Disco Necklace, Part 2

End shot first (it doesn’t work most of the time, but sometimes it will when you jiggle it)

I began the week by trying out my last circuit design. I set everything up and began methodically testing with a multimeter by my side.

I could get the correct voltage threshold to my transistor and the motor circuit working separately, but integrating them just was not happening. After many hours trying, I gave up on my light concept and decided I’d allow the motor speed to be controlled by a potentiometer.  I put together the electronics in a (seemingly) nice package.

The potentiometer wasn’t in the best of spots, as it could block the battery cover from being removed, but I figured it’d work. I then laser cut a prototype for an enclosure.

It was alright, but I didn’t know how to make the components accessible, or how to get the exact positions of the motor shaft and potentiometer head so I could include them in the laser cut files. But I figured I could leave the top unglued and drill those holes after cutting.

But things starting going horribly wrong from here. I started soldering up my potentiometer. Originally, I was gonna make a small proto board to handle all my connections, but since there were so few, I decided to solder them all together directly.

This was a mistake for a number of reasons. First, I had problems with the connections and it made it harder to debug. I had to scrap the first potentiometer after I had soldered everything. Later I would realize that my wires would make fitting into my enclosure much harder.

Then I laser cut my enclosure out of acrylic. I hadn’t really thought through how the necklace part would work, but I shoddily drilled two holes for the necklace but then realized I did it to the wrong parts…. so I made another attempt at that, and then drilled holes in the top for the motor and the bottom for the potentiometer.

I went about glueing the acrylic together but couldn’t find my epoxy in the adhesive cabinet. I luckily was given some e6000 but I struggled to get the tiny finger slots in the acrylic together, as there were no right angle clamps available. But I got around it and tried gluing my pot onto the battery holder. This was a disaster, the pot wouldn’t stay.

Ok everything was sort of glued together and the circuit was still functioning. But my electronics couldnt fit in the case, it wasn’t deep enough and the width didn’t give me any room for error. Plus it was difficult getting all my holes to line up and I realized I didn’t give much thought to which direction was “up” in my case design, so holes weren’t in the right places relative to each other. To add to my problems, the motor wasn’t really held in tightly enough by the zip tie.


I was about to give up and start over. I started trying to laser cut new prototypes. But then I decided to hack it together. I removed the zip tie thing holding my motor and attached it directly to my battery. I folded the cables and taped them to the battery case (which I cracked somewhere along the way). I stopped trying to attach the pot to my battery and just placed it in its hole and taped over it. It’s barely stable enough. But I couldn’t get the top on at all and just resigned to have the top be open. I glued the motor back to the disco ball and gave up. It works sometimes if you jiggle it.

If I had to redo this, I’d change a number of things. First, I’d up the prototype fidelity to get all the holes positioned on the laser cutter. I’d also consider another enclosure method that would allow easier access to the battery. I’d also modify the circuit to try and use smaller batteries. And I’d have been more considered when soldering and placing components. But really I wish I could have gotten my original circuit working,

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