80\20 T-slotted aluminum hardware rules, but it’s kind of expensive and even the 20-series is just a little too big to make sense for a lot of electronics DIY stuff.
Makerbeam is a 1cm profile series that should be the perfect compliment to 80\20, and at first glance it’s great and seems semi-affordable even for small amounts, but that’s just looking at the extrusions.
I got 4 sticks of 300mm MakerBeam for $18 to try out and thought- hey, this isn’t too bad. Way more than wood but this is reusable foreverish. But I mistakenly thought that a standard M2 nut could work in the slot. I was wrong. Pan head M3 bolt wont fit either, you need a square head bolt or a flat nut… no big deal, right? The M3-5 hammer nuts for 80\20 are like $10 for 50 so I can deal with that.
Nope- the makerbeam M3 flat nuts are freaking outrageous- like a buck each for about .01 cents worth of stamped metal with an M3 hole… freaking infuriating.
The whole point of getting this stuff is that I’m not a machinist, so if I have to start making my own fasteners this goes sideways fast. But… I figured out you don’t have to be a machinist to make something workable.

Just needed snips, drill, screwdriver, and a little file helped. A sane person that owned a functioning drill press would do even better.
Started with scrap copper sheet I’d pulled out of a laptop heatsink years ago (Hoarding heatsink materials pays off very occasionally). Cut off a strip thin enough to slide in the MakerBeam slot and drilled some M3ish sized holes. I don’t have an M3 tap so I just filed out a little and turned an M3 through it.
The surprisingly cool part is that even if the hole is off- when you put it in the slot and screw it down it does sort of a brake press action on the nut and it trues up in the slot. They’re not as strong obviously but if you’ve got loads that can tear copper I guess just pay the buck. I figure this could also be a decent alternative the brackets which are also outrageously priced, but actually I’ll probably just use 80\20 for most stuff because this isn’t trivial enough to make dozens of nuts whenever I need them so it’s actually not all that workable, just more so than paying $1 per nut.