Slides for the Fall 2022 class on Slicing with Cura

1. Slicing with Cura
Vicky Somma
vicky@tgaw.com
This slideshow is available at https://www.slideshare.net/VickyTGAW/slicing-with-cura-2022pptx
Steven Langerholc
steven.langerholc@fairfaxcounty.gov
John McGillvray
john.mcgillvray@fairfaxcounty.gov
Sunny Carito
sunny.carito@fairfaxcounty.gov
David Newhall
dnewhall@gmail.com
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2. Overview of the Session
● Quick Review – Cura Interface
● Quick Review - Repairing Models
● Preview Mode and Print Feasibility
● Things to Look For After Printing
● Post-Processing Scripts
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3. Note on Cura Differences
Depending on the edition or version of Cura you have, the icons and terminology
can have some differences. For example, “Shell” instead of “Walls”
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4. Review - Navigating
Scroll Up to Zoom In
Scroll Down to Zoom Out
Hold Scroll Wheel to Pan
Hold Right Mouse Button to Rotate View
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5. Review – Cura Adjustment Tools
MOVE
● Fit more on build plate
● Avoid any bed issues
● Correct first layer inconsistencies
SCALE
● Correct any units or sizing issues
● Adjust for better detailing
● Scale down for faster prints
MIRROR
● Print two back to back designs for ornaments
● Fixing modeling oversights- Cookie cutters and
stamps need to be backwards.
ROTATE
● Fix orientation issues
● Fit more items on build plate
● Minimize support
Learn More - https://support.ultimaker.com/hc/en-us/sections/360003607779-Adjustment-tools
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6. Cura - Right Click Menu
You can right-click on your imported 3D Models to get a menu of additional options
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7. Cura – Getting to Settings
By clicking on the three line icons next to search settings (if necessary click on
“Custom >” first), you can control how many settings you see in Cura.
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8. Cura – Getting to Settings
Don’t know exactly where a setting
you are looking for is? Search for it!
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9. Cura – Getting to Settings
Hovering your mouse over
a setting will give you an
explanation
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10. Review - Fixing Modeling Issues with 3D Builder
If you suspect there are model issues Cura is not fixing, Windows 10 includes the
free 3D Builder tool.
1. Click Add
2. Click Load Object
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11. Fixing Modeling Issues with 3D Builder
3. Click on the Repair
Warning
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12. Fixing Modeling Issues with 3D Builder
4. A progress bar keeps
you abreast of the
processing.
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13. Fixing Modeling Issues with 3D Builder
5. Click on the model to
select it.
6. Click Save as
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14. Fixing Modeling Issues with 3D Builder
7. Set the Save as type to
“STL format (*.stl)” and
hit Save
8. Hit Save again on the
warning prompt.
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15. Checking For Issues Before Printing
Some things can be spotted in “Prepare” mode. Cura helps with color-coding if
objects are too big as well as highlighting tough overhangs and model errors.
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16. Review – Preview Mode
Scrolls bars allow you to drill down and up through the layers. If you want to
glimpse something from below you can pull the bottom of the scroll bar up.
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17. Preview Mode – Color Scheme
Changing the Color Scheme can give better visuals. For example if you are
trying to read details, you might like the single shade coloring of “Material Color”
mode. If you are looking at overhangs, the different colors of “Line Type”
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18. Preview Mode – Print Feasibility
Expected Print Time
Can this print be completed in the workday?
First Layer
How does that first layer look?
Is there a good base on that first layer?
Is everything you expect to touch, touching the bed?
Should a brim or raft be added to increase the contact
area/foundation?
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19. Preview Mode – Print Feasibility
Missing Details and Walls
Rotate around the whole object to examine it from all
sides. Are there any missing details or walls?
Unattached and orphaned parts
Sometimes you’ll find parts floating and unattached to the
rest of the piece. It could be a part way off to the side.
Hint: Support material may be obscuring issues.
Unchecking “Helpers” in Color Scheme
window will let you get a better look
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20. Layer View – Print Feasibility
Delicate, Fast Layers
Keep an eye out for layers that are so small they will print quickly in succession after each
other. Those warrant some attention because the filament may not be able to cool before it
starts the next layer. Overheating can cause small, fine details to warp or be distorted.
An example would be a spire top to a church model.
Overhangs
Zoom in and peek at the overhangs of the piece. Does each layer seem to have a good
foundation below it to build off of? Tough overhangs could lead to drooping and curling in
the piece. Curling could be particularly troublesome if your nozzle knocks it.
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21. Strategies to Decrease Print Time
 Make the object smaller with the
Scale tool.
 Increase Layer Height
 Decrease Infill % or change the
Infill Pattern (Concentric is the
fastest)
 Repair the Model (It could take out
some inefficiencies or odd internal
geometry the printer doesn’t need to
worry about)
 Send to a printer or branch with a larger
nozzle size (0.6mm prints faster than
0.4mm)
 Increase printing speed (in Cura or on
the JellyBox LCD)
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22. Strategies to Decrease Print Time
Reflect on Orientation – taller objects mean more layers and take more time.
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23. Strategies to Help with First Layers
● Use the Move tool to move the item down (by decreasing the Z coordinate) to
ensure better contact. Anything under the print bed gets ignored.
Note: Later Versions of Cura,
you might have to uncheck
“Drop Down Model”
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24. Strategies to Help with First Layers
● Use the Rotate to a put a better side on the bed
-or-
better place on the current side.
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25. Strategies to Help with First Layers
● For items with low contact area on the bed (particularly tall, wobbly items),
consider a Brim or a Raft in the Bed Adhesion settings.
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26. Review – Brim Versus Raft
Brim prints extra perimeters/outlines outside of your first layer
Raft prints a multiple layer platform first and then your object on top of it.
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27. Strategies to Help Details and Missing Walls
● Scale the object bigger
● For vertical detailing, decrease the layer height
● Under Shell (or Walls), check the Print Thin Walls settings
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28. Strategies to Help Details and Missing Walls
● Under Shell (or Walls) setting increase the Horizontal Expansion value
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29. Strategies to Help Details and Missing Walls
● Try to repair the model. Oddities in
“Face Normals” can also confuse the
slicer and cause things to disappear.
Face Normals – all the
surfaces of your object
have an inside and an
outside.
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30. Strategies to Help Details and Missing Walls
● Consider the orientation. The Layer Height is often smaller than the Line
Width (which is close to the nozzle size). As a result, you’ll get better
detailing on vertical faces.
Photo Credit: Desktop Makes
These prints by Desktop Makes
are both the same 3D Model.
The one on the left was printed
upright. The one on the right
was printed flat on the bed.
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31. Strategies for Unorphaned or Unattached Parts
● Send the part back to the patron for corrections (Recommended )
● Import the part into Tinkercad and add extra geometry to connect things
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32. Strategies for Unorphaned or Unattached Parts
● You can also install and use the “Mesh Tools” Plug-In in Cura to “Split
model into parts”. This allows you to move, rotate and reposition the
individual parts to optimize their printing. You can also delete what you don’t
need.
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33. Using Mesh Tools to Split Parts
Under Marketplace, you can install Mesh Tools
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34. Using Mesh Tools to Split Parts
Once Mesh Tools is installed, you can right click on the part and select Mesh
Tools->Split models into parts.
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35. Using Mesh Tools to Split Parts
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36. Strategies for Prints with Fast, Delicate Sections
● Lower extruder temperature
● Allow more cooling by slowing down layers
under the Cooling Settings:
● If the layer is going to print slower
than the Minimum Layer Time, the
printer will slow down its printing
speed.
● As a safeguard to making sure the
printer doesn’t go too slow, a
Minimum Speed is defined.
● The Lift Head checkbox tells the
printer to lift the extruder off the print
and wait if the Layer Time is too
short.
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37. Strategies for Prints with Fast, Delicate Sections
-OR-
● Print multiple copies at once or with other models that are just as tall. The
printer working on those other pieces naturally give the layers time to cool.
You can also consider placing those pieces farther apart on the print bed so
the nozzle has to spend more time traveling.
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38. Strategies for Overhangs
● Learn your printer’s capabilities– print on it, get to know it. Consider some
calibration or “torture test” models.
#3DBenchy by CreativeTools
https://www.thingiverse.com/thing:763622
Mini All in One 3D Printer Test by majda107
https://www.thingiverse.com/thing:2806295
Print What You Know, Print What You Are Passionate About 38

39. When Supports Can Be Turned Off
● The printer can handle small gaps (bridging) unassisted.
● Small embossed details
● Areas with good contact area below it
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40. Strategies for Overhangs
● Make adjustments to the model, like adding a 45 degree taper.
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41. Strategies for Overhangs
● Think about orientation. Is there a way to rotate the print so the overhangs are
less severe?
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42. Strategies for Overhangs
● Decrease your layer height. Smaller layer heights typically do better on
overhangs than big layers
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43. Strategies for Overhangs
● If curling is expected, consider adding a small value to the “Z Hop When
Retracted” setting under Travel. This raises the nozzle up as it travels
keeping it from hitting or scraping against your object. This is helpful if you
expect to have some overhangs curling up.
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44. Strategies for Overhangs – Z Hop in Action
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45. Strategies for Overhangs – Make Overhangs
Printable
Under Experimental settings, Cura has a
“Make Overhangs Printable” checkbox.
This will change the shape of the model
when it slices to make the overhangs less
severe.
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46. Strategies for Overhangs – Make Overhangs
Printable
The model changes are visible in Preview mode.
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47. Support Structure Setting
Normal – the supports drop
straight down from the area from
the overhanging section
Tree – The supports aren’t a
straight tower. Instead, they
branch out to minimize contact
with the print while maximizing
contact with the build plate.
Photo Credit: Ultimaker
● Add Supports.
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48. Support Placement Setting
Everywhere – The supports can start from
the buildplate, but also from the object itself.
Touching Buildplate– the supports only start
from the build plate / printer bed. If an area
needs a support and that structure does not
reach the bed by going straight down, it is not
supported.
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49. Support Blockers
Cura lets you define support-free areas by placing “support blockers” on your model. This allows you to
prevent supports in areas that wouldn’t need it or in areas where it would be cumbersome to clean up.
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50. Supports - Use Towers
Supports can fail too, particularly tall, thin supports. For tiny overhang areas, the
Use Towers setting will tell Cura to make a larger diameter for the support to
give it more stability.
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51. Troubleshooting Issues After Printing
● Strength Issues
● Ghosting
● Blobs/Zits/Seams
● Puckering in Top Layer
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52. Increasing Strength for Weak Points
Model is printing, but breaking. Thin areas near supports may need extra strength
to survive cleanup.
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53. Increasing Strength for Weak Points
● Consider increasing your Wall Line Count (or Wall Thickness) in the Walls
(or Shell) section.
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54. Increasing Strength for Weak Points
● Consider increasing Infill Density (Under the Infill section)
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55. Increasing Strength for Weak Points
● Change the Infill Pattern (Gyroid is reportedly the strongest)
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56. Increasing Strength for Weak Points
● Check Alternate Extra Wall under Wall (or Shell) Settings
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57. Increasing Strength for Weak Points
Other quick notes:
● Orientation can matter
● If it seems like a bonding issue (how well the layers are sticking to each other),
we may want to look at temperatures and flow.
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58. Troubleshooting - Ghosting
Ghosting - Vibrations on the
machine can cause “echos” of
details.
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59. Troubleshooting - Ghosting
Learn More about Ghosting: https://www.youtube.com/watch?v=KaFp6Eqk0QI
Lower the vibrations of the machine:
● Make sure the machine is on a
sturdy surface
● Make sure the machine frame is
rigid (add braces or shock
absorbers)
● Slow down the print to
decrease vibrations.
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60. Troubleshooting - Blobs and Zits
Little blobs and zits on the outside of the print.
● Change retraction and coasting settings
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61. Troubleshooting - Blobs and Zits
-OR-
Control where the “seam” is.
○ Random
○ Fastest
○ User Defined
○ Sharpest Corner
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62. Troubleshooting - Puckering Or Gaps in Top Layer
Can happen with too few Top Layers
over too low of Infill.
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63. Troubleshooting - Puckering Or Gaps in Top Layer
● Under the Shell (or Top/Bottom)
section:
○ Increase Top Layers / Top
Thickness under the Shell (or
Top/Bottom) section
● Under the Infill section
○ Increase Infill Density
○ Increase Overlap between Infill and
Perimeters
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64. Post-Processing Scripts
When we slice, we make a text-based “gcode” file filled with instructions for the
printer. Post-Processing scripts lets us add extra actions/instructions to that file.
We can use this to display extra information on our LCD or pausing for a color
change.
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65. Post-Processing Scripts
● Under Extensions go to Post Processing and hit Modify G-Code
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66. Post-Processing Scripts
● Click on Add a Script
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67. Post-Processing Scripts
● Select the script (in this case “Filament Change”) and fill in the details such
as the Layer you would like to do the change at. How do you know the
Layer? Check Preview mode!
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68. Post-Processing Scripts
● The Post-Processing scripts stick around until you remove them. You’ll be
reminded there is a Post-Processing script in place by a </> icon next to the
Slice button.
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69. Learning More
● Adjustment Tools section on Ultimaker Cura’s site
https://support.ultimaker.com/hc/en-us/sections/360003607779-Adjustment-
tools
● Print Settings section on Ultimaker Cura’s site
https://support.ultimaker.com/hc/en-us/sections/360003548619-Print-settings
● Chuck Hellebuyck’s Cura Tips and Tricks Playlist
https://www.youtube.com/watch?v=su_m5zV9rvA&list=PLRFPlUhDTTlm0Aq
W9EGhxglCt_OKvAwxI
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