Getting a 3D Printer – Part 1: Introduction, CAD Program



I’ve been thinking about getting a 3D printer for a long time, ever since I started designing random things in Solidworks. I design a lot of bits and pieces for my projects, and have mostly been using Ponoko, and while the quality is pure amazingness, and it’s nice to not have to worry about process problems too much, it gets a little annoying to have to wait 2-3 weeks for your things, especially on prototypes that require a few iterations – you’d be waiting for couple months. It also gets expensive after a while.

I finally got myself a printer (in a kit), assembled and calibrated it, and now it’s printing beautifully, so I’m now going to try to write about things that worked for me, things that didn’t work for me, things I figured out, etc, to hopefully save you some time should you decide to go down this route.

Getting a 3D printer set up is not nearly as difficult as I thought it would be, and it had been an awesome learning experience, so I’d recommend it, if you know how to design stuff in 3D (and if you don’t, you should! it’s not really that difficult!).

It’s definitely OK if you don’t have an engineering degree, as long as you know some basic high school physics. There’s really nothing difficult about putting together and setting up a printer, and drawing stuff in 3D.

CAD Programs

I’ve been using Solidworks, which is awesome, but also costs couple thousand $s per license. Autodesk Inventor is extremely similar, and also cost similarly, but they have a free “student version” that has full professional version features, and all they require for verification is school name and URL, so I’m experimenting with that also. Unfortunately, there is not really a comparable parametric design program that cost any less, and I believe parametric design is the way to go for any serious stuff.

Note: Parametric design –¬†¬†basically drawing feature not to scale first to establish basic hierarchies and relations, and then adding constraints until the design only has 1 solution. For example, to draw a 1 cm cube, one would start by drawing a square by first drawing 4 straight lines connected in a loop on the same plane, then specify that the 4 lengths should be equal, one of the lengths should be 1 cm, and the opposite sides parallel, and 2 of the adjacent sides perpendicular. Then the design can be “extruded” to a height of 1 cm, and at this point the design is fully defined (only has 1 solution).

There are some free/cheap offerings like Google Sketchup, TinkerCAD, and Autodesk 123D, but I found them extremely limited.

If you can’t draw 2 holes in a cube with an arbitrary distance between the centers (no snapping to grid), I classify the program as toy. Unfortunately, Google Sketchup, TinkerCAD and 123D all fall in that category. 123D has SOME basic parametric capabilities, but AFAIK only within features, and not between features.

So if you are just starting and are a student, I would recommend Autodesk Inventor. It’s one of those cases where professional solutions are much easier to use than hobbyist programs, because with hobbyist programs you would be fighting program limitations all the time. The hobbyists programs may work for very simple designs, but why spend time learning them just to have to learn another program in a few weeks when you want to move on to more complex designs?

An AI/Solidworks tutorial would be way out of scope of this series of blog posts, but there are tons of tutorials online, so start digging!

All these programs can export STL (Standard Tessellation Language) files, which is the format accepted by all “slicers”, programs that generate step by step instructions for your printer to produce the shape from the 3D model.

Note about Solidworks and STL – apparently Solidworks sucks at producing STL files, which is strange, being one of the industry leading programs for mechanical design and the STL format being the standard format for 3D printing, which is fairly common nowadays. If your slicer produces weird results from your correct-looking Solidworks files, just get netfabb Basic, open the STL file, repair it, save it, and it should be sliced correctly now.

Slicers and other programs required to actually get your designs printed are dependent on which 3D printer you are using, and will be covered in a future post.