2022-10-19 NOTE: After months of use I've noticed the M2 servo-screw starts to spin free in the arm. I intend to heat-inset an M2 standoff NUT into the arm. That should solve the spin. I'll update with photos and notes when complete, but wanted to get this message out there immediately. I absolutely love the useless box! Thanks!

You'll now see 2 stl files for the main box: Version 01: ub-box.stl - printed with battery holder for use w/ diy paperclip conductors (not great) and 2.5mm lid-holes, which are too loose for Mx2mm screws. Please ignore ub-box.stl for now. Version 02: ub-BetterBox.stl - for use with off-the-shelf AAA battery holder (fastened w/ M3x8mm) and 2mm lid-holes, which are just right for Mx2mm screws. Use This ub-BetterBox.stl. It just works.

Simple, because it uses no microcontroller. Supplies: 2 AAA batteries, a AAA battery holder, a 6-pin toggle switch, an SG90 servo, and a micro-limiter switch.

AAA Battery Holder: https://www.amazon.com/dp/B08DR6L8F8/ 6-pin switch: https://www.amazon.com/dp/B079JBF815/ SG90 Servo: https://www.amazon.com/dp/B072V529YD/ Micro-Limiter: https://www.amazon.com/dp/B07P23TWX2/ M*2 screws (various) https://www.amazon.com/dp/B08G8733Y4/ Paperclip (for battery box) https://www.amazon.com/dp/B09B9GPZ3T/

First, props to ericthepoolboy for drafting this tight little container. It was too small for my SG90, then I saw cogsy and blarbles had remixed. I have made minor tweaks, but it's very much based on--or fully using--what came before. Thanks y'all!

Remix First: I created the perfect arm. This harmonious curve of symmetry is thicker at the head and tail to better hit the targets, and it is sized to hit the toggle switch at just the right spot to maximize down-force and promote lateral movement. More on this below. Second: Strengthened the holes into which the micro-limiter fastens, and bumped it over a smidge (2mm in ub-box (version 01), a further 2mm in ub-BetterBox (version 02).) Thirdly: Modified the box. I recommend the ub-BetterBox.stl but I'm leaving version 01 up here in case you or I ever want to play around with it. Otherwise, this is just another remix of a remix. Glorious internet of remixes.

The Arm and the Toggle Switch A delicate secret lies at the heart of the Useless Box's operation. It is the ability of the arm to push the toggle. Many (most) 6-pin DPDT Toggle Switches are stiff and do not easily move. Hit 'em low and they won't budge. Hit 'em high and they resist. Some have found a solution in disassembling the DPDT and snipping the rod by 1-2mm and reassembling. I tried this. This does allow the toggle to move more easily, but it also introduces errors as the rod may sometimes not have enough pressure on it to maintain contact with the contact-plates. Delicate business. Last resort. Ill advised. And not required! Do Not Mangle The DPDT Toggle. Better to use a whole un-mangled DPDT. And for that, you need 2 things: First you need The Perfect Arm Then you need Reliable 3v power Thus have I labored. Behold: (1) The harmonious curve of symmetry that is The Perfect Arm. This arm is a perfect fit for the box provided. Adjustments to the box dimensions may require adjustments to the arm. But knowing it can be done should help you succeed. (2) I loved the idea of printing with battery box in place, but for some reason my paperclip half-ass battery box wasn't reliable. ( ¯\_(ツ)_/¯ ) So I gave up on ub-box.stl and created ub-BetterBox.stl. This box uses a AAA battery case for better power reliability. Problem solved.

Screws In addition to the materials listed above (with links) you'll need a variety of screws. M2s at various lengths and one M3 for the battery case. M2 x 1012mm (x2) for limiter switch M2 x 12mm (x2) for the flip lid "hinge" M2 x 810mm (x2) for the servo M2 x 8mm (x1) for the arm M2 x 8mm (x4) for the DPDT lid M3 x 8mm (x1) for the AAA Battery Holder

Paperclip Gonna need one jumbo paperclip (see picture.) This is for the battery box, to make connections. Outdated. Please Use ub-BetterBox.stl instead.

How To With the two wiring diagrams provided you should be able to get there. Everything connects to the DPDT (6-pin toggle switch.) In both of the diagrams (annotated & Frizing) please assume the toggle is leaning to the right, away from the servo. Doesn't matter really, tho, bc you can simply rotate the toggle switch if you wire it backwards. :-)

NOTE Which reminds me, in your finished product, make sure your toggle is Straight On, else the arm will have trouble pushing it sideways.

For the DPDT Toggle Circuit, imagine the upper 3 pins are negative (-) and the lower 3 pins are positive (+) except for the lower left, which is connected to the upper right (see pics.)

Keep your wires as short as you can as it is a tight fit in this box.

Where did this project begin? Earliest record I can find is this instructables from 2009. That's where the annotated wiring diagram comes from. The Fritzing diagram is mine own.

Rubber feet on the bottom help this sit nicely wherever. Also, if you're giving this as a gift, consider ways to personalize the flip-up lid. Think: Branding.

Video https://youtu.be/M8kQxafmoNA https://youtu.be/vtoa8lEEwY4 https://youtu.be/UXe74k-RMMk