[Dick Linn]

Last year we used 1" x 1" x 1/8" wall square tubing to make a ladder frame (single platform). Each corner and cross member was sandwiched between small 1/8" thick top and bottom plates (about 2" x 3") and bolted with 10-32 x 1 1/4" alloy steel cap screws (typically 4 per bracket pair). Internal bracing used short pieces of aluminum angle on the sides to keep the top clear of obstructions. It was strong, very stiff, and required only cutting and drilling. It could also be reconfigured easily. Best of all, it only cost about $40. in materials. The square tubing is a LOT cheaper than 80/20 or other extruded types, about $1./ft., though probably a bit weaker for it's weight. I think it was some softer 5000 series alloy, not 6061-T6. Last year was the first time we didn't have any problem making weight.

If you are on a budget and don't have welding capability, try it. Buy the tubing at a metal supply place in 20 ft. lengths, not Home Depot! Allen head cap screws are about $8./100 at MSC and the nyloc nuts are cheap.