3D Printing and Modeling

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Materials

Review of different filaments

Prusa has a nice materials guide with interesting information.

PLA

eSun PLA+ is recommended by several people.

Find a Model

  • Thingiverse Has a wide variety of .STL files to download and use. A great source of ideas.
  • The Smithsonian Museum has many interesting models. Natural history and man-made - anyone want to 3D print a copy of the Apollo Command Module escape hatch?
  • NASA has files for their space craft and more.
  • CADMAPPER will give you terrain AND the buildings that are on it.
  • Board Game accessory holders, easy tool to design your own.
  • CGTrader Lots of models for purchase, including a number of celebrity heads.

TIP: If you have a virtual reality headset, you can import your model to AltspaceVR and interact with it in VR! We have some instructions on how to do this.

Get Your Model Printed

Own Your Own 3d Printer

Having your own printer gives you unlimited time. But you also must be willing to care for the machine. At Maker Nexus we use the Prusa MK3s printers. During our COVID response they ran continuously for months without a problem. Or join Maker Nexus and use our printers!

Your local Makerspace

You're on this wiki, why not join your local community makerspace?

The UPS Store

Some UPS Stores are now offering 3D printing. I used the UPS Store in Menlo Park. I exchanged email with them, sent them an STL, got a price, and picked up my part the next day. The part was extrusion printed, but in a very good quality. Their price was a bit more than Shapeways for the same part.

Shapeways - excellent, moderate price, two weeks

http://www.shapeways.com I have printed lots of stuff with Shapeways. Their print quality is very high. They offer a number of different materials. Their web site is easy to use and powerful. The only downside is that it takes 2-3 weeks to get your stuff. They also allow you to have your own store. They let other people buy your parts and you decide how much of a markup you want to add.

Modeling Software

Parametric Modeling

Parametric modeling allows you to specify constraints on your designs. One constraint is the length (dimensions) of your design and that makes it easy to adjust the dimensions later. You can also specify angles, tangents, co-linearity, and much more. Some solutions actually require that you dimension everything. One issue for the newby is that when you have only a few constraints and change one the software might "solve" your geometry in a way that you did not anticipate - you use the Undo button a lot until you get used to it. Once you understand constraint use it is very powerful.

  • Fusion 360 parametric modeling for hobbyist and very small businesses. This is a very powerful professional, yet easy to learn, modeling tool. All your designs can be dimensioned which makes it easy to go back and say, "I want this wall to be 23mm instead of 22" and see the whole model regenerate. You can export an .STL file for import into a Slicer. We have a page of Fusion 360 tips.
  • FreeCAD is an open source alternative to Fusion360. It is very powerful but a bit quirkier than Fusion360. If you enjoy open source software, this will do a very good job for you.
  • OnShape is a browser based solution. It works a lot like Fusion 360. The free version makes your models open-source. That might be a problem if you're doing a work thing, but if you're just a hobbyist then why not share your designs with the world?
  • OpenSCAD is a text based parametric modeling solution. They offer a GUI to help you make a well formed modeling file, but the basic file is all text based. You specify objects and locations in space, and boolean operations on them, and more. It's like the MarkUp language of 3D modeling. Some people swear by it because they can know exactly what's going on - no fancy GUI to hide operations from you. You can make extremely sophisticated models with this.
  • Solid Python is a Python library that generates valid OpenSCAD files. If you want to write your own program to generate models in OpenSCAD, try this.

Organic Modeling

This is when you are making some lifelike part. A little figure, a model of a hand, a free form art work. These don't have constraints, you just grab parts of the mesh and pull it into a new position.

  • MeshMixer for creating and editing STL files is now part of the Autodesk suite and is included in Fusion360.
  • Blender - Used by artists and modelers the world over. A very, very powerful open source application. I tried to use it but felt like a guy who's driven an old car now sitting in a jet fighter trying to fly the thing. Wow. I've seen spectacular things come out of Blender, but not from my hand.

Simple Modeling

These solutions are the easiest to use and are a good place to start if you just want to make something quickly.

  • SketchUp offers a free version that is very popular with hobbyists. The easy user interface allows one to quickly construct objects. They can be constrained, but that is a bit more work.
  • TinkerCAD is so easy that kids can use it right away.

3D Scanning

If you want to duplicate some thing, there are several ways to create an STL file of that thing.

  • High Quality Laser Scanners - Can cost a couple of thousand dollars, but do a great job at capturing fine detail. I've used the Next Engine 3D Scanner to duplicate an old drawer pull with many features.
  • Low Cost Laser Scanners - Can cost a couple of hundred dollars and can do a good job on items that have moderate detail. Some of them are do-it-yourself kits. I'm told they can be finicky to get aligned. Search the internet for "3D scanner".
  • True Depth Camera - If your smart phone has a camera that reports depth, apps are available to create a model. I've used Create 3D by Standard Cyborg (free) on my iPhone 12 to get superb results. The iPhone 12 only has true depth on the front facing camera, which is awkward for capturing a object other than your face. However, I took several scans and stitched them together with MeshLab (free) and the result was exceptional.
  • Photogrammetry - This software constructs a 3D model from a bunch of photos. If you want a model of a teapot, you circle the object taking a hundred overlapping photos. You can use this software to construct a much bigger item like a whole house, a room, or even an archaeological site. The more high quality photos, the better the detail. Two I've used are Regard 3D (free) and Agisoft Metashape (free demo mode).

Cellphone True Depth Camera

  • Capture 3D: Scan Anything

Capture 3D runs on smart phones with true depth cameras. (The front facing camera on iPhones, for example.) Scanning your face is dead easy and you see the model right on your phone. As you move the phone you need to keep the object mostly in view - makes sense. If you don't, the process stops and you get a model of what you've scanned so far. Since this is just the front facing camera it is a bit tricky to get an object all in one scan.

To use the model requires some post processing. You go to Standard Cyborg's web site and download the models you have created as "point clouds." Then use software like the free MeshLab to stitch your point clouds together and create an STL file. Once you know how to use MeshLab the whole process is very easy.

Photogrammetry

I've tried two software apps on my Mac and both did the job. I walked around a person in a chair and took about 140 overlapping photos. After an hour of processing I got a model of the person and also much of the room behind them. The resolution of the model's face was far below that of the true depth camera work, so I did not follow up on these packages.

  • Regard 3D (free) is an open source solution with a gajillion options. I eventually read their documentation and followed what it recommended. It didn't work for my project until I selected L1 for both options on camera triangulation. Then I got nice results. It is a few years old and the database did not have my iPhone model in it. At first I blamed my guessing at the missing "sensor size" parameter for my bad results, but in the end my guess of 5mm seemed to work as well as the commercial software did on the same photo set.
  • Agisoft Metashape (free demo mode) I'm not sure how long the demo mode lasts, but this did pretty much what Regard 3D did but without all the worries. I could click each step in the processing pipeline and the software just did it. In the end the result was not that different from Regard 3D, but I did not closely compare the output.

Point Cloud and Mesh Software

Sometimes your scanning software will only give you a point cloud and not a mesh. Or you'll want to manipulate the mesh a bit to remove artifacts. In my case I had three point clouds from a scan of a head. I needed to align them, create the mesh, and export it.

  • MeshLab download This is some fabulous open source software. I tried fooling around with it and got frustrated until I found a fabulous step-by-step tutorial that told me exactly what was needed. I could now do the process again in just a few minutes. The tutorial is on the web. We also have a copy in the MN Members Drive

I found a mesh was difficult to deal with in Fusion360. Fusion360 has a mesh to BREP feature, but that left me with a ton of triangles and I still had trouble manipulating it. Their community recommended a paid feature to convert a mesh to quads, but then another recommended a free tool:

Fusion360 can be difficult to understand when using a mesh or a surface or a tspline object. Here are some things to remember:

Meshmixer can be used to make a surface stl file into a water tight model

Printer Control Software

Slicers

Slicers take your .STL model and do the work to generate GCode that can be sent to a 3D printer.

  • Prusa Slicer is a great tool for your needs. It provides a lot of control over the slicing, grouped into simple, advanced, expert. There are a large number of settings - visit our Prusa Slicer Tips page.
  • Slic3r is the software that Prusa built their slicer on top of. Open source, you may find that leading edge features are here before they appear in the Prusa Slicer.

Remote Control and Monitoring

  • Octoprint Runs on a Raspberry Pi and, depending on your printer, will let you monitor and remotely control the print. With a camera attached to the RPi you can watch your print from anywhere and intervene if there's a problem.

Maintenance and Troubleshooting

Troubleshooting software

  • Pronterface runs on your laptop and sends commands to your 3D printer from a graphical user interface. It can be very helpful in diagnosing issues with your printer.

Calibrate the Extruder

An interesting article on calibrating the extruder on a 3D printer. The basic steps are to ask the printer to extrude a specific amount of filament, measure the actual amount of filament used, then adjust the extruder constant (steps per mm of filament used) to reflect the actual value. Then remeasure. On one printer, I found the default was extruding 102.5mm when it was supposed to be extruding 100. I think this was making rough top layers on my prints. It can also affect what you think is the correct height adjustment for the first layer if you rely on a printed patch that you feel for smoothness. The linked article walks through the process, including a couple of g-codes you need to be able to send to do run the test and set the adjustment.

Techniques

Other sites

Best Practices at 3D Hub.

How to get and print a 3D landscape of anywhere

Annealing your printed PLA model can dramatically increase its strength.

3D print your own filament to give you new colors or variegation. Then print with your own custom filament.

Design of snap joints in plastic. A great reference.

Ceilings in your model

The MakerBot software defaults do NOT do a good job at putting roofs over some parts. To correct this you need to modify your device settings. Look for the "create a profile" button. First select the correct device, material, etc. Now click Create A Profile. Give it a name. It will now open in Notepad. Look for the setting of "roofThickness". Set it to 3.

You could try changing "roofLayerCount_disabled" to "roofLayerCount_enabled". I have not tried that.

Design Tips

Designing for tolerance in your printing process A good discussion of part tolerances with FDM printing and how to include these tolerances in your design.

Avoid supports by designing your model to be folded.