Adjustable Z Probe for Bed Auto Leveling (i3 Prusa Style)




Introduction: Adjustable Z Probe for Bed Auto Leveling (i3 Prusa Style)

About: I'm an architect, I live in Genoa (Italy) where I also have my firm that works for setup and arrangements for scientific exhibitions and museums; I also draw comics and illustrations for children. I like to...

Hello All,

This is my third Instructable, and it is a close examination of another job that you can find here:

From an Ikea Footstool to (Poang) 3D printer!

With this probe you can easily add an Auto Bed-Leveling system to your i3 Prusa Rework style printer (link my Poang 3D)

The Probe is Adjustable and you can mount the stand part directly on the bracket of the extruder.

Step 1: Gathering Components and Printed Parts

At the end of this Step you can find the printed parts used for the assembly;

You can find the printed parts also on Thingiverse.

You need also an Hall magnetic sensor like this one from

I've used in addiction 2x mini-magnets 5x5x5 mm and 3x 3 mm screws and bolts.

Step 2: Final Assembly

The Probe is designed for having a 23 mm displacement on a stand that remains fixed to the extruder,

so you can place it ad then upgrade your marlin firmware easyly.

Two screws and bolt are fixed on the stand, for blocking x and y movements of the probe as shown.

The third screw is on the top of the probe, blocking the Hall sensor to the probe (may me you can use a little washer for better insulation, in my case the red one).

It's better to have a middle position for the beginning, and then move up or down the probe to find a good balance.

In the Front side of the probe:

- To the top you have the first slot for 5x5x5 mm neodymium magnet, insert here and glue it.

- In the rectangular slot below you can to insert a nail with glued on the top side the second magnet 5x5x5 mm

NOTE: For the polarity you must to have the first magnets that attract the second one naturally.

The probe works usually with the second magnet and nail below the hall sensor, after tasting the bed the probe reach a lowest position and the first magnet attract the nail, leaving out the probe from the printer's movements.

Step 3: Done!

This is the final position on the left side f the Extruder's bracket.

You now wire the Probe to the electronics and update your firmware settings (in progress)

Enjoy it!

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    3 Discussions

    Gary AT
    Gary AT

    3 years ago

    So how long does the metal probe have to be and do you any anymore pictures of where the first magnet goes ? Thanks Gary


    4 years ago

    Nicely done! voted...


    Reply 4 years ago

    Thanks a lot!