The Ultimate iPod Touch Stylus -- The Prototyping Phase

It takes a great deal of wisdom to know when to stop conceptualizing and ideating, and to finally begin prototyping. As any long-time industrial designer will attest, there rarely is an "ultimate" design to anything...even though I've claimed such with the title to this blog entry for my most recent stylus design. Design is a fluid, evolutionary, and iterative process. And there is usually more than one solution for any given design problem. Which is good for us designers. It keeps us in a job.
At any rate, as I've found though an endless number of design projects, once you've laid out a good potential design on paper, it's time to drop the pencil and make it real. Since I like to revel in the creativity of the design process itself, it's sometimes hard to pin my ideas down to one actionable end. Creativity can be an insatiable beast...so sometimes I've got to cut it off, close the bar, and roll away the buffet (so to speak)--whatever it takes to just nail down a design so the prototyping and "real-world" problem solving can begin. Without "pulling the trigger" and building your design, the conceptualization zone may be the only place that you play in...and it's not necessarily the best place to be. I really prefer to see something completed so that I can touch it, heft it, use it, rather than just dream about what it might be. Pretty sketches and computer renderings can only go so far. So, after a boatload of sketching and conceptualizing, I've locked myself into a final design direction for my iPod stylus.
To get everything planned out and ready to fabricate the stylus, I determined all the dimensions I needed to build the stylus by modeling up my favorite sketch of the device in SolidWorks. Once I was convinced that things were going to work in the "virtual" world, I took my design to the shop, with shop drawings in hand, determined to cut some metal, assemble the stylus, and verify its real function. I had designed the stylus to be turned on a machine lathe using 6061 aluminum (for its corrosion resistance and ease of machining), with a tungsten core (from a TIG welding electrode) for good weight distribution (see the photo below). There's nothing like having a pen with the proper weight to it--and the mass of the tungsten seemed to fit the bill well, especially given the small size I was shooting for with this design. To verify the fit and sizing of all the pieces, I made sure to have my trusty calipers handy (also seen in the photo below). I used to swear by the old-school dial calipers, but have recently "upgraded" to the digital flavor...which seems to work alright. Before I get going too far in my explanation of this project, though, I should probably mention here that I'm not actually a bonafide machinist. I learned a few things in industrial design school, but never had all the specific instruction to make me a real, certified machinist. I've dabbled in the art of machining for a few years now, but have never really needed to understand all the ins-and-outs of machining that are paramount to somebody using a lathe or mill on a day-to-day basis. As a designer, all you really have to know is what a machine can or can't do in a manufacturing setting--simply so you can design appropriately for the processes used to manufacture your products. As a result of my lack of expertise, some of the processes shown here may not be 100% up-to-par by machinist standards, but they still helped me get my design 100% done with (at least) 98% of the quality that my perfectionist tendencies were looking for--and that's good enough for me. So that's my disclaimer.

To do all the dirty work of turning, I used one of the finest Chinese-made pieces of equipment that our state-funded shop could provide (see below). It's definitely not the "tightest" of machines (as bits and pieces keep falling off of it), but if you use it correctly, it can still produce good results--heck, with my critical dimensions, I was able to stay within +/- .002"...not bad for a non-machinist! I always fall back on the wisdom that it's the craftsman, not just the machine, that makes a work of art--which helps me feel better about not having the nicest equipment all the time. And since students can be some of the harshest users of tools, these lathes tend to perform well enough for what we do here.

To get started, I took some aluminum rod stock and put it in the headstock of the machine...

...and then tightened the rod in place with the chuck key, making sure the rod was centered correctly in the jaws of the chuck during tightening. When doing this yourself, ALWAYS REMOVE THE CHUCK KEY WHEN YOU'RE DONE. I've seen a lot of dented machines and holes in walls from a chuck key flying off at Mach-9 as the lathe was thoughtlessly turned on before removing it. Also, if your material extends out of the chuck, it's good to not extend it any more than two times the diameter without support at the other end--this will keep it from deforming or bending during various turning operations.

Next, I used a cutter to smooth out the end of the rod (called "facing") in preparation for upcoming machining  steps. In machining, irregularly-shaped material can cause all kinds of hazards, so it's usually best to clean up the shape of your stock material first.

Once the end of the rod is smooth, a center-drill (placed in the tail stock of the lathe) will put a nice little hole in the end for additional drilling or support by a live center.

This particular stylus design has a hollow center so that the tungsten weight can be added inside. To hollow it out, I drilled into the end just as deep as the inside hole needed to be.

I then extended the aluminum stock further out of the chuck and moved the live center in place into the drilled hole so it would support the stock as I performed the next cutting operations.

I measured out the length that I needed for the part (plus a little bit at the left end for support) and started in with the parting tool.

The parting tool is made to cut your completed part off of the rotating rod, but it can remove a lot of material at once. For that reason it works very well for rough-cutting material and getting it close to the shape you'd like. I took the parting tool and dialed it into the rod in several successive plunges until the rod was near the diameter that I wanted.

I then switched to the cutting tool to help smooth out the surface of my part. I frequently measured the part with the calipers to ensure that I was maintaining proper dimensions:

Since I wanted my stylus to be more "shapely" than straight, I worked the X and Y dials on the machine until the cutting tool had shaved away everything that I didn't want:

When it comes to complex contouring on the lathe, unless you've got a good CNC lathe, the part will need to be smoothed out quite a bit. To get all the "chunkiness" out of the surface, I used a course-toothed file (which won't load up with aluminum the way a fine-toothed file will) to dial-in the shape. This step is very similar to the final shaping steps commonly done on a wood lathe.

I used progressive grits of sandpaper (from 100-grit all the way to 500-grit, in 100-grit increments) to further smooth out the surface:

Once completed, I used a hacksaw to cut off the part...

...and the results looked pretty good. Just a little clean up on the hacksaw-cut end (which was quickly addressed with some sandpaper) was all that was needed to complete this part of the stylus.

I went through the same procedure to fabricate all the remaining parts for the stylus (shown below).

The completed set of parts looked like this (below). All that was left to do was cut the rubber grip to fit the barrel of the stylus, and then to insert the tungsten weight and stylus tip. Since the stylus needs electrical conductivity through the tip and into the fingers of the user, a band of aluminum from the barrel extends into the middle of the grip. With this aluminum contact strip and my fat fingers, it's almost impossible for me to hold the stylus without contacting aluminum at least somewhere on the device.

Although it's insanely hard (and will easily scratch glass), tungsten is a bit brittle. Thin tungsten rod, like this TIG welding electrode, can be broken with relative ease, just as if it were made of ceramic. (There are actually different alloys of tungsten that have varying degrees of increased toughness, but this wasn't one of them.) I broke the rod to the right length for insertion into the barrel of the stylus...

...and then checked it for fit in the stylus (see below). I did additional trimming of the tungsten using a stone-wheel bench grinder.

Next, I trimmed the rubber grip to size with an X-Acto knife.

I then assembled all the stylus parts together, along with the grip.

For the stylus tip, I used a bit of eraser (from a Pentel Clic Eraser)...

...cutting the eraser to size so it would snuggly fit inside the stylus' tip:

I pushed a piece of carbon fiber cloth (as in my "homebrew" stylus demo) into the tip, followed by the eraser tip, and then screwed those onto the body of the stylus.

Finally, I could verify whether or not this stylus was a good, functioning design. And, yes, it worked just as planned! A well-functioning product is always a good follow up for a lengthy build! But a product that functions well and looks good, well that's something worth posting!

In total, I racked up about eight hours of machining and fabrication time for this little tiny project...mostly because I could only work in one to two hours sessions (just fitting it in between all my other teaching, advising, and service responsibilities)--which always requires more time for setup and cleanup in this shop that is used by so many others. Projects seem to go much faster when there is a good, dedicated chunk of time to do things in. But we do what we can.
Now that I've got a new, proven stylus, I can move on to bigger and crazier projects...and I can now design them (at least in part) on my cute little iPod Touch. Design is fun. Keep rockin'.

The Ultimate iPod Touch Stylus -- Entering the Design Phase

After my previous experimentation with making a quick "homebrew" iPod Touch stylus, I got all excited about building a more refined version that had a bit more design and flair to it. In typical product design, we break down the development of any product into multiple, bite-sized phases. Usually, a new project starts off with a research phase were at least some amount of research is conducted to figure out any unknowns and get you headed in the right direction (unless you're working in an area of industry where you think you've got it all figured out already). This phase is then followed by a design (or concept development) phase where multiple ideas are presented, explored, and sifted through to find the most viable design direction. In order to further verify the effectiveness of a design concept, computer models and prototypes are then produced in a design verification phase. If things work well in testing these concept prototypes, the successful design moves into a manufacturing phase (which is often further broken down into manufacturing prep, manufacturing verification, and post manufacturing changes, if needed). Having been in industry for over a decade now, this process is pretty much ingrained in me. I automatically go through these steps with just about every project I'm involved in, whether professionally or in my own shop space, and often feeling like something's outta place if I skip one of the steps. 
Since I researched and figured out some of the basics about how to make a viable iPod Touch stylus a few weeks ago, I decided to jump into the design phase and start exploring some ideas. Over the past little while, I've let some random stylus concepts marinate in my noggin, and started cranking out sketched "ideations" (industrial design lingo for "idea creation") to get things solidified on paper. As a rule of thumb, I always try to start my ideation sessions with some good dimensional references--just to keep me honest. Without those references, it's easy to design something that is way out of proportion and, ultimately, unusable. Just because a design looks great on paper, doesn't mean it's good to go. Actually, one reason conceptual products often look intriguing to us is because they are out of proportion with what we're used to seeing--but that doesn't necessarily mean that they'll function well or are even manufacturable without some extensive amount of tweaking. This is the exact reason why it's easy to get disappointed when you see the difference between the uber-sexy concept show car on the revolving platform at the yearly car show in the conference hall downtown, and the bland-ified production version you may see of the "same" car on the dealership sales floor a couple years later. That whole "form follows function" thing will always bite ya' in the butt if you let it. 
To get my designs started with some proper proportioning, I created some referenced sketches from the very few "knowns" I had: the rubber grip for my stylus (which I had intended to cannibalize form an existing pen to save me the hassle of molding my own), and the minimum comfortable stylus length (so the stylus wouldn't be too big and bulky) that I'd found experimentally by using pens of different sizes. To get the dimensions of the grip, I took apart a pen with an appropriate grip that I thought would work well for my swanky stylus, as shown below. I chose a blue-colored grip because I just like blue--a lot. Always have. It's a true Johnny color. 

 I then took out the calipers and began taking measurements of every dimension I needed, including the length and diameter of the barrel where the grip fit onto it...

...and the length and thickness of the grip itself.

I took all these measurements and made a quick CAD drawing (in SolidWorks, my modeling software of choice) that I could use as an underlay for sketching (shown in the upper left of the picture below). I scaled this properly proportioned drawing into both smaller and larger versions, and then sketched over these to create several concepts that I found interesting. Just for kicks, I used a bit of marker and colored pencil to give the sketched forms some "volume" so they would communicate my designs more effectively.

Since I do have a rudimentary stylus to work with already (the one I built as my first post here, using a carbon fiber tip and a mechanical pencil), I thought I'd include a little sample of what it can do--of course, by showing another concept stylus sketch (drawn in Sketchbook Express):

Now that I've gone through some sketched ideations, I've satisfied myself with a good stylistic direction and it's time to roll into the prototyping and design verification phase...which I'll document in an upcoming post. Keep rockin'.

Hard Drivin' Leather -- The Case Obsession Continues...

As a college professor, I'm constantly shifting large amounts of data around. This digital data ranges from graphic files to student research projects to large 3D models, so I need a high-quality, reliable storage device that won't leave me high-n-dry with an untimely crash, or otherwise be too "dainty" to handle any necessary moving from one teaching environment to another. However, as an incurable industrial designer, my sense of design and innate appeal for uniqueness compel me to change whatever it is that somebody else thought I'd like into something that I really would like. After making all those cases for my iPod (I've produced four of them in only four weeks now), I began rethinking the blandness that surrounded my portable hard drives and decided to rock out my own new hard drive case. Since I recently had to get a new drive anyway (I got a 500 GB Seagate drive to replace my three-year-old, chock-full 120 GB Western Digital drive), I thought I'd take the opportunity to do something with it in leather. 
Almost every hard drive case out there (or, at least the ones that come as an included accessory from the hard drive manufacturer) is built from black-colored materials and looks extremely generic. Some may say that black colors (or non-colors, depending on how you look at it) make a "fashion statement"; but, I think it's boring. No...it's way boring. But, of course, I mention that right after my last few blog entries on making an iPod case out of black leather. To be honest, though, I usually use my brown leather case rather than my black one...simply because everybody out there seems to have a black case for their electronics (except for those folks who have a wildly-colored silicone case, which, these days, is also overdone), and I prefer to maintain at least a little bit of uniqueness from the crowd--even if I otherwise try to blend in most of the time. With all the black-colored products available today, I can't help but think that the reason we have so much of it is based more on tradition than anything else. It probably all stems from the manufacturing practices of yesteryear--ones that started back at the beginning of the industrial revolution when the color selections for durable paints over metal surfaces were very limited. Even Henry Ford, the father of the assembly line, placed himself in the annals of quotable history when he said that people could have any color of Model-T they wanted, "as long as it is black". Over time, people have become so used to seeing black products, that it has become synonymous with conservative style in product development, and is therefore relied upon as a way to make products that will deliberately appeal to a larger population--which typically means more sales, and hence more money, for manufacturers. Add to that the fact that color changeover in the middle of a mass-manufacturing run is extremely time consuming and costly, and you begin to realize why we don't see more truly custom-colored items out there, even though the coloring technologies for most materials have improved dramatically over the past 100 years. 
So, to make a long explanation short, if you want something to stand out in a crowd these day, it's not really that hard; just make it look different from all those black, bland, conservative, similar, background noise objects in the product market. (The marketing/business book, "Purple Cow", by Seth Godin, does a good job of discussing this topic in-depth.) To further illustrate my point, check out the photo below: one of these cases is not like the other. At the very least, I'll bet you could easily guess which one would be the most tempting for a thief to steal. (Which is actually a very disconcerting thought when you consider all the work that went into the custom-built case.) I don't know about you, but my vote's for the one that ain't black.

The top and bottom of this case are shown in the photo below. The top has a simple snap that opens to access the USB port on the drive, and the back has a specially designed set of flaps created to secure the USB cable to the case. 

To build this case, I started with leather-forming press, just as I'd done for the iPod cases.

I formed one piece for each side of the drive...

...punched holes along the sides, and began stitching:

Before stitching up the entire case, I placed the drive inside, and then finished up the stitch the rest of the way around. This sealed the drive in the case--which is fine with me; there are no user-serviceable parts inside, there are no batteries to replace in it, and it doesn't get particularly hot or need ventilation during operation. So, I figured, "what the heck...why not?".

To finish up the stitch, I threaded a curved stitching needle and passed the thread ends through one of the sewn holes so it would go between the halves of the leather.

I tied these threads off and then tucked them into the seam (to be glued down with super glue later).

I then trimmed off the excess material...

...cut out the USB cable management strap...

...and snapped the strap in place.

The USB cable tucks under the strap (where the cuts in the leather provide relief for the cable to easily  fit beneath the strap)...

...a flap folds down and snaps in the middle of the looped cable...

...and then the strap can be snapped around to the top side of the case to close everything off.

When I want to plug the drive in, I just un-snap the strap, pull out the USB cable, and plug it into the drive's USB port that is accessible through a pair of "lips" on the case. (Notice the hole in the case, next to the snap on top, that make it possible to view the white indicator LEDs which show that the drive is working.)

Once plugged in, it is ready to do its business. (Also note that the snaps on the USB cable management strap work nicely as feet for the bottom of the drive. I thought this ended up functioning well as a nice double-duty feature to the whole design.)

When it was finished, the drive had a much more desirable feel than it did when it was just a boring little "commodity" drive. Now it looks like it's got much more worth to it...even though it really didn't cost that much more to fabricate. It did take a little bit of time to make it all, but the results were well worth it to me. But, then again, objects always seem to be "worth" more to you when you put actual work into them, rather than just work to acquire them--which is one of the many reasons why DIY-types (like myself) do any of this stuff anyway. Rock on.

Leather Case Construction--Part 3: Trimming and Finishing

This post demonstrates some simple techniques for trimming the stitched leather case shown in previous posts. However, some of these cutting methods can be used with just about any thick, flexible materials similar to leather. Before going hog-wild with the cutting, I prefer to mark out the places where I'll be cutting just to make sure the shape of my cuts look right. When cutting into leather, there are no Ctrl-Z keystrokes to undo mistakes, so I map things out first to save myself the hassle of trying to turn "lemon"-craftsmanship into an overall mediocre, "lemonade" project. When working with dark colored leathers, a white colored pencil works well to draw up all the cut marks, and it erases relatively easily with a polymer eraser. Conversely, light colored leathers can be marked with a dark colored pencil. Regardless of the color of leather, I try to keep my guidelines light (though legible) so I can erase them quickly if I need to make changes. In the photo below, you can see the shape of the hole on the front for the screen, as well as the dimple through which I can access the power button through the securement strap (which will wrap around to the back), and then a little shaping for the end of the strap as well. I've left out the holes for the camera (which I'd rather just leave covered up unless I really have to take a low-res picture while I'm out 'n about). My little point-n-shoot Canon takes better pics than any iPod, iPhone, or web-cam I've seen yet (which shows the difference between specialized hardware verses the "hey, why don't we put a camera in it, too" mentality that so many marketing-pushed electronics have these days). Plus, if I have the lens covered, I won't have to listen to that nagging "big-brother" fear in the back of my mind that figures Apple could secretly see at all times if they wanted to (though I'm sure that they've got better things to do than watch me sketch, play Pac-Man, and pick my nose).

On the back of the case, I put marks for a slight cut that will provide additional access to the power button, along with an opening on the back panel so I can easily push out the iPod when I want to remove it. I've also put in marks for the headphone and cable connector at the bottom. The other control buttons on the device can still be pressed through the case, so I decided to leave them off for simpler cutting and an overalls cleaner aesthetic.  

For basic cuts through single layers of leather, I just used a pair of sharp scissors.

For straight cuts, I used, a straight-edge ruler. Here I'm using an X-acto knife (though a utility knife will work as well) to do the damage. I always use mat board or a cutting mat beneath my blade so I don't gouge into the table top--which helps keep my wife happy. It usually takes multiple passes with the knife to get through the leather (unless it's really thin), so I try not to move the straight edge at all as I make one cut after another on the same line. When cutting next to the stitches, I try to leave about 1/8 of an inch so I don't cut into the threaded holes.

 The finished edge cuts looked like this:

To finish the corners I just used the scissors. The scissors tend to work well with rounded outside curves.

Next, to help with the cuts into the front and back panels of the case, I made an insert from mat board (similar to the one I used to form the wet leather for the case in a previous post) and slid it into the case. This gives a good firm surface to cut into, making clean cuts more attainable.

Using the X-acto blade, I cut out the power button access at the opening at the case...

...and then cut out the access hole on the back. It takes a steady hand to make sure these cuts come out smooth, so that gives me yet another reason to lay off the caffeine.

For the screen opening on the front of the case, I wanted slightly rounded corners, so I started by popping a hole in each corner with a hole punch and hammer.

 I then used the blade and ruler to connect the outside tangent edges of those holes, and then completely cut out the scrap.

To get the holes ready for the dot snaps, I used the hole punch and a hammer again.

I then fit the dot snap post into that hole...

...and put the anvil (flat side up) in beneath it.

The snap then went over the post...

...and the setter locked the post and snap in place with a good couple wallops from the hammer.

The finished dot snaps (at least one half of them) looked like this:

 I then punched holes in the strap, put the round-headed posts through the hole...

 ...positioned the anvil behind it (with the dished side of the anvil up)...

 ...and then put the dot snap over the post.

A couple firm pounds on the setter with the hammer...

...and, shazam!...instant snaps for my sassy case strap. It's probably a good idea to put some felt on the inside of the snaps where they meed the iPod inside the case--they can cause scratching over time. I just put a piece of tape over them instead since nobody every actually looks inside the case. (I know that's a design "cheat", but it works. So deal with it.)

After sliding in the iPod, you can see how super-duper-sexy the whole case looked (even with some of its minor imperfections).

It looks classy from the back, with a strap included for more secure holding...

...and from the front it looks like something I spent good money on. If you don't count the cost of the tools (which I never do, since I usually use them on unknown numbers of future projects and "amortize" their cost over lengthy amounts of time), this little case cost all of about 3 to 4 bucks in leather and thread, plus some nominal costs for the scrap mat board and other supplies.

 I'm currently making a little case in which my portable hard drive will be permanently stitched, which I may post in a bit, too. Once you've got a good setup for forming, stitching, and trimming leather, it's fairly easy to pop these bad-boys out real quick-like. Given the time it takes me to make a case like this, I could feasibly make one of these little guys each night after work (assuming all other important responsibilities were minimized). As life goes, though, my short nights tend to be filled with a frenetic juggling act that shoe-horns one project after another in between the disparate activities of intermittent diaper changes, entertaining a couple toddlers, and giving my wife an adult listening ear and occasional shoulder rub. But I guess it's all those little loving activities that round me out more than I'd otherwise be if I were left to my own devices--most likely regressing into a sad, lonely life as a design hermit who would spend all his time locked away in the shop, so deeply engrossed in projects that he'd waste only enough time to eat the bare minimum allowable sustenance required for basic physiological survival. (Basically, I'd probably turn into a design Gollum..."design, preciouuus". Ick.) Good balance works much better for me. And it feels much less selfish.
At any rate, I hope these little demo's and ramblings are of benefit to the other hopelessly creative-types who I know are out there. Keep designing, keep building. And rock on.