I thought long and hard about how to mount everything. The big issue is that the solenoid throw is parallel to its longest dimension. Unless I wanted to try and make some sort of hinged hammer this meant mounting the solenoids at a right angle to the chimes, meaning the whole arrangement was going to be quite wide. I wound up designing a 3D printed unit that had a shelf for mounting the solenoid and two arms from which to hang the chime. This meant the chimes were about 3 inches apart, so the whole thing wound up being about 17 inches wide. I went with a 20 x 8 inch piece of acrylic to which to mount them all along with the electronics (I couldn't 3D print everything as a single unit because of build area constraints).