The key to my whole system was the electrode system to handle igniters for MMX. OF course, this is where I ran into most of my problems. My first prototype had worked for ignition and holding the igniters in place but was not very durable, was unwieldy an and a royal PIA to mass produce. I had intended for the electrodes to be connected directly to the launch system in place of the normal lead wires. One of the revelation that came to me is that this would violate my intention of interchangeability between racks; in a pinch, I would not be able to use the MMX leads for another pad or vice versa. Then I realized there was no reason to get rid of the electrodes. I would just have the clips connect them. That way the clips would still be present for other sorts of launches if needed.
I rethought the electrodes and was frustrated by trying to electrically isolate the pair. I had visions of a sheathed, insulated bolt to hold them in place but quickly found that there was nothing extant that I could find to use. I did not want to rely on wood screws that might pull out and the project languished while I tried to figure what to do. Eventually, I realized that the electrode could be bolted on just one side and still stay in place. I just added a bit more material to one side for the holes. Since the electrodes would go on opposite sides of the head, they would clear each other. I drew up a template and printed it out.