The steering wheel has made some progress after a long time CADing and re-CADing, printing out pieces for sizing, and testing how it feels in my hands. It is now physical! I do have a regular sheet metal steering wheel that I bought online for cheap, but it's a little big and I couldn't fit as many bells and whistles as I wanted on it.
I had a few iterations of shoulder levers that didn't feel right. The biggest problem was finding the right shape to get a good amount of contact with my pointer fingers while also allowing for a significant range of motion. In the end, I went with a simpler straight-bar shape but that extended a little bit deeper int the z-direction to contact more of the width of my finger. The metal tubing for the grips and torsion springs for the shoulder levels all came from a rusted out bike at GoodWill that I bought for a couple bucks.
I do have a lid CADed out but I'm waiting to print until I'm sure the contents of the wheel are final for this first iteration. I've toyed around with the idea of a dedicated button for the horn as well as some status LEDs to help debug.
Here's another picture from the back. It's cool I guess.
Yes, everything is still PLA. I know that PLA isn't great for things that take any sort of beating but PLA is cheap and super easy to print. Once these initial PLA parts start breaking, I'm going to replace them with PETG and see how it fares. I haven't ventured outside of PLA before but I'm sure I'll do so by the end of the first test drive.
Also on the way: a new 1st stage speed reducer! The chain drive, as pointed out by others, isn't great. It's loud, spews grease everywhere, and gets hot real fast. I ordered some timing pulleys off of Amazon and am hoping they can more gracefully handle the high output of the motor.