3D Prints

  • 06 Jul
    Process Drives Product Design Creativity, Part 3

    Process Drives Product Design Creativity, Part 3

    The ideation phase of product design is too often glorified. You’ve seen it — the beautiful sketches, the compelling imagery — the fake stuff. Don’t get me wrong, this is a fun and important stage, but a pretty sketch is meaningless if not supported by logical, critical, and thorough analysis. That kind of analysis — that’s what I do! For more on the work leading up to this point, please review part 1 and part 2 of this series. We ended part 2 with a definition of our product. Now we embark on a three-pronged process of ideation, design, and prototyping.

    We will design and prototype a planter consisting of a hard vessel using a removable filter (in place of rocks) and an integrated drain. The planter will use changes in mass to signal “time to water” with an indicator.


    Now we design a first draft of our product. This isn’t going to be the be all end all, instead, this is the model that will test the basic principles of our concept.

    First, determine the necessary components of the design and write it all down. When I get an idea down on paper, I almost always come away with something better than what was in my head. Here are some snippets from my notebook.

    Wait, this is basically a finished design, where did it come from? When did I decide to use a compression spring?

    Cutting Corners

    That’s right, I’m cutting some corners. I could excuse it by saying that this is just a prototype, blah, blah, but the truth is that I have a mechanical design more or less in my head that I want to implement. Once we selected our concepts from the morphological chart in part two, I knew what I was going to make. Sometimes this happens. It can be a problem.

    It is likely that there is a better solution than this one. I won’t uncover it because I’m skipping opportunities for design and analysis. On the flip side: we need to get this thing done! I want to test the basic principles and then use the thing and see if I like it. If I like it, then I can go back and explore the missed opportunities. If I don’t like it, or if I’m the only one, then this is good enough!

    What is important, though, is that we are intentional in our corner cutting. I want to be able to look back and quickly see those corners. For me that happens two ways: one, physically marking a relevant page and making a note in my notebook; and two, maintaining a list of assumptions and corners cut. OK, now that I have appropriately excused any shortcuts you may notice…let’s get back to it!

    The System

    While I’m making the sketches shown above I’m concurrently identifying, naming, and defining the parts of the system. Once I have a good grasp on what parts are involved I make a list of them and their necessary functions. Let’s do it here.


    • Contains filter
    • Allows plant to be easily removed
    • Fits tight against pot
    • Does not move in operation
    • Could be rigid or flexible


    • Fits tight against basket
    • Supports basket
    • Allows water to flow out through bottom
    • Engages with spring
    • Reveals indicator
    • Moves up and down with changes in mass
    • Can be removed entirely, but only intentionally


    • Retains spring
    • Acts as bearing surface for pot
    • Contains drained water
    • Has water feature

    At this point in the design questions come up. We know that the plant sits in the Basket/Pot assembly and the whole things moves up and down using the force of a spring. How much does it need to move? What exactly is the signal? How much will the mass change from water loss?

    The first question to answer is the latter: how much will the mass of the pot assembly change with moisture loss? To answer this, I use the internet. A quick search for something like “weight of wet potting soil” will quickly get you the information you need. I ran the numbers for 4″ and 6″ pots and found that for a 4″ pot I should plan to detect a change of somewhere between .3 and 1.5 pounds. That’s a big range, so I did a little testing.

    At the time I had four starts (basil, mint, lavender, and tomato) that had been sitting out for a couple of days. They were dry and needed water! I took their mass before and after watering, and I found that for a 2″ pot the change in mass between dry and fully saturated was between .15 and .41 pounds with an average of .3lb. Thus, for a 4″ pot (4X the volume) I should expect a change of about 1-2lb, average of about 1.2lb.

    Now that we know our change in mass: how precise do we need to be? How much travel do we need for our specified weight range? Can we find a spring that can do it?

    I started with a reasonable estimate of the amount of travel needed: somewhere between 1″ and 2.5″ of spring travel in the trigger range. That leads me to a spring constant of around 1 in/lb. Well, turns out a spring with that much travel and that light a spring constant is hard to find! McMaster had nothing, but I found a likely candidate on Century: spring 12420.

    Great, next: what is the signal? And what does this thing look like?

    Let’s start with the signal.

    I started this sketch thinking that I could have a signal band on the pot that moved up and down. The position of the band relative to the window on the base would be your indicator. Then I thought, what if the window were adjustable instead? Well, to do that, all you need to do is put a band on the outside and make the signal feature on the pot fixed. Good enough!

    Concept Sketches

    It’s very common to make an underlay as a sketch aid. Underlays provide a framework for your sketch, letting even poor sketchers like myself communicate a concept. To start, I modeled the system components roughly (as cylinders). Here’s a screenshot from Fusion 360 of the mock-up parts plus a couple 3D printed vases (one is self watering) that I imported for reference.

    I took screenshots of line-representations and threw them into a word document to make underlays. They look like this:

    The left image is the trigger point and the right is fully saturated. Now I have something that I can use to guide my concept sketches! Before we move ahead…be warned: sketching concepts is not one of my strengths. This is when I most often partner with an industrial designer or two. Here are some highlights from my sketches…

    This one, above — just no.

    Names are important: let’s call this one Hot Rod. Hot Rod really appeals to me on a mechanical design level. There’s the opportunity here to design a perfectly constrained mechanism! I modeled it quickly in CAD, though, and found it visually awkward with no obvious fix. Check out the models, below. I actually got the design all the way to “ready to print” but just couldn’t tolerate how it looked. Here’s a screenshot from my working environment (how I see it while I’m modeling) plus a quick render.

    Ugly, right? Let me know if you have any ideas about how to make this approach more attractive. I know there is a good solution! Make note: this would be the fastest way to test the concept. Rubber band, spring, two bic pens, and two printed parts.

    Next up, our winner!

    Let’s call this one the Maesprung Planter (Mason + Sprung). The Maesprung uses the same basic principles as Hot Rod, but does it in a way that is visually simplified. It’s also a little less mechanically compelling, but that’s OK. I quickly mocked this up in CAD to help visualize the concept.

    CAD Design

    We already have a solid start on the CAD design. I often work in CAD while I’m deciding between concepts. With the work we’ve done, finishing the 3D model is a fairly quick job. After about 4 hours of work I had parts ready to print. Let’s take a look at some screenshots.



    As I designed the model aspects and features of the product came and went. For example, I designed a coaster and a cap to be printed in the same elastomer as the band, but the cap was too much, and the coaster seemed awkward and was certainly not necessary to test the product. I’ve also abandoned the root basket part, choosing instead to pot the plant simply in the pot. We can set aside the root basket for a product enhancement down the road.

    Print, Prototype, and Plant!

    Here’s our planter! Next: print the three parts, add plants and dirt, water, and see what happens. I chose a much neglected spider plant to be our test subject. It was bone dry!

    I measured the weight of the plant/pot once potted (but dry) and again after watering. Dry: 1.45 pounds. Saturated: 1.96 pounds. So almost exactly a half pound difference between bone dry and saturated. It seems like we might want to water again at about 0.1-0.2lb heavier than dry. Here’s about how high that is:

    So we can see that we’ll want to have the band slammed all the way down on the base if we want to use the bottom of the pot as the trigger level. That’s lower than I was expecting. In the next version I may have a color change on the pot to serve as an indicator. Then I can have the band sit higher on the base.

    OK, we got this thing printed, planted and ready to go. But we forgot to ask an important question:

    What do we need to learn from our prototype?

    Here’s what I did with the prototype.


    By David Perry 3D Prints Product Design
  • 04 Feb
    3D Printed Products are Better; Where’s Yours?

    3D Printed Products are Better; Where’s Yours?

    I recently completed my first project with a new client — Dana of Spectrum Acoustics. Folks like Dana are my ideal customers — passionate about their work and determined to improve their product with new technology. Dana approached me with a labor-intensive part that he’s been manufacturing with a table saw for his speaker systems. He hired me to redesign the part in CAD and manufacture it for him with 3D printing.

    3D printed products often mean big savings in time, money, and parts. When he switched to a 3d printed product, Dana saved 66 parts cut on the saw, 216 holes drilled in aluminum, 432 drilled and tapped holes, and 432 bolts!

    20140723_183427_resizedEach not-printed waveguide is a TON of manual work!

    Dana uses his patented speaker and waveguide design in line arrays and spiral arrays for everything from auditoriums to festivals and outdoor events. Line arrays carefully channel sound through aperture path length corrected gaps to maximize constructive interference and minimize deconstructive interference — increasing throw and dispersion. Our 3D printed waveguides used in conjunction with mechanical barriers provide frequency ranges that simply cannot be achieved with normal line array construction methods. As you walk around Dana’s line array setups, you hear fewer gaps in the sound across a greater range of listening angles. No matter where you are in the audience, you get good sound. As speakers improve and come down in cost, Dana uses smaller and smaller speakers, minimizing cost and maximizing sound quality and sound stage.

    Folks like Dana are my ideal customers — passionate about the work they do and determined to use new technology to improve their product or invention.

    Dana knows all about sound and speakers, but not as much about CAD design and 3D printing. He thought about purchasing a printer, but wisely decided to hire me to design and produce his waveguides. By hiring me, Dana gets to focus on what he’s best at: producing great sound, and I focus on what I’m best at: creating great 3D printed products.

    crossSectionIsoThe capabilities of 3D printing allowed me to improve performance by aligning the waveguide to the speaker surface.

    Not only did we save Dana loads of assembly time, but the 3D printed waveguides directly improve his system performance. Additionally, Dana can easily scale or reconfigure his design. Unlike a traditional plastic mold, we can quickly and efficiently reconfigure the speaker positions or scale the product for smaller speakers.

    2014-11-19 15.38.22The 3D printed waveguide can easily be re-configured for different speaker sizes and arrangements.

    Folks often lament the fact that we don’t have a Star Trek Replicator — that 3D printing isn’t good enough. So many are sitting and waiting for 3D printing to change the world, but what they don’t realize is that it’s up to us to make that happen. People like Dana are on the front lines: taking the plunge, 3D printing his products, and making his business more competitive. Come join the ranks — get in touch to make your own 3D printed product!




    By David Perry 3D Prints Client Projects
  • 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. If you are willing to try and fail (repeatedly): you can make anything! 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. It could make anything! 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
  • 31 Oct
    Have a 3D Printed Halloween

    Have a 3D Printed Halloween

    It smells like fall outside, and it smells like melting sugary plastic inside! Tonight, kids in all neighborhoods will make the rounds, collecting candy and showing off their costumes. It’s a golden opportunity to squeeze in a little STEAM (Science, Technology, Engineering, Art, Mathematics) excitement!

    For Halloween, we’ll be giving away 3D printed figurines with our candy, and the same models will emerge from the mists on the printer in our driveway laboratory. Holidays provide great opportunities to have fun with 3D printers. Here are some of my favorite Halloween printing projects:

    1. Print out giveaways for trick-or-treaters! The constant thud of Snickers in your pumpkin bucket can get boring–mix it up by handing out custom printed figures! We’re giving out TARDIS models, scary pumpkins, and spectres. To see these models and other good Halloween prints, check out my Halloween thingiverse collection. All of the objects I’m printing were downloaded from Thingiverse–no 3D modeling required!
    2. Jack-o-Lantern1Make your own costume props. I found a project from Tunell in Flagstaff, AZ, he says: “My son’s Harry Potter halloween costume came without Harry’s glasses. I couldn’t believe it! I designed some that will fit nicely on his face. They are small and designed to fit a 5 year old.” Perfect example! If you know how to make a quick 3D model, there are so many options. There are also a ton of props on Thingiverse, like Tunell’s Harry Potter glasses, so hop on and see what you can find.
    3. Make Halloween decrations with your printer. I 3D printed some coral candle fixtures from Ecken on Thingiverse. These will sit out next to the 3D printer with a battery operated tea tree light to provide the right spooky ambience. I’ll also have some dry ice and water nearby in the roundom vase I printed for Maker Faire. You can download Halloween cookie cutters, creepy spiders, skull LED lanterns, and more. For a great variety of holiday projects, be sure to check Make and Instructables.
    4. Create something new! Sometimes the weirdest and creepiest things come from your own ideas – or better yet, your kids. How about the combination of a cat and the ubiquitous 3D printed octopus? Free CAD tools like Blender allow direct modification of STL files (the file you download from Thingiverse) and new tools like Matter Remix make it really easy to customize existing STL files.

    We’ll upload pictures from Halloween, so check back to see how we used 3D printing to get kids excited about technology and creativity!

    If you want to talk over a project idea or you need help figuring out what CAD system to use, contact us for a free initial consultation. We can also bring the printing to you–how about a fresh take on birthday party entertainment?

  • 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