Industrial Design for Makers

The first steps are the most important and set the direction the product will take. The client and designer agree on all the constraints and problems that need to be solved by the final design. Some concerns are for the manufacturer, some for the consumer. For this project, the revised design should be:

• Inexpensive to manufacture, meaning low tooling costs. No sense in dreaming up an injection-molded design if the molds will cost too much or take too much time to create.
• Easy to assemble. We’ll assume the person buying this kit would have some basic skills and tools.
• Low-cost in its components. The price of the kit can’t be too high, and we’ll assume the customer will provide his own hacked camera and circuit.
• Cool-looking and inspire purchase. It should be a “wow!” and not a “meh.” The design of a product alone can make the sale.
• Light, strong, waterproof, and easy to fly and take pictures.

A real project for an actual manufacturer would have many more concerns like product safety, patent infringement, green manufacturing,
end-of-use disposal, etc. This list is enough for our exercise.

Designers use ideate to describe the active process they use to generate ideas. To realize and explore directions, designers draw many rough sketches. Quick notations spread over the page as ideas flow forth, like visual stepping stones. These aren’t meant to be pretty pictures or even drawings that anyone else will see: they’re used to express and explore ideas. Think Leonardo da Vinci’s codices (he even wrote his notes backward so no one else could read them!).
The point of the ideation phase is to create as many related ideas as possible: more ideas will lead you to better ideas. Have a playful sense of humor with the ideas. Don’t settle on one idea yet — keep ’em coming!

Here are some of the ideation sketches for the Balloon Cam.

Note these design threads:

• Look for a simple solution: some kind of shell in a shape that holds and protects the camera and circuit board.
• Unify the elements: use the strings to both support and align the components.
• Simplify features to streamline use: give access to the switches to turn the camera on and to start the auto shutter circuit without opening the housing or reconnecting the camera.
• Make flying the balloon easier: add a weighted docking station to hold the balloons before flight.
• Add a hand-cranked reel. The designer makes notes, corrections, and improvements in sketch form, expressing, evaluating, and re-expressing as he goes.

The designer selects the best combination of ideas and refines them into a proposed design. This requires more finished drawings, with plans, elevations, and a rendering of what it looks like to communicate the detailed design to the client. If the client approves the paper design, then it’s on to developing
the prototype.

One constraint of this design project is low tooling costs. Vacuum forming is the perfect solution: light but strong plastic shells can be vacuum formed using low-cost patterns. Vacuum forming is also easily doable for the DIYer (see MAKE Volume 11, page 106, “Kitchen Floor Vacuum Former”).

The mold makes parts that can be used for both the top and bottom shells. Leaving the flanged rim on one part makes the top shell that fits over a smaller, trimmed bottom shell. It can even be molded in colored plastic so that no painting is required.

Here, drawing is used as a tool to solve a 3-dimensional problem: where to locate the camera, printed circuit board, and 9-volt battery inside the saucer shape. Side elevation and top orthographic views show the location of each component and the minimum size and shape of the basic shell. Further refinements simplify the design and remove the 3 protruding lobes. Instead, recessed features guide the support lines and at the same time provide mating horizontal surfaces to hold the shells together.

The next step is to make the prototype. The domed part of the vacuum-form mold is made from urethane foam, easily turned on a lathe using hand tools. First cut a round blank of foam and mount it to the lathe. Use a cross-section view from the elevation drawing to make a same-size cardboard template gauge for checking the progress of turning the exact shape. File the shape and check frequently with the gauge. If you don’t have a lathe, you can file the foam by hand, freeform.

Make 3 equally spaced rounded slots with a mill: first, mount the turned foam in a dividing head and mill the slot with a 5/8″ end mill. Index the head by 120°, cut the second slot, then index to 240° and cut again. If your mill has an adjustable head, add 2° of draft for easier unmolding. If you don’t have a mill, you can lay out the location of 3 equally spaced holes on the foam with a compass and drill three 3″ holes. Then carefully cut the slot with a handsaw.

To make the lipped flange feature, cut a second oversized disc from fiberboard and mount it to the foam. Drill 1/16″ holes all around the edges to provide airflow for snug vacuum forming.

Vacuum-form the shells from 0.030″ styrene sheet and trim to check the fit (above). The geometry of the curved dome shape, the flanged rim, and the 3 recesses all act together to create a rigid and strong part even when made from thin plastic.

Building preliminary prototypes like this often requires making small revisions. To hold the camera level in the curved shell, add a small bracket made from bits of styrene, solvent-bonded in place. In our theoretical exercise, this bracket would be a third part, vacuum-formed alongside and at the same time as the shells for very little additional cost. See the exploded view drawing.

To keep costs down, the buyer of the kit would do all the finishing work and assembly:

• Trim the 2 shells and bracket, and solvent-bond the bracket to the bottom shell.
• Drill a 3/4″ hole in the center for the camera lens (above).
• Drill a 1/4″ hole for access to the camera’s mode button, and cut a square hole to view the camera’s LCD (above).
• Cut another square hole for the timer circuit’s new on/off mini slide (above).
• Drill three 1/8″ holes in the flats of both shells for the support strings to run through.
• Fasten the camera and circuit inside the bottom shell with velcro tabs. It’s important to be able to remove the camera easily to upload the photos to a PC and change the camera’s battery.
• Punch holes in 3 pairs of velcro dots and fasten them around the 3 string holes.
• Make the rigging: tie three 36″ lengths of 12lb test fishing line to a split ring. Tie a bead 24″ from the ring on each line. Thread each line through a hole in the assembled shell, and then tie the ends together to another ring. Be careful so that the shell hangs level when supported by the 3 beads — that way the camera will face straight down for taking pictures in flight.

For the working prototype the reel handle is cut from wood and a crank is fashioned from styrene sheet and rod stock. A bent wire form acts as a line guide. A water-filled milk bottle serves as a weight that clips to the handle. Mounting the reel of fishing line off-center looks odd, but works great: when you take your hand off the crank, the line tension automatically stops the reel from spooling out and the balloon stays where it is.

The redesigned version of the Balloon Cam is much easier to use for taking aerial pictures: the docking station provides hands-free setup, the camera and circuit are much easier to turn on, and the shells pop open to allow access for changing batteries and downloading pictures. It even looks cooler with its cute, retro-UFO look as it hovers and flies around.

But how to manufacture the parts for the reel handle in quantities to make affordable kits? Hmm, that’s another job for the industrial designer — back to the drawing board!