The goal of the project was to challenge myself in building something complex with limited manufacturing equipement, while I was on co-op at Tesla. I was able to buy a Raise3D E2 3D printer, capable of printing more advanced 3d printing materials. Therefore most things had to be printed.
Design Requirements:
- 3D printed as much as possible
- Portable and small as possible
- Easy to ride
- Durable and strong
Current Designed Specs:
- 20 mph top speed
- 36 V system
- Up to 2.1 kW continuous
- Single motor belt drive
- 6.5 in pneumatic wheels
- Front rear running lights
- 31 in long
Design Requirements:
- 3D printed as much as possible
- Portable and small as possible
- Easy to ride
- Durable and strong
Current Designed Specs:
- 20 mph top speed
- 36 V system
- Up to 2.1 kW continuous
- Single motor belt drive
- 6.5 in pneumatic wheels
- Front rear running lights
- 31 in long
Deck
Designed in Fusion 360, I was able to gain experience using a different CAD package. The deck is composed of 4 sections printed out of carbon fiber infused PETG that interlock and bolt together, with 3 high strength aluminum tubes running through the length for reinforcement.
Trucks
The hangars are made of Markforged's Onyx, which is nylon infused with milled carbon fiber strands, making it strong and durable, yet still enough to not deform too much when riding. Bolts with captured nuts are used to reinforce the 3D printing layers, parallel to the printing direction.
The baseplate is made of Markforged's 17-4 PH Stainless Steel, printed on the Markforged Metal X. Metal is needed as the Onyx version does not hold the kingpin in place, and deforms when trying to turn, significantly impacting turning radius and stability.
The baseplate is made of Markforged's 17-4 PH Stainless Steel, printed on the Markforged Metal X. Metal is needed as the Onyx version does not hold the kingpin in place, and deforms when trying to turn, significantly impacting turning radius and stability.
Electronics
For the battery, I used a pre-built 10s2p battery pack from Mboards, with a built in BMS. Largest contraint with choosing the battery was size and supply. Lithium-ion battery cells were in short supply at the time of the project, therefore had to settle with a 10s (36V) instead of the usual 12s (44V) I tend to use. Using the lower voltage reduces overall performance, as well as requires more amperage to achieve performance, therefore the motor controller and motor run hotter.
I used a VESC 6 (vedder electronic speed controller) motor controller from Trampaboards. They are open-source speed controllers purpose built for these applications. Paired with a Bluetooth module and app, all VESC settings can be adjusted on the fly.
Using The Wand remote from Trampaboards, data such as speed, battery percentage and range, as well as VESC and motor temperature can be seen mid ride.
The motor is a 6380 outrunner from TorqueBoards. Rated at 170kv, it provides a good max rpm while having great torque. Max 80 amps.
I used a VESC 6 (vedder electronic speed controller) motor controller from Trampaboards. They are open-source speed controllers purpose built for these applications. Paired with a Bluetooth module and app, all VESC settings can be adjusted on the fly.
Using The Wand remote from Trampaboards, data such as speed, battery percentage and range, as well as VESC and motor temperature can be seen mid ride.
The motor is a 6380 outrunner from TorqueBoards. Rated at 170kv, it provides a good max rpm while having great torque. Max 80 amps.
Manufacturing
Almost the entire project was 3D printed on my Raise3D E2 (except for the trucks). I was able to make almost all parts in my apartment, only a Dremel and soldering iron were needed. Large issues that I faced were primarily warping, the large deck parts were initially printed out of polycarbonate. However, the printed came out extremely warped. Switching to carbon fiber infused materials solved this issue as the carbon fiber reduces warping and hold great dimensional stability.
Other issues faced were the hangars not being strong enough in direction of printing. I first used carbon fiber polycarbonate, but its interlayer adhesion strength is not enough. Markforged Onyx has much better interlayer strength. That along with the bolt reinforcements created a robust hangar.
Other issues faced were the hangars not being strong enough in direction of printing. I first used carbon fiber polycarbonate, but its interlayer adhesion strength is not enough. Markforged Onyx has much better interlayer strength. That along with the bolt reinforcements created a robust hangar.