I've bought them off eBay, CL and Kijiji. But mostly I get them (for scrap metal prices) from my local metal recycling/scrap yard. I drop in there every once in a while and wander around for a half hour. Almost always I'm able to pick up a few that aren't full of holes and sometimes they even come loaded with (expensive) Allen Bradley 800-series switches like e-stops, start buttons, selectors and pots. Bill
Harvey, here's a few pics to show you how I did mine. The sensor on the Tachulator is has both a photocell to pick up the revolution marks as well as a LED to provide enough light so the sensor can differentiate between light and dark to send pulses. I removed the motor and top head cover to gain access inside to the variable pulley assy. I made a little aluminum block to mount the sensor near the front right corner inside the housing with the sensor level with the flat face on the lower half of the pulley assy. Then made up a small wire harness to connect to a Cat 5 receptacle which I mounted in the lower pulley housing (after making the appropriate hole for the connector to attach from the outside). A Cat 5 cable has more wires than the 4 you need, so even a 4-wire phone cord would work. I didn't use the sensor disc they provided. Instead I painted the flat face of the lower pulley flat black. Then hand painted every other section around the pulley face in white. If I recall, this gave me 6 white and 6 black sections. When I wired up the coiled Cat 5 cable to the Tachulator inside my control panel, the 2 wires for the sensor LED are powered thru the Power switch to the Tach & DRO, which in turn is powered by the master Power switch (that powers the VFD). I did it this way so when I turn off the master Power switch, it kills power not only to the VFD, but also the Tachulator and DRO which obviously don't need to be on when your not using the mill. Hopefully the pics help you. Cheers, Bill
