Solar-powered dowel-sawing machine is a perfect desktop distraction

Alex's Almost Useless Machine is a solar-powered desktop amusement that slowly saws through dowels whenever the light is bright enough to power its motor. It's mesmerizing.

This little machine uses a so called solar engine to drive the motor. This solar engine is able to collect tiny amounts of energy over time and stores it in large capacitors. When the voltage reaches a certain level, it opens up and uses all the stored energy at once to drive a motor. These engines were used to drive tiny BEAM-bots and were quite popular a while ago. A lot of information can be found at on how to build them and how they work.

The Almost Useless Machine (via Wired)


  1. BEAM bots! I once built a BEAM cockroach. Photophobic little circuit board on tiny wheels that hangs out under the edges of cupboards, comes out at night, and scurries back to the corners when you turn on the light.

    1. That sounds great. Is there a link to how it was made?

      How did you make it come out at night? I could imagine creating something that moved away from the light (using two photoresistors as antennae), but I would imagine it would just end up under the couch and never both to come out again.

      I want to make some of these to entertain my cat…

      1. BEAM bots are pretty cool.  I made one from a kit I got from a number of years ago.  Used two pager motors, a solar cell, a “supercap”, and a couple of phototransistors.  It would look for the most intense source of light and drive toward it, which sounds like the opposite of what Ian described.  It also had wire “antennae” for obstacle avoidance.  It was fun to put it on the deck in the sun and watch it wander around avoiding shadows.  I think any geek would love one.

    1. It would great to see one sawing the head off a wooden James Bond. Or a ‘Roger Moore’, if you prefer.

  2. It is a solar powered drag saw.

    Here is a gasoline model

    Here is the much noisier steam powered model….and there is nothing steam punk pretty about this monstrosity

    I’m big into old skills and tech from the farm so this solar gizmo is pretty cool. A mix of high tech and old school together.

    1. Sir, that is badass. I am now going to make a small steam engine just to cut dowel rods on my desk. Had no idea they made such wonderous things!

      This is why people love steampunk- because of things like this that actually did something useful once upon a time- not hot glueing random gears to a pair of goggles.

      1. If you ever make a steam powered one please share it with us. I love to see it. 

        That steam powered video is cool to watch the piston at work. You cannot even view the machine well due to the escaping steam…but that adds a level of bad ass’ery to it.

  3. Having seen Cory at the St. Louis County Library last night, I think he may have actually been blogging while still AT the library.  His talk only ended like, ten minutes before this post.

  4. What is now needed is a solar powered dowel-forming device, sitting next to the dowel-sawing device. A twig-plant is not nearly as clever.

Comments are closed.