K9 Diaries - Filling Time

K9 Traction Unit CAD Model

Alongside the body shell building, there are also the other systems, notably the base with the drive system, I'd done the modelling, so now it was time to export the parts and 3D print them.

The speed of the motors requires a double reduction. The chain output sprocket has to be matched to the same spec of sprocket and chain. The seconds chain will be the old sprockets from Chompalot, from when it had 4 wheel drive. The bits I needed to make on my printer were the interfacing bits, such as between the wheel and sprocket, or between the intermediate sprocket and the shaft. Also holes for the bearing.

After much printing and adjusting and reprinting I finally produced the platform which K9 would sit on. 

Initially I tried using the motor controller I had originally sourced, however it soon proved not to be up to the task, and with a puff of smoke, the decision to buy a 2x32 Sabretooth was made. Once it arrived it was swiftly plumbed in, and worked beautifully.

Also progress was made on the side screen to be driven by a Raspberry Pi. Below is the rear of the assembly showing the Pi mounted on the back of the display. an 8 inch 4:3 ratio LCD HDMI input monitor, again source from eBay.