X axis belt shim to correct the belt path and improve accuracy for ELEGOO Neptune 2

thingiverse

This is an X-axis belt shim for ELEGOO Neptune 2 series 3D printers. It makes the X belt parallel to the X axis (gantry) and equalizes the nozzle travel scale over the all position on the axis. Therefore, the accuracy of the printing is improved. ## Installing You can print two shims and install on the toolhead, one is stepper side clamp the other is idler side clamp, under the gantry. |Stepper side|Idler side| |---|---| ||| *** ## The theory If the belt is NOT parallel to the axis: ⊿Xin ≠ ⊿X1 and ⊿X2 < ⊿X1. Therefore, the nozzle travel scale is changed related to the position on the axis.  Correct belt parallel to the axis: ⊿Xin = ⊿X3 and ⊿X4 = ⊿X3. Therefore, the nozzle travel scale is equalized to all positions on the axis.  ### Neptune 2 series stock belt path The stock X belt path of ELEGOO Neptune 2 series is NOT parallel to the X axis. |At left end of the gantry, belt inside the gantry|At left clamp on the toolhead, belt outside the gantry| |---|---| ||| ### Correcting belt path of Neptune 2 series It is 5mm off at the stepper side and is 3.8mm off at the idler side.  *** ## CAD file You can find the cad file on [the project GitHub repository](https://github.com/marbocub/Neptune2-practical-mods/tree/main/X-Axis-Belt-Shim).