual diagonal or dual rear? The length of your motor will determine if you can run DR vs DD. about 54-55mm length (6355 is 63mm diameter x 55mm long, 5065 - 50mm x 65mm) Just so you understand constraints.

Dual ESC's are simple to wire. Simplest is with a simple Servo "Y" cable. Removing the red power lead on one (so your Rx only gets one 5v source to power it). Alternatively with the VESC you can run one servo wire from the VESC to the Rx, and then use 2 wires between the VESC's to communicate over canbus.

Programming card - absolutely. For the XERun and FVT you need to get the card to at least configure the brakes. For the VESC you do the programming with the software BLDC tool.

Capacitors - yes if needed. VESC has one 2200uF or the new triple cap setup. XERun and FVT come with their caps already.

Batteries - you will want a setup specifically for the voltage/#S you want to run. I'd recommend starting out with 2 x 3s for 6s to start then you can add 2 more later for 12s if you get a VESC. Either way you will want to get the highest voltage your ESC can support. So if you go the XERun or FVT route you will want 6s max. Mamba XL2 - 8s max. VESC 10/12s depending on your motor (>200kv - 10s, <200kv - 12s). That might change w/ his newest 4.8 VESC.

I would skip the BMS on your budget. It's a lot more complex and for only 2-4 batteries a good charger is where i'd spend the $.

Get a good DC charger. iCharger or similar. You'll need a power supply as well. Look for the 12v server power supply off ebay - best voltage for the $.

Keep reading up on folks builds and start your own build thread. List what you'd like to use and folks will chime in with suggestions/comments if they see anything wrong.

Welcome to ES and good luck!

 

[aired_e39]

I just wanted to say thanks to the both of you.

Sl33py, you gave me so much good information so now I'm going to begin to digest. Great information for getting a plan started.

 

[sl33py]

Did you figure out your planned build yet? Post it up and we'll help you pick or raise concerns if something looks out of whack.

GL!