Mechanical Skeeball built from Knex

We don’t really know what to say. This Skeeball cabinet is built entirely from Knex. It works exactly how you’d expect Skeeball to work. You plug in quarter and it dispenses balls and keeps score.

[Shadowman39] worked on the build for more than a year. Everything that went into it is a Knex part with the exception of a few rubber bands, and the paper numbers that are used on the scoreboard. There are six motors which drive the machine. Four of them are responsible for turning the scoreboard digits, the others handle ball return.

The link at the top starts off with a bunch of images of the various parts, but you’ll want to watch the video after the break for a closer look. It shows the coin hopper in greater detail. It’s built to only accept quarters and to reject all other coins.

[Read more...]

Sliding camera mount is good enough for amateur photography

[Unihopper] built this sliding camera mount to add some motion to his freestyle unicycle videos. It’s extremely simple, but still pulls off a pretty nice effect as you can see in the clip after the break.

The image above shows the mount without a camera attached.  You can see the threaded peg on the block in the foreground which is used for that purpose. Felt has been wrapped around the base of the block, which rides in a wooden channel. The string, which connects to an eye hook in the wood block, is attached to a spool on the far end of the plank. A K’nex motor drives that spool, slowly sliding the camera toward it.

Unlike other toy-based sleds, the use of a track system helps to maintain proper orientation of the camera. Obviously this isn’t going to achieve the perfectly smooth and precise motion you’d get out of a sled system like this rail and linear bearing version. But honestly, most of us don’t have cameras of the quality to warrant that type of high-end system. [Read more...]

K’nex whiteboard plotter

knex_plotter

[Jerry] has been wanting to put together a whiteboard plotter for some time and just recently got around to building one.

The plotter draws pretty much about anything he can imagine on a white board measuring just shy of 2′ x 3′. The design first started off with a Basic Stamp board at the helm, which he sourced from another project he no longer had any use for. The Stamp worked for awhile, but eventually he ran into problems due to the board’s limited 128 bytes of program space. Needing a more robust micro controller, he switched to an Arduino mid-project, which he says runs the plotter far faster than the Stamp ever did.

The plotter uses a pair of stepper motors mounted on a horizontal platform situated above the whiteboard. Much like this large-format printer we featured earlier this week, the steppers vary the length of a pair of fishing lines, moving the pen precisely across the board.  As you can see in the image above, [Jerry] has been able to create some pretty intricate patterns with his plotter, and we imagine they will only get better with more refinement.

Be sure to check out his site for more details on his build process as well as several additional samples of the plotter’s capabilities.