What kind of accuracy to expect from a CNC router

Even on less expensive CNC routers achieving high accuracy is possible. Whether your CNC is using open-loop stepper motors, hybrid steppers, full closed-loop servo motos with encoder feedback achieving high accuracy of +/- 5 thou (0.005 “) is possible. Anything less than 5 thou would be harder for the end-user and the price of a machine with the guarantee of +/- 1 thou accuracy is exponentially higher than a machine with 5-10 thou. Having quality components such as low arcmin gearbox, helical rack and pinion, well-tuned servo motors and a square gantry certainly help with machine calibration but even without them, there are certain steps users can take to increase machine accuracy by simple calibration. Before going any further have a look at the blog about CNC backlash and try to correct backlash issues first.