Elegoo Neptune 3 Direct Drive - Sherpa Mini Extruder

Why?

I bought the Neptune 3 to print RC Planes and was frustrated by some of the extrusion issues I was seeing. The Sherpa Mini is a lightweight and reliable extruder, so it was a no-brainer to add it.

While this does add some weight (~150g-ish) to the x-carriage, it shouldn't be a problem at normal speeds for PLA/TPU. The x-axis is significantly lighter overall, since the stock extruder and stepper weigh 380g+.

Warnings:

You will need to be able to cut/solder the new stepper connection to the existing wiring or use a JST-PH connector kit and a soldering iron to terminate the new stepper connection with a plug that will plug into the existing wiring harness.

You will also need a soldering iron or some other method to install the M3 heatset inserts.

Parts Needed:

1x  - Annex Engineering Sherpa Mini Extruder

1x  - PTFE tubing (comes with Sherpa Mini kits)

2x - Brass M3x5x4 Heat Set Inserts

4x - M3x12mm screws (two for extruder and two for mount)

Optional Parts:

JST-PH Connector Kit (for stepper connection)

ZipTies

Printing:

Files have been oriented for printing and don't need supports.

Scale the parts up to 101.5% if you are using ABS. No changes should be needed for PLA or PETG. I used ABS but PLA should be fine.

Install:

1. Power down printer
2. Remove existing extruder
3. Remove PC4-M10 fitting on the top of the hotend
4. Remove fan shroud screws
5. Install M3 heatset inserts into the mount. They will be where the SherpaMini will attach.
6. Push mount down onto red aluminum part where the PC4-M10 fitting was. It should be a snug fit and sit flush with the top of the carriage.
7. Route existing wires out from underneath mount.
8. Screw mount/fan shroud back onto carriage with longer M3x12mm screws.
9. Determine correct length of PTFE tube to put between the Sherpa Mini and the hotend. Install spacer over this length of PTFE to keep it aligned.
10. Install Sherpa Mini with 2 M3x12mm screws.
11. (optional) Route stepper wires back through existing wire loom.
12. (optional) Use JST-PH kit to make connection from stepper wiring to existing cable.
13. Screw the PC4-M10 fitting into the printed guide and reinstall it where the extruder used to be using old screws from the original extruder. Reconnect what is now a ‘reverse bowden’ tube to it.
14. Trim reverse bowden tube to appropriate length and install into top of Sherpa Mini.

Configuration:

Direction:

Make sure your extruder is turning the correct way. If it is turning backwards, you'll need to either swap wires or make the change in Marlin.

E-Step Calibration:

Determine the new esteps needed for accurate extrusion. A good place to start is 887.