I've put aside the flyback research for the moment while I build and test the original boost converter.
I have most of the components already, but I've come to the realization that I need to learn more about inductors and how they're built before I do this. The thing is I simply searched for 470uH 3A toroidal inductors in ebay, and got
these crappy ones that I'm pretty sure won't even handle 1A. What's worse, the ones I got had 0.3mm wires, not the 0.7mm advertised. So yeah, all but useless.
I've spent an afternoon googling about toroidal inductors and it's a bit daunting TBH. Apparently it's not as simple as picking a core size that can fit the necessary number of turns of the necessary wire gauge to obtain the desired inductance and current rating/resistance. Looks like there's a host of different core materials that affect the calculations.
I'm going by this right now:
https://cromwell-intl.com/radio/copper-wire/ There's a table specifying the different inductance indexes for every core type, and the formulas to derive the necessary number of turns for a given target inductance. Seems straightforward enough.
I also did a search in Digikey to get an idea of the resistance and core size of inductors in the ballpark of what I need. Most seem to be 1.280" Dia x 0.650" W (32.51mm x 16.51mm). Unfortunately the datasheets I checked don't say anything about core material or wire gauge.
Is there a standardized method to derive the kind of inductor you need? Would you star by picking the core material, then the size, wire gauge, etc? The problem is, as far as I can tell, all those things are interconnected: a thicker gauge requires a larger core. Materials with larger Al index can be smaller, but then the wire needs to be thinner too, but a thinner wire will produce more resistance with the same number of turns... What a mess!

I'm sure there's an easy way to approach this. Any pointers appreciated