PROXXON BFB2000 KT150 CNC conversion kit

thingiverse

Fully printed easy to build conversion kit for the BFB2000/KT150 mill/drill press by PROXXON. Inspired by https://www.thingiverse.com/thing:1927516 and even using the same .dxf drill template for X and Y, only modified for NEMA23 motors. I used cheap 2A and 1.26Nm=180oz motors by "ACT MOTOR" with dual shaft to be able to still operate the axes by hand. The type is 23HS6620B and its length is 56mm with 21mm shafts on both sides. They have plenty of torque. Their axes are 6,35mm in diameter. The handle for the Z axis can be attached using a reducer (8mm->6,35mm). The handwheels for X/Y are 70mm in diameter and therefore a pleasure to use. Print the Z-part with the NEMA mount on the buildplate and supports touching buildplate. The XY mounts are printed with the circular cutout on the buildplate and optional supports for nicer holes. Material is PETG. The coupler for the Z axis is a standard 20mm diameter one (8>6,35mm, the cheap "spiral ones). The couplers for the X and Y axes are rigid ones. The KT150 table did not have any bearings at all on its axes and my design relies on the NEMA23 motors' bearings to eliminate backlash completely. The trickiest part is to get them wobble-free. 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. I drilled holes through the rigid couplers and shafts in order to enable maximum torque transmission. You need to drill and tap 3 M4 holes for each axis (with one optional hole for Z). For the Z axis mount you 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 (3 for each axis) are needed. The Motors are attached with M5 bolts with washers and nuts. The CNC controller I made cheap standard perfboard from parts I had lying around. One could totally use one of the ubiquitous 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) which is also used by the ESTLCAM 11 controller. Initally I installed GRBL but found the ESTLCAM controller way easier to set up and use. Video of the device in action: https://www.youtube.com/watch?v=x_0UUdYdHBc Note: the Z part you're seeing is the first prototype part which I had to print in two parts and join with epoxy because I had underextrusion on one layer. I decided to save ressources and leave it in place. The final part uploaded here is debugged and optimized but has not been printed yet. Dust shoe: https://www.thingiverse.com/thing:2832427