X and Y Tool Offset Calibration

This instruction set reflects improvements added in software application version 3.0.4. In the Settings menu of the user interface, check the Updates tab to make sure your software is up-to-date. You can find instructions to update the software in the Maintenance section, under Software Update

This guide will walk you through the process of calibrating the relative positions of the two toolheads in the X and Y axes. The objective of the calibration is to line up the material printed by T1 with material printed by T0. Without this procedure, the two tools may be misaligned, and the material printed by the two toolheads may be shifted in the X and/or Y axis.

The M218 G-code command is used to apply offsets to T1 in the X and Y axes. This offsets the coordinates of T1, shifting where it prints to line up with T0.

When to Calibrate the X and Y Tool Offsets

This X and Y tool offsets calibration is necessary for any prints which use both toolheads on the same model. This includes support material prints.

Calibration of the X and Y tool offsets must be done every time a hot end assembly has been manipulated in a way that affects the nozzle’s relative position to the nozzle on the other toolhead. This is part of normal operation and the machine may require minor adjustments and recalibration over time.

The following procedures require recalibration of the X and Y tool offsets after they have been completed:

  • Replacing the heater block assembly (HBA) or otherwise removing it from the hot end heat sink.
  • Removing the hot end heat sink from the probe or adjusting its position.
  • Significant changes in bed and chamber temperature (>20°C) may also require recalibration.

It is best practice to run the X and Y calibration print as part of the setup process before each dual toolhead print to confirm the tools are properly aligned. Use the same material(s), nozzle size, and printing temperatures that will be used to print.

X and Y Calibration Files

We provide a set of 3D models for the X and Y calibration process. The following XY offset scales are available:

  • 0.4mm nozzle - 0.1mm precision
  • 0.4mm nozzle - 0.2mm precision
  • 0.6mm nozzle - 0.1mm precision
  • 0.6mm nozzle - 0.2mm precision

Click here to download the XY offset scales.

Use the 0.4mm nozzle files to calibrate X and Y for prints using nozzle sizes between 0.25-0.4mm.
Use the 0.6mm nozzle files to calibrate X and Y for prints using nozzle sizes between 0.6-1.2mm.

If you suspect that your X and Y offset is greater than ±0.8mm, use the 0.2mm scale first and then refine the offset using the 0.1mm scale.

You will need to import these files into Simplify3D, orient them correctly, and apply the processes that you will use for your print.

How to use the X and Y Calibration Files

The X and Y calibration files are used like a vernier caliper. There is a fixed main scale (T0) and the vernier scale (T1) constructed such that it is spaced at a constant fraction of the fixed main scale. Two sets of calibration files are provided, one with a vernier constant of 0.1mm and one with a vernier constant of 0.2mm.

If you use the calibration file with a vernier constant of 0.2mm, each mark on the vernier scale is spaced 0.2mm further away than the previous mark starting from the zero point at the center of the part. Once printed, one of the marks on the vernier scale should line up with the fixed scale. To calculate the offset, you count the marks from the centre (zero point) of the vernier scale to the mark that lines up with the fixed scale and multiply this by the vernier constant. Marks to the left of centre are negative offsets, while marks to the right are positive.

For example, if you printed the scales with the 0.2mm vernier constant and got the results shown below, you would need to make the following adjustments:

  • X +0.4mm (0.2mm x 2)
  • Y -0.6mm (-0.2mm x 3)

XY Offset Scale - Not Aligned

X and Y Calibration Procedure

Required Tools & Equipment

  • Calibration Models
  • Putty knife or other part removal tool

Prepare to Print

  1. Load your filament on both toolheads. Follow the Filament Loading instructions provided in the Installation section.

  2. Perform the Z Calibration procedure for both tools. This procedure includes preheating the bed and chamber. Keep these set to your operating temperatures throughout the calibration process to maintain thermal equilibrium.

Prepare X and Y Calibration Files

The following procedure uses the 0.2mm XY offset scale for the 0.6mm nozzle with ABS loaded in both toolheads to describe the X and Y calibration procedure. If you are using different materials, nozzle sizes, or require 0.1mm precision, the steps are similar, but you will need to use the appropriate calibration files and process settings.

We recommend using two spools of ABS filament of contrasting colors for the first time you calibrate the X and Y tool offsets, and any time you wish to practice. Using filaments of contrasting colors make it easy to distinguish the printed features on T1 from the printed features on T0.

The X and Y offset scales can be printed separately or together depending on your requirements.

  1. Download and unzip the XY offset scales.

  2. Import the following files into Simplify3D:

    • X - 0.2mm offset scale - 0.6mm nozzle (BASE).stl
    • X - 0.2mm offset scale - 0.6mm nozzle (T0).stl
    • X - 0.2mm offset scale - 0.6mm nozzle (T1).stl
    • Y - 0.2mm offset scale - 0.6mm nozzle (BASE).stl
    • Y - 0.2mm offset scale - 0.6mm nozzle (T0).stl
    • Y - 0.2mm offset scale - 0.6mm nozzle (T1).stl
  3. Select the three X models and perform the following operations:

    • Click on Edit and then on Group Selection.
    • Click on Edit and then on Align Selected Model Origins.
    • Move the grouped X models to the desired location on the print bed.
  4. Select the three Y models and perform the following operations:

    • Click on Edit and then on Group Selection.
    • Click on Edit and then on Align Selected Model Origins.
    • Move the grouped Y models to the desired location on the print bed.

    X and Y Model Groups

  5. Make sure that the X and the Y offset scales are oriented as shown in the figure below. Make sure that the following conditions are met:

    • The X offset scale + is towards the right side of the build plate.
    • The Y offset scale + is towards the back side of the build plate.
    • A scale factor of 100% is used.

    A scale factor of 100% must be used. If the offset scales are printed at a scale other than 100%, the resulting adjustments will not be accurate.

    XY Offset Scale Placement

    It is important to make sure that the T1 scale is printed with the T1 toolhead. Failing to do so will result in a failed calibration.

    The models for the base layer can be printed with either T0 or T1.

  6. Add the process that you will be using for T0 and select the 4 models that will use this process. Make sure that the primary extruder for the layer is T0.

    XY Offset T0 Process

  7. Add the process that you will be using for T1 and select the 2 models that will use this process. Make sure that the primary extruder for the layer is T1.

    XY Offset T1 Process

  8. Click on Prepare to Print!, select both processes, and Continuous Printing: layer-by-layer.

    XY Offset T1 Process

  9. Review the process preview. Make sure that the T1 process is only used for the T1 scale.

    XY Offset Process Preview

  10. Save the generated G-code file and upload it to the machine.

    Depending on the materials being used, the following may need to be adjusted in your process settings:
    - Print speed
    - Brim
    - Raft
    - Thin wall

Calibrating the Toolheads

All units are in mm.
Default offset values are 0 mm for X and Y. Offset calibration should not require changes of more than 5mm, usually less than 2mm in either axis.

  1. Note the current T1 tool offsets:

    a) Navigate to the Terminal tab of the user interface and enter M218 T1.

    b) Note the X and Y values displayed on the screen. These are the current T1 tool X offset and Y offset. An example output is shown below.

    < M218 T1
    > Hotend offsets: X:0.00 Y:0.00
    
  2. Heat the hot ends to the appropriate temperature(s).

  3. Navigate to the Files tab. Start the calibration test print by tapping Print beside the calibration print G-code file.

    Printer components may be extremely hot. Always wear safety gloves and long sleeves when working inside the machine. Failure to use safety gloves and long sleeves can cause burns.

  4. When the print is complete, remove the printed scales using a putty knife and inspect the results. If the center lines do not align, determine the required offset by finding the lines that are aligned.

    See section X and Y Offset Calibration Example for a full example of the calibration process.

  5. Calculate the new T1 offset as follows:

    • New X offset = Current X Offset + Measured X Offset
    • New Y offset = Current Y Offset + Measured Y Offset
  6. To apply the adjusted T1 X and Y tool offsets, make sure the print has stopped, and enter M218 T1 X[X offset] Y[Y offset] in the Terminal tab. If you prefer, you can adjust one offset at a time by entering M218 T1 X[X offset] or M218 T1 Y[Y offset]. The machine will automatically home the axis or axes you have adjusted and save the offset(s).

    You cannot modify the X and Y offsets while the machine is printing. You will see the following error message pop up in the bottom-right corner of the screen if you enter the M218 command during an active print. `M218` error message during print

  7. To fine-tune the calibration, repeat the process until you are satisfied with the relative printing position of the two toolheads.

    Once you have calibrated the T1 X and Y offsets, it is necessary to probe the bed with T1 again to compensate for the change in probe positions in the X-Y plane.

  8. Perform the Z Calibration procedure for T1.

X and Y Offset Calibration Example

  1. Determine current T1 offset using the M218 T1 command:

    < M218 T1
    > Hotend offsets: X:0.00 Y:0.00
    

    The offsets have not been adjusted from factory state: X:0.00, Y:0.00

  2. Print the calibration print G-code file.

  3. The following is observed by the operator by determining which lines are aligned on the scale:

    • X-axis: The T1 tool is printing -1.4mm (-0.2mm x 7) when compared to T0.
    • Y-axis: The T1 tool is printing +0.4mm (0.2mm x 2) when compared to T0.

    XY Offset Scale - Example Print 1

  4. Calculate the new T1 tool offsets:

    • New X offset: 0.00 - 1.4 = -1.4
    • New Y offset: 0.00 + 0.4 = 0.4
  5. Apply the new T1 X and Y offsets by entering the following command into the terminal:

    M218 T1 X-1.4 Y0.4
    

    The machine homes in X and Y to apply the offsets.

  6. Confirm the T1 offsets by using the M218 T1 command:

    < M218 T1
    > Hotend offsets: X:-1.40 Y:0.40
    
  7. Print the calibration print G-code file to verify if any further adjustments are needed.

  8. The following is observed by the operator by determining which lines are aligned on the scale:

    • X-axis: The T1 tool is printing -0.2mm (-0.2mm x 1) when compared to T0.
    • Y-axis: The T1 tool is printing +0.0mm (0.2mm x 0) when compared to T0.

    XY Offset Scale - Example Print 2

  9. Calculate the new T1 tool offsets:

    • New X offset: -1.40 - 0.2 = -1.6
    • New Y offset: 0.40 + 0.0 = 0.4
  10. Apply the new T1 X and Y offsets by entering the following command into the terminal:

    M218 T1 X-1.6
    

    The machine homes in X to apply the offsets.

  11. Confirm the T1 offsets by using the M218 T1 command:

    < M218 T1
    > Hotend offsets: X:-1.60 Y:0.40
    
  12. Print the calibration print G-code file to verify if any further adjustments are needed.

  13. The following is observed by the operator by determining which lines are aligned on the scale:

    • X-axis: The T1 tool is printing +0.0mm (0.2mm x 0) when compared to T0.
    • Y-axis: The T1 tool is printing +0.0mm (0.2mm x 0) when compared to T0.

    No further adjustments are needed.

    XY Offset Scale - Example Print 3

  14. Probe the bed with T1 to compensate for the change in probe positions in the X-Y plane.

Congratulations!

The X and Y tool calibration process is complete. You are now ready to start dual-material printing with your AON-M2.

Last modified: September 23, 2020