Probably the most critical part so far, this plate had to tie the pack together,and provide secure connection points for the BMS wires to each cell.
With anything like this where the cells were not uniform, I had to take the 3 dimensional stack of cells with connector blocks, and make an insulating plate that would line up with the connecter blocks and the 9 standoffs. I aproximated the positions of the blocks, and then adjusted the drawing to compensate for as built variations. I finally got the drawing where I wanted it, and machined the plate. I was happy when the plate fit nicely.
I loosened the threaded rods when the connector blocks were secured to allow the cells to shift the tiny amount that was required to get them all at the correct height and position.
Next step is to make the case, which will have to allow mounting of a standard relay assembly.