Ok so heres a diagram i drew up..feel free to ask q's
and thanks for the info and concern 2door...to tell the truth i have absolutely no idea, i think ill go look at home depot for steel pipe. last time i went, all i saw was galvanized and EMT.
It sounds like you only looked in the electrical section.
Home Depot and Lowe's do carry some better metals, usually near or in the hardware section. Ask somebody where the "weldable sheet metal" is.
The drawback of what they have is that neither the selection or the prices is very good, but it can be helpful. The largest steel tubing is only 3/4", I think. If you need thicker steel pipe, you may be able to use the schedule #40 and #80 black pipe in the plumbing section. This is pretty soft mild steel, but it may be useful.
There is also places like mcmaster-carr and metalsonline. Their selection is much better but the cost of cutting & the cost of shipping makes this a
very expensive way to go. You can easily end up paying 3-4X times as much as what the metal really costs this way, so it's worth looking at other options if you have any at all.
---------
Look in your local phone book for "metals suppliers"; most big cities have at least one.
You may have to buy a full length if they won't sell by the foot, but the price per-foot will still be much less than the pre-cut pieces that the hardware stores sell--and the metals suppliers will have a much wider variety of sizes and shapes to choose from. (a full length can be anywhere from 8 to 20 feet; bring a hacksaw and measuring tape so you can cut it up to get it in your car. Some places charge for cutting......)
If you get to a metals supplier, first
ask if they have a scrap pile at all. They often have short pieces left over from big customers who ordered pieces cut to length, and they love it when somebody comes in and asks to buy part of their junk pile. These pieces may not be in the exact sizes you wanted, but they may be close enough to work and are usually sold for considerably less than what they'd usually cost if you ordered them specifically. Bring cash and have exact change.
You can also ask at local welding shops where to get "bicycle-frame-size" metals.
Some welding-supply shops will also sell metal themselves, but usually not much useful for building bicycles. Most I've seen only have the BIG beams and plate for trailer-building on-hand, and don't deal in anything but full pieces. They will probably know the nearest places to get smaller stuff in the area, however.
~