I ride bikes........and I use bikes to work. I consider my bikes "working bikes". I only have pictures of a finished product and I will do the best I can. I have built and broken lots of trailers. It has taken my years to get this far and this one is not perfect either.
The solid weight I can carry will surpass the safe use of conventional V-breaks and I had 5 pallets stacked on it only to get a small bounce going down the road. (Tire pressure is everything!)
This is not my own design. I rode pedal taxi for years in Phoenix. This trailer is made from a hand truck and is modeled after a 3 passenger taxi that came from San Diego.
This main photo is on a "test" run (for beer!) and taken by myself.
Step 1: Get a Hand Truck.
This is a Harbor Freight hand truck with 10" wheels. Unfortunately, I started this project just before I found out about Instructables. I will do the best I can and will answer question.
I used a grinder with a cut off and grinding wheels, hack saw, tubing bender, drill, and a welder. Other than the hand truck you will need some 1/2" iron pipe, 5/8" iron rod stock, 1" flat washers, and various parts for the hitch. (in later steps)
1.I cut the welds off the center tube at the cross members and cut the tube itself at the handle where your hand goes.
2. At the bottom cross member cut the outer tube on both sides and you will have a large U with 2 cross members and some tube from the handle still attached.
3.Cut off the tongue of the dolly flush at the tire guards.
4.Use a tubing bender and bend the center tube to fit YOUR bike.(this picture is how I sized this trailer around the tires on MY bike (700c not 26"). Your situation will be and look different. The 1/2" iron pipe is used to size the distance to your hitch)