I have been working on this for a couple weeks.  It's a collapsible, customizable, self-contained, super light, 3D printed sluice box!  I know there are other folding sluice boxes, but none of them actually fit in a backpack, or are light enough to carry in one hand.  This solution would be EXTREMELY helpful! I'm on my phone trying this, so when I get to my laptop, I'll write in a bit more.     So I'm currently in the CAD stage.  I have a guy that does 3D printing f