Filled Holes on Skin
Filled Holes on Skin
Feature holes in a skin are filled in with cured resin during printing.
How to Identify
Skins are the name for a thin, solid covering over a lattice. Holes are sometimes designed into the skin as a design feature and/or for drainage of resin.
Filled Holes on Skin can be diagnosed as follows:
- Holes appear as dimples rather than openings.
How to differentiate from similar appearing defects:
- Overcure may appear similar for small holes. The difference will be that overcure will occur equally in all holes printed in the XY plane in most cases, whereas filled holes on skin may only occur in some holes in the XY plane, particularly holes near the center of the part.
- Excess Resin may appear similar for small holes. The difference will be that excess resin in the holes will have a shinier surface finish than the skin around it, due to curing after printing rather than during.
Cause - Poor Resin Flow
Solution - Print Preparation or Part Design
Troubleshooting
It is recommended that you review all the possible solutions before taking action to ensure you are pursuing the best course of action.
If the best course of action is not apparent, try the troubleshooting options in the order listed. Refer here for more tips.
Print Preparation or Part Design Adjustments
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.
Explanation & Causes
Explanation
During the settle down phase of printing a slice, resin is flowing out from under the part. At the same time, oxygen is recharging after printing the previous slice. As the oxygen recharges, you can picture this as the slice image getting increasingly less blurry. At full charge, the contrast in the slice image is at its full clarity.
The filled holes on skin defect occurs when the settle down phase is moving too quickly for the resin flow and oxygen recharge to have reached its optimal printing condition before curing the slice.
Reference DLS Printer Dynamics for more information on the phases of printing a slice.
Refer to the animations below to see a magnified view of how this hole appears during the settle down phase under both bad and good conditions.
Defect occurs when the settle down phase is too fast for proper resin flow and to recharge the oxygen for full clarity in the slice before curing.
The hole prints as expected when the settle down phase is long enough for proper resin flow and oxygen recharge to reach full clarity in the slice upon curing.
Causes
Print Preparation or Part Design
How the part is oriented, supported, or designed is causing the defect.
Root Issue | Problem | Why Defect Presents |
|---|---|---|
Oriented | The skin and holes are oriented in the XY plane during printing. | The settle down phase needs to be longer for the resin to flow properly across a large cross section parallel to the window. |
Designed | The holes are too small. | If the settle down phase needs to be made too long for an efficient production printing time, the holes can be designed larger to compensate. |
Print Plan Adjustments
Print Plan Adjustments adjust the print plan to optimize mid to high volume production and/or address part defects.
In doing so, adjustment may both prevent or cause defects. Below are adjustments that can cause this defect.
Printing Stage | Parameter Type | Type of Adjustment | Why Defect Presents |
|---|---|---|---|
4 Settle Down | Delay Timing | Decrease | The settle down phase is too fast for proper resin flow and oxygen recharge. |