MachTach gear tooth sensor mount for 9" South Bend lathe

thingiverse

This allows the MachTach gear tooth sensor to be mounted behind the head stock so that it can run against the 76-tooth bull gear. You may need to upgrade an older unit by purchasing a new microprocessor chip from Henry. The slot in the back of the base is for a 1/4-20 nut, while the hole in the bottom of the base takes a 1 1/2-inch 1/4-20 bolt used to clamp the base to the V-way using the shoe. Clean out the hole with a 1/4-inch drill bit and run a 1/4-20 tap through the hole in the top of the base mount. The top piece can be moved so that the attached sensor is positioned close to the gear teeth. Then, use a short screw to clamp the top piece and hold it in position. I included a photo of the unit sitting on the V-way in front of the chuck to show how it is put together. It's difficult to get a good picture when it's installed in its working position behind the head stock, but you can see it in the working position in the second picture. I used small wood screws to fasten the sensor mount to the top piece and thick crazy glue to attach the cover plate. I wanted a cover plate to protect the sensor PCB from oil and stray swarf. You may have to trim the cover plate to get a good fit. I've included the Sketchup files for those who want to change or fix things.