Setting the Z offset
Here we will calibrate Robo R2 by setting the Z-Offset and making sure your first layer is applied correctly. We will be covering three ways of zeroing in on your Offset. The first is the Z-Offset Wizard found in Utilities> Wizards; the second is the Fine Tune Wizard, also under Utilities> Wizards; the final is manually adjusting your Offset in the EEPROM manager.
What is “Z-Offset”? Simply, its the distance between your nozzle and your print bed when the print bed is at home (bottom of printer), which is technically known as a Home Offset. This offset can change by adjusting the bed springs, not seating your print bed correctly, or even a shifting hotend.
Select UTILITIES on the touch screen. Then select WIZARDS from the list. From here you’ll select Z OFFSET WIZARD. Now, the printer will wait to calibrate its home position.
Follow the directions on the screen by using the calibration card or a standard sheet of paper. Press on the ‘Up’ arrow to raise the bed up toward the nozzle of the printer. Slide the calibration card in between the nozzle and bed and continue pressing the ‘Up” button until you feel little resistance on the card between the Nozzle and the print bed. Note: You still want to be able to slide the calibration card back and forth but with enough resistance that it is touching both the bed and the nozzle.
If your bed is too high and the calibration card does not have enough room to slide between the nozzle and the bed, press the down arrow until the calibration card can pass freely but with a slight resistance between the nozzle and the bed.
Fine Tune Wizard
If you are experiencing the nozzle dragging (too low) or your prints are not sticking (too high), you can fine-tune your Z-Offset by going to Utilities> Wizards> Fine Tune Wizard. It’s a little more work, but you will tune your offset by actually printing on the bed! Your Robo R2 will print a series of vertical lines, one at a time. Between each pass you can increase or decrease the Z-Offset value as needed.
To use the wizard, follow these steps below:
Note: It is very important to make sure that the print bed is level by adjusting the thumb screws below the print bed before starting this wizard.
- To start, select ‘Utilities’ from the home screen, then select ‘Fine Tune Offset’. Select the material currently loaded in the printer. Then the wizard will ask you which corner you’d like to start from. This simply sets where the printer will start printing out the test lines. You can start from whichever corner you prefer.
2. Once the printer homes and positions itself to begin testing, you will see a visual reference on the screen to help you know what to look for in order to find an ideal Z-Offset value.
3. You will come to the “Adjust Offset” screen, where you can set the adjustment increment, move the bed up or down, and test the offset. We recommend testing the offset first so you can get a visual reference to fine tune the current offset. Move the bed up and down with the provided buttons on screen, and test with the ‘test offset’ button to see if it looks satisfactory.
4. When you’ve found a satisfactory Z-Offset value, press the forward arrow in the top right corner and select ‘Save’ to finish the wizard.
Manually setting Offset in EEPROM Manager
If you are a printing veteran and are comfortable with manually setting your Offset, you can do so under Utilities> Options> EEPROM> Home Offset. In the “Z” screen you will see the value of your current Offset, as well as two arrows that will increase or decrease this value. The arrows are arranged so that they correspond with raising or lowering the bed. A smaller value brings the bed closer to the nozzle, while a larger value increases the distance away.
If your Offset seems close but prints are still not sticking, you can decrease the value by 0.1mm - 0.2mm and try again. Generally only small changes may be needed.