Large manufacturing companies have employed automation for years. Assembly lines, automated machine tools and robots populate most medium to large manufacturing facilities. Until recently however, this technology hasn’t been readily available to small business or hobbyists – sometimes referred to as makers. Now, digital fabrication has come to the maker masses. Instead of table saws, drill presses and x-acto knives in basement workshops, garages and studios, makers around the world have the choice of either local fab labs or they can outsource their digital designs for making on the Internet. I have opted for the latter to test the digital manufacturing cloud.
Making in the Cloud
How well does the fab – in – the – cloud process work and what are the implications for future design and manufacturing? I will report what I learn as I design and make a test project. I’m using Ponoko as my fabbing portal; a global clearinghouse, where people can design, make, buy and sell things constructed with digital fabrication methods. BTW, what is digital fabrication; it’s several different technologies that use robotics to cut, shape or print two or three dimensional parts using a variety of materials.
For the test, I want to design and make something that I cannot easily create by hand or by common machine tools. I also want to use more than one fabrication method and material offered by Ponoko. I have chosen a light fixture. Aside from a standard socket and light bulb, there is considerable freedom in the form a lamp can take. It can be almost anything with a bulb and power source. For simplicity sake my lamp design is built around an energy efficient 8 watt LED flood lamp screwed into a US standard (E27 110 volt) socket available from any hardware store.
I’ve decided to create a complex shape for the central lamp housing, printed in 3D. I also determined that the lamp “shade” will be made from several pieces of another laser cut material that will be attached to the central housing by pushing the parts together with tabs and holes.
I started with a few hand drawn sketches and some fast, crude cardboard mockups but it quickly concluded I should be taking full advantage of the tools at my disposal; both digital design apps and the capabilities of 3D printing. I’m moderately proficient with Rhino3D and I could quickly create and visualize more complex shapes than I could readily draw and or hand model with clay. I started with a symmetrical fixture housing and proceeded to make it more complex by twisting the ribs or that would support the individual leaves of the lamp shade.
Not wanting to get overly involved with design – this was a production test after all, not a design competition – I settled on the design shown above. It consists of a housing with twisted ribs containing the LED bulb and wiring connection and 8 snap – on “leaves” made of flat material. The Rhino screen shot below shows the two basic parts of the lamp; the printed housing and the flat leaves
Preparation and Fabbing
Once you have completed a design you upload it. Ponoko provides quite a lot of documentation, including templates and an upload process that validates your design so you know if it can be made according to the fabrication method chosen; e.g. 3D printing, laser cutting, or CNC routing. In my case the lamp housing is 3D printed and the “leaves” are 2D laser cut. For the 3D print I had to export from Rhino as a stereo lithography (stl) file, taking care to make sure I had a “watertight” model with all surfaces closed. This took a fair amount of trial and error. I had to export the pattern for the “leaves” from Rhino and convert it within Illustrator to an .eps file. Pononoko offers a large selection of materials. I could have selected aluminum, sheet acrylic, or several types of thin sheet plywood, including bamboo, but I chose acrylic for the “leaves” and durable (white) plastic for the housing. To make things somewhat more demanding for the laser cutter I created a pattern of elliptical cutouts on the “leaves.” With a little fiddling and online help I was able to upload both files and get immediate feedback that my files were good to fab.
The lamp housing will cost about $270 and the laser cutting about $30. If the finished parts match my quality expectations I consider this a reasonable price for what amounts to a complex prototype. Of course I’ll be interested in the part quality, the fabbing schedule (I don’t know that yet) and how a refined design might improve both cost effectiveness and aesthetics. The larger question is how a service such as Ponoko might figure as a viable business partner in the inevitable transition to digital manufacturing.
Stay tuned for my reports on the finished parts and lessons learned.