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BLV mgn12 mod

For Anet A8 / Prusa i3

This project turns the Anet A8 into a precise 3D printer, with MGN12 rails mounted on an aluminum extrusion frame. With small changes it is compatible with Pheneeny's AM8 mod. The result is a much more reliable, accurate and faster printer.

Download all files Thingiverse Remixes Facebook group

BLV mgn12 mod

Why MGN rails

Low and mid range printers usually move on linear bearings or Delrin wheels because they are cheaper than MGN rails, and the price is accuracy and reliability. MGN linear rails are stiffer, very precise and smooth. They allow faster printing without losing quality, and because the rails are fixed to the frame, they block unwanted motion from bent threaded rods or the other axes. That is why high-end printers use them. Affordable MGN rails on AliExpress made this upgrade possible.

Good to know

  • Patience required. The MGN rails must be perfectly straight and aligned. Rushing this step causes problems later.
  • Source file. The STEP file is in the project ZIP. If you remix it, follow the license (CC BY-NC-SA) and mark your work as a remix.
  • Bed position. You may need to re-center the bed coordinates in Marlin, or move the Z extrusion to center the bed.
  • Simplify3D. A build plate for Simplify3D is available.
  • Share it. An "I made one" photo on Thingiverse or in the Facebook group is always appreciated.

Mod variations

  1. Anet A8 converted to AM8 (original 440 mm height) with the BLV mgn12 mod. If you already own an AM8 and want to keep its height, use 350 mm rails instead of 400 mm.

  2. Anet A8 converted to AM8 with a taller 500 mm Z axis and the BLV mgn12 mod. Build the AM8 with these changes:

    • instead of 2 × 440 mm 2040 extrusions → 2 × 500 mm (or longer) 2040 extrusions
    • instead of 2 × 340 mm 2040 extrusions → 4 × 364 mm 2040 extrusions
    • longer 400 mm threaded rods

    Not all the AM8 parts are needed, see what to print. 3. Anet AM8 freestyle with the BLV mgn12 mod. The parts are modular and can be fitted as you like. For a custom size with a bigger bed or a taller Z axis, choose the extrusion lengths and attach the parts to them.

Requirements

An Anet A8 (or a similar Prusa i3 style printer), the AM8 frame upgrade, basic technical skills, spare time and a mid-range budget.

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BLV mgn12 mod
BLV mgn12 mod for Anet A8 / AM8
Test print
Test print, part 2
Prusa mgn Cube test
Printing the X motor mount, Prusa mgn