How can I start designing my own 3D objects?

How can I start designing my own 3D objects?

If you get to the point where you tire of downloading and printing other people’s designs – or if you discover that you have a need that no one else has figured out how to address – you may be motivated to learn 3D-modeling.

If you’ve ever come up with a plan – a picture on a piece of paper – to build something out of wood in your workshop, you have the basic skills to get started with imagining something three-dimensional. You’ll take the process one step further and replicate you’re idea in electronic format. There are computer programs that will help you with that step. They’re all referred to as Computer-Aided Design (i.e., CAD) programs.

What CAD Program Should I Start With?

You can pay A LOT of money for a CAD program, or you can get started for free with an amazingly powerful, online, designer called Tinkercad.

The company, Autodesk, that created Tinkercad also sells a couple of state-of-the-art professional CAD programs: AutoCAD, Inventor, and Fusion 360. The point is that they’re going to be around for the long term and they know what they’re doing when it comes to 3D-design.

There’s a very large community of Tinkercad users and some great tutorials on YouTube. Autodesk has a rich set of instructional videos there as well.

Tinkercad is expressly designed for use by teachers and their classrooms. It’s easy to create a set of related and monitored logins. Note that one of the fun features of Tinkercad, if you’re a STEM/STEAM teacher, is that it even supports building and testing electronic circuits and programming code.

Designing DIY Assistive Technology – like what?

What assistive technology is a good candidate to be implemented as a 3D-printed, DIY device?

Individuals with disabilities don’t fit the “mass market” model specifically because their abilities and needs vary so much. 3D-printing tools have the inherent capability to easily modify the size of an object prior to printing; and color choices of filaments are almost unlimited; but the best AT device candidate will be one that is highly customizable through built-in parameters whose values can be set by the user prior to printing.

3D-printing is a slow process. Very large items will take a very long time (days) to print. If they must be printed in parts, and the parts then have to be assembled, the aesthetics and strength of the final device may be affected or could require additional hours of post-processing. On the tiny end of the spectrum, the smaller an 3D- printed part, the weaker it will be – particularly along the layer lines.

Without invoking fringe materials like polycarbonate filaments that require specialized 3D printer parts and greater expertise to print, 3D printing filaments and the devices they produce are not rated to support significant weight or operate outside of normal room temperatures.

The device cannot require transparency or softness, nor extended periods directly in contact with the user’s skin – most 3D printing materials produce rigid parts and have a rough surface. These two characteristics can make them irritating if placed in contact with the skin for a long time. One could sand the surface of the part to make is smoother or wrap it in a softer material, but an optimal device would be one that goes directly from the printer into use, not one that requires lots of post-processing.

A key feature of 3D printing is the ability to rapidly make changes to a design, print the modified design, and test the modifications – if necessary – to repeat the process with new modifications. A device that is a perfect fit for everyone, right from the start, will be much cheaper to produce using mass production methods. Be sure to check whether your idea isn’t already being provided by a commercial AT supplier.

The best DIY designs are remarkably simple to assemble – simple skills and simple tools. Parts that snap or screw together are unlikely to become a barrier to therapists, individuals with disabilities, or their caregivers. There’s already significant inertia in the system without introducing more by requiring advanced skills to assemble a device.

3D-modeling tools and 3D printers are optimized for creating models and printing objects that can easily be specified as a collection of x, y, z coordinates. It is possible to form an organic object in clay and then 3D-scan that object to produce a solid model but a 3D-printer will struggle to print it. Large amounts of support will be required, or it will have to be carefully sliced into sub sections and then glued together. Such models provide few opportunities for modification without repeating the process from scratch. In addition, they tend to meet the needs of one, and only one, individual.

Oh, and if you get into modeling assistive technology, I encourage you to post your designs at least to Thingiverse or Printables, and Makers Making Change to share with others. Use one of the Creative Commons licenses to ensure that the people who need your creation aren’t discouraged by a price tag.

Keep it Safe!

I was shocked when I came across this journal article that says “PT Professors believed that 3D-printed crutch tips could replace missing crutch tips on their pre-existing crutches.”

Uncovering Challenges and Opportunities for 3D Printing Assistive Technology with Physical Therapists – McDonald, Comrie, Buehler, Carter, Dubin, Gordes, McCombe-Waller, Hurst

They’re wrong! They don’t understand the limitations of the technology and they haven’t done a real cost-benefit analysis.

A commercial crutch tip costs $6.60. A 3D-printed crutch tip costs $1.47. If the 3D-printed crutch tip fails, how much will that cost?

The bottom line is: never use a 3D printed device in a situation where failure of the device could result in injury to the user!