Electric Mountainboard Winter Build - Trampa Holypro - Dual SK3 245kv / Max6 ESC


Here is my attempt to create a Canadian road/winter friendly build. I based this build on a Trampa Holypro 35 and dual SK3 245kv / Max6 ESC. I designed the motor mounts, ESC enclosures, TPU seals, Lipo checker enclosure and wheel pulleys. For the battery box, I used a Pelican 1150 box. Right now, the ESC enclosure is splashproof (the ESC are already waterproof, so I am not really worried about it) and there is a TPU seal printed in order to insolate the wires. I design the motor mount in a way I can add motor protection at 250 degrees around the motor, making almost a complete enclosure (the photo are showing the first version, I wait for new PETG spools to print it!). The battery box is perfectly watertight (I have printed TPU seals for all wires, connectors). If you want to check the details, I have created a tutorial draft for this build.

What I have left to do:

  • Design something to keep the battery box warm inside for allowing LiPo batteries to work properly when the temp is low. I was thinking about hand heaters, but I have not tested this yet. Does anyone has tested something similar?
  • Motor protection would be splash proof but I am wondering how to ensure to prevent snow/water to go in the motor around the motor pulley… does anyone have a solution to protect completely a motor (for an e-MTB)?
  • Design belt protection (I have integrated into my current design enough room to add belt cover + mudguards).

Also, I was wondering if the belt work as good under very low temperature: is it cold resistant?

Do not hesitate to comment and share your own experience :slight_smile: English is not my native language so please forgive any mistake :smiley:

Here is a video of the first ride: https://www.youtube.com/watch?v=JfdFzbUw5ZE

… and a few photos:


Really nice build! Loved the tutorial. Will be watching your progress closely as i too have snow for half the year. Heat trace wires for battery enclosure warming? Just a thought.

Hello @Lionpuncher Heat trace wires might require more voltage in order to heat up enough no? (at least the heat trace wires I know!). are you thinking of using one to heat up the enclosure and then unplug the heat trace and go to ride? I am not sure if heating at the beginning and then rely on the lipo for continue heating the enclosure is enough. If not, using one additional battery to make something similar might worth the extra weight. I will try also the hand heaters because it is a very cheap option but thank you very much for your comment and your idea, I will definitely investigate this track!

1 Like

@PEX if this is for the winter, @barajabali used to have tire chains available for sale…


thanks @treenutter but I am planning to print my chains if needed :slight_smile:

1 Like

@Lionpuncher my investigation led to this 5V heating pad…I will try it with something like a small power bank for phone

1 Like

Perfect! Seems like a good place to start. If it isn’t enough, i have to think there’s other designs that exist.

Nice build. Never thought that items can be above the board also :smiley: For heating things… Why not just use magnet wire or kanthal wire?

Offtopic: Just curious, how much your board weights in total?

Approx 13kg. without batteries. Nice idea! I was building my own resistances for e-cig a few month ago before quitting smoking, it seems not complicated to adapt something similar. Plenty of options for my battery box, thanks!

1 Like

Quick feedback after two evening rides by -5C (feeling -14C) last week and 6C (feeling 2C) yesterday. My motor protection works well but I tough that projections would come from the back and not from the inside of the board, the motors are still protected but I will improve the enclosure to correct this. I tried to ride on frozen grass there is no traction problem at all, this is a monster! The tires were humid and the belt two, but the motor were dry after my rides. Regarding the temp, the enclosure is very efficient on keeping the temp up the battery were nicely warm during my 2 rides. I will test the USB warmer when the temp will be lower but right now there is no impact at all on my range or battery efficiency.


Really nice build!!! I’m curious what Lipo’s you’re using and how many mAh?

I’m also interested in seeing how it does in the snow! I’m looking forward to trying my Urban Carver setup in the Canadian snow this year (I’m in Southern Ontario)


Thanks @cosmicc89 :smiley:

I am using 4 sets (by order of preference):

  • 2 x 4S 5000 mAh 60C in series (8S 5000 mAh) (for short but intense runs / 10km range max)
  • 2 x 6S 5000 mAh 60C in parallel (6S 10000 mAh) (for longer but intense runs / 15km range max)
  • 4 x 4S 5200 mAh 15C (2P2S -> 8S 10400 mAh) for my long runs (20km range max)
  • 2 x 3S 8000mAh 30C in series (6S 8000 mAh) (when I have only these left… 15km range)

I will make videos in the snow as soon as I have enough snow :smiley:

1 Like

Very cool, thanks for the detailed info. I like seeing what other people use and what kind of range they get.

And looking forward to more videos!

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

  • 2 x SK3 6374 190kv 4000w motors
  • 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!

1 Like

Really nice. Can we get a photo of the battery checkers when they are turned on?

I will take a picture when i can but in the meantime here is a video in which you will see the checkers on (the motor mount on the video was an early design but it’s the same setup) https://youtu.be/ZuXeHWPnI8s.

Also you will find the specs and the other screen configurations here http://makertuts.com/enclosure-isdt-bc-8s-1-8s-lipobattery-checker/

How did you mount your Pelican? Super clean build man, really nice stuff!

1 Like

Thanks :slight_smile: I drilled 4 holes in the pelican box and the board and used 4 m3 screws to mount it.