PROXXON BFB2000 KT150 CNC conversion kit

thingiverse

Fully assembled easy-to-use conversion kit for the BFB2000/KT150 mill/drill press by PROXXON. Inspired by the innovative design at https://www.thingiverse.com/thing:1927516, I created a modified .dxf drill template for X and Y axes using NEMA23 motors. To maintain manual operation capabilities, I chose affordable 2A and 1.26Nm=180oz dual-shaft motors from "ACT MOTOR," type 23HS6620B, with 56mm length and 21mm shafts on both sides, offering ample torque. The axes have a diameter of 6,35mm. To attach the handle for the Z axis, I used an 8mm->6,35mm reducer. The handwheels for X/Y are 70mm in diameter, making them a pleasure to use. Print the Z-part with the NEMA mount on the buildplate and supports touching it, while printing the XY mounts with the circular cutout on the buildplate and optional supports for nicer holes. I used PETG material. The coupler for the Z axis is a standard 20mm diameter one (8>6,35mm), while the couplers for X and Y axes are rigid ones. Since the KT150 table lacked bearings on its axes, my design relies on NEMA23 motors' bearings to eliminate backlash completely. To achieve wobble-free performance, I had to overcome a few challenges. On the Y-axis, it worked out well for me, but X has some wobble on the motor side, which is absorbed by the partially flexible PETG mount. To enable maximum torque transmission, I drilled holes through the rigid couplers and shafts. You will need to drill and tap 3 M4 holes for each axis (with one optional hole for Z). For the Z axis mount, you will need 1-2 flathead 8mm M4 bolts and 2 80mm long M4 bolts with cylindrical heads. For X and Y, only some short M4 bolts are needed. The motors are attached with M5 bolts, washers, and nuts. I built a CNC controller using cheap standard perfboard from parts I had lying around. You could use one of the ready-made boards (Woodpecker board, Arduino GRBL shield, etc.). Mine is based on the GRBL 1.1 standard pinout (with an Arduino Pro Mini and DRV8825 2,5A drivers) used by the ESTLCAM 11 controller. Initially, I installed GRBL but found the ESTLCAM controller easier to set up and use. Watch a video of the device in action at https://www.youtube.com/watch?v=x_0UUdYdHBc. Note: The Z part you see is my first prototype, which I had to print in two parts and join with epoxy due to underextrusion on one layer. I decided to save resources and leave it in place. The final part uploaded here is debugged and optimized but has not been printed yet. Check out the dust shoe at https://www.thingiverse.com/thing:2832427.