This is a carrier a built to go in the trailer hitch on the rear of my travel trailer. It was designed to hold my generator and gas cans and whatever else I decided to put on there. It is extremely sturdy. Can easily hold 500 pounds.
I made it out of 2" x 2" x 1/8" angle iron for the main frame.
The two support pieces across the bottom that I lined up with the generator bolt holes are 1 1/2" x 1 1/2" x 1/8" angle iron.
The main tube that connects with receiver hitch is a 2" x 2" x 1/4".
There is a 16 gauge piece of steel welded in the frame to make the floor of the carrier. This is the final version. Notice I also added hoops around the carrier to tie things down to the carrier. This picture was taken after it had traveled 600 miles to Southern California.