Part Defects

Shift Lines

14min

Shift Lines
Shift lines can occur when parts move during printing.

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How to Identify
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Cause - Instability﻿
Solution - Print Preparation or Part Design
Cause - Instability﻿
Solution - Print Preparation or Part Design
Cause - Unknown
Troubleshooting
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Process, Material, and Hardware Checks
If any of these conditions apply to your print, take the corrective action and reprint to see if the problem is resolved.
Review the first slice and verify that the part's surface is fully on the platform.
Update the model to have a flat base if that is the intention
Use the Snap to Platform﻿ feature in Carbon software to ensure that your part is on the platform.
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M1 and M2 Printers
Ensure the platform is seated properly on the kinematic mounts.
Verify platform is installed properly
Clean the platform's kinematic balls and clean & lubricate the kinematic pin mounts on the platform per monthly maintenance﻿
DO NOT bake parts on the platform which will cause misalignment of the kinematic balls.﻿
Reference cleaning and installation instructions for your printer: M1/M2 Printer﻿.
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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.
Change orientation to keep sudden large cross sections on, or near, the platform rather than late in the print.
Change orientation on unstable parts
Equalize asymmetrical orientations
Move the part's center of mass closer to the platform
Reorient tall, thin parts to be shorter
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Add more supports for large cross sections later in the print.
Add supports to stabilize part near shift line locations
For asymmetrical parts or parts with a center of mass far from the platform
For tall, thin parts
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Redesign part to add stability
Add bevels or fillets to transition to large cross sections gradually.
Add structure such as gussets or ribs to
Asymmetrical parts or parts with a center of mass far from the platform
Tall, thin parts
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Reference Print Plan Adjustments﻿ for guidance on the following parameters.
﻿3 Pump Down Parameters﻿ 
Platform Speed Parameters
Motor Down Speed
﻿Other Parameters﻿ 
Enhanced EPU Force Feedback Enabled
If problems persist, please reach out to Carbon Support.
Explanation & Causes
Explanation
Shift lines occur from instability during printing as a result of print forces and resin moving. When a part is unstable, printing forces can move the part out of position such that when the next slice cures, the slices do not line up properly.
Parts especially prone to shift movement:
Tall, thin parts.
Parts with the center of mass far from the platform and/or off-center with the base slices.
EPU parts (due to low stiffness).
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Shift lines are more common on older printers and less likely on newer models. In order from more likely to less likely:
﻿M1﻿
﻿M2﻿
L1
M3/ M3 Max
Causes
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Root Issue
Problem
Why Defect Presents
Slices
Flat base not snapped to platform
The part is rotated slightly such that the platform cross section is not fully adhered. Without a stable base, the part can move during printing.
Slices
Bad slice
A slice or part of a slice is missing which makes the part unstable without its geometry full intact.
Cross Section
Small to large cross section later in the print
Forces increase later in the print from large cross sections and this can move the part.
Unstable Geometry
Asymmetrically oriented part
Parts that are susceptible to lateral forces can move during printing.
Unstable Geometry
Parts with the center of mass far from the platform
Parts that are susceptible to lateral forces can move during printing.
Tall, Thin Part
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Tall thin parts are inherently less stable and can move if not prepped for printing properly.
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Root Issue
Problem
Why Defect Presents
Misalignment
Improper seating
M1 and M2 printers rely on kinematic mounts to keep the part platform properly positioned and stable. If the platform in not seated properly on these mounts, the platform itself can move which in turn moves the part during printing.
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Printing Stage
Parameter Type
Type of Adjustment
Why Defect Presents
3 Pump Down
Platform Speed
﻿Increase﻿
Increased Motor Down Speed increases forces on the part as it moves down to the curing position.
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Root Issue	Problem	Why Defect Presents
Slices	Flat base not snapped to platform	The part is rotated slightly such that the platform cross section is not fully adhered. Without a stable base, the part can move during printing.
Slices	Bad slice	A slice or part of a slice is missing which makes the part unstable without its geometry full intact.
Cross Section	Small to large cross section later in the print	Forces increase later in the print from large cross sections and this can move the part.
Unstable Geometry	Asymmetrically oriented part	Parts that are susceptible to lateral forces can move during printing.
Unstable Geometry	Parts with the center of mass far from the platform	Parts that are susceptible to lateral forces can move during printing.
Tall, Thin Part		Tall thin parts are inherently less stable and can move if not prepped for printing properly.

Root Issue	Problem	Why Defect Presents
Misalignment	Improper seating	M1 and M2 printers rely on kinematic mounts to keep the part platform properly positioned and stable. If the platform in not seated properly on these mounts, the platform itself can move which in turn moves the part during printing.

Printing Stage	Parameter Type	Type of Adjustment	Why Defect Presents
3 Pump Down	Platform Speed	Increase	Increased Motor Down Speed increases forces on the part as it moves down to the curing position.

Scratches and Scuffs

Shrink Line

Shift Lines

How to Identify

Troubleshooting

Process, Material, and Hardware Checks

Base Slices

Hardware

Print Preparation or Part Design Adjustments

Orientation

Supports

Design

Print Plan Adjustments

Explanation & Causes

Explanation

Causes