Product Design

  • 16 May
    Design Process Drives Creativity, Part 1

    Design Process Drives Creativity, Part 1

    This August I’ll lead a group of high school teachers in Clackamas County through a 3-day seminar to help them teach students to design and be Makers. What’s the best way to do that? Teach the teachers to make stuff! First lesson: you can’t just say “Here’s a problem, go make a solution.” Instead, you teach a consistent process that can be applied to almost any challenge. I know that I will always find creative and effective solutions to a wide range of problems. Why? Because my design process ensures it. The process gives me something to lean on when I get a difficult project, and it will give students (and teachers) the courage to go be Makers.

    I know that I will always find creative and effective solutions to a wide range of problems. Why? Because my design process ensures it.

    I’m working through a design of my own in preparation for the seminar, and I’ll be documenting the process here on the blog. I’m breaking this accelerated design into three chunks:

    1. Problem definition: requirements, constraints, and design objectives
    2. Concept generation and selection: functional decomposition and morphological charts
    3. Design and test: paper to computer to prototype

    I’ll tackle each chunk in a separate post, and they’ll be released weekly.

    Part 1: Problem Definition

    Each challenge is presented as a new client showing a “design firm” a potential project. With only this written statement from the client the teacher teams must develop design objectives, requirements, and constraints. Remember: the best solution may not be what the client has in mind! Here’s the challenge I pose myself, spoken from my client’s perspective.

    “Here’s the problem, and lots of people have it — I have a hard time keeping my indoor plants alive, I just can’t remember when I watered them. Did I do it recently? Did I just casually dump the rest of my water glass in, or did I give it a good soak? If I water them now will they be too wet? I can’t tell by looking at them and I don’t want to get all dirty sticking my finger in and also ruining my arrangement with a bunch of holes! So instead I just water whenever and hope I get lucky…wait, is that mold?”

    “I keep these plants on my desk. I tried a small self-watering planter. Great idea, really, and they can work great, but I bumped it the other day and sloshed dirty water all over my sketchpad! Besides, I can’t use those for my succulents, here, because they need to dry out almost completely. So there’s gotta be a way to do this better. Here’s what I’m thinking: an internet enabled pot that tracks moisture content!”

    “Look here, I’ve put together a little something. The pot for the plant has this sensor built in, right here, where it detects the soil moisture. Then, that runs into this little computer taped over here and the data is sent through this ethernet cable and into the cloud. Then you log in on your phone and voila! You could have an app that says, ‘hey, water your Jade tree.’ Great, right?”

    “It’s working great but I can’t seem to get the sensor to read very reliably, oh and I fried this board the last time I watered. So we need a water-tight and nice pretty way to hide all these cables and electronics. I need your help to make this work.”

     This is a problem I have all the time, so I’m thrilled to get to solve it! Now, I’m not sure that the electrified-sensor-internet approach is the right one. I’d prefer something simpler, something that’s purely visible and tactile. I think that’s what most people would want, so I’m going to back up, frame the problem, and come back to my client with three compelling solutions.

    Regularly and intentionally reviewing and revising your constraints, requirements, and objectives is an important part of the design process.

    Defining the problem means developing three things: constraints, requirements, and design objectives.

    • Constraints are somewhat firm limits imposed by physics, manufacturing methods, available resources, or design decisions you already made.
    • Requirements are features or functions that the product must have or perform to be acceptable.
    • Design objectives (the most fun) are the goals of your design, which you will aim to accomplish as best you can given the constraints and requirements.

    These three crucial components of any product design will change and evolve as the design develops. Regularly and intentionally reviewing and revising your constraints, requirements, and objectives is an important part of the design process.

    So how do you start? For a major project with sufficient budget I employ a technique known as QFD, or Quality Function Deployment. For this, we’re just going to read over the problem statement, use our brains, and write stuff down.

    First, write down the problem as you understand it. Write it again, and try to break it into more measurable language.

    Help user keep plant alive.

    Remind user to water plant.

    Design an indoor planter that assists the user in maintaining optimal moisture content.

    Great! That’s the goal. What is required of the finished product? These are our requirements.


    • Product shall not leak if bumped during regular use.
    • Product shall allow re-planting.
    • Product shall be waterproof, but not submersion proof.
    • Product shall be manufacturable at a reasonable cost.
    • Product shall accommodate a variety of plants: from garden herbs to succulents.


    • Product must not be larger than 150mm in any direction. (about the size of a tissue box).
    • Product must be prototype-able using the tools at our disposal.
    • Product must not require any special tools or consumables.

    Design Objectives

    In order to decide on design objectives, we need to better understand and define the system. In particular, what are all the things that effect the soil moisture content of an indoor plant? Write down all the variables you can think of. Ask other people, search the internet, and write it all down. I like to make a table of variables. Then I rank each variable for various categories. For this design, each variable gets three ratings from 1-5. Those ratings correspond to these questions.

    A. How much influence does this variable have on moisture content? 1 (little) to 5 (lots of influence)

    B. How much difficulty does this variable cause for the user? 1 (user doesn’t think about it) to 5 (constantly nagging)

    C. How easy is it to influence this variable with the container (our design)? 1 (practically impossible) to 5 (very easy)

    Next, combine those rankings to get a single value. I have chosen to weight the final value as: A*(B+C). This gives more weight to the degree of influence of any single variable. Now — none of this is set in stone! Use your common sense. Are you going to design a container that controls plant respiration rates? No, because you can’t.

    Here’s my variable selection matrix. Pardon the informality (and slanted lines), you’re seeing the inner workings here!

    Using this matrix and my sense, I rank the top five variables and eliminate others. Now I know what I should focus on with my design!

    Now I carefully analyze the selected variables to understand how they work and what they do. It’s a thorough but informal analysis; typically a combination of rough sketches and text that more resembles conversation than engineering analysis. Here are some sketches from this process:

    After careful thought, here are my design objectives:

    Product shall signal or prompt user at a certain soil moisture level.
    Product shall encourage and reinforce proper watering technique.
    Product shall maximize the ratio of volume to surface area, within reason.
    Product shall include features such that the user need only add plant and soil.

    OK, let’s take a break!  We know what our design must do, we know what constraints we need to work with, and we have a list of objectives that we’re designing for. Next, we’ll dive deep into the product’s function with a process called functional decomposition. Then, using the functions produced by decomposition, we’ll start generating concepts with the use of a morphological chart. Then we’ll combine concepts to make more concepts and analyze them all with another selection matrix! You don’t want to miss it.

    By David Perry Product Design
  • 22 Oct
    The F-F-Fiddle Means You Can Make Anything: Here’s How

    The F-F-Fiddle Means You Can Make Anything: Here’s How

    You don’t need to be a master craftsman or an industry expert to make something new and exciting. Before I made the F-F-Fiddle, I’d never made a musical instrument. I started playing the violin when I was in grade school, and I’ve always wanted to make a violin, but I thought I’d wait until retirement — the barriers to entry for that kind of craftsmanship are so high. Then, in early 2013, I bought a 3D printer. Suddenly I had this robot that could make complex, accurate parts that I modeled on the computer. All I needed to do, then, to make a violin, was to design and model it on the computer and print it out. Shoot, I can do that all day! Let’s walk through the process I used to make the F-F-Fiddle: Research, Ideation, Design, Prototyping, Iteration. This is the same process that you can use to make, well — anything!

    1. Research

    All of my projects start with some research. For the F-F-Fiddle, I had to learn about electric violins. What do electric violins look like? What are the important components? I pinned violins that I liked to a Pinterest board to collect inspiration.


    I also took apart an old (junk) electric violin that I got for $20 from a friend. Now, I love destroying things, but taking things apart is seriously important — it’s the best way to learn how your parts need to go together. I re-used the components from the junk violin for my first F-F-fiddle.

    You gotta break it to make it.

    You gotta break it to make it.


    2. Ideation

    Armed with enough info about electric violins to be dangerous, I began the ideation phase. I modeled the necessary components (that I took out of the junk violin) in CAD and printed underlays — or outlines of the required parts that I could then sketch on. My sketching skills are poor, but regardless of skill level, the process of drawing is vitally important! I think it wakes up parts of your brain that (for me) typically lay dormant.

    I brought in my friend and excellent industrial designer, Dan Nicholson, during this ideation phase. Dan helped me refine my design intent and was able to beautifully communicate it with pen and paper. By working side-by-side, Dan and I developed the same vision for the F-F-Fiddle. Even though his sketches were relatively rough, we both knew exactly what we wanted to see in the instrument.


    3. Design

    With Dan’s sketches in hand, and a clear vision for the F-F-Fiddle, it was time to make the thing real. This is where the design goes digital. During the computer design phase, I have to make decisions to balance my design intent (my design vision) with the realities of violin ergonomics and my manufacturing method — 3D printing. For an design engineer like myself, these hard decisions mark the beginning of the real challenge (and fun). This process took a couple of weekends, about 30-40 design hours.


    4. Prototyping

    I printed out the first F-F-Fiddle as quickly as possible — there is no better way to learn than by making! Sure enough, it didn’t work — the strings were way too far from the fingerboard, the bridge too flat, and the electronics were terrible. What this first one did do was validate the concept — it help the string tension, and it made noise. I knew at this point that it was possible to 3D print a violin!


    5. Iteration

    The rest of the process is iteration: perform a redesign based on feedback from the prototype, then make another prototype — repeat. My first order of business was to make a playable instrument, then to make it more durable, and then to continue with improvements for playability and ease of assembly. After another 30-40 hours of work I got to the point where the parts printed reliably and the violin felt more-or-less like a real violin — it was ready to be released to the wild!


    A lot of these steps may be familiar to you if you’ve made stuff before. The process used to make things is at the same time both universal and unchanging while it’s also being transformed by advances in digital design tools and 3D printing. No matter what you’re making or how, what’s important is that you work the steps — Research, Ideation, Design, Prototyping, Iteration. Each step is crucial to a successful project, but the real magic happens when they’re combined.


    By David Perry 3D Prints Product Design
  • 02 Apr
    3D Printing Biomimicry Leads to Righteous Ripping

    3D Printing Biomimicry Leads to Righteous Ripping

    Where the soft calls of ocean mammals meet carefully extruded polycarbonate plastic,  high-performing and beautiful surfboard fins are born. Boardshaper Roy Stuart has combined two things that will save the world: biomimicry and 3D printing.

    [I wrote this blog for product design blog, Solidsmack. It’s re-posted here with permission.]

    Most surfers these days ride with three fin, or ‘thruster,’ setups. Thruster fins offer a good balance of performance and stability. Some use two fins, which is less stable and more maneuverable and typically used only in small water. Beginners, long boarders, and folks that like retro equipment use single fin setups. Offering much greater stability, single fins also limit performance significantly. To get a sense of the difference between thruster and single-fin performance, imagine a ‘70s surf video of riders smoothly flowing along a wave, and then contrast that with modern surfers shredding the heck out of it. That difference is due, in part, to the better performance of thruster fins.

    Roy Stuart’s Duke board is a beautiful $369,000 take on classic single-fin style boards.

    From what I read on the internet, Roy Stuart’s focus is on the basic essence of surfing — catching waves. He likes to do it with large wooden boards that are elegantly crafted over long periods of time (years). To improve the performance of his single-finned masterpieces (as well as others’), Roy optimized the flow across the fin by adding a series of bumps, known as tubercles, to the leading edge of the fin. This forces water into faster currents which in turn increases performance. The use of leading edge tubercles (bumps) for improved performance is not new, Humpbacked whales have used them for millennia!

    A humpback fin, photo taken by MrMoorey on Flickr.

    Humans have long been inspired by nature, but in this day of pocket screens and wearable computers it’s easy to overlook the natural solutions that surround us every day. Despite this, there is a rapidly growing trend towards biomimicry — the use of the natural world as inspiration for solutions to human problems. Bio-inspired solutions often result in astounding efficiency gains, and fluid flow is a common application. If you’re interested in learning more about biomimicry, check out Ask Nature as well as Jay Harman’s recent book, The Shark’s Paintbrush.

    Biologically inspired designs often require complex geometry that can be difficult to make with modern production methods. 3D printing offers a manufacturing technique that is similar to many of those found in nature — like a sea creature building a shell — and presents a new set of design constraints that encourages organic shapes and experimentation. For his fin, Roy considered a variety of manufacturing methods, but found them all either too difficult (machining a tall skinny thing causes deflection) or too expensive (tooling costs). He ended up partnering with a local design and 3D printing firm — Palmer Design and Manufacturing, for the development of the fin.

    I contacted Palmer Design to get some information on the project, and was very pleased when Andrew Palmer responded with insight into their design process.

    Yes, it is this easy. From Palmer Design and Manufacturing.

    Palmer designed the fin in Solidworks, as you can see from the process shot, above. While Andrew declined to comment on their specific slicing software and printer setup, he did imply that they use a secondary piece of software that allows them to specifically control internal part geometry. By controlling infill geometry and using polycarbonate — a very strong printing material — the folks at Palmer were able to overcome their biggest challenge: fin strength.

    The majority of the fin looks like it’s printed with rectilinear infill — often considered the strongest choice. 

    The fin is printed vertically with an FDM process. This build orientation means that as the fin flexes against it’s broad faces it is pulling the deposited layers apart. The bonding strength between layers is often the weakest link in a FDM part, but for part resolution and printing ease, it doesn’t make sense to print the fin in any other orientation. The strength Palmer has achieved here is impressive, and you can watch them break a fin.

    Roy’s original fin, right, blows my mind with beauty. Picture from Roy’s website.

    There are presently 17 versions of the fin. Picture from Roy’s website.

    Each fin takes 2-6 hours to print. Using 3D printing, there’s no penalty to making a greater number of unique parts, and at present they have about 17 different versions. (3D printing will save the world.)

    By combining his knowledge of surfing and board construction with biologically inspired aerodynamics and additive manufacturing techniques, Roy Stuart is now able to sell performance enhancing and affordable surfboard fins. For those of us that work in product design and manufacturing, biomimicry and 3D printing will continue to produce better products, more efficient processes, and game changing (anti-gravity) manufacturing methods. Considering the global problems we face, it’s important that we understand, embrace, and contribute to these changes.

    Title photo of Roy Stuart by Alan Gibson from the New Zealand Herald, copied from Matrix Surfboards.

    By David Perry 3D Prints Product Design
  • 05 Sep
    How to Design for 3D Printing

    How to Design for 3D Printing

    3D printing is the fastest way to go from CAD model to physical part. 3D printing also allows the designer to break many of the rules that apply to subtractive manufacturing techniques like CNC machining. With these powers combined…3D printing is awesome! But it’s not a free ride, to make great products you have to learn how to design for 3D printing.

    3d printers, like any manufacturing method, have limitations. Inexpensive machines (<$3000) are generally all Fused Filament Fabrication (FFF) types, so that’s what we’ll focus on for now. These machines construct 3-dimensional parts by building them layer-by-layer with extruded plastic. Generally these printers print one layer at a time on a fixed X-Y plane. After one layer is complete, the build platform moves down by one layer thickness (or the print head moves up), and another layer is deposited.

    So, how do you design for 3D printing? Easy — learn these ‘rules’ that I use when I design 3D printed parts.

    Keep in mind, rules are only guidelines; please stretch and break these as much as you can to learn about your machine and its capabilities.

        1. Design your part to have a flat surface. While it’s not critical, it’s very helpful to have a nice flat surface to select as your first layer. You can have your slicer fake it with support material, but support material is a pain to clean off and can mess up your beautiful layered surface finish.
        2. Keep under-hanging angles near or below 45°. If you keep your underhangs at or below 45°, you won’t need support material! They’ll all come out looking very nice and you’re more likely to have successful prints on the first try.
        3. Keep bridges to about 30mm or less. Bridging–the act of trailing filament between two supports (forming a bridge)–is fun. As long as you keep them short, it’s easy, too. If you’re planning a bridge on a large part, try to test it out first to make sure your part won’t fail. Nothing’s worse than having a print fail towards the end of a large part!  EDIT: I just bridged 80mm. It took a couple layers to firm up but I was blown away that it worked as well as it did. It just goes to show…BEND THE RULES!
        4. Design your own support material. You can minimize the supports needed and the effort required to remove them by designing them yourself. Obey rules 2 and 3 and keep the supports small enough to easily trim with a pair of snips.
        5. Use the X-Y gantry for complex geometry. The X-Y gantry moves with very good resolution. The Z: not so much. I think the topographic look formed by the layers of material is really cool, but if you have complex geometry that you want to come out just right, try to use the X-Y gantry as much as possible. Common examples include holes, text, and logos.
        6. Load along the layers. If you are designing a part that sees some load, design it in such a way that the loading does not try to pull apart the layers. Any applied forces and bending should be along the layers. Think about it like this: if you only printed half of your part, do you still have the necessary geometry to support your loading scheme?

    Now you know it — how to design for 3D printing. Go make stuff! Keep these rules in mind, but be sure to stretch them.

    By David Perry 3D Prints Product Design