wannavolunteerFT: Cheap and dirty, that's how I do woodwork!!! Sides and ends are 1X6 pine, bottom is 3/16" what could be called masonite (DW used to work for them!!). Sorry, off topic!!
Just butted up, glued, and 1-1/2" nails from a nail gun. Plenty of glue and nails!! Front and back are faced to the sides. Wheels are from leftover 1X6 cut with a 3" hole saw, then power sanded as round as I could before I got bored!!! All cherry stained, although it doesn't quite match the Jayco paneling. Wheels are axled with SS hex bolts with body washers on all meeting surfaces, and nylock nuts to hold together. Only about 3/4' of wheel is below the bottom of box, just enough to have the axle bolt in an area of good wood and still roll well.