How To How to, tutorials and instructions for Onefinity CNC machines. Controller (Buildbotics) Discussion Info about our controller. Assembly This category is to discuss the assembly of the Onefinity CNC. Troubleshooting (X35/X50) A place to request or offer help troubleshooting the Onefinity CNC. Upgrades This category is to discuss upgrades of the Onefinity CNC. Controller (Buildbotics) FAQ 4th Axis (Rotary) (Buildbotics) The Onefinity Buildbotics controller does not officially support 4th axis (rotary) but some clever users have made some aftermarket solutions. X-50 The X-50 is an upgradable X Axis for your existing Onefinity CNC. Featuring large 50mm Hollow Linear Motion Shafts for great rigidity, a larger Stepper Motor with up to 40% more torque, and a 1616 Ball Screw that delivers 60% more speed. The X-50 series is available in all three rail lengths, Machinist - 16", Woodworker - 32" and Journeyman - 48".