Built a Moby yesterday – my build notes:
If you’re building Moby from the Competition Super Kit, there’s a fair bit of cutting required to do so. My cut list:
- Cut one 1x2x35 c-channel into two 1x2x15 c-channels, with a 5-hole piece left over as scrap.
- Cut two of the 2x2x25 angles to 20 holes long. The instructions also show the corners cut out of one side of the angle – you don’t need to do this, just cut them to length.
- Cut two 1x2x35 c-channels to 25 holes long (you need a total of 4 1x2x25 c-channels; the kit comes with the other 2).
- Cut two 3" shafts from a 12" low strength shaft (you need a total of 6 3" shafts; the kit comes with the other 4).
The omni wheels at the back of the robot just barely clear the two c-channels holding the two halves of the robot together. The clearance is tight enough that after my first pass at screwing the parts together, I had to loosen all the screws and retighten them with the c-channels as far forward as possible (there’s a little bit of play with the screws loose because the holes are a bit bigger than the screws).
In steps 1 and 7, it wasn’t clear to me what holes the bearings needed to go in on the c-channels from the angled projections shown. I ended up getting most of them wrong and having to move them around based on where shafts needed to go in later steps.
Here’s a clearer illustration of where the bearings go:
As mentioned above, the default drive program will not control Moby if you connect the motors to the specified ports. Worse, it thinks all four motors are part of the drivetrain, so if you start the default drive program and try to turn the robot, bad things will happen to the mobile goal lift.
I wasn’t able to find a listing of which ports are mapped to which controller buttons for the default drive program so I just wrote a quick blocks program to drive the robot:
moby.v5blocks (7.3 KB)
In addition to the mobile goal lift bending itself if you try to push past its range, the c-channel connecting the two halves of the lift can also cut into the motors’ plastic casings when the lift is all the way up – some anti-slip mat zip-tied to the top of the motors for padding would probably be a good idea.