# Scan Based Calibration Last Updated: December 7th 2024 {% hint style="warning" %} Make sure `mode:` is set to **scan** in your printer.cfg prior to following this page OR use `PROBE_SWITCH MODE=scan` prior to following this guide. {% endhint %} Make sure you're in SCANmode ```gcode PROBE_SWITCH MODE=scan ``` Then make sure you save ```gcode SAVE_CONFIG ``` Home the machine in X and Y: ```gcode G28 X Y ``` Position the nozzle in the center of the bed. You will need to adjust the coordinates for your machine. ```gcode G0 X125 Y125 ``` {% hint style="warning" %} At this point, you might note that your Endstop Z is TRIGGERED, this is normal, and will be resolved once you run the next command. ![](/files/H6vj4GnsWg9HoIsB9x8e) {% endhint %} Start the calibration process: {% hint style="info" %} If you regularly print with a hot chamber (60oC+) it is worth calibrating with a hot chamber. {% endhint %} ```gcode CARTOGRAPHER_CALIBRATE ``` You can either use the web interface to adjust the nozzle height from the bed, or `TESTZ Z=-0.01` to lower it. \ \ Use a piece of paper or a feeler gauge to measure the offset. Once finished remove the paper/gauge and accept the position. ```gcode ACCEPT ``` Save the results to your config file. ```gcode SAVE_CONFIG ``` ## Initial Tests Home your printer. ```gcode G28 ``` You can test the accuracy. ```gcode PROBE_ACCURACY ``` You can also measure the backlash of your Z axis ```gcode CARTOGRAPHER_ESTIMATE_BACKLASH ``` To make use of the backlash estimation that is given. You will get results spit out starting with ```gcode Median distance moving up ``` In this line will be a measurement called "delta" Take note of the value. Locate the configuration section marked: ```gcode backlash_comp: 2.01 ``` Update this section with your new estimated backlash compensation. It is a good idea to do this compensation test at all 4x corners of your build plate and then again at middle of build plate. If you are on a printer with belted Z and the values in each corner deviate heavily. This would indicate a loose belt on that corner. If youa re using a printer which supports either `Z_TILT` or `QUAD_GANTRY_LEVEL` you will need to ensure that your probe is positioned above the bed when performing this, open up your `printer.cfg` and find the appropriate section, for example your QUAD\_GANTRY\_LEVEL section may look like this: 
[quad_gantry_level]
gantry_corners:
   -60,-10
   410,420
#  Probe points
points:
   50,25   # Point 1
   50,275  # Point 2
   300,275 # Point 3
   300,25  # Point 4
#--------------------------------------------------------------------

speed: 100
horizontal_move_z: 10
retries: 5
retry_tolerance: 0.0075
max_adjust: 10
You should in your console navigate to each point to ensure that your probe is not hanging off the edge, you can do this using a `G0` command such as `G0 X50 Y25` for point 1, or `G0 X50 Y275` for point 2. If at all points, Cartographer is safely over the bed, you should be good to go for running a `QUAD_GANTRY_LEVEL` or `Z_TILT` . You can now run a Bed Mesh Calibration (I would advise doing either a `Z_TILT` or `QUAD_GANTRY_LEVEL` before. ```gcode BED_MESH_CALIBRATE ``` ## Setting Z Offset Before modifying your Z Offset, make sure that you have set your Z position to 0, to do this you can run the following command. ```gcode G1 Z0 F1500 ``` Once you have done all of the above, it is worth re-calibrating the Z-Offset. This can be done in Mainsail or Fluidd using the graphical interface. \ \ OR you can use G-Code in the window to console to do so ```gcode SET_GCODE_OFFSET Z_ADJUST=+0.01 MOVE=1 SET_GCODE_OFFSET Z_ADJUST=-0.01 MOVE=1 ``` Once the offset has been perfectly calibrated apply that offset using the following command ```gcode Z_OFFSET_APPLY_PROBE ``` And now save your config. {% hint style="warning" %} If you are regularly changing your bed, please look at creating different models for your different beds, more information can be found [here ](/original-plugin/fine-tuning/cartographer-models.md) {% endhint %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.cartographer3d.com/cartographer-probe/archive/scan-based-calibration.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.