Showing posts from January 5, 2020

2x2 Useless Machine

Another very overdue Maker Central project, I wanted something for people to fiddle with on display at the exhibition and I've always wanted to jam a load of useless machines together into the same housing so it was a perfect opportunity. I took my standard useless machine  and stretched the skin in both directions to accommodate four mechanisms.   This box was intended as a quick prototype for a larger 5x5 useless machine, the principles were proven but the box wasn't entirely functional. The upper row of mechanisms had nowhere to brace across in the bottom of the box and I forgot to make any wiring holes between the internal panels. It sat unloved on my bench until a tidy up this week when I realised I should dismantle the 5x5 machine and sell the individual mechanism. I resurrected this 2x2 as a much more compact memory of the project. The additional panel across the bottom is simply glued in place (rather than the hook system of the usual skin) but at least it

Hairdryers and Blowers

The race track for maker central  was built to race wind powered strandbeest against wifi controlled strandbeest , the trouble with the wind powered version is finding the wind indoors. This means letting people blow spittle all over everything, providing some kind of wafting device which usually ends up as a whacking device or an electric fan. I bought a few cheap hair dryers but they barely shifted any volume and couldn't make the blades spin. I've used these squirrel cage blowers before for other projects and know they can really shift some air. The fan runs off a simple 12V power supply which is passed through a microswitch in the handle. The lever for the switch bent into a button shape to form a trigger, that way the fan is only on when it is required and pointing in the right direction.

Tripod Repairs

I've been using a cheap and nasty tripod for a very long time, it's a bit broken and rickety but it's functional so I haven't felt the need to replace it. Now that I have a functioning 3D printer though it was a good exercise to create the parts needed to fix it. First up were the rubber feet, one of these disappeared early on, the new one is made from PLA and isn't as grippy but at least it's not a bare metal end with a chance of scratching the worktops. I was lucky enough to model the odd shaped hole in a way that just about gripped the metalwork, not too tight or too lose. I applied a few spots of superglue to them all to ensure that none of them get lost again. Next up, one of the knobs was cracked. It was still holding together but it spirals apart when you turn it in one direction. Getting the curves on this part was a good exercise, I simply left the hole in the middle at 4.5mm wide and used an M5 tap to thread it. I removed the

Maker Central Race Track

Maker Central happened in May last year, I used to enjoy travelling to all the maker faires and creating new and interesting projects for each of them. I did the same for Maker Central but for some reason never blogged about it. I'm clearing out my photo backlog so here's a few things from May. Because I was selling my remote controlled strandbeest kits I thought it would be a good idea to have a racetrack where people could try to blow the sail powered kits faster than the motor powered kits. Hacky Racers were also exhibiting at the event so I thought it would be fun to but a 'slacky racers' theme on it for people who didn't go to the effort of making a full sized vehicle. I expect this may make another appearance at future events, it's easy enough to rebrand due to the sticky labels and sellotape used around the edge.

Large Countdown Timer Improvements

I made a large countdown clock for a LRP event last year, once the event was over however there aren't a lot of uses for a 99 minute countdown. I offered to put in some additional functionality and turn it into a real clock using an RTC chip. These DS3231 are super cheap anyway and I probably should have included it first time around. The second issue was that the tape I used to diffuse the lights had absorbed some moisture and gone horribly wrinkled. Once the RTC was installed I ended up replacing the front cover with some Mylar stencil material which is damp proof but clearly doesn't do as well at diffusing the light. Internal to the clock I laser cut some packing foam in the shape of the 7 segments and inserted those into the gaps for the digits. This did a much better job at diffusing the light and made the whole thing functional again. The RTC is battery backed and should hold it's time for a while, it's currently reset by programming on the Arduino

Custom Decision Spinner 2

The previous spinner didn't spin as well as I wanted so I went off to think about how I would do it differently if I had to do it again. Taking inspiration from the various fidget spinners out there I came up with this alternate design. Instead of spinning a super light arrow, this one spins the whole wheel (again using a bearing). It's a standard 3mm poplar arrangement for the wheel and the arrows but the secret sauce is a 4mm thick, 4mm diameter, insert between the arrows, going through the bearing. It spins a lot more freely and this is definitely a better way of doing it. The attachment to the arrows is a bit weak though and it would probably be better with a 4mm diameter dowel going through all three layers ( svg here )