I used to be an architecture student so I know how to scale up objects, I've also studied graphic design, basically I'm working with a small scale model that I have broken into pieces and projected onto my wall using a projector, I measured the wheels (20") and kept the projector in place and that way all pieces stayed at a 1:1 scale size, I know its not 100% accurate but its the closest I can do. I traced the parts on cardboard cut them and hot glued them together. This is kind of a long process but it will give time to save money and figure out the rest of the project