Science Project

Entry 1

In order to replicate I'll need a signal generator, a magnet, and the coils.
Thankfully I was able to find a 3 channel signal generator for under $200. It's probably worth noting here that I am *extreamly* budget constrained. The signal generator was a huge expense for us, so most everything I need I'll have to make myself If I can't get it very cheaply.
On that note, I'll need to make the coils myself by hand. I'm sure there's some service providing custom coils to spec but there's no way on earth I could afford that. In the paper they said they designed their coils based on an optimal ratio of coil size to magnet size. Since they were working on small haptics and using a small magnet their coils are pretty small. my neodymium magnet is almost the exact same size as there's but is off by a little bit - but thanks to them providing the ratios I was able to adjust the coil size accordingly. The study used magnets that were 8x5x3 mm. mine are 10x5x2 mm.
The coils are pretty small and will be tricky. these are the dimensions (in mm)

(note: the z coil is nested within the 'inner' coil)
Technically these should be precise to the tenth of a mm, but I rounded for simplicity sake. If I can't replicate their results, I can always make new coils that are more precise. As far as I can tell these should work just fine, they will just be slightly sub optimal.
Just last night I finished making 3D models of spools for the outer and inner coils. I actually tried to make one end a removable cap, so that I can slide the coil off the spool when I'm done. My printer is non-functional at the moment so I'll have to use the one at my local library. It's been a while since I've designed 3D parts, and it was my first time using FreeCAD (I formerly used Fusion360), so I hope it comes out right on the first try because I don't want to make a dozen trips to the library.
I've been pondering how I'll secure the coils so they don't come apart when I remove them from the spool. So far all I've come up with is to use spray adhesive before removing it from the spool. I'm worried that I'll accidentally glue it to the spool though. I've considered wrapping wax paper around the spool first, that way I'm gurrenteed to at least get it off the spool.
Hmm... perhaps I should print multiple spools in my first trip to the library just in case.

Well, that's where I'm at right now. The signal generator should be delivered today but it does me no good till the coils are ready, so I'll update then :)

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