Cross Section Line
Cross Section Line
Sudden change in resin flow dynamics creates a horizontal line.
Cross section line can be diagnosed as follows:
- Thin lines or creases on part surface.
- Lines are sharp (does not appear gradually).
- Lines are horizontal (parallel to the build platform).
- Lines appear on all sides of the part.
Corresponds to Change in Part Geometry
Lines will occur when the cross section changes suddenly during the print. Most commonly this occurs when
- A bridge closes.
- A part that is building off the platform in two or more areas joins together later in the print.
- A small cross section changes suddenly to a large cross section, or vice versa.
Deepest Pixel Print Graph
The deepest pixel print graph in the Print Plan Adjustments interface can provide a strong clue to the potential occurrence of a cross section line.
This poorly designed bracket has a sudden vertical spike where the top of the bracket is filling in. This is due to the cross section changing suddenly from thin walls to a large top.
When the geometry transitions from a thin wall to a large cross section surrounding an unvented volume, a Cross Section Line can occur in conjunction with the Vacuum Line defect. Both defects may need to be addressed.
Cause - Sudden Cross Section Change
Solution - Print Preparation or Part Design
Cause - Sudden Cross Section Change
Solution - Print Preparation or Part Design
Cause - Sudden Cross Section Change
Solution - Print Preparation or Part Design
Cause - Sudden Cross Section Change
Solution - Print Preparation or Part Design
This line is occurring in conjunction with a vacuum line. The lower lines (not circled) are vacuum lines only.
The following solutions will address print or part-related causes of the defects. Choose among the suggested actions below and select the best approach for your application. Usually only one type of adjustment is needed.
If problems persist, please reach out to Carbon Support.
Cross section lines occur when changes in part geometry cause changes in resin flow dynamics. When the resin flow pattern changes in speed and/or direction, UV light can scatter in a manner that temporarily affects curing on the surface, resulting in the appearance of a horizontal line on the part.
The effect is most apparent when there is a sudden change in how far resin must flow to fully reach the depth of the printing cross section. This distance is known as the deepest pixel. When the deepest pixel is a short distance in one slice and suddenly a long distance in the next slice, the chances of a cross section line increase. The most common geometry changes for this defect are when:
- A bridge closes.
- A part that is building off the platform in two or more areas joins together later in the print.
- A small cross section changes suddenly to a large cross section, or vice versa.
Slice Before the Cross Section Line
The resin is flowing both inside and outside the part and the deepest pixel is a shorter distance for resin to reach.
Slice that Creates Cross Section Line
The curing slice changes to a larger cross section that closes the bridge and now resin only flows outside the part. Not only does this change the flow pattern but the resin now must also travel farther to reach the deepest pixel.
Root Issue | Problem | Why Defect Presents |
|---|---|---|
Orientation | Cross section changes suddenly between small and large. | The deepest pixel changes suddenly disrupting the flow pattern. |
Orientation | A bridge closes or two separate areas of the part connect later in the build. | An area that was previously open for resin flow is now closed, disrupting the flow pattern. |
Design | Cross section changes suddenly between small and large. | The deepest pixel changes suddenly disrupting the flow pattern. |