Here's a how-to on a small roller drone I made. Enjoy!
First, you will need these pieces. The treads are 7 lengths long, making it 14 needed in total.
First, build these two bits.
Next,connect them like so.
Now build these two things.
Then, connect them like so, and add the trans green slope to the peg to stud connector.
After that, attach the two components and build the base.
Then,connect the base and he head, and add the light grey ring with axle which could hold a multitude of tools.
Finally, roll the treads around the open balljoints and you have finished!