Smoothieware Z Calibration

The move of Morgan controller firmware to Smoothieware brought with it a couple of advantages.  One of the most handy, the automated Z grid.

NOTE: The multipoint Z grid is stored on the SD card, and only needs to be performed if something changed, like the bed readjusted etc.  This is not required every time you print.

Normal Z Check

Following the firmware update of 23 April 2016, an In print  z adjustment has been added.  Rather use that for fine tuning z-height between prints, but be sure Z has been adjusted using the guide on this page first.

Make sure the Morgan is attached to your PC, and run Printrun (pronterface).  Connect to the Morgan

  1. Home the machine by clicking on the Home decal: Home
    The Printer arms will move to the home position, and the bed will move down to the parking position.
  2. Check and calibrate the Z position, we need to place the print head close to the bed.  Run one of the following commands in the command line on the lower right of the Pronterface to do this:
    • On 380x220mm Plexi beds:  (Default Morgan Pro)
      G28 G0 X190 Y110 Z20 F5000
    • On 200x200mm heated bed systems:
      G28 G0 X100 Y100 Z20 F5000
    • On 720x450mm Plexi beds: (Default Morgan Mega)
      G28 G0 X360 Y225 Z20 F5000 
    • Custom Bed sizes: Calculate the middle of the bed by dividing the X and Y sizes by half:
      G28 G0 Xxxx Yxxx Z20 F5000 
  3. The print head should be in the middle of the bed, and about 10mm from the bed surface.  Jog the bed to be close to the nozzle using “Z-” jog controls in pronterface.
    control_z
  4.  In case of Trouble: If the Z movement is limited and stops before it reaches the bed, do the following:
    1. Measure the distance between the bed and the nozzle
    2. Issue the following command
    3. M306 Z(measured distance)
    4. Return to point 1 of the Normal Z check calibration.
  5. Aim for a business card width (0.2mm).
    Use small steps: 1mm initially, and 0.1mm steps in the final stages to prevent the head from crashing into the bed. 
  6. The height above the bed can be best judged by tapping on the arm while very close to bed.  When the head is close it will tap on the bed.  When on the bed / spacer card, it will just stop tapping.
  7. With the head in this position, issue the following command to calculate the offset.  This stores the current machine Z position in temporary memory as the zero point.
    • M306 Z0
  8. Make sure the system SD card is ejected (Safe removal) in your operating system NB: Do not physically remove the SD card from the smoothieboard.  Only eject the mass storage device (SD) in the PC operating system while connected to USB and keep printer on and connected to pronterface.
  9. Issue this command  to store the settings in the permanent memory.
    • M374
Automated Z Grid correction
  1. Plug in the probe in the connector on the front right of the power supply plate before continuing to the next step.Probe connection
  2. Issue the following command to initial the automatic adjustment:  This will home the machine and get it in the correct position for the attachment of the probe.
    • G32
  3. Attach the probe to the nozzle.  It slides onto the print head as in the image below.  Make sure the tip is in the recess, and the shoulder of the probe rests securely on the hot end block.
    probe attachment
  4. Press the small switch on the probe’s tip when done.  The machine will proceed to probe the bed surface in multiple points on the bed. and return to the removal position when complete.
  5. Remove the probe from the hot end and disconnect at the connector.
  6. Perform the Normal Z Check and adjustment in the section  above.
  7. Again, make sure the SD is ejected in the PC operating system (“Safe removal” in windows), and issue the following command to save the probed data on the SD card.
    • M374
Notes (optional):

You can adjust the size of the data grid.  Recommended (Default) size for the grid on Morgan Pro is 7 rows in X, 5 columns in Y:

  • M370 X7 Y5

To change the current grid size, enter the desired values for X and Y into the command above run it before running the automatic Z-probe routine, G32

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