Auto bed leveling for your Vertex!

Hi everyone,

I developed an add-on for your Vertex to use the build-in auto bed leveling in the Marlin firmware.
In order to use it, I had to add a servo motor with a switch to the Vertex head and modify some wiring and code.
The servo is connected to pin 53 (SS) while the switch is connected to the Z-axis endstop.
The SS-pin is broken out on the LCD connector however, it’s not in use by any component of the printer. I build a female-male connector,
which I put between the connector on the mainboard and the LCD flat cable, with a wire soldered to that particularly pin.
I wanted to avoid any soldering to the mainboard since it would void my warranty.
The servo is powered by a custom made PCB with 7805 to supply 5V to the servo, I also used to traces of the PCB to connect the servo signal and the switch because I used a 4 pole cable to connect everything on the Vertex head with the electronics.

On you can find the servo holder to mount the servo on the place of the 2nd head (sorry dual head users, you can’t use this add-on for your printer).
The modified firmware is also available on, I enabled the auto bed leveling feature, servo support and fixed the flowrate in E-steps + the load & unload sequence.

LINK to page of this add-on.


Dylan Van Assche

Nice job, it’s cool you can. But tbh I really don’t see why you would want to do this? (I only see this as a huge advantage on delta style printers)
I mean levelling the bed if U install springs is super easy.
Plus your bed needs to be perfectly horizontal in reference of your rods anyway.
So you can’t really remove the set screws to gain z-height. So what advantage did this create? And how much build-space is lost by this?

But still, modifying stuff to fit your own personal needs deserves A High Five Good job!

Kind Regards


Well, my heated bed is in the middle a little bit higher then at the outside…
This can fix it and makes it possible to print at 0.05mm since the bed is far more flat :slight_smile:
I lost 10mm on the X-axis, that’s all :slight_smile:
Thanks for the compliment!


Hy Dylan,

very interresting and amazing work, but i do not understand how it works. (what is the servo doing ? the switch is in curious position …) .
Please can you tell me more or where can i get more information please ?


The servo moves the switch down to the bed when the Vertex needs to measure the Z-axis.
On Youtube you can find some videos how it exactly works:


Hi Dylan,

thanks for the information, now i understand.
But with this you can measure a sloping surface and not a bumpiness as you have with your bed, isn’t it ?

Another thing is the repeat accuracy of that switches. Can be ± 0.15 mm, means every measurment can differ 0.3mm, is temperature dependent etc … Years ago i have to construct a machine which measures a surface automatically and i have to use “Mycom” -switches specialy made for that with ± 0.01mm, but are expensive.

The switches are indeed a problem. I have cheap chinese switches and they are terrible.
I don’t use the auto bedlevelling at the moment since the chinese switch has an accuracy of ±1mm (really!)

I’m looking for better switches…


Just a suggestion: you can use a photo sensor, like used in our Vertex (or often in old 2d-Printers, including the mechanical parts to detect paper or wheehls etc) and the machanical trigger can be a leaf spring, bent to something like an U, one end is mounted fix (on the servo) and the other ridge ends between the photo sensor. Cheap an very accurate, should be ± 0.01 (can be improved with a filter slice in front of the receiver of the sensor)

Yes that’s true but I will first try a simple quality microswitch since a lot of people use it so it should work.



dank u wel for the nice report.

can you describe, how the connection to the Z-Stop was made, even better with some pictures.
I have a capacity sensor here and the only problem I have is the connection to the Z-Stop.
So if you can give me a helping hand on this, it would b nice.

  1. need to know how you connect the signal
  2. need to know where you put the signal to the Z-Stop (on board or at the Z-Stop itself, using the cable already going to the main board)
  3. may be some drawing with pin numbers - anything I can figure out the connection :slight_smile:

Images are welcome


I tried a capacitive sensor but I couldn’t get it working.
I’m sorry :frowning:


Hi Dylan,

Do you have a more specifick url for where to find the firmware?
The thingniverse link lands on a main page and not to any specifick page from you.
I converted my vertex to have a capacitif sensor (works fine BTW) but i cant get my autolevel working.
I tried to copy some of the programming from my K8200 with autolevel (works also fine) to the vertex but it refuses to level.
So i must be missing something and can’t figure out what my problem is.

Hope you can help me out here.

Met vriendelijke groet,

Sander Ekeler