It is important to get the Z calibration correct to prevent improperly calibrating or support tip plugging, especially with smaller slices (5 and 7 slice). If the support layer thickness is set too small, the back pressure on the tip increases which can plug the tip and causes the support material to mushroom. This document describes the preferred approach for obtaining the correct Z calibration. This approach uses the smallest reading on the support layer box with a rectangular cross-section.
Note: Do not measure for Z adjustment until the Calibration Model shows the XY
Offset to be less than 0.002 inch (0.05 mm) for both the X and Y axis.
Step 1 Peel the Support layer from the Z Calibration box.
Step 2 Measure the thickness of the Support layer with a caliper or micrometer:
A. Measure at the center of all 4 sides of the support layer box (figure 1).
B. Take the smallest reading from the measured sides.
C. Using a box knife or Xacto knife, cut the support layer box at the center of the leg
with the smallest reading. The cut should be perpendicular to the leg).
D. Using a loop/magnifier, inspect the cross-section from the cut support layer box.
E. Verify that the cross-section is rectangular in shape. If it is too small, increase the
calibration by 0.001 inch to 0.002 inch and then repeat the calibration build. Repeat
steps 1-5 until you see a rectangular cross-section.
F. The rectangular Z thickness value from the smallest slice height reading is the
current Z thickness (table 1).
Step 3 If the measured value is within ±0.0005” (0.01 mm) of the Model Tip slice height (table 2), no adjustment is necessary. Proceed to step E.
Step 4 If the measured value is outside the ±0.0005” (0.01 mm) value, subtract the measured value from the slice height of the Model Tip being used (table 2).
• If the Model Tip Slice minus the Measured Support thickness is a positive number,the Z correction is +Z in 0.001 inches.
• If the Model Tip Slice minus the Measured Support thickness is a negative number,the Z correction is -Z in 0.001 inches.
• Example: For a T16 Model Tip - slice height of 0.010” (from table 2); measuredthickness of Calibration Box = 0.012”; Calculation 0.010 - 0.012 = - 0.002; Enter0.002 in the - Z menu option (see 5.D).
Step 5 Enter the Z Adjustment Value from the Tip Offset menu (table 3)Step 6If an adjustment entry is required, re-run the calibration model on a clean build sheet.
For more information, download the full document here.