some projects start with a breadboard--others start with a bare wooden plinth. 
this one is a bit quick and dirty, so the parts (at least for this version) are 3d printed in a hurry.
here's a quick test fit. the two coil forms at the bottom turned out pretty nice, but i think i'll redo the other parts. brass would be a good look, i think.
coils are wound now. i did 100 turns each.
to hang the two steel needles, i picked some nylon fibers out of this piece of rope. it needs to be quite thin and strong to support the needle assembly without applying too much torque of its own.
you can't see the lower needle because it sits inside the two coils.
if you hadn't guessed what this project is, it's an astatic galvanometer. there are two needles to try and cancel out the effects of the earth's magnetic field. the glass bell jar protects them from stray air currents.
the sensitivity is quite good, it deflects at only a few mA. and this is with only 200 total turns of wire!
i just now realized that i haven't placed the coils correctly. they should both be wound in the same direction to create a uniform field. 🙃
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