Rapid Prototyping

C. Alex Simpkins, Jr., Ph.D.



The rapid prototyping revolution

We are currently experiencing another renaissance similar to the personal computer revolution which occurred in the 80's and 90's. The final form of these devices (and how they will be integrated into society) has not come to fruition yet, but there definitely is already a multi-billion dollar industry which has emerged. It is a time where small groups of individuals are innovating every day.

There was a time when the average person questioned why anyone would need a computer unless they were an engineer. Now little children make use of computers, and they are part of nearly every facet of civilization. That potential exists in for technologies that allow people to fabricate objects from raw materials easily.

Rapid prototyping can be additive, where objects are built by adding material from nothing, or subtractive, where objects are created by removing material from a raw shape such as a cube of aluminum. Both methods have advantages and disadvantages. The most popular 3D printing methods today are additive. Some examples are the RepRap and MakerBot type printers. There are many things to explore and get to know when becoming involved in the world of rapid prototyping. It is supported by a massive online community, and volumes of web pages, books, videos, and conference type gatherings.

What will be the end result of this wave? Who knows. What is determined is that society is always to some extent in flux, and that the ability to fabricated objects from ideas easily will have a large impact on how we see and experience the world.


Mendel and other open source 3D printers

I'm currently tuning a Makergear Prusa, and an Ultimaker 2+, and will upload some examples, links, information, and hints soon! So far the Ultimaker has been terrific, once a few inital bugs were worked out. The Prusa has its issues, but can turn out decent parts. It tends to be finicky, and there are newer designs. That printer is gradually being upgraded as time passes and parts need replacing, and improves with each upgrade. Getting it to turn out accurate parts with regularity is not a trivial task.

As a practicing engineer, designer, experimenter, crafstman, etc these types of printers are terrific tools. They are already making massive changes in how people can build prototypes. If you take a look at Makerbot's Thingiverse website, you can see there are people developing, for example, robot hands who would never have had the resources to do so. Sensors and actuators have dropped in cost drastically - an accelerometer that, in the early 2000's I purchased as part of a robotics project for around $1000 can be purchased with higher precision specs for under $3 now. Parametric design software that used to be over $20000 for a basic license is becoming more available (or in some cases free), and that also has a huge accelerating effect. Overall it is a wonderful time to create.

Go out and design something (then print it out and use it)!


Stratasys FDM 2000


see maelabs.ucsd.edu and go to tutorials and guides

The lasercamm cuts 2d parts out of many non-reflective materials. These parts can be used to build up 3d shapes. The precision of 2D rapid prototyping lends itself well to templates for routing, drilling, or circuit printing. A laser method of cutting lets one make inside cuts very easily. For example, the autonomous robot below was designed in CAD, and produced (at least the parts for it) with a LaserCAMM from a sheet or two of acrylic.

Additionally, the contest table for which this robot was designed was produced on a LaserCAMM after being designed in CAD.

Laser cutting machines have advantages over 3d printing currently in terms of time - you can realize a completed laser cut part in seconds or minutes, whereas 3d printing anything but the most tiny of parts takes hours. Printers are getting faster due to new processes and approaches, so this may change. Also one can 3d print an entire assembly, whereas that may be more difficult with a 2D laser cutter.

No machine is perfect - they will all have advantages and disadvantages. The key is to gain the insight you require in order to select the best tool for the particular application you are faced with.



otherwise nothing of note yet...but keep checking...