Printrbot+ Micrometer Z Adjuster

thingiverse

Replace your Printrbot LC's Z-axis adjustment screw with a micrometer head for easy and accurate calibration. The idea comes from Plexus on printerbottalk.com, who deserves credit for the design. To install it, follow these steps: 1. Obtain a micrometer head (0-13mm) and a 6-32, M3.5 threaded rod around 8-10cm long. Also, get a locknut or pair of nuts and a compression spring (40mm extended length). 2. Print the holder using blue RepRap PLA filament with 0.2mm layers and 100% infill every 2 layers. Adjust the OpenSCAD file if necessary based on your micrometer head diameter. 3. Remove the original Z adjuster screw and ensure the holder fits properly, resting on the original plywood piece and hooking over the left (X0) side of the bridge. 4. Clean up the holes for the micrometer head and allthread as needed. Install the micrometer head with the scale pointing towards the top bracket's hook and secure it with a metal screw. 5. Assemble the spring, allthread, and locknut. Adjust the micrometer to zero and compress the spring so that there are a few millimeters of compression after the allthread touches the micrometer. 6. Adjust the micrometer to about one-third to half of its total travel and measure the required length for your printer, adding 6mm for the plywood thickness. Cut the allthread accordingly. 7. Enlarge the hole on the underside of the Z adjuster tab to allow the allthread to slide through freely. Ensure it's in the correct position before proceeding. 8. Install the holder by sliding the allthread through the original hole and securing it with a cable tie, attaching one small tie to the original adjuster and another high on the side for a snug fit. 9. Turn the knob to rehome and enjoy your new Z-axis adjustment system! Don't forget to give credit to Plexus from printerbottalk.com for the design inspiration.