Tips for Teaching 3D Modeling & Printing

I decided to write this tips list based on my experiences teaching 3D printing and 3D modeling for about three years now at a public Makerspace called HATCH. Being a publicly funded Makerspace means that all of HATCH’s classes are free and as a result I end up teaching a wide variety of students the ropes of digital 3D. I’ve taught everyone from 12 to 65 years old, from computer neophytes to experienced engineers looking to get an introduction to 3D printing.

1. Do your research & set your criteria.

For researching I recommend just going to Google and typing in “3d cad software right for you“. You can also try looking for “3D CAD for organic modeling”, “3D CAD for hard surface modeling”, “for engineering”, “for design”, “for game modeling”, etc. I also have also written an article that explains what 3D models are made of and what workflow types are out there.. It comes with my opinions on some CAD software as well – though it’s missing some notables like Vectary and OnShape. If you do check it out, the meat of the article is really in explaining what CAD is/how it works.

For some good places to ask questions you should definitely check out the official forums for popular CAD softwares. For software-agnostic websites, check out CG Society, Polycount, Computer Graphics World, Core 77, Solidsmack, or 3D CAD Forums.

When setting your criteria, you can use this list as a reference:

  1. Cost (how much can you afford?)
  2. Ease of use (do people regularly comment on the program for being easy or hard?)
  3. What do you want to make? (Characters are organic, machines are hard surface, CAD for production, or CAD for video games, or both?)
  4. How do your students access it? (Web based or local install?)
  5. How much existing knowledge is out there? (Tutorials, wikis, etc.)

The biggest challenge I had when setting up my class structure was to find a program that was reasonably powerful, yet easy to use and most importantly free. The latter was especially important because it was the only way I could teach CAD at HATCH, where most people have to bring their own computers and thus have to install it themselves.

There are several free packages out there (heck, Autodesk gives all their stuff away for free if you say you’re a student) and what I needed to find had to fit the following criteria: free, easy to use, expandable (i.e. not a dead-end for people to learn) and appropriate for all age ranges. I ended up deciding on 123D Design, which fit the bill nicely. Unfortunately, the software has been discontinued, so now I’m trying to decide between teaching Vectary, Onshape, or both. If you’re wondering why I don’t teach TinkerCAD, it’s because everyone teaches TinkerCAD and there’s a lot more out there. I’ve included a list below of some software that I’ve seen and used, ranked subjectively by difficulty:

2. Try everything.

Ok, so you’ve done your research and set your criteria. Now what?

The easiest way to get into 3D Design is to try every software you can find and see what you feel is the most comfortable for you and what you want to make. Obviously if you’re teaching beginners you’ll want to keep their abilities in mind, but as a general rule of thumb if it takes more than two or three clicks to perform an operation, or there are more than 10 or so tools visible at a time, then it’s probably too complex for someone just starting out.

However, the point of this step is just to encourage you as the educator to get out there and see what’s what. Sure you probably won’t teach 99% of what you try, but giving all those programs a test run will give you context for what you’re teaching, and that’s really important to knowing what tools your students will grow into after they learn the beginner tool you teach them. I started with Milkshape 3D before moving to Sketchup, then finally my current main software Modo.

Also, don’t try just what’s popular. There’s a lot of tools out there, and sometimes industry is slow to adopt them due to prior knowledge or systems in place. As long as you understand the major surfacing types and workflows, you can be sure you’re giving your students a systems level approach. Subdivision modeling is the same in all sub-division modeling software. If your students learn the rules of Sub-D in Rocket3F, then they’ll be able to model in Sub-D in 3DS Max, too. If you teach them how to use NURBS and booleans in 123D Design (seriously sad Autodesk is discontinuing this package) then they’ll be prepared to use them in SolidWorks.

3. From hand sketch to CAD.

When teaching your students to design something on their own, I highly recommend walking them through a hand-sketching phase first. They don’t have to draw well – the point of this exercise is to get them thinking about their drawings in three dimensions. Challenge them to turn their parts around in their head and draw it from different views. The most challenging thing for a 3D beginner to learn is to think in 3D. Most people tend to think of things in “flat world”, and volumetric objects are difficult to conceptualize. By practicing with a pencil and paper first it helps them to design and conceptualize what they are going to make before they sit down in front of the computer, which makes for a much easier time when modeling.

4. Consider exploratory lessons.

If you can, have your students go out and do some research on their own. Tell them to look up what 3D Design is used for, and what CAD software exists. See what they might want to make and what they might want to make it with. This will inform you of which approach to take with your class and hopefully get the students more interested in what it is they’re learning by virtue of having a direct hand in choosing what it is. 3D Design is a broad topic and can include designing for production, movies, video games, engineering, industrial design, and of course, 3D printing. So by getting your students to explore the field, either in class or out of it, you can help them get a better idea of what it is they want to know.

5. Start simple & work with the software’s strengths.

Don’t pick a program like Sketchup (which excels at blocky architectural objects) and make the first project modeling a dog or a person or a plant. Likewise don’t pick Sculptris and try to model a house. 3D modeling is generally split into two categories: hard surface or organic. Organics are anything that is organic or curvy in nature. These objects are characterized by a lack of hard lines and are generally more forgiving of misplaced vertices because these objects are “squishy” and no one expects them to be perfectly rounded.

Meanwhile, examples of hard surface objects are robots, cars, etc. These objects are typically looked at in reflective settings, so it’s really important that all their vertices be correctly aligned to provide continuous curvatures and even surfaces.

Choosing the “right” software for your intended modeling application can make those initial forays into the 3D world much easier. I put “right” in quotation marks because in reality any 3D software can make anything, it’s just about degrees of difficulty. You can make organic objects in Sketchup, and you can make a house in Sculptris – but it will usually be harder than doing it in other packages. By learning the underlying technology behind the software (polygons, NURBS, etc.) you will better understand your student’s growth paths into professional 3D Design.

Now when it comes to actually planning your lessons, being able to navigate the 3D space is the most fundamental aspect of 3D modeling, so you should start here. Many students have difficulty with the concept that they have to move a virtual camera around a virtual object. I think it’s because most software we use is always viewed from a fixed perspective – you’re not “rotating” anything in Microsoft Word, for example. Adding the ability to go behind an object confuses lots of people who are just starting out – so mastering this element is key.

Only after this is complete can you start teaching them tools like extrusion, beveling, etc. But again work with the software’s strengths – start with something simple and work your way up. In Sketchup, I start with a house, which teaches viewpoint manipulation and basic drawing/extrusion. Then I create a simple robot, which uses those same skills and adds grouping geometry and tolerances. Then I create a plane, which adds more complexity. Focusing on one or two tools at a time per lesson is a recipe for success when it comes to 3D modeling since many of those tools will be used over and over again.

As a side note, teaching manufacturing principles like draft angles and engineering tolerance can be done in any software – even software designed for organic sculpting. You don’t need an engineering software package to tell people that objects won’t come out exactly like how they are on the computer – and you can demonstrate this using virtually any package. It’s an important concept that all students who want to print their designs need to at least be aware of.

6. Print often.

The connection that’s made when an object goes from on-screen to in a person’s hand is pretty awesome. The “wow” factor is awesome and immediately engages students. It also makes the time and effort of learning the software worthwhile. Finally it helps to improve student’s ability to conceptualize 3D space. For these reasons I recommend getting people printing as often as you can, starting with the very first class.

After you explain the class, have your students go on Pinshape or Thingiverse to grab a model they like so you can print it overnight. When teaching 3D for the first time it will be difficult to make sure students produce a completely printable model*. Instead of trying to teach them both principles of good mesh design and how to use their 3D software, have the students focus on just learning the software and then manually check and repair their models after class. Trying to teach CAD software and the basics of 3D printing in one class is often too much information for people to handle. However getting your students printing as soon as possible, as much as possible, will engage them in the process and hopefully inspire them to learn more.

*You can improve their chances by using a solids-based modeling package like TinkerCAD or OnShape. Mesh-based modeling packages like Sketchup or Vectary will make it more likely their models will have errors.

7. Build a curriculum that ends in something other than “print something”.

This one was a big problem when 3D printers first came out – a lot of times a school would get them, spend the whole class getting students to print something and then calling it a day, leaving the printers to gather dust on the shelf.

3D printers are tools and they are a means to an end – not an ends to themselves. I’ve seen teachers use 3D printers as a way to teach robotics, but I’ve also seen teachers use 3D printed life masks of Lincoln to talk about history. Still others have joined the e-NABLE project and printed prosthetic hands for kids as class projects.

Your 3D printer can be integrated into any number of classes and you have every subject to pull from for inspiration. If you’re teaching 3D printing or 3D modeling as a core subject then teach it within the context of something else – like building a miniature model of something or explaining engineering principles with printed prototypes.

Having your 3DP curriculum fit into a larger context will make students more engaged in what you’re doing and it will make the printers a whole lot more useful to you and your school. Share the load with other teachers if you can. For example, if the art teacher teaches the basic 3D software then you can augment your math class with 3D printed models that the students produce.

The gist of what I’m trying to say in this tip is this: use a project-based approach to teaching 3D printing. If your students already know CAD, great – but don’t just show them how to use the printer, show them what they can use it for.

8. 3D is from beginner to expert, not young to old.

This one is just a quickie but I wanted to point out that, as with computers, you should rank 3D proficiency from beginner to expert – there is little to no correlation with age, only experience.