Cut a 2 x 10 (left over from building) 61" long. Metal crate is about 58" wide. Attached to harbor freight swivel casters to the boar. Crate sits down on the board, with a couple of 1" EMT conduit (ditto, left over from building) to keep the board from slipping away. Note a 2x4 is too thin, 2x6 or 2x8 is needed to keep swivel wheels stable.
Big Box store had the "wood to metal" screws. Noted the box stated 1 7/16" length (hard to read in the photo). This secures a 3/4" plywood top to the top of the crate (you need 3 4'x8' sheets, hint allow for a 1" to 2" overhand all the way around, allows things to be clamped to the edge.
WARNING: Do not let steel chips settle onto the aluminum. Above screws are perfect to go into the metal 1 x 1 form, but if too long screw will poke out the backside. Steel shavings will rust, so keep them off the aluminum!
Still need to cut out some poster board to fit into the ends of the wings (to keep Texas mud daubers out).
