Step 5: The frame
The frame is pretty simple - you need two long pieces of material to hold the axles off the ground, and something to separate them the appropriate distance from one another.
I added a little standing platform on both sides just to make it easier to get on and off - but it isn't necessary
2x4 studs or other common materials will work fine - you certainly don't need to use hardwood like is pictured in mine
You will also want a way of pinning the axles so that they don't turn or try working their way out while moving.
Note the notch in the middle cross pieces to accommodate the webbing