The Golf Cart battery system is finally done! Well, almost. We had the whole thing ready to go, and then we realized something catastrophic, but I’ll get to that a little later. I started the week off discussing some ideas with Tim on how we could mount the lager orange battery cables to the battery system feasibly, considering that the individual cells don’t have any direct mounting points. We sketched some simple ideas.

This week was convoluted, considering that we had Thursday off from school. During school, I worked on the battery system, specifically setting up and configuring the BMS system for it to safely charge and balance all cells. In order to interface with the BMS (can be found on XiaoXingBMS here) you apparently need a special UART tool that they sell. To me, it looks like a regular USB-UART Serial cable, but after using the Adafruit USB to TTL Serial cable I found that I couldn’t establish communication with it to extract any valuable information from it.

I began the week by trying to start a print on one of the Fusion 3 3D printers at school, but the extruder ended getting totally jammed up and broke some of the structural plastic pieces over-night while I left it going. Considering that the PLA that the extruder parts were printed in were already old and brittle, when the PLA got snagged on something, the plastic was the first to go.

This week started off a little bit differently. Rather than diving straight into the perpetual golf cart project, I was in need of a brass bushing for a 911 Distributor rebuild. Existing ones cost over $150, so with a little help from Tim, I was able to make my own free of cost. By cutting down some brass stock and turning it on the lathe, we created the bushing with tolerances of around 1/1000th of an inch.

In shop this week, I spent a good amount of time helping my friends with their own projects. I spent time helping Tim get his blog website completely overhauled. Ultimately Andrew and I convinced him to use Hugo which is far superior in every way to Wordpress. There was some trouble figuring out how to deploy his site to vercel (we never got it fully deployed) so for this week at least, he will continue to put his blog posts on his old website at https://timmyhunt.

First blog of the new school year! Being the first few days back in the shop, there were a few chores and tasks that had to be completed before anything else. Over the summer, Mr. Christy purchased a whole new assortment of parts and chips that needed to be sorted. Once this was finished, I jumped right back into things- right where we left off. The golf cart has a new charger that I was able to install this week, reducing charging time drastically.

This week, I spent most of shop time working with the golf cart. The new battery arrived so we put it in place, and we gave it a quick test-drive even though not all batteries were balanced yet. We finally charged all batteries and got them to each be within 0.2 volts of each other which will allow us to connect the equalizer modules. Hopefully this will prevent us from ruining another 300 dollar lead acid battery!

I had less shop-time this week than normal. On Tuesday, my entire Spanish class had to take the AAPL proficiency test, which ended up eating all of my fifth period and over half of my sixth period that would normally have been spent in shop working. On Monday, we were scheduled to take the exam during sixth period, after our health class, but it ultimately ended up getting canceled half-way through.

This week involved an assortment of work on various projects. With the seniors gone, the entire school felt a lot quieter. Luckily, I inherited one of the best spec. PCs in the shop from one of the seniors which will be great for when I get to working on the golf-cart’s AI autonomy system! I’m working on dual-booting it with Linux + Windows 11. I also printed and installed the new dashboard panel for the golf cart which will display statistics regarding battery level, range, voltage, and alerts.

This week, I continued working on the Sumo Bot project. I re-printed the frame and milled another PCB, then soldered all the components together. We will be making two robots for the competition. Likely, the bot will be ready to test and debug early next week. Although in the process of printing, I noticed that one of the Fusion 3s wasn’t working. Will graciously fixed the jammed extruder on the printer, but it was still having unexpected difficulty when homing the Y axis.