Balancing board (with safety stops)
I thought of building one of these when I was trying to think of something to build for my nephews. I had experimented with balancing a board on a roller some years ago, finding it surprisingly easy to balance.
Easy being relative. Easier than riding a unicycle (which I can't), but harder than maintaining balance walking on a railway track.
I started with a piece of 3" ABS pipe and short piece of plywood just 52 cm long. While that was long enough to balance with, I had several incidents where the board shot out from under me. It's a bit painful landing on a concrete floor. So I modified the design to make it a bit less dangerous.
I added two safety stops to the underside. These are designed to prevent the board from running completely off the roller. But they also have to be low-profile enough that they don't limit the board's range of motion. At the height I made them, they have so far prevented all shoot-out-from-under-you accidents without limiting the range of motion for normal balancing.
The roller is just a piece of 3" ABS pipe, 87 mm outside diameter, and 38 cm long. The roller should be a fair bit longer than the board is wide, otherwise it's too easy to run the board off the end of the pipe.
I wrapped some carpet around the ends of the board. This prevents the end of the board from gashing the floor. It also makes for a better grip on top of the board, and should make for a softer landing in case of accidents. Although, since I added the stops, I haven't fallen off it yet.
The carpet is held on with some 1/2" #8 sheet metal screws with wide flat heads. With the screws tightened all the way down, they don't make for an appreciable protrusion in the carpet. That's important, I do expect people to fall on this thing from time to time!
The safety stops are screwed on, not glued, just to make it less likely that they might pop off spontaneously.
Click image to enlarge.
You can also download the SketchUp model
Got an email relating to the balance board from Gavin Hay:
The balance board, or as we call it in the circus trade, Rola Bola. Yes, that's right, I am a circus artist all be it a solo one. In fact I am a professional street performer. This is the other me when I'm not working with wood.
So, I wanted you to know that the rola bola is easier if you have a bigger diameter tube, and it really helps if either the tube or the base of the board is covered in some grippy rubber stuff. Also if the tube is heavier you have a slower rocking motion. The other thing is that the 'stops' are better right at the end of the board, but maybe for kids it's safer to have them where you have. Dislocated shoulders are a common injury for this apparatus. A disclaimer might not go astray.
More kid's toy creations:
The Hui game