Electric Mountainboard [V1] – Dual 245kv Motors + Max6 ESC Tutorial & Parts

PEX - Electric Mountainboard Trampa Holypro DIY - Custom motor mount

This electric mountain board has a perfect ratio between torque and top speed with crazy acceleration!

The purpose of this page is to detail all the required parts and steps to build your own electric mountain board.

  • Budget for mechanical parts and electric components: $380 (USD)
  • Budget for the mountain board with wheels, trucks, and deck: $620 (USD)
  • Overall budget: $1000 (USD)
  • Build time: 10 hours to one weekend
  • Theoric speed of my current setup: 50km/h – I reached 55km/h with this setup!!
  • Range of my current setup with 8S 10000mAH: 20km

This page is detailed and aims to popularize the concepts and use of each component for beginners. For advanced makers, please go directly to the parts list and wiring diagrams.

Check also my Electric longboard tutorial! (cheaper and easier build to start with)

Read this section before to start

Check the conditions of use of this website and particularly the disclaimer

Learn how to ride a skateboard first, it’s very important to learn skateboard basics before to start this project. This will prevent you from injuring yourself by taming the engine’s propulsion in addition to attempting to manage your balance and steering.

This project requires tools and specific equipment. I personally add to use a soldering station because my batteries’ connectors were not standard and I had to use a hot glue gun, a hex key set, an electric screwdriver, my rotary tool to adapt my truck to my motor mount and to create a handle in my deck. These tools could be totally optional and I will detail one setup below that require just some tapes, screws, hex keys and sockets. In addition, you can check the list of tool that I would suggest to any hobbyist. I would like to recommend to buy a skateboard tool as it brings together all the socket sizes needed to set your trucks and wheels and a screwdriver

Check the Basics of a diagram of an electric skateboard

Electric Mountainboard parts

This setup is composed by 4x 4s 5200mAh Batteries, 2x 245kv motor, 2x 160A ESC. I have designed my own motor mounts, ESC Enclosure adapted and 72T wheel pulley and it has reduced my budget significantly. This build will cost approximatively 1000 USD. FYI, I had very good results with a 6S setup, especially when I am downtown and I don’t need to go or can’t go full speed. It’s smoother for commuting with stops and pedestrians. So, I have an 8S set for when I want to cruise at higher speed and 6S set when I am commuting.

You are free to source similar parts on your own, but note that I have tested this part list and it works well. Using any other parts is your own responsibility: check the specifications of the suggested parts to be sure that it matches your locally sourced part.

If you don’t want to design your own motor mounts, enclosures and pulleys, please check the kits I propose here.

Build parts

Main components

Connectors

  • 2 x XT60 to XT90 adaptors (I wanted to be able to switch from one build to another, using only XT60 as all my builds are not using XT90 as well as my charger)
  • 1 XT90 Series Cable (choose Type C)
  • 10AWG Silicone Electric Wires (Red and Black) – I used 1 meter
  • XT90 Connectors (I used 3 Pairs, to create a battery lead)
  • 1 x XT90 Parallel Cable (to connect both ESC to the battery lead)
  • 1 x XT90s Anti Sparks Connector (to make a XT90 Key and prevent sparks, might be overkilling if you use MAX6 ESC as they already have a anti spark protection but I prefer to double it)
  • JST XH Extension cable (Depending on the battery cell number you choose. I used these for connecting the Lipo Checker on top of the battery box to the batteries balance cable inside the box)
  • 6 x 5.5mm Bullet Connectors (to adapt the motor’s bullet, as I received them with 4mm bullets, and the ESC’s are 5.5mm)
  • Servo Cable Splitter (to connect the Receiver to both ESC)

Batteries and chargers

  • The batteries I use are not sold anymore, I bought the 4 last pieces from Hobbyking. Some units are available on eBay but they might be fake or overpriced. I will list Batteries in another Tab in this section so you will have choices. I love the ZOP Power sold by Banggood. I have 4 of them for my other builds and they are cheap but very reliable.
  • 2 x Lipo checkers (These are basics and for this build, I chose to have quality and precise lipo checker this time, I have the iSDT BC-8S 1-8S  Lipo checkers. and I have to admit these are amazing!!)
  • 1 x ISDT Safe Parallel Charging Board
  • 1 x Charger. You need a robust charger with at least 8Amps charging capacity
  • 1 x Power supply + 1 Power chord adapted to your country (mine is 110V only). You need a 300W min. power supply rated for 8A minimum to charge the batteries. I would recommend that the power supply is rated for at least 300W to fully use the recommended charger but you can find cheaper alternatives that are rated for less (it will just be less efficient). I have bought a new one a few weeks after (this one) as I wanted something light and easy to travel with.

Tools and Misc.

DIY / Custom Part

Misc.
Gears/Protections

 

Build

Wiring schema

Wiring diagram - PEX Eletric Mountainboard

Wiring diagram - PEX Eletric MountainboardESC Configuration

Connector

The objective is to remove the 2 T-Plug connectors that come with each ESC, shorten the wires and add a new male XT90 connector.

Please use safety glasses and proper tools as you could hurt yourself. If you have never used a soldering iron and you are not sure about getting into the conversion of the connector, ask someone who has the experience to do it.

Requirements

  • Electric Mountainboard [V1] - Dual 245kv Motors + Max6 ESC Tutorial & PartsSoldering station
  • Welding wire
  • 2x XT90 male connector
  • Heat shrink tubes

Steps:

  1. Cut the black wire at about 6cm from each ESC unit T-Plug connector
  2. Cut the red wire at about 6cm from each ESC unit T-Plug connector
  3. Strip about 5mm of the end of the black wires
  4. Insert each black wires into a piece of heat shrink tube
  5. Strip about 5mm of the end of the red wires
  6. Insert each red wire into a small piece of heat shrink tube
  7. Solder each red wire to the + side of one XT90 MALE connector and then the other XT90 MALE connector
  8. Insulate the solder by heating the heat shrink tubes
  9. Solder each black wire to the – side of one XT60 MALE connector and then the other XT90 MALE connector
  10. Insulate the solder by heating the heat shrink tubes
Electric Mountainboard [V1] - Dual 245kv Motors + Max6 ESC Tutorial & PartsThrottle calibration
  1. Connect the batteries to your ESC(s)
  2. To calibrate the throttle min/max, hold the set button down before you turn on the ESC and keep it down as you power it on
  3. Release it as the red light blinks. Release too soon or too late it will not get into the throttle calibration mode.
  4. Turn on your transmitter with all commands set to their neutral position
  5. Use the throttle command to reach the maximum position for acceleration and hold the position
  6. Press the calibration button, you should hear beeps
  7. Release the throttle to the middle position
  8. Use the throttle command to reach the maximum position for braking and hold the position
  9. Press the calibration button, you should hear 3 beeps
  10. Release the throttle to the middle position you should hear beeps
  11. Test the throttle to ensure that the process is done: you should be able to accelerate.
  12. Turn your transmitter off
  13. Turn the ESC(s) off
ESC programming

Link to the product page

Link to the manual

Link to the software (if you want to use a computer)

Change the settings as follows:

  1. Running Mode: Fwd/Br (you can also use Fwd/Rev/Br if you want to have reverse mode)
  2. LiPo Cells: Auto Calculation
  3. Low Voltage Cutoff: Intermediate
  4. ESC Thermal Protection: 105C
  5. Motor Thermal Protection: Disabled
  6. Motor Rotation: I have both CCW because I have tested my wiring with the motor before changing parameters in the ESC. You can either switch two cable of the motor or change the value here if you motor do not spin in the correct direction)
  7. BEC Voltage: 6V
  8. Max Brake Force: 50% 
  9. Max Reverse Force: 25% (or Minimum)
  10. Start Mode (Punch): 1
  11. Drag Brake: 0%

Transmitter + Receiver setupElectric Mountainboard [V1] - Dual 245kv Motors + Max6 ESC Tutorial & Parts

Motor mount

ESC + Radio receiver

Battery enclosure

Overview

Issues and feedbacks

Motor shaft

The SK3 motor shaft is perfectly circular. However, most engines of this type have a flat face which allows tightening one of the motor pulley screws which makes it possible to fix the pulley to the shaft with a better grip. During my maiden ride, the pulley of my left engine began to slide on the shaft and almost be stuck to the support of my engine … it could have blocked the pulley and severely damage the motor. I therefore file each shaft to add a flat face.

Discharge rate of my batteries

My 4S battery set was rated for 15C discharge (30C burst) and I experienced some jerky starts. I would recommend batteries with discharge rate higher than 30C.

Carrying the board

It’s very heavy compared to my electric longboard!! In order to travel, I just grab the front truck and let the rear wheels on the floor and I just pull it. I am working on a handle to make it easier.

Update #1 – 20171120 – Motor protections

  • 3D Printed enclosure for the motors and the belts

Update #2 – 20171127 – Announcement

I am in the process to upgrade my setup with the following parts:

  • 2 x FOCBOX VESC (I am very satisfied with the Max6 ESC! the FOCBOX is a slightly upgraded VESC and it was on sale for Cyber Monday so I took the opportunity!)
  • 2 x SK3 6374 190kv 4000w motors (Again, it was on sale!)
  • 8S / 10S / 12S battery setups
  • Bluetooth module for mobile tuning on the field
  • Hall sensors (I will add sensors to my SK3 for ultimate smooth starts in snow/hills)

I am also designing new items:

  • Dual FOCBOX enclosure
  • New motor mounts (lighter, smaller footprint and with integrated belt tensioners)

Stay tuned!

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