I picked a couple of worn out rolling boards from a local warehouse that were being thrown out. The were both the same size and between the 2 they had 5-6 decent wheels on them. I wanted to make a rolling wood cart to store loose pieces and cut-offs as part of my #commit2it submission of garage organization.
I took the board I wasn't using and ripped several strips down for what would become the framing of the wood sections. Then I cut smaller sections to add spacers. I glued and screwed everything to make it extra strong. I used a left over 2x3 for the vertical supports, and notched one side, again for strength. I finally added a left over piece of 5mm ply board at an angle for scrap "sheets" to lean against.