This is one of the best demonstrations of the principles behind a differential drive and how the system is optimized for performance. Created in 1937 by Chevy. (For the impatient, discussion begins around the 2 minute mark).
The principles behind the design of these quadcopters apply to the design of any product.
The lesson here is that some high performance tasks are easier than others and understanding the physics of the problem tells you which ones are easy and which are hard.
A lamp that changes color based on your facial expression:
Wired cover story this month:
In the Programmable World, All Our Objects Will Act as One
Arduino Yún with on-board WiFi
Vittorio Cuculo took an Arduino, an RGB LED, and an IKEA lamp and programmed the system to recognize your facial expression and change the color of the light based on how it thinks you’re feeling. I’ll say that again. How it thinks you’re feeling. Sure, it’s a simple interaction and it may be easy to argue the utility of such a system, but projects like this represent significant steps into the future of our interactions with the physical objects we own even though the steps may appear, at first blush, to be small.
via Arduino Blog
Diagrams. Charts, graphs, and maps. Nearly everyone on a product team makes them yet few of them are great. How do you make them better? As regular readers know, I’m a big fan of fundamentals and this video by Virtual Beauty brilliantly communicates the fundamentals of diagrams:
Via the always inspiring Flowing Data
Interested in learning more? Start with Edward Tufte:
A beautiful 10 minute film produced in 1930 by Ralph Steiner showing the internal workings of gear mechanisms, cams, indexers, counters, and many others.
We’re not talking about that Android phone, Windows phone, or iPhone in your pocket. This 1947 video from Bell Telephone Systems shows all the pieces of a 300 Series phone, designed by Henry Dreyfuss, coming together. If “Tommy Telephone” annoys you the way he annoyed me, skip ahead to about the 3:15 mark when the phone parts make their appearance.
It’s interesting to see not only the parts, their geometry and how they fit together, but also the materials used. Not surprising to see copper, nickel, and gold on the list. The lead surprised me for the moment before I realized the product was designed in the 1930’s. Wax, leather, linen, cotton? Yes.
Seeing all the pieces of such an iconic, ubiquitous product come together reinforces the great respect I have for early industrial designers.
Back before nearly every piece of manufacturing equipment shipped with computers and motors, automated equipment was driven by cams; mechanical cams not “Computer Aided Machining.” I saw such a machine when I was a young man. Remembering how impressed I was watching this machine execute a dozen or so movements all driven by a single cam shaft with multiple cams, I set out on a video search for footage of such machines. After way too many hours this is the best I could find. It’s footage of a vintage multi-spindle lathe from a now-defunct machine shop in the UK.
It might not be as exciting as watching a 5-axis machine cut a motocross helmet from a block of aluminum, but at about 90 seconds in you can see one of the cam shafts driving some movement. There is a good overview shot at about 2:01 and an interesting close-up on about 5 axes of movement at about the 2:30 mark. There are 7:15 minutes altogether with footage of a few machines.
The equipment may be a bit different, but the process fundamentals are mostly the same. This vintage 1938 film takes you on the journey from ore to industrial steel with a lot of furnaces along the way.
Photographer Todd McLellan takes the product take-apart to a new level by artistically arranging the parts and photographing them, then photographing the parts, presumably, being tossed into the air.
The products he takes apart are a few technological generations old but it is still insightful to see how they look on the inside and marvel at the complexity. Younger engineers will be amazed at the level of detail achievable in the pre-CAD era.
More at http://www.toddmclellan.com/; click the “New Work” link on the left and have a look at the video of the deconstruction and photography process.
It’s a classic that you have probably seen before and here it is again for quick and easy reference:
- Good design is innovative
The possibilities for innovation are not, by any means, exhausted. Technological development is always offering new opportunities for innovative design. But innovative design always develops in tandem with innovative technology, and can never be an end in itself.
- Good design makes a product useful
A product is bought to be used. It has to satisfy certain criteria, not only functional, but also psychological and aesthetic. Good design emphasises the usefulness of a product whilst disregarding anything that could possibly detract from it.
- Good design is aesthetic
The aesthetic quality of a product is integral to its usefulness because products we use every day affect our person and our well-being. But only well-executed objects can be beautiful.
- Good design makes a product understandable
It clarifies the productâ€™s structure. Better still, it can make the product talk. At best, it is self-explanatory.
- Good design is unobtrusive
Products fulfilling a purpose are like tools. They are neither decorative objects nor works of art. Their design should therefore be both neutral and restrained, to leave room for the userâ€™s self-expression.
- Good design is honest
It does not make a product more innovative, powerful or valuable than it really is. It does not attempt to manipulate the consumer with promises that cannot be kept.
- Good design is long-lasting
It avoids being fashionable and therefore never appears antiquated. Unlike fashionable design, it lasts many years â€“ even in todayâ€™s throwaway society.
- Good design is thorough down to the last detail
Nothing must be arbitrary or left to chance. Care and accuracy in the design process show respect towards the consumer.
- Good design is environmentally friendly
Design makes an important contribution to the preservation of the environment. It conserves resources and minimises physical and visual pollution throughout the lifecycle of the product.
- Good design is as little design as possible
Less, but better â€“ because it concentrates on the essential aspects, and the products are not burdened with non-essentials.
Back to purity, back to simplicity.
Though Dieter was primarily an industrial designer every one of these points are equally applicable to product engineering.
Check out the interview for some additional context.
Concepts apply quite nicely to physical products:
via Minimal Mac.
When you’re designing high-volume products every penny counts. That’s what the finance guys tell me anyway. Although cost is always a concern, I find most industrial designers and product design engineers don’t have a good concept of what a $0.17 cost-adder means for a product with an annual volume of 20 million units (answer: add $3.4 million to your budget). The math is pretty simple but there’s something about seeing the number in front of you that brings home the reality. So I made this quick and dirty chart to give us a quick and easy reference.
And who doesn’t need another reason to open Excel? Click here to download the Excel spreadsheet.
Comments are happening on the new Form Loves Function Discussion Forum.
Designing plastic parts is deceptively complicated. There are many factors to consider along with the obvious part function, performance, and cosmetic requirements. The checklist below outlines most of the important factors affecting performance and cost for any given application. Not all of these items will be applicable to every part you design, but going through this list will undoubtedly give you a better understanding of your part and what it needs to do. This understanding will undoubtedly help you make changes to optimize the part design.
It’s a long list but don’t let that dissuade you. Every item on the list will affect part cost and performance.
Injection Molded Plastic Part Design Checklist (in no particular order):
- What is the function of the part?
- What is the expected lifetime of the part?
- What agency approvals are required? (UL, FDA, USDA, NSF, USP, SAE, MIL spec)
- Will the part be implanted in humans?
If so, biocompatibility is your first concern.
- What electrical characteristics are required and at what temperatures?
Some material properties of concern: Electrical Resistivity, Surface Resistance, Dielectric Constant, Dielectric Strength, Dissipation Factor, Arc Resistance, Comparative Tracking Index.
- Will the part be used in an optical system?
Some material properties of concern: Refractive Index, Gloss, Haze, Transmission (in desired spectrum, ie IR, visible, etc.)
- What temperature will the part see? And, for how long?
Some material properties of concern: Coefficient of Linear Expansion, Specific Heat Capacity, Thermal Conductivity, Maximum Service Temperature, Deflection Temperatures, Vicat Softening Point, Glass Transition Temperature, Flammability, Glow Wire Test.
- What chemicals will the part be exposed to?
Most material manufacturers test their materials with common chemicals. Contact individual suppliers for the results of their chemical compatibility testing.
- Is moisture resistance necessary?
Some material properties of concern: Water Absorption, Water Absorption at Equilibrium, Water Absorption at Saturation, Maximum Moisture Content.
- How will the part be assembled? Can parts be combined into one plastic part? Will one plastic part need to be divided into two or more?
- Is the assembly going to be permanent or one time only?
- Will adhesives be used?
Some resins require special adhesives.
- Will fasteners be used? Will threads be molded in?
- Does the part have a snap fit? Glass filled materials will require more force to close the snap fit, but will deflect less before breaking.
Some material properties of concern: Flexural Modulus, Flexural Yield Strength.
- Will the part be subjected to impact? If so, add rounds to the corners to minimize stress concentration.
Some material properties of concern: Izod Impact, Charpy Impact (Unnotched), Charpy Impact (Notched).
- Is surface appearance important?
If so, beware of weld lines, parting line, ejector location, wall thicknesses, surface texture, draft, and gate vestige.
- What color is required for the part? Is a specific match required or will the part be color coded? Some glass or mineral filled materials do not color as well as unfilled materials.
- Will the part be painted?
Some paints require a primer which may attack the molecular structure of the material. Some paints require a thermal cure so you will need to verify the material will withstand the oven cure temperture.
- Is weathering or UV exposure a factor?
Some material manufacturers test their materials for UV exposure. Contact individual suppliers for the results of their UV testing. If no testing has been done, plan on doing the UV testing yourself. UV exposure is often overlooked and be very detrimental to the physical properties of the part.
- What are the required tolerances? Can they be relaxed to make molding more
- What is the expected weight of the part? Will it be too light (or too heavy)?
- Is wear resistance required?
Some material properties of concern: Rockwell M Hardness, Rockwell R Hardness, Coefficient of Friction (Static), Coefficient of Friction (Dynamic). Surface finish is also a factor so adjust draft to allow for the desired finish within the tool and plan for no ejection on wear surfaces..
- Does the part need to be sterilized? With what methods (chemical, steam, radiation)?
This requirement is similar to chemical compatibility. Some materials are tested and results published by material manufacturers, others will need to be tested for your specific application.
- What is the worst possible situation the part will be in? (For example, will the part be outside for an extended period of time and intermittently put in water, or maybe see a constant high load while submerged in gasoline.) Parts should be tested in the worst case environment.
- Will the part be insert-molded or have a metal piece press-fit in the plastic part? There are tooling, process, and residual stress implications of insert molded features and press-fits.
- Is there a living hinge designed in the part? Be careful with living hinges designed for crystalline materials such as acetal.
- What loading and resulting stress will the part see? And, at what temperature and environment? Will the loading be continuous or intermittent?
Some material properties of concern: Ultimate Tensile Strength, Tensile Yield Strength, Flexural Modulus, Flexural Yield, Elongation at Yield, Elongation at Break, Tensile Creep Modulus, Deflection Temperture..
- What deflections are acceptable?
- Is the part moldable? Are there undercuts? Are there sections that are too thick or thin?
- Will the part be machined?
Some materials are more amenable to machining than others.
This list is intended to be a starting point for plastic part design and is not a comprehensive design guide. Your part in your specific application may have requirements not listed here. If that’s the case, please leave a comment. We would love to hear about it.
Comments are happening on the new Form Loves Function Discussion Forum.
Everyone’s favorite Vice President of Search Products & User Experience, Marissa Mayer, talks about how innovation happens at Google. Well, how it happened three years ago anyway. Her 9 keystones are still relevant today:
- Ideas come from everywhere
- Share everything you can
- Hire brilliant people
- License to pursue dreams – Google gives employees 20% of their time to work on individual pet projects (50% of the projects launched in the second half 2005 were “20% time” projects)
It turns out when you take really smart people, give them really good tools they make really beautiful, amazing things that are really exciting and they do it with a lot of passion and momentum.
- Innovation, not instant perfection –
the key is iteration.
- Data is apolitical – decisions get made based on data, not on rank of the decision makers within the company
- Creativity loves constraint
- Users, not money
- Don’t kill projects, morph them
The question and answer session after her lecture is also quite enlightening.