Kossel Delta Calibration (Marlin FW)

1. Introduction

Correct Kossel calibration is crucial succesful prints.
Printed parts tend to bend or even do not stick to the build plate without it.


2. Autoleveling using Z probe

2.1.1 Prepare your Z probe

Attach Z probe and make sure the connector is plugged correctly

2.1.2. Go to the menu and navigate to Configuration, click

2.1.3. Navigate to Delta Calibration, click

2.1.4. Click on Auto Calibration

2.1.5. Confirm leveling after autohome – click with the button

2.1.6. Make a tea and wait a few minutes

2.1.7. Stow Z Probe after leveling and confirm with a click

2.1.8. Store settings, better do it a few times just to be sure


2.2. Z height calibration

In my Marlin 2.0 configuration Z probe height is set to 15.0 mm.
Each Kossel setup has a slightly different distance between the tip of the nozzle and the probe.
Without these steps the calibration would be useless.

2.2.1. Go to Menu – Auto Home

2.2.2. Go to Motion

2.2.3. Go to Move Axis

2.2.4. Set Soft Endstops to Off

You have to send it to off so you can move your extruder head to negative distance.

2.2.5. Put a piece of under under the nozzle

2.2.6. Go to Move Z

2.2.7. Move the nozzle until it touches the paper

The safest way is:
1) Use Move Z 10 mm – move it the closest you can to 002.0 mm, not less!
2) Use Move Z 1 mm – move it to something like 002.0 mm, not less!
3) Use Move Z 0.1 mm – slowly move z position step by step until the nozzle touches the paper and there is a friction between the nozzle, paper and bed.
4) Write down the number you see on LCD, you will use need it later


2.3. Height adjusting

2.3.1. Check the actual height

Navigate to: Menu -> Configuration -> Delta settings -> Height
You can see that the actual height after autoleveling is 275.15 mm

2.3.2. Calculate the new height

Height after autoleveling has been set to 275.19 mm and we have measured (step 2.2.7.) that Z offset is -1.8 mm which means that we have to add 1.8 mm to the height: 275.19 + 1.8 = 276.99 mm

2.3.3. Set the new height

Start turning the knob until you see the calculated height, confirm by click

2.3.4. Store settings

Click on Store Settings a few times

2.3.5. Test the configuration

1) Turn off the printer and wait 10 seconds
2) Turn on the printer
3) Navigate to Menu – click on Autohome
4) Perform the steps from 2.2.7. with a paper under the nozzle
5) If you need to adjust the height, go again through the 2.3. steps

2.3.6. Print something to test your settings

The best way to make sure you have measured and calibrated the height correctly is to print something.
You can choose some standard testing cubes, ripple test or a delta calibration pattern which covers almost the entire printable bed area.
If you still have any bed leveling issues, perform the leveling again.


2.4. Change Z probe offset

You do not have to do do this, but it will be much easier to calibrate the printer next time – you can skip all 2.3. steps

2.4.1. Calculate new offset

Go to Menu -> Configuration – Probe Z Offs and check the current offset
In previous step we have measured that the height difference is – 1.8 mm
The new offset will be – 15.00 + (-1.8 mm) = – 16.8 mm

2.4.2. Change the Offset

Change offset to the calculated new one, of example – 16.8 mm and confirm

2.4.3. Store settings

You must store setting as always.


2.5. Print something

I fell in love with this Ripple test.
It works better then the standard calibration cube and you can spot your printer’s issues more clearly.