Filled base for DIYnder v2

This is a simple weighted base for the DIYnder which uses cement grout and old screws. It means you dfon't have to find a gym weight to fit over the standard base. Place an M6 nut in the slot and check the bolt will screw itno it. Fill the base section with old screws etc and add cement grout to fill the gaps. Vibrate it to get the air out. Then put the lid on with four M3 screws. Add more grout through the round hole, shaking it to distribute, until it is full. Make sure the space where the r