Prusa i3 as router CNC - Y axis direct drive

thingiverse

This design is not from me. I adapted it from giulio prelli's. Congratulations, Giulio! You can improve the accuracy of Y axis of your Prusa by using direct drive method. As always, all the bearings are 608ZZ and rods 8mm. The frame is 6mm Upgrade 22/01/2018: I would want to remark that the thing is only for router CNC, *NOT* for 3DP. So, please think twice before make comments. We do know that 3DP need high speed on X and Y axis. This is not the case. This thing comes to replace the X and Y mechanisms of a Prusa structure for using as router CNC machine. Most of the machining centers use a similar scheme: direct coupling between motor and axis, through shaft coupling. Only low/poor quality machining centers use belt transmision. This is because in machining centers you need precision more than speed. Also you need a stronger structure to avoid vibrations from the spindle. In machining centers, the axis is led by two bearings at each end. They make all the force to sustain the axis. As machining centers have, the axis of this design has *two* support points (one near to the motor and other at the end), and *one* traction point (at the table). The point of the table has two nuts in order that reduce the backlash. Note that there are only 4 screws for fixing the two nuts. You can adjust them more or less to increase/reduce the backlash. Use please rectified screw, like I show in the pictures. The mechanism also will work fine without the bearing at the end of the axis. If you use it, you will be able to see that the bearing near the motor is firmly fixed by a screw, protecting the axis motor, but the other one is free, to permit any small movement. Finally, the weight of the whole table is led by two *brass brushing body.stl*, so the axis wont support its weight at all.