Yet Another Railcore 2 Spool Holder

thingiverse

So @chainsol created a one-arm remix of my two-armed quick-n-dirty spool holder, which gave me several ideas, and I couldn't leave anything untouched, so here's my remix of his remix etc.:D This design features a screw in the top surface to clamp to the extrusion. It utilizes two brass heat-set inserts, although you might be able to get away without either one. There is a part that isn't printed; this is designed for 1/4" steel rod as the spool carrier. (6mm will work if you're not in the USA:D). One of the heat-set inserts goes into the end of the spool holder arm to clamp the 1/4" steel rod, and you might not need it; you could glue it in just fine. The other goes into the clamshell; you might be able to substitute an M5 nut, but I used a brass m3 heat-set insert that's 3mm long and 5mm wide. (I bought an assortment on Amazon, and I highly recommend them to anyone who's 3D printing stuff they want to screw together!). The thumbscrew on the clamp also has a heat-set insert in it. I will probably make one with a captured nut and upload it later, but right now you'll need it to make it work. The thumbscrew will take a ~30mm M3 screw that pokes up through the pivot first. Then the clamshell clamps down easily. The spool roller should work fine; you might want to put just a tiny bit of grease in there if squeaking bothers you. I've printed some helical bearings from a customizer and a vase-mode cylinder that slides over them, but that's overkill. You can also use these: https://www.thingiverse.com/thing:2932314 They're the best airsoft BB bearings I've found, and I made a vase-mode cylinder they press-fit into and used it, too. The helical bearing was just to see if I could pull it off.