How to mount microswitches. They generally have 9mm hole spacing which is too close together to fit into standard 1/2" Meccano hole spacing. However, the 12b angle bracket has a slot which leaves just enough room to mount microswitches without MM. (Meccano Mutilation 😄). Note: My measurements are read from my digital vernier gauge. Not perfect, but close enough to get the message across. PS, Someone told me my original photo of this method appeared in one of the Meccano magazines. Great to hear. Anyone is free to use my photos. If I put it on Facebook, it's ok to use it so share away. 😀