Ender 3 Pro Nozzle Endstop (Mk. III)

The nozzle endstop for the Ender 3 pro moves the Z trigger point from the X axis bracket location on the stock design to the nozzle. This has the advantage of allowing for compensation of themal expansion of the nozzle when the machine homes itself. By compensating for the thermal expansion the machine will “always” (within given tolerances) the correct distance from the bed. 

I designed this part to use the original Z endstop board that is included with the printer. This means less special parts are needed to get up and running. However, there are still a few small parts that are needed to assemble.

This design as of now uses 2 M3x6mm self tapping screws for plastic / wood. The original design called for M3 brass inserts but I was unhappy with the design. Using the self tapping screws give the endstop board a nice tight fit to the housing and reduces the BOM at the same time!

Let's get started!

What you will need to build the endstop

• 35mm M5 steel dowel pin
• Original Ender 3 Z-Endstop
• 2 M5 20mm T-Slot nuts
• 2 M3x6mm self tapping screws

Once you have the components, we can get to the printing part.

The part is designed to be printed with minimal settings. The only thing that really must be done with to flip the part on its back so it prints as showing the picture. As far as print settings you really don't need anything crazy. I went with 3 tops, bottoms, and walls and 20% honeycomb infill. There should be zero need for supports.

While the only part needed to make the endstop function is the main body component, I did design a shim to raise the body off the printer frame by 6mm. The shim was more for my own needs but if you find you need a shim you can download the included step file and modify as needed for your machine / bed combination.