Robot Car Chassis

thingiverse

This is my first original design, working with the universally popular Robot Car Kit widely used by hobbyists. For several reasons, I've chosen the 2-wheeled ones. These kits usually come with a laser-cut chassis made from acrylic, which is easy to mass-produce but very fragile: I accidentally mishandled mine and it ended up shattered on the floor... At this point, I was also aware of the limitations of the original kit, so in designing mine I added several new features: - The rear wheel doesn't support sharp turns, it sways too much, so I'd be using a ball bearing to improve its stability. - I wanted to have as much space on the top side as possible, so the battery pack (a phone Power Bank, in my case) had to be positioned on the bottom side to free up more room for other components. - The motor supports were weak and prone to cracking, so I've re-engineered them with a stronger design. The first version (purple in the photos) had the pieces glued together: it's worked beautifully, but I wanted something even easier to put together that didn't need precise measurements when assembling. I then modified all the pieces with inserts, and with the attached design the pieces snap together and stay in place without glue: I left a screw slot in case the two main halves weren't firm enough, but I ended up not using it in the final assembly (it's there in the original glued build). YMMV, obviously: it may happen the inserts are too loose (use a bit of glue) or too tight (nothing that a bit of sandpaper can't solve). The pen holder is optional (and it's the only piece that doesn't snap in place - you can use glue or nut & bolt): I've modified it from [this](https://www.thingiverse.com/thing:1052725), making it bigger to fit the markers available around here. I've made all the other pieces with Tinkercad, and the designs are available separately. The full chassis is on [Tinkercad](https://www.tinkercad.com/things/gGIWb2aqz0D) __Update 12th May 2018__ I've uploaded a different version (the new pieces are marked with _v2_, if there's only one version of the piece then it's unchanged), with the following differences: - The back is now as long as the front, so the total length of the chassis is 200 mm: this allows for the positioning of a battery dedicated to the motors, while the power bank still provides the 5 V for the electronics. - The wheels are now mounted backwards, to have the center of rotation in a more neutral position. - The hole for the pen is still centered between the 2 wheels, so its position is behind the holes for the wiring. New pictures have been uploaded to show the changes. __Update 19th May 2018__ Added an optional support for optical encoders: a picture shows how they're mounted over the existing motor support. There's one, that needs to be mirrored, same as for the motor support. __Update 20th May 2018__ Added a different, low profile pen holder, embedded in a fake cockpit: this is exclusively for aesthetics, and print as a single object, however it's also available on [Tinkercad](https://www.tinkercad.com/things/aVVQlMA9k00), if you want to use only part of it