APPENDIX B ■ APPENDIX BWhat if you don’t have the money to buy a 3D printer, don’t have the knowledge to choose a printer, or
aren’t sure you’re ready to make the investment? Fortunately, many 3D printing services exist where you
upload a design file and they mail you the printed object. Moreover, these services often have industrial
equipment that can produce higher-quality prints and can print in materials that consumer printers don’t
support, such as metal or ceramic.
Many local libraries and hacker spaces also have publically accessible 3D printers. This allows people to
obtain parts without shipping delays and to learn from each other.
Rapidly Improving
There were many different technologies in the early days of 2D printers: typewriter-based, dot matrix,
thermal ribbon, wax, ink-jet, and finally laser. Printers competed on speed, quality, colors, price, and
resolution. Guess what? Those same criteria apply to 3D printers, with a couple of additions: output material
choices and support of complex structures.
I could write an entire book on the subject of three dimensional printing. But, many other authors have
already done so, and the 3D printers are evolving so quickly that the written material quickly goes out of
date. Therefore, this chapter will instead concentrate on applying consumer-level 3D printing technology
specifically to the Sandwich robot in this book.
Printing the Motor Coupler
The most complicated piece of Sandwich is the part that connects the motor shaft to the Lego wheel. Over
the years, I’ve tried many ways to perfect this coupler and decrease the time and equipment necessary (see
Figure B-4). Now, with a 3D printer, the coupler can be printed in 20 minutes at home without filing, cutting,
drilling, or applying epoxy.
Figure B-4. Improvements in couplers. Left to right:telescoping tubing, milling machine, lathe, and 3D printer