Rotary Encoder DRO for a Lathe Tailstock

摘要

Having fitted DRO's to the saddle and cross slide of my lathe, I've always been dissatisfied with the scribed lines on the tailstock as the only measure of how far it has been advanced. Doesn't often matter for drilling, but if you're using a D-bit or similar it does. My Colchester lathe came with a re-settable graduated dial on the tailstock, but my current lathe didn't. There are several ways of overcoming this, CH Thomas described the fitting of a re-settable graduated dial to a Myford Super 7, and Graham Meek has described a more sophisticated version in MEW recently. Probably the simplest way is to fit a linear slide as shown in Simon Burt's entry to the Stephenson Trophy, see MEW 297.I decided to do it differently, using a rotary encoder driven off the tailstock handwheel. Co-incidentally I entered this for the Stephenson Trophy as well, not thinking it would win, but Neil only had one entry at the time. Now he has had a request from a reader for a write up, so here it is. It will come as no surprise that this once again uses an Arduino microprocessor.