This two part case allows a crumble controller to be kept safe once the initial testing of a program has been done. Normally, connections are made with croc-clips or conductive thread, but this solution uses solder tags to create a robust system. The solder tags are held in place with M3 6mm machine screws and nuts. There are simple hexagonal recesses on the back of the case to prevent the nuts from turning while they are being fitted. I haven't included anything to keep the case together (other than a small amount of friction). I use a rubber band cut from an old cycle inner tube to keep the two halves together and stop them falling apart. With thanks to Redfern Electronics for supplying dimensions a long, long time ago...