I met Roger Cheng and his Sawppy Rover at Maker Faire 2019. Since then I've been thinking of building my own Sawppy Rover but I wanted to do it a bit different. I decided to scale it down to 66.6% of original to make it easier to 3D print the parts.
I experimented with just how small I could go by first printing a wheel at 33.3% of original. It lost a lot of detail and didn't even print the tread lines. Then I tried a print at 50% of original. The tread lines appeared but they had gaps. I finally arrived at 66.6% which is two thirds of original size. I chose this reduction percentage because it allows me to utilize some MicroRAX 10x10mm aluminum channel that was given to me several years ago by the manufacturer. Roger's version used 15x15mm channel.
I plan on using micro gear motors to drive the wheels and micro servos to turn steer them. I'll probably use an Arduino to control things at first but I'd like to eventually use a Raspberry Pi.