Only want to start by saying this mod is credit by team RoBo. I made the decision to make my own variation predicated on their layout

Vehicle Bed Levelness Compensation (ABLC)

Questions and Answers:

What's Vehicle Bed Leveling?

Vehicle Bed Leveling is when the bed levelness is fixed through mechanical actions to accomplish a bed that's leveled against the nozzles move. This really isn't exactly the same as ABLC

What's Vehicle Bed Levelness Settlement?

ABLC is the procedure for probing the bed using a measurement device compensate for this by transferring the Z axis up and down and to find out the degree malfunction of the bed. There isn't any mechanical variation but instead applications damages.

Why is it referred to as Auto Bed Leveling?

Likely for simplicity sake. Thus why I titled this Degree. It is usually okay to cut words in case your purpose continues to be made.

The way that it operates:

The Robo3d has a security measure put in where when the nozzle touches the bed, the fanatics will unseat from their home so as to not place force on the bed and get "thrown" out. This really is what people refer to when they " throw their nuts".

Using this rule of the nut unseating, they attached a switch to it and used a coupling nut in it's location. The switch links to the coupling using a plastic mount. The switches subsequently activates against the x idler as well as the x motor buggy !

With this particular switch set up, the couplings as well as when the nozzle touches the bed start to unseat the switch will deactivate sending a sign to the ramps board an endstop has been strike. It is used for the probe detector as well as the Z0 detector.

How mine differs:

With my layout the switches are run in string to avoid a failure position. Were a failure in the cable or the switches the RoBo3d would only raise up during the regular z process of it's , not throw the nuts. Just Click Here to see the reason why I ran my switches in string.

Note: in case you have auto bed leveling from RoBo3D don't use my firmware without changing your wiring


Assemble it

Components List:

2x 5/16"-18 Coupling (Or M8-1.25 Coupling for those on metrical sticks)

2x Micro switch (1x along with the 1 on the Z axis)

2x M3 - 25mm

2x M3 Nuts

4x M2-10mm (2x in addition to 2 fixing Z switch)

Printed Parts:

RoBo 3D auto amount switch mount


By fixing the switch to the mounting plastic start. Prior to fixing the switch it is probably simplest to screw thread on the coupling. The mount should enlarge enough to go round the threaded sticks.

With the M3 nut is secured by the mounting bracket in place and screw and start to tighten it down, but enough the plastic can nevertheless slide on the coupling.

Until the switch is just activated fix the mount space from the idler. The switch should activate readily when it is pressed down on by the idler, but deactivate immediately after the coupling starts to unseat. This might require some fine tuning however as soon as it is secured by you it should remain accurate.


With the switch in place it is time

Present Autolevel owners:

In case you have RoBo3D's Degree switches your parallel switches can turn into string but it needs soldering to the NO leg and unsoldering from the NC leg. Then you certainly cut one of the legs short (say on red) and then another one long enough to solder onto, then you certainly change your wiring to signify below.

New to Autolevel owners:

Follow the wiring diagram to wire your switches in location. Solder to get the spans needed and you'll most probably need to cut. Colour/polarity isn't essential.


Control It


With the switches wired in place it is time to shift the firmware. This is actually the same Vehicle_Level firmware used by team RoBo, but changed with 1 crucial difference:

const bool Z_MIN_ENDSTOP_INVERTING = true;

changed to:

const bool Z_MIN_ENDSTOP_INVERTING = false;

Which is traditional.

Download the firmware below.

Use Arduino or MatterControl software

It must even be taken into account this firmware will work on any RoBo 3d with or without auto-level.


With the firmware it is time to find out the Z cancel between when the switches activate and when the bed touches.

Start by homing all axis, ensuring the Z houses in the middle of the bed.

Using MC or Repetier lift the nozzle up .1millimeter at a time until you are able to slide a sheet of paper underneath it, counting how many steps it took. Once you can just fit the paper under, remove the paper and lower the nozzle by .1mm. This really is your Z cancel

Change the G code:

With the firmware it is time to configure the auto-degree script to run and calibrate the Z height. Add this code in the beginning procedures for your slicer after the G28 codes.


G1 Z0.5 ;Fix Z cancel
G92 Z0 ;Define new Z home
G29 ;Autocalibrate bed


That should be everything. I find it helps to track the output signal from the G29 sequence in the terminal. You will have the capacity to address it faster that means in the event that you see an unusual number.

Please I would like to know in the event you've got some questions

Ace Hardware sells M8-1.25mm couplings for anyone that's them locally.

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