MossRoad,
I have three frames in my driveway. One is my poor excuse for a welding table and has a vice mounted, one is simply a table, and the other is a heavy duty receiver hitch carryall that has been converted into a scrap iron basket. All have wheels on one end so I can lift the other end and move them around. I need to weld a couple of the larger tubes on the sides on one end of each frame so I can slide a pair of 3/4" tubes into them making handles. This will make them easier to lift and push without my legs bumping into the bottom of the frames.
The workaround is to weld angle iron into the appropriate size rectangles and slide the pipes into them, or use a hole saw to cut 3/4" holes into flat bar and weld it onto the sides of the frames. Either of these methods should allow me to more easily push the carts a round and to use one set of handles for all three carts.