Sorry I'm a little late- I'm new on the forum, and definitely new to nerf blasters in general. I've been shopping around on Thingiverse (more like pulling teeth) to find things that didn't involve large amounts of hardware. I've found this one that seems to work alright on paper, but my printing time is limited, so I haven't tried anything yet: the Meaker Mk 18 Assault Pistol. For something way simpler, there's this Foam Dart Pistol. There are bunches of remixes for that one, and it doesn't require much in extra stuff (rubber bands, something to melt filament with?). Seems great for starters, and you can make it as powerful as you want. Hope that helps, and have fun!