Making Lathe Tachometer - Part 1

A few posts ago I offered some general ideas on adding a tachometer to TouchDRO setup that covered some theory and a basic example circuit. Since then I've received a ton of emails asking for more details, so in the next few posts I will provide a detailed start-to-finish example of building a tachometer for my Jet 1024 Lathe. In the post "DIY Tachometer for Your Mill or Lathe" I covered the basic of tachometer operation and provided a basic tachometer circuit using a IR emitter/receiver couple. A number of people wanted to use a Hall effect sensor with a magnetic encoder disk, so I will go that route for this design. Along the way I will use this project as mini-tutorial for some of the basic TouchDRO functionality.

ER-40 Collet Chuck for JET 1024 Lathe

ER-40 Collet Chuck mounted on the lathe

Every time I get to use my JET 1024 Lathe I have a hard time wiping the grin off my face. The machine is very sturdy and accurate for its size, and has served me very well so far, but has a few minor annoyances. For example, the spindle has a straight 1.25" bore with no Morse taper. Recently I had to make a few dozen studs for a steam engine project using a 4-jaw chuck where using collets would've been much more efficient and convenient. Since using collets in the spindle is out of question, the only option left is to use a collet chuck, so last month I set out to either make or buy one. After going back and forth between C5 and ER-40 I ended up choosing ER-40 for various reasons.