Measure the distance from the ground to your aircraft's front wheel's center. Get a measurement from the ground to the center nuts in the middle of the wheel. As a general rule, multiply this number by 4 to get an accurate length for your tow bar. For example, if your wheel's nuts are at 12 inches, your tow bar length should be about 48 inches, or four feet -- this is a good standard size. Measure the distance between the two nuts (width).
Place the steel tube into the bench vise and mark the calculated measurement for the tow bar length and mark it from the end. Use the welder and cutting torch to cut the tube to the proper length. Save the cut portion of the tube.
Reposition the tow bar main shaft in the bench vise so it is equal length on both sides. Weld a 12-inch perpendicular handle out of the excess tubing to the top of one end.
Weld two pieces of tubing to the opposite end, going out in the width of the aircraft wheel nuts. Weld a tight spring between the two forked pieces. Make sure the open ends of the tubes face in toward the main shaft. Keep them even in height, as these slip over the tow nuts, with the spring adding tension to keep them in place on the nuts, letting you pull or push.
File down any burrs or sharp edges on the ends of the tubing. Wrap the handle in duct tape to make a tackier grip for the tow bar.
