3Drag Central z-axis with trapezoidal leadscrew, (Velleman k8200)

thingiverse

NB: My advice is to use this mod instead:http://www.thingiverse.com/thing:1854399 This design improves the Z-axis of 3Drag from a mechanical point of view, and it's an alternative version of Sgabolab's central z-axis idea for 3Drag.https://www.thingiverse.com/thing:1496357 NB: Check immediately if your trapezoidal nut fits this design (I uploaded the solid model .stp). You need to improve the Z-axis of 3Drag from a mechanical point of view. The final electronic resolution will not be higher than the standard one. To assemble the mod, you'll need: * A trapezoidal lead screw with a diameter of 8 mm and a length of 40 or 50 cm. * You can use leadscrews with different leads or pitches (8mm/turn, 4mm/turn, or 2mm/turn). * Two SKF 6004 ball bearings. * Three M5 x 10 mm screws with socket heads. * Ten M5 x 12 mm screws with socket heads. * Two M5 x 60 mm screws with socket heads. * Twelve M5 nuts. * Four M3 x 30 mm screws. * Four M3 x 8 mm screws with socket heads. * Four M3 nuts. * Six M3 set screws (6 or 8 mm long). * Various M3 and M5 washers. See the images for the assembly. The gearing has a ratio of 4/5, and depending on the lead of your leadscrew, you'll get the following resolution with 1/16 microstepping: * An 8mm/turn leadscrew will move the Z-axis 10mm/turn, resulting in 320 step/mm and 3.125 um/step. * A 4mm/turn leadscrew will move the Z-axis 5mm/turn, resulting in 640 step/mm and 1.5625 um/step. * A 2mm/turn leadscrew will move the Z-axis 2.5mm/turn, resulting in 1280 step/mm and 0.78 um/step. These configurations have been studied to use layer heights of 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, and so on (multiples of 0.05 mm). This is because a full step of the motor corresponds to 10mm/200=0.05, 5mm/200=0.025, or 2.5mm/200=0.00125. P.S.: If you're using an 8mm/turn leadscrew, pay attention to the backward motion and make sure to avoid it during printing. Remember to update the steps/mm parameter of the Z-axis on your printer.