Skate-oko-asaurus: The self replicating skateboard
We build a lot of skateboards for fun at Inventables. Some of the guys even sell them at local craft fairs. They thought it would be cool to have a CNC router optimized for skateboards that was easily portable. I first thought about putting wheels at one end, then realized the machine itself could be a skateboard. We thought it would make a perfect Gonzo Build.
A Gonzo Build is something we came up with at Pumping Station One CNC Build club. The concept is that we try to build an original, “one off”, CNC machine in one evening. They also tend to have a whimsical aspect to them, so we don’t take ourselves too seriously. We usually get about 8-12 people to help build. If parts need to be fabricated, they must be done that night on -site.
Building a stock Shapeoko 2 in one night is a challenge in itself, but we decided to up the challenge by totally tricking this out with every feature we could think of. We did have a few master CNC building ringers in the group, like Tait Leswing and David Ditzler.
Here are the stats of the machine.
- 1200mm x 250mm work area
- Skateboard specific wasteboard supported by additional extrusions. It is narrower than a stock Shapeoko 2 and about 3 times as long.
- Drag Chain
- gRAMPS Controller running grbl 0.9.
- Quiet DC spindle with full speed control.
- Feed hold / Resume / Reset buttons
- Homing switches on all axes
- Auto Z zero with Z probe
- Trucks and wheels
- NEMA 17 motors with dual Y stepper drivers.
- Portable dual 24V/48V power supplies with master power switch.
Most of the Shapeoko parts came from reject area at Inventables, so there are a few dings and scratches.
The wasteboard was cut from 5/8″ particle board on the PS1 Shobot. It has a grid v carved into the work area. There are threaded inserts for clamps, primarily around the perimeter, but there is a truck bolt pattern strategically placed so a cut out board can be flipped or remounted accurately . It is supported below by 2 additional MakerSlide pieces and tied to the MakerSlide rails above. It is the bed turned out very rigid. It does deflect a little with heavy rider but pops right back. After the build, I added several coats of spar varnish to ward off the dusty footprints. Biggest guy to ride it so far tips in at about 230lbs.
We set our selves a goal of completing before midnight. Done or not, I was going to ride it at midnight. We thought we were finished about 20 minutes early. Everything worked fine except the Z axis was not moving correctly. It had the classic stutter and random motion of one coil wire not connected. We tried to find the problem, but over 2 meters of drag chain slowed us down. Midnight came some we dropped it to the floor and I rode it across the shop.
As a skateboard, it is pretty much a joke. On the first ride, we didn’t even have long board trucks, so the turning radius was huge and you can easily scrap an edge. The front has a handle cut into the nose of the bed. The ideal way to move it around is to lift the front and drag it on the back wheels.
