Electric Longboard (CyberBoard)

UPDATE: Battery V3 coming soon! Featuring 1kWh of power at 42Vs. It will use a new cooling design that utilizes liquid immersion cooling designs I have made my self and am currently building; this will enable super charging! I'll explain more when I post the build log for that in another Instructable. Shout out to the Hacksmith's James Hobson for inspiration!

Hello everyone, in this Instructable I will be sharing how I built my CyberBoard. As any good builder should I will be sharing BOTH my failures and successes with this build in order to help prevent you recreating my mistakes. I go through many variations of each of the parts that I designed and fabricate to reach optimal performance. I will go ahead and say ahead of time that the look and layout is not for everyone hence the name "Cyber-" in the name (in reminiscence to CYBERTRUCK).

Before we begin there is a safety and disclaimer that I have made Step 1 because that is important to practice since the amount of power that we are dealing with can injure of even kill you. So PLEASE READ THE SAFETY STEP. Thank you.

So you want to build an electric vehicle of sorts and have chosen to use a skate/long board? You have come to the right place! For me personally I wanted to build a DIY eSK8 because I can't ride a regular board to save my life because my lack of balance. But the main reason was because as we move through time electrification has begun to retake* the auto industry and intercity travel. Plus who wouldn't want to experience the immense and sudden feeling of instant torque that comes with using a motorized board? With this let's begin!

*more about this in the sources section

Additional information will be commented into the pictures to help guide you.

More pictures, information, and fixes will be added periodically.

Supplies

I'll add to the list as needed anything listed is either from Home Depot or I didn't have a link yet.

Tools Used: (With Links!)

- Propane Torch

- Soldering Iron https://www.amazon.com/gp/product/B07S4GPM66/ref=p...

- Solder + Flux

- 3D Printer (Ender 3)

- Basic Tools

- Drill https://www.lowes.com/pd/Kobalt-24-Volt-Max-1-2-in...

- Bits

- Phillips/Flathead

- Metal Saw/Miter Saw

- Angle Tool https://www.lowes.com/pd/Blue-Hawk-14-in-Blade-x-2...

- Sander/Sandpaper

Bill of Materials:(With Links!)

- Skate/Long board https://www.amazon.com/gp/product/B071FC2SBW/ref=p...

- RC Controller https://www.amazon.com/gp/product/B07DPMVVKN/ref=p...

- Motor https://hobbyking.com/en_us/turnigy-sk8-6364-190kv...

- Motor Pulley + Gears https://www.mboards.co/collections/pulleys-and-mou...

- Batteries https://liionwholesale.com/collections/frontpage/p...

- Wires Various: (As much as you need)

Extension Cord (Orange)

10 AWG

12 AWG

22 AWG

- Connectors: (all on Amazon)

3x XT90 Anti-spark Connectors Sets

2x 5mm Brass Connectors Sets

4x 10mm Brass Connectors Sets

LED Connectors

Balance Wire Connectors

Assortment of Circuit Connectors

- ESC (in my case FSECS 6.6) https://flipsky.net/products/fs-esc-6-6

- VESC Tool Software https://vesc-project.com/vesc_tool

- Charger https://www.amazon.com/gp/product/B07P863S9D/ref=p...

- Circuit Breaker https://www.amazon.com/gp/product/B0756D7P5N/ref=p...

- Voltage Readout Display

- Unicorn Puke (RGB LEDs)

- Nuts and Bolts (As needed) (Lowes/Home Depot)

- Aluminum 1" 90° Angle (~8ft.) (Lowes/Home Depot)

- Aluminum Brazing Rod (Lowes/Home Depot)

Step 1: Safety First!!!

With any project that is pursued safety should be the number one concern.

You should wear gloves, masks, and safety glasses when appropriate.

Disclaimer: I am NOT responsible for injury/death that can possibly occur in this project with either the final build or the during the build. I by no means claim to be an expert in EV tech but am sharing knowledge to help you.

I only say this because injury is something with any project and I have fell off the board once out of my own negligence but I have also burned my hand from brazing, soldering, and welding. I have even got a burn from a battery because of not paying attention. I say this simply to help you stay safe. With that said about the battery I am using 18650 Li-Ion batteries that are "safer" than LiPo batteries but I still take precautions when charging them initially. I also have a safety release connector for connecting the two batteries in case I need separation. More on all of this later.

Step 2: Objectives

The biggest thing that I was unsure of when I started was what I wanted to do. It is good to have some sort of objective or end goal for this build. Since I enjoy the feeling of instant torque when I pull down the trigger on my receiver that was a focus. I also wanted to focus on range. Here is a list of objectives that I had plus ones to consider.

Objective List:

- Safety

- Torque

- Range

- Stability

- Cost

- Functions

- Speed

- Ride Height

- Design/Look

Step 3: Layout of Electronics

To start, I would like to thank Robert from FEx-Systems for helping the electrical schematics. Link to his Instructable profile in the sources.

Although this may seem like something that you can skip over let me assure you that that is not the case. When I made the version one of the board I skipped this step and in the end it led to me burning out 40 batteries prematurely and forcing to me to buy another set. In the schematic I made sure to include a few features such as a battery safety key, a distribution board, balancing wires, voltage readout, and the ability to fast charge. Some of the pictures will be backwards but that was because of how they were put together with the bottom of the board facing up. A custom circuit was even made in order to create a distribution board that both stepped down the voltage for the readout to 1/10th and so that the 37v nominal doesn't burn out the unicorn puke. By also using a wiring schematic we are able to see where all the wires need to go to and takes the confusion out of it all when it comes to building the board. Unless you are following my build to a T then your layout will be different than mine in a way. There is also a basic setup that makes it easier to understand.

Step 4: Selecting a Motor and ESC

Remember the goals/obj. that we set for ourselves earlier? This is where it begins to take light.

The motor and ESC are important because they will determine the attributes of the board to a degree. The ESC and motor will both limit the amount of Amps that can be utilized. The other factor that determines the board will be the battery, and as I have said before, we will talk about it more later. But I digress.

The ESC that I used is the FSESC 6.6 from FlipSky while the motor is a Turnigy 190kv 6364 from HobbyKing of all places. I linked both products in the BOM list for more information. These two paire perfectly since the motor was rated at 60 Amps max and 2600 watts max. For reference with a 12s battery paired with this ESC and motor give a power of 2.6kw. This converts to ~3.5 horse power! I chose to make this board a one motor setup because of reasons such as 2 of these motors would be hella overpowered but also because of cost restraints at the time. I also used a heat sink from an old car amp that fit perfectly around the ESC since some of the energy that passes through WILL turn into heat. This is important because just like a voltage regulator for a CPU/GPU if they aren't kept cool/stable then it will start to have fluctuation in it's power output and will perform worse and ultimately when too hot fail.

There are several other options for motors and ESCs to choose from. If you want to understand more about motors specifically then I would recommend watching Jeremy Fielding on YouTube.

Step 5: The Battery and Case

The battery is something that took the most time for me to put together for a few reasons: 3D printing time and designing the case. For the battery I wanted to fix my $100 mistake that I previously made (as described in my mistakes step). I decided to build a modular pack that was easy to replace both each pack but also each battery in a pack. For my battery I made each pack 1s 5p which totaled to make two sides that are 5s5p each. The battery totals a 10s5p battery with 12.5Ah in it. Before I get too much further into this I do want to state that you can get legit batteries for as cheap as $2.50 each brand new. I cannot understate how important it is to not skimp on the batteries, NEVER EVER buy any battery that has the name "Fire" in it. These are the batteries that essentially didn't pass the QC but are still sold in short. You NEVER want to skimp on the batteries as they control your life when you are on that board just like the other main parts like the ESC and motor. Quality batteries will last a lot longer and are more reliable. If you are wanting to salvage batteries then be my guest but be sure to take the precautions that are involved with that process. I also do not recommend using eBay for that because the vultures on there tend to over price out of their minds.

I used Samsung 25R batteries that are 3.7v nominal (4.2v max) with 2500mAh in each and with a 10s5p setup this gives us a total of 37v nominal (42v max) and 12,500mAh. Since this was a DIY battery the total monetary cost was ~$145 and patience to wait for printing and making the packs. But this is opposed to a $400+ battery for the same specs. Here is a link to the ones that I bought (on sale at the time):

https://liionwholesale.com/collections/frontpage/p...

So why did I use 18650 Li-Ion batteries instead of LiPo batteries that are commonly used in RC? One of my objectives was to have range>speed which is one of the reasons. The other reason that stood out to me is that LiPo batteries have a bad habit of when they do go critical they go all out. If you searched for an explosion of both types of batteries you will see that the Li-Ion are a lot safer if they fail. The reason for this is because LiPo batteries are rated to discharge at 30C. Li-Ion batteries aren't rated nearly as high. This is why people that use the smaller more compact LiPo cells will have a faster speed but they also will sacrifice range.

I have the modular packs available to download on Thingiverse but only in one size, sorry. I printed the cases with red or blue on the side corresponding with the negative and positive terminals. The layout of the battery along the board is something this is important too so that you don't bend longer batteries. Or make a metal case like I did.

https://www.thingiverse.com/thing:3815912

The case was made from 1" aluminum right angle that was cut and brazed into a frame shape and placed an aluminum sheet on the bottom followed by kap tape and silicone to make it water resistant. Even though these batteries won't explode of catch fire as much as a LiPo battery I still prefer to have precautions in place. The bottom of the case is protected by double pane acrylic sheets.

Step 6: Charging

The time has come to test your completed battery. In this step I would recommend that you disconnect everything from the battery that isn't needed (IE: ESC, motor, in my case it is 2 sets of 5 so disconnect the link between them AKA "The Key"). This will put you a little on edge as we are utilizing lithium ion batteries. BEFORE you BEGIN charging I suggest taking the battery to a location that is unable to catch fire. In my case I put it on top of a metal table in the garage and since it was summer time it was actually better for the batteries since they were warmer to charge. Li ion batteries don't like the cold! Since my battery design doesn't use an internal Battery Management System (BMS) the batteries weren't completely balanced. Before I had put the entire pack together I actually charged and measured each 1s5p modular packs to get it close; but I digress. When beginning to charge you should do so at 1C. Example: my battery is 5 cells per side and 5 batteries linked together. So with this it was 2.5 x 5 = 12.5 A. On the first charge I did NOT use that amount, I charged slowly at 5 amps so that the batteries could become conditioned to their new setup. This took a very long time but it has been worth it so far. Faster charging (at higher than 1C requires cooling to be more safe) but is doable. When you charge your own you need to probably watch it for the 30 minutes to an hour. Check the temperature of the batteries often even after you are done watching them. If you choose not to watch them and they catch fire, besides me not being responsible for this occurrence, they burn for a while and cannot be put out easily. Look for videos on YouTube to see safety and fires. In my case I am using 18650 batteries and they are a lot safer than the lithium polymer packs used in RC.

Step 7: All My Mistakes and Previous Versions

I learned so that you don't have to! Or you can still try it out and improve it perhaps. Each picture will have a description on them if it is needed.

Step 8: Version 1 Battery

This battery seemed like a good idea initially to me because not only were the materials super cheap but it was also dense and fire resistant. But it was bulky and heavy. I don't recommend this if it is under a board as it will scrape on the ground when you lean to turn. It did work though and it kept the batteries cooled using a passive air flow through the case as the board was propelled forward. The V2 battery uses the same modular packs but is house in an insulated aluminum case that has silicon on top to water proof it from stagnant water. The bottom side features a double pane acrylic to be able to see the batteries 'cause they are purdy. Of course to add to that it also has a blue under glow.

Step 9: Version 1 Charging Connector

This was used with the V1 battery as it was designed specifically for it. This was functional and kept liquids from entering the top of the charging ports and causing a short. I tried to use them in the V2 battery pack, but alas they were too big and didn't fit with all of the other components/electronics that went into the junction box.

Step 10: Version 1 ESC Case

This was a good idea gone wrong. I initially wanted to use this as a custom junction box for all of the circuits and components while featuring active cooling. I did keep the breaker (150A) but put it with the junction box for the V2 battery. It was a good idea but not as nice and functional as the V2 ESC case.

Step 11: Sources!

Having places to source your information is great and can help others if they don't understand what you are talking about, for simplicity I will only be posting links:

https://www.energy.gov/timeline/timeline-history-e...

https://www.instructables.com/member/FEx-Systems/

https://www.youtube.com/j69films

I will add more to this guide and experience as I go or think of more to add. Thank you for visiting and if you made this far I really appreciate it!