Between January and now, I have made hundreds (or so it seems) of decisions about the design basics and specifics of my travois. Each aspect of the travois can be designed in multiple ways, and it’s not always easy to decipher which design is best.
Even the term “best” is not necessarily applicable because the “best” design might not work “best” with my specific constraints/goals – i.e., the travois must be durable, lightweight, inexpensive, collapsible, and easy for the refugees to assemble.
As I have learned more at each step in the process, the design of the travois has changed. Here is a sample of some of the many, many changes the travois has undergone:
One of the most difficult decisions was how “best” to design the bottom joints and their interaction (or non-interaction) with the axle. Should the axle cross the whole frame or should it be two pieces welded to the joints on each side? Should angle irons be welded onto the underside of the joints and then have the axle run through them? Should the axle be welded directly onto the steel joint or should it be embedded in a hole drilled through the center of the wood? Should the metal joint be made of two plates of metal bolted through or should it be a single piece of metal that is wrapped around one part of the frame but open at the other part of the frame? What should the thickness of the metal be for the top and the bottom of the joint? Should the bottom plate be thicker than the top plate?
After a lot of work, I finally designed the joint, had it fabricated at Custom Steel, and assembled it for the first time.
I must say that I am glad I finally have made all the decisions necessary for the prototype I will bring with me to 3M.