--- title: Looping slug: troubleshooting/looping description: Discover effective solutions for addressing the "Looping" part defect from Carbon DLS printing. This comprehensive document explains how to identify, troubleshoot, and understand the root causes. docTags: createdAt: 2024-06-14T01:01:51.816Z --- ::::VerticalSplit{layout="left"} :::VerticalSplitItem **Looping ** Portion of a horizontal strut is stretched out of position during printing. ::: :::VerticalSplitItem ::Image[]{src="https://api.archbee.com/api/optimize/3CesIL2dYMCHPZvRjp8S0/W8-_QtOZyyRi2BuQAqwXg_image.png" size="70" width="1080" height="1080" position="center" alt="Looping" showCaption="false"} ::: :::: # How to Identify Looping can be diagnosed as follows: - Looping occurs on struts that are running horizontal, or parallel to the platform, during printing. - The defect appears at the center of the strut's span. - Looping appears as though part of the strut has been pulled away from the rest of the strut, leaving a gap. - Minor cases of looping may appear as a bump on the strut. :::hint{type="info"} [Fanging](docId\:zQDgUjoItnihiqplRqdvt) and [Pillowing](docId\:SoJJs8eTsSqI8gguqItLZ) are defects that arise from the same issue but appear at different locations or features: at strut nodes or surfaces, respectively. ::: ::::LinkArray :::LinkArrayItem{headerType="IMAGE" headerImage="https://api.archbee.com/api/optimize/Nvx7WdIjE2XFpMaBlbCES-R29E7NGASgn02gOi3n1bq-20240812-160225.jpg"} **Cause** - Inconclusive ::: :::LinkArrayItem{headerType="IMAGE" headerImage="https://api.archbee.com/api/optimize/Nvx7WdIjE2XFpMaBlbCES-DCwEOObRpyP_ccxyVlEC3-20240812-160234.png"} **Cause** - Inconclusive ::: :::LinkArrayItem{headerType="IMAGE" headerImage="https://api.archbee.com/api/optimize/Nvx7WdIjE2XFpMaBlbCES-uvDlt8AoZ3EZ_o0Ofccln-20240812-160244.jpg"} **Cause** - Inconclusive Minor Looping ::: :::: # Troubleshooting :::hint{type="info"} 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](docId\:pPm8gmeGCY_0fkFwgTCyj) 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. ::::::ExpandableHeading ### Orientation :::::VerticalSplit{layout="middle"} ::::VerticalSplitItem Reorient the lattice to minimize the length of horizontal struts. :::hint{type="info"} Supports may be needed with a new orientation. ::: :::: :::VerticalSplitItem ![Orientation](https://api.archbee.com/api/optimize/3CesIL2dYMCHPZvRjp8S0/WGUShwkieQQMUvjDnawiE_image.png) ::: ::::: :::::: ::::::ExpandableHeading ### Design :::::VerticalSplit{layout="middle"} ::::VerticalSplitItem Add struts to provide more structure at the problematic horizontal struts. :::hint{type="info"} *The performance of the lattice will change.* ::: :::: :::VerticalSplitItem ![Design](https://api.archbee.com/api/optimize/3CesIL2dYMCHPZvRjp8S0/Y9GYjLuI0qiMrdgA0_xqA_image.png) ::: ::::: :::::: :::ExpandableHeading{isOpen="true"} ### Print Plan Adjustments Reference [Print Plan Adjustments](docId\:NxUK0dltz_vemEAU0DIpN) for guidance on the following parameters: [1 Pump Up Parameters](docId\:XP2lRJPJ4njFl_Z8N58rL) - Pump Height Parameters - Minimum Pump Height - Minimum Distance from Peak - Distance from Peak Multiplier - Platform Speed Parameters - Motor Up Speed [3 Pump Down Parameters](docId\:y816PQpbuQT5CpIYeoliO) - Platform Speed Parameters - Motor Down Speed ::: :::hint{type="info"} If problems persist, please reach out to [Carbon Support](mailto\:support@carbon3d.com). ::: # Explanation & Causes ## Explanation Looping occurs in a lattice when a portion of a horizontal strut is stretched out of position during printing. Because of how the slicing plays out over the lattice geometry, only a thin portion of this horizontal strut is cured before the next slice captures more of the strut. This makes the affected partial strut a thin, unsupported overhang which is therefore weak during the pump up stage. While the platform moves up, the weak partial strut is temporarily held in place by the surface tension of the dead zone, pulling it out of shape before the tension is broken. When the platform moves back down, the strut is even weaker in its stretched out shape, leaving it susceptible to be pushed in the other direction under the pump down forces. This is the position the malformed partial strut stays in when the next slice cures, leaving it to appear disconnected from the rest of the strut. This defect usually occurs with elastomeric resins that are soft and pliable during printing. Reference [DLS Printer Dynamics](docId\:U7XYytjyDp3BvsYy2qKcU) for more information on the stages of printing a slice. *Z dimensions for pump height and slice thickness are exaggerated in the diagrams below for visibility.* ::::VerticalSplit{layout="middle"} :::VerticalSplitItem ![Lattice sliced to capture a portion of a horizontal strut](https://api.archbee.com/api/optimize/3CesIL2dYMCHPZvRjp8S0/Zw0HyaZJisUPDTBb3zoYL_image.png "Lattice sliced to capture a portion of a horizontal strut") ::: :::VerticalSplitItem ![Looping on a printing slice](https://res.cloudinary.com/carbon3d/image/upload/Education/Troubleshooting/Part-Defects/Looping/Looping_v0101_300px-24x.gif "Looping on a printing slice") ::: :::: ## Causes ### Print Preparation or Part Design ::::VerticalSplit{layout="middle"} :::VerticalSplitItem How the part is **oriented**, **supported**, or **designed **is causing the defect. ::: :::VerticalSplitItem ![Print Preparation or Part Design Cause](https://api.archbee.com/api/optimize/3CesIL2dYMCHPZvRjp8S0/LhaBjVT_Yxhp03FPtHLyF_orient-and-support-quick-view-v0101-xxs.gif) ::: :::: | Root Issue | Problem | Why Defect Presents | | ---------- | ------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------- | | Oriented | Part is oriented to have longer struts printing horizontally (relative to platform). | Horizontal struts may be sliced to have thin partial struts that are susceptible to looping. | | Designed | Lattice is designed to have longer struts. | Short struts are less likely to be weak even when sliced to have partial horizontal struts. | ### Print Plan Adjustments ::::VerticalSplit{layout="middle"} :::VerticalSplitItem ![Print Plan Adjustments](https://api.archbee.com/api/optimize/3CesIL2dYMCHPZvRjp8S0/BzaP59syjyUMWREOHSLmE_print-plan-adjustments-v142.png) ::: :::VerticalSplitItem [Print Plan Adjustments](docId\:NxUK0dltz_vemEAU0DIpN) 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 | | -------------- | -------------- | ----------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- | | 1 Pump Up | Pump Height | **Increase** | Increased pump height provides more space for the weak partial strut to be stretched out of shape. | | 1 Pump Up | Platform Speed | **Increase** | Increased Motor Up Speed provides less time for the weak partial strut to break from the dead zone surface tension while also increasing suction forces. | | 3 Pump Down | Platform Speed | **Increase** | Increased Motor Down Speed increases the pump down forces that push the weak, stretched strut out of position. |