This is the first thing I've built with a significant number of t-nuts in vertical extrusions, and I'm finding them mildly aggravating... assuming I'm using the correct screws in the first place, couldn't an M6 screw longer than 10mm be used? It's finicky getting them unscrewed enough to give clearance to rotate and seat the t-nut without entirely unscrewing it, and losing the t-nut down the channel (and having to do it all over again, and stressing the panels more every time...) I'll try answering my own question and swap in some longer ones, it seems we've got the depth of the washer, the acrylic, and the extrusion channel all available. On a slightly related note, do the docs anywhere mention the exact extrusion dimensions and the t-nut dimensions (wing width)? Cheers, this is great fun.
I had some 'fun' doing that as well, though I found I started to develop a touch for what worked after them falling off quite a few times. I found for whatever reason using a very quick motion to tighten them helped swing them into place with a better hit rate but it ended up being all touch. I'd love to know if anyone has a sure fire method as well. When I built my laser cutter with 2020 and T-nuts I had the same issue but there the acrylic was thin enough that I could use a magnet to drag the T-nuts back into place without removing the panel. Didn't work here unfortunately.
I fastened the Nut to the screw first then rotate it vertical, install it in the extrusion and untighten then tighten it, never had a problem with that process. not a single nut fell off!
What am I looking at? Square neodymium magnet with a hole in it? Seems like a nice screw retainer. I also found I can use a magnet to move the t-nuts around the extrusions; it's a little help in pulling them back up, but the best part is helping them snap to horizontal. That said, a magnet strong enough to reach the t-nuts from the outside of the extrusion is a little dangerous to have around other ferrous tools.