This past week I have been burning the midnight oil for several days designing a 1/6th scale electric car model. The tally so far for the design has exceeded 50 hours. This vehicle or something like it has been on my mind for years and I am happily now making a model with my Makerbot 3D printer. Printing of the first parts for the model started today and will continue for some time in the future until it is completed. With that in mind here are a few photos of some of the first parts.
I wanted as much detail in the model that I could make and so have decided to have a full suspension complete with working shock absorbers. The puzzle to figure out in the design of the shocks was how to hold it all together. This was accomplished using a small press fit 3/32nd diameter steel pin. The pin is slid into the upper portion of the shock through the slotted inner lower piece. This holds the assembly together without the need for glue. With the 3/4 inch long by 1/2 inch diameter spring and the slot in the lower portion of the shock assembly makes the shocks fully functional. I made the press fit pins by cutting them from a piece of steel rod that I had left over from the Gyrokite project. I used a carbon fiber disk and my Dremel tool to cut the pins to length while they were held firmly in a table vise. (A two second job for each pin.)
The first two of four shocks needed I completed today. They are 2 1/4 inches from mounting center to center (uncompressed) and are 1 and 7/8th inches compressed. I would have completed all four shocks but the hardware store only had a couple of springs that I needed so the other two will have to wait until I can acquire more. All four shocks took three hours to print on the Makerbot.
Here are a couple of good computer images of the electric car model (without a body). It is complete in scale right down to the correct electric motor and lithium battery packs. The model as I said earlier will have a working front and rear suspension and also will have a working rack and pinion steering system. The model will be 24 inches long and 13 inches wide. Overall height will be 7 3/8ths inches. Being this size it will be an impressive model comparable to my Makerbot Semi and trailer and allow me to put nice detail in the building of it. I have a wooden figure of a person that will fit exactly into the model. It (Him? or Her?) stands 12 inches tall and would be six foot tall in real life if and when this model ever becomes a real vehicle some time down the line here at the Tinker's Workshop.