gain access to a structural member for the safe installation of ceiling fans or heavy lighting fixtures mounting base 11 of fig1 may be fashioned utilizing ordinary sheet metal die processing and stamping procedures to make the various holes and shapes on the base preferred materials for reinforcing brackets bases and struts such as mounting base 11 include zinc plated mild steel due to that material 39 s strength durability widespread availability and manufacturing facilities other metals may be used such as aluminum brass or u201c pot u201d metals keeping in mind that different thickness may be required to achieve the strength and bracing characteristics preferred materials for spacer 28 and threaded bushing fastener 33 a can be made from zinc plated hot or cold rolled steel and can be either swaged press fit or spot welded in position after location holes have been created on mounting base 11 for these components shown in fig2 is a three and one half inch plastic electrical box 20 a four inch plastic electrical box 21 and a 3 5 inch metallic electrical box 12 with mounting base 11 in position to be installed between the one of the electrical boxes fig2 is an exploded isometric view of all of the components that a typical.