3D Printing with SketchUp (2014)

Appendix A. Resources for Your 3D Printing Success

In this reference section, you'll find fast answers to common problems and questions that I had while learning how to model in SketchUp, and while learning the specifics of 3D printing SketchUp models. There is also a curated list of my favorite programs and websites used in relation to 3D printing.

Troubleshooting nonsolid models

These are some common problems that may prevent your model from being solid. Use the Solid Inspector extension to help highlight these problems.

Tip

In a solid model, every edge is bounded by exactly two faces. Any more, and there will be internal faces. Any less, and there will be a hole.

The following troubleshooting guide table is meant to be printed out for quick reference when you need it:

Problems	Solution
Intersecting or overlapping faces	Use the Intersect with Model command to create edges at the intersections, and then delete the internal faces. If the intersecting faces are separate solid groups, use the Outer Shell tool to combine them.
Holes in the model	Draw a line over one of the edges bounding the hole to form a face. If this doesn't work, use the Line tool to connect the hole's open edges. Since a triangle shape will always make a face, try stitching the hole together with triangles. If the edges are very small (less than approximately 1 mm long), you will need to scale the model up to fill in the holes.
Duplicate faces	This problem can be tricky to spot because the problem area highlighted by Solid Inspector looks perfectly fine. It happens when multiple faces form in one place. Simply select and delete the faces one-by-one until you make a hole, then Undo one step to replace the last face. Making a copy of the model with the Move tool also corrects the problem, and may be faster for models with many duplicate faces.
Group inside a group	Nested groups or components will not be identified as solids by SketchUp, even if all the other requirements are met. Solid Inspector does not highlight this problem either. The solution is to move the nested group outside the context of the main group using the Cut and Paste in place commands under the Edit menu.
Internal faces	Any geometry that is inside the solid model, not a part of the surface, will prevent the model from being a solid. Select and delete this geometry. To see the inside of a model, you can use the Section Plane tool. Another good method is to cut a portion of the model, and then use Paste in place to replace the Cut geometry when you're done working inside. On models with curved surfaces, use the Soften Edges dialog box to make the surface look smooth. If there is a hard edge visible where the model should be smooth, check that area for internal faces.
Reversed faces	Reversed faces will not prevent SketchUp from showing a model as solid, but you'll have trouble trying to print the model. Right-click, then click on Reverse faces to correct this problem. If there are many reversed faces, right-click on a front face, then click on Orient Faces to fix all of them at once. If the Orient Faces command doesn't work, you probably have internal faces in the model that need to be removed.
Stray lines	Stray lines are lines connected at only one end. Simply erase them, or use the Cleanup extension to automatically remove them.

SketchUp extensions

Extensions, also called plugins, extend SketchUp's functionality and can be found in many places on the Web.

Where to find extensions online

The following websites are the best places to download extensions:

· Extensions Warehouse at http://extensions.sketchup.com/ is the official extensions site. It is also available directly inside SketchUp and can be found by navigating to Window | Extensions Warehouse.

· SketchUcation Plugin Store at http://sketchucation.com/resources/plugin-store-download. This is an extension for downloading and managing extensions, having the largest collection of SketchUp plugins online, with instant install, plugin sorting, and more useful features.

· Smustard at http://www.smustard.com/. It is a collection of free and for-pay plugins.

Extensions and plugins mentioned in the book

The following extensions and plugins are mentioned in this book:

· SketchUp STL at http://extensions.sketchup.com/en/content/sketchup-stl converts SketchUp models into the common .stl format for 3D printing

· Solid Inspector at http://extensions.sketchup.com/en/content/solid-inspector checks for errors preventing solid groups and components

· CleanUp³ at http://extensions.sketchup.com/en/content/cleanup%C2%B3 automatically deletes stray lines and performs other tedious tasks

· Import DXF at http://sketchucation.com/forums/viewtopic.php?f=323&t=31186 imports existing artwork in .DXF format

· Edge Tools² at https://extensions.sketchup.com/en/content/edge-tools² cleans up imported .DXF and .DWG files

· Make Faces at http://www.smustard.com/script/MakeFaces fills in imported linework with faces for pushing/pulling into 3D

· Roundcorner at http://sketchucation.com/forums/viewtopic.php?t=20485 is used to add fillets to your 3D model, making the corners rounded

· BezierSpline at http://sketchucation.com/forums/viewtopic.php?t=13563 is used to make complex curves

· Joint Push Pull Interactive at http://sketchucation.com/forums/viewtopic.php?p=496773 is used to make wall thickness; it works best on models of simple to medium complexity

· Add Terrain Skirt at http://sketchucation.com/forums/viewtopic.php?p=359903#p359903 quickly adds a flat base to terrain models, making them solid for printing

· i.materialise 3D Print Service at http://extensions.sketchup.com/en/content/3d-print-service uploads a model directly from SketchUp to i.materialise

More useful extensions

The following extensions are also useful:

· Curviloft at http://forums.sketchucation.com/viewtopic.php?t=28586 is used to create complex curved surfaces.

· Bounding box at http://extensions.sketchup.com/en/content/draw-boundingbox draws faces on the bounding box of a group or component. It is useful for aligning odd-shaped objects.

· Artisan priced $39 at http://artisan4sketchup.com/ adds subdivision capabilities inside SketchUp for organic modeling.

SketchUp training

If you're new to SketchUp, use the following resources that I referred to when learning how to model:

· SketchUp's official training [http://www.sketchup.com/learn]; free videos, downloadable step-by-step tutorials, and more, directly from the SketchUp team.

· Google SketchUp 8 for Dummies, Wiley Publishing at http://www.aidanchopra.com/book-info, written by one of the SketchUp team members for SketchUp 8 in an easy-to-follow format. The vast majority of the book still applies to current SketchUp versions.

· SketchUp School at http://www.go-2-school.com/, video training from experts, also available for free on YouTube at http://www.youtube.com/user/4sketchupgo2school.

Companion programs for 3D printing

The following programs work with 3D models, providing functionality that SketchUp lacks:

· Netfabb Basic at http://www.netfabb.com/basic.php is a free program for manipulating and fixing errors in STL files.

· Netfabb Cloud at https://netfabb.azurewebsites.net/ is a powerful free STL repairing hosted online. Use this to clean up models and fix errors such as missing faces, and internal geometry.

· Meshlab at http://meshlab.sourceforge.net/ is used to convert many files to import into SketchUp or convert models exported from SketchUp.

3D model repositories

The following websites host models that others have made. Download them and modify for your needs. A huge time-saver if you can find a model close to what you need!

· Thingiverse (http://www.thingiverse.com/) is the largest collection of files for 3D printing online

· SketchUp 3D Warehouse (https://3dwarehouse.sketchup.com/) is a vast collection of SketchUp models, most of which are not printable without making them solid

· GrabCAD (https://grabcad.com/) are engineering grade models, most of which will need conversion to allow import to SketchUp

3D print services

If you don't own a printer, you'll need a print service to have models made for you. Even if you do own a printer, you may need a model printed in a material you don't have access to. There are a couple of different business models that print services use.

Industrial services with a shop platform

The following services allow designers to order high quality models as well as sell designs to the public. The printing and customer service is fulfilled by the print service. Designers are paid if someone purchases their model.

· Shapeways at http://www.shapeways.com/ usually has the best prices and awesome customer service. It has offices in New York and the Netherlands.

· i.materialise at http://i.materialise.com/ has an excellent selection of materials, good SketchUp support, fast priority service, and cool contests. It is based in Belgium.

· Sculpteo at http://www.sculpteo.com/en/ can print SketchUp files, offers fast printing times, and has innovative tools for designers. It is based in France.

· Kraftwurx at http://www.kraftwurx.com/ has a huge variety of materials available, by far the largest selection—platinum and many more. It is based in Texas, USA, with printing hubs around the world.

Crowdsourced print services

The following websites act as a platform allowing anyone to list their printer and accept and fulfill printing jobs. You can usually find a local printer using one of these services. Most printer listings are for small desktop printers, but there are also many small businesses with industrial printers and engineering staff on hand to provide personalized help.

· MakeXYZ (http://makexyz.com/)

· 3DHubs (http://www.3dhubs.com/)

Contact me

I sincerely hope this book has brought you value on your SketchUp to 3D printing journey. If there is anything else at all that I can help you with, please e-mail me directly at <marcus@denali3ddesign.com>.