1/2" EMT two inch spacing drill jig for #6 machine screws

thingiverse

This is a jig for 1/2" EMT conduit which can be used to drill holes for #6 machine screws, spaced 2" apart with a drill press. Designed for use with my pixabulb clip design.The holes are 1" from the end of the mount.You can press #6 nuts into the hex holes on the top piece. They should tap in lightly with a hammer. I recommend a dab of CA glue to keep the nuts in place. The nuts act as bushings to ensure that repeated drilling of holes does not damage the jig significantly. I used a similar jib to drill 100s of holes in EMT for a previous project and the nuts worked well to protect the holes.The bottom piece has holes for #8-32 threaded brass inserts which you can press in with a soldering iron. I originally used a tapped hole but found that the hole would strip out with repeated use. The brass inserts are FAR more reliable.For the first use, hold the jig lightly and slowly bring the drill bit down. Let the bit center on the nut and pull the jig into alignment. Once it is lined up, hold the jig firmly and drill through the nut; this will basically remove the threads.Once that is done, use #8 machine screws on the 6 perimeter holes to tighten the jig onto the EMT. Drill your holes, and then loosen the #8 machine screws and slide down, lining up the last hole drilled with the first hole on the jig. I usually just stick a #6 machine screw in to help ensure the EMT is lined up perfectly. With this technique you can drill a long line of holes in EMT without worrying they will get out of alignment.