Mike's Elegoo Mars z-axis stabilizer

thingiverse

Human: rev 1.0: Initial Release Addition 1: Two variants with precise dimensions (only for printers without deviation) Addition 2: Housing 14.3 variant - for bearings with 14.3mm height instead of standard 14.0mm Printing technical parts with my Elegoo Mars resin printer, I noticed a significant measurement deviation within the 0-2 mm range above the printing base. Thanks to Jan Mrázek's findings about this issue, it is clearly a design flaw of the z-axis gear. (See: https://blog.honzamrazek.cz/2019/09/testing-the-precision-of-elegoo-mars-volume-5-whats-wrong-with-the-z-axis-and-how-to-fix-it-finally/) Instead of making modifications inside the housing and risking my warranty, I tried a design on top of the z-axis. This way, you don't need to open anything for installing this mod. The z-stabilizer is mounted on the upper side of the axis using the rock-solid axis cover as the fixing point. In addition to the 3D printed parts, you will need a proper bearing capable of taking forces along the z-axis without tolerances. This build uses the standard angular ball bearing of type 3200 2RS TN or an alternative 5200 2RS TN with 14.0 mm height. Now, I have added an alternative housing part for 14.3mm bearings. Choosing a good bearing brand and spending some money is a wise decision to get a stiff axis. All parts are designed to print okay on a non-modified Elegoo Mars machine, taking into account that the first mm are off. However, machine tolerances may require further workmanship. If you need more precise part data or your printer is okay as it is, collect the "precise" versions of two files. Installation: Remove the upper axis cover by unscrewing the two screws. Turn down the seat screw some distance. Then put the bearing over the axis and screw in the endcap part until it's fixed in place. Next, up-screw the seat while holding the endcap plus axis in place and screw everything together as a tight fixed sandwich. This fixes the bearing in its correct position. Reinstall the axis cover or put it into the housing part and fix it later on. Now insert the bearing with axis into the housing. It should fit tightly without moving in axis direction. For calibrating the right fit, it is sufficient to move up the print arm close to the z-stabilizer. Everything gets in place automatically. Ready to print! Print the housing part directly on the base but with internal support! Find attached the fitting CiTuBox file and as a fast start, a direct printable file for all needed parts. The file is calibrated for printing with black Elegoo Resin. No hollowing needed. Try some calibration objects and enjoy the new unleashed full precision of your Elegoo Mars. (See staircase print after installing this mod!) Have fun! Mike Update: I would advise not to print both screws with black Elegoo resin. It turned out that black is too brittle. Elegoo grey or similar resin does much better and breaks less easily.