GRIZZLY THE BEAST
VIDEO UPDATED VERSION: https://www.youtube.com/watch?v=GkbS5wBx1F4
VIDEO REVIEW (Belt drive version): https://youtu.be/hG2AWRF3NqQ
This is my second and inevitably my most awesome esk8 build so far! After the roads started getting worse in my region and because I love mountain biking I felt a need to take my esk8 adventure off-road. At first I wanted to make a budget EMTB but I discarded that idea fairly soon. If there is one thing I learned from my first build it’s that buying cheap is often buying twice. Doing good research is essential for making a nice working board in which all the components operate in harmony. For my first build I barely used the esk8 forums, but now that I’m part of this amazing community it’s easy to find information and get tips from experienced people. I also used the video series of @Lee_Wright for my battery build which was really helpful. After spending most of my savings and a lot of time on R&D I got an amazing powerful fun torque machine!
I am sure I will keep working on this baby for quite a while… slowly upgrading it.
For the cost of this build… well… I stopped counting but I estimate it to be around € 1500 including shipping, import fees and additional parts and tools I had to buy.
I am going to start off with showing you some fun stuff because that’s what most people will firstly notice in these posts anyway
I drove the board through some hilly forests and it works like a charm, tackled every hill I encountered with success. It is just lovely to fly through the woods with a Trampa board strapped to your feet.
Two days ago I joined a group ride at a racing track in Belgium (circuit Zolder) and met some fellow builders also active on the forum, was great seeing them in person! Of course here I tested the road capabilities of the board (will definitely be needing some weights to balance my wheels though). Hit a top speed of 40 km/h and the torque proved amazing. The board absolutely kicked ass during a small drag race.
(I know one mount has shifted… thats cuz I hit a rock while going 25kmh through the forest… have to re adjust the position sometime soon…)
- Trampa HS11 brake deck 15 ply
- Vertigo trucks with red springs yellow dampa’s, and gunmetal baseplates
- Prima alpha tires
- Matt black superstar hubs with blue anodized spokes
- Ratched style carbon print bindings with gunmetal mounting brackets
- Old style Trampa pro belt drive (motor pulley: 15T wheel pulley: 66T)
- Custom designed and 3D printed top mount battery and vesc enclosure
- Dual FOCBOX
- 12s6p Samsung 30Q homemade battery
- Bestech D140 BMS
- Dual Turnigy sk8 6374-130kv
- GT2B remote (3D printed custom enclosure)
- Metr pro module (recently added)
- 12s 6a charger with Female XT60
The board and drive:
I bought the pro belt drive from @atenner , he’s a great guy and im thankful for him selling me the drive at a great price. This purchase gave me almost all the parts I needed for the drive. However, it was quite a hassle to put the old drive together due to the large amount of screws. This was partly the reason @atenner sold his drives and replaced them with the new versions of the Trampa belt drive. However the drive looks stunning when mounted.
Then I needed some motors, I thought about buying maytech 130 or 150kv motors but couldn’t find any that were in stock so I ended up buying the hobbyking 130kv sk8’s which are a great value IMO (at least until now). I had to make custom motor shaft spacers to ensure the motor shaft will not come loose and align the motor pulley with the wheel pulley. I ended up shortening the brass spacer that comes with the sk8 motors as my spacer. I used the dimensions of the motor shaft spacer that comes with the Trampa motors since the dimensions can be found in their documentation.
Also got some 3D printed guards to fit on the mounts… the drive looks absolutely stunning!
At first I wanted to go with a NESE battery setup, but when I got offered a sunkko 737g spotwelder for cheap so I chose to spotweld my battery. Later on I found out that the sunkko spotwelder wasn’t ideal due to the fixed welding contacts and the bulky battery pack I was making. I ended up choosing a 12s6p setup and choose Samsung 30Q cells which I got through a groupbuy by @pjotr47 this really turned down the costs of my battery. I also got a Bestech d140 charge only bms for a good price from a forum member.
I build the battery during a weekend, having never build a battery before and being a noob in electronics I think it turned out pretty well. I isolated the positive sides and in between the P groups and following @Lee_Wright ’s tutorial I beefed up the negative and positive terminals of the pack. I have to admit I was quite nervous while building a pack this large but being patient and planning the build really helped making sure I didn’t blow up my house.
I wanted to design my own battery box because I am not really a fan of the peli cases. I wanted the design to be simple so I choose a simple square box design. I made two square cut-outs on the side where the focboxes would be mounted to allow the heatsinks to do a better job. I also made one large hole on the side to mount a water proof connecter for routing my motor and sensor wires. On the bottom I placed 4 holes for m6 bolts to attach the box to the board. A large aluminium plate was used as a shim to provide a larger surface area for clamping. I covered the aluminium plate and bolt heads up with thick paper and foam to prevent it from rubbing on any components. Lastly I added a hole for the loopkey and the charger port. The first case was printed in two parts because I didnt want to let my printer run for 60 hours…
A week ago I ended up altering the design and printing a new case in one piece to improve the strength and some other small things (the box broke when i accidently full throttle smashed the board into a wall… lol
I also added O-rings, a rubber mat between the enclosure and the board and a rubber strip on the lid so the box should be at least splash proof.
(Old enclosure but you get the picture… )
I designed a loopkey and chargeport holder and port covers for the XT90 and XT60 which in turn could be mounted in the enclosure and the enclosure lid (inspired by @mmaner ’s designs). https://www.thingiverse.com/Creavenger/designs
For the remote, I 3D printed a case from thingiverse: https://www.thingiverse.com/thing:1713157
I used this mod for my streetboard aswell and I like the simplicity and the feel in my hand even though it’s a bit bulky. The GT2B never let me down and does what it is suppose to do at a great price point.
I started this build while I was writing my engineering degree thesis… When I felt so done with my thesis, I would go work on my board which kinda helped me through the process of graduating I guess. Of course the board also distracted me from my work sometimes…
But standing on my board all suited up after the graduation made me look back and appreciate this amazing hobby. It’s really a great fun and a good learning experience!
Stay tuned for more I guess…