Hey Electrified Miata team, here's the latest update in the never ending quest to go faster. The band is back together and that makes me absurdly happy. What band you ask? The band of people, that helped make the Pantera, the Electric go-Kart, the Electric B2600 and now the Electrified Miata. There is something very special about a team meeting and working to construct something fun. I missed having this great group of people together, working on a project. Thank you very much to all that helped once again, on that quest to make dreams come true!
Just like in a musical band, everyone in this band plays a different instrument. Bruce picks up the Leaf charger. Our goal with this instrument is to understand it better, so we can make it play our tunes.[what tunes?] A working charger will be required to play in our band, so some dissection is required to get a visual identification on the various components and how they are connected. Here's a 30 second time lapse from Bruce of him of taking the bottom section apart.
Whew, that was a fair amount of delicate work. Thanks Bruce!
Ed, comes in next and picks up the wire loom. He has the required tools for this
job in his pocket, a nice knife. We start to unwrap it and remove all the tie-wraps and electrical tape. This tune requires patience as we don't want to damage the wires underneath. Old electrical tape on the hands is not that fun. Thanks Ed! Of all that cabling (right), here is all that is required (left) between the inverter and motor
Joe enters, and starts on another vital component, battery pack assembly. One down side to having our own form factors is 'some assembly required' Joe gets to play with these pieces to assemble them in a very specific pattern.
He does this until we have a 10 x 20 grid assembled. I had one side assembled (a nice break between thoughts in software) and Joe completed the other side. Then Joe inserted 200 pre-checked batteries in one side and carefully finagles the other side to fit. A small block and hammer to keep the beat and snug the top down finishes off our second pack. Thanks Joe! Joe is also the one who exclaimed "Bill's putting the band back together" giving me the idea for the
theme of this weeks blog.
Brian stopped by later to check on our progress and we chatted about the future. Specifically we talked about the user interfaces and motor couplings. We agreed that using a cheap touch pad/tablet should work as long as it runs (or can be made to run) a recent version of Chrome. Anyone have a used tablet that runs (on can be made to run Chrome)? Donations accepted. As long as the touch display works while plugged in, that should be good enough. We also talked about the motor shaft coupling. Brian suggested we 3d print a test spline section to verify dimensions once we have a cad drawing. Thanks Brian!
I had my own part to play in this band. Early in the week I had finished checking 1000 batteries. From all of them, I discovered 14 cells and were significantly different than the rest. One was quite different and I set that one aside for my first soldering experiments. I added two cells and then charged all 16 of them, 4 cells at a time and assembled them into our 'test' pack.
This will be used to power our raspberry Pi's and possibly
other lower voltage items. We'll also do our first pack wiring on this one to find the
best techniques. I had come up with these little jumpers but Ed thought it would be better just to lay the wire across the batteries. I agree and that will be my task for next week to assemble this test pack, minus the BMS portion which Joe is prototyping. I was also playing with the software portion of the motor controller. Here's a video of me testing the power up and power down sequences.
I did the happy dance, and had to show my wife once I got the output pin numbers correct in the program. The software should be ready next week to attempt our first "chat" with the inverter.
Again, if anyone has a used tablet device they are willing to part with, please let me know. Thanks so much for reading. It's not too late to join us in the fun - contact me (using this link if you don't have my number)