I purchased that with my Shoptask when I bought the machine in 1998. I couldn't get it to work. I was thinking out ideas for fitting a dog-clutch to the machine a while back and it occurred to me that it wasn't my fault - the thing is a flawed design.
What it does is cycle through green-yellow-red "traffic lights" triggered by a sensor on the spindle. When it gets to "green" you are supposed to engage the lead screw. The problem is that the tumbler reverese on the lead screw has 28 teeth. Half a tooth off and you engage it wrong. Even at the slowest speeds I was not able to time my reflexes reliably to make this work. Its not like having a threading dial and half nuts where it will work if you are less than half a turn off. This is 28 times harder to engage right.
I now use the "chalk mark" method for repeat pickup, which is slow but reliable. I will probably use the sensor from the electronic threading thing as a spindle speed pickup for Mach2, when I get my CNC stuff done.
When I get CNC I will be looking at thread milling with the rotary table for the stuff I am doing now.
Al
