While CNC machine tools are very popular today, there are a lot of people who are still working manually. Part of the reason for that is because CNC tools are more expensive, need CAM software to reach their full potential, and require a knowledgeable CNC programmer and operator. Manual machining can also be quicker for simple one-off parts. But if you are going to machine manually on a mill or lathe, a DRO (Digital Read-Out) is very beneficial. Hackster member PracticeMakesBetter came up with an affordable way to add a DRO to just about any tool.
A DRO dramatically improves the ease at which you can perform machining operations. Usually you’ll have a DRO for each of the machine’s axes that tell you either the absolute position or the relative position of that axis. Instead of having to do the math in your head using the tool’s dials, you can simply move the axis until the readout matches what you’re looking for. DRO retrofit kits exist already, but one that you build yourself can be customized for your machine and be more affordable. The easiest way to do that is to attach a rotary encoder to your crank handles, but that ends up being very inaccurate because of backlash.
PracticeMakesBetter’s design eliminates that possibility by measuring the actual movement — not just the position of the crank handle. For his lathe, as an example, PracticeMakesBetter attached his DRO sensor to the carriage so it’s always monitoring the actual position. The sensor is a rotary encoder, which is turn by a belt. The encoder is connected to an Arduino Uno board, which also drives the LCD readout. The design can be adapted to fit a range of machines and lengths, and adding additional axes should only require more rotary encoders and the mechanical parts to mount them. If you want to make manual machining a more pleasant experience, this is a great weekend project to tackle.