Thursday, August 29, 2013

3D Printed Sunglasses *Updated*

Completed sunglasses design

I finally took on the challenge of designing and building a pair of sunglasses from scratch.  It was a fairly tricky process but watching the model slowly take shape over time was rewarding in itself.  The design was inspired from a quick sketch of the kind of sunglasses I imagined a Japanese samurai would wear.

Sunglass concept art

The frames look a bit "off" without lenses, but the build is just an experiment for now.  As I up the ante in terms of the next project I design, I'm getting closer and closer to my goal of 3D printing an entire full-scale wearable helmet.  It may be a little while longer before I jump into that project though.  Shots of the printed sunglasses are pending!


The glasses came out well after printing.  The design had to be split apart as the 1-piece design was too big for the printer's build platform (4.9" x 4.9").  The temples were attached to the frame after the fact by welding the joint connection with spare resin and a UV laser pointer.  The plastic frame body could use a little more rigidity but flexible frames have good utility too.  The fitment is good and reminds me of another start-up company which has taken the idea of offering 3D printed glasses which are custom-designed to be perfectly molded to your face.

I don't think I'll be trying to have lenses installed.  Right now the design is just a proof-of-concept prototype.  However, I may choose to do so with a future design iteration, until then...

 The 3D printing revolution has arrived and the possibilities are endless!

Sunday, August 25, 2013

3D Printed "Tempest" Earrings

Just wanted to put up a quick update with the results / progress of the 3D printed "Tempest" earrings from an earlier post.  I threw together an "energy ball" model and printed off a set to match the earring bodies that were created earlier--then linked everything together with gold jump rings.  They're now completed.  I'm really happy with how they came out and I'm looking forward to the next project!

Thursday, August 22, 2013

3D Printed Plastic → Metal; Pseudo Alchemy

Nickel-plated 3D printed plastic models

3D printed objects definitely look great in their natural finish.  However, there are a variety of ways to improve upon and modify the existing surface through coatings, finishes, and surface treatments that can be applied to printed objects to add another level of dimensionality with regard to a material's appearance in addition to the potential to develop new unique material properties.  One system in particular that is compatible with 3D printed plastic models can effectively "transmute" the surface to metal--the electroless plating process.

Electroless plating is analogous to electroplating in that both are surface treatment processes.  However, electroless plating does not require an electrical power source but instead is an auto-catalytic chemical reaction revolving around chemical reduction as opposed to an electrical reductive process.  This key difference is what enables traditionally non-conductive materials like plastics, wood, etc. the ability to be plated with a thin layer of metal.  Electroless plating is possible with a variety of metals including copper and gold.  However, nickel is the most commonly used plating metal due to its exceptional hardness & corrosion and wear resistance.  Nickel is also a very good base metal in preparation for subsequent surface treatments and coatings.  Nickel coated plastic models can be also be soldered and applied toward unique electronics and lighting projects as well.

Electroless nickel plating solids prior to dissolution

Realizing the potential of this technique, I wanted to try my hand at replicating (it) to learn more about this process.  There are a seemingly limitless number of recipes for nickel-based electroless platings.  However, using what materials I had on hand, I applied a formula using nickel chloride as the metal source and sodium hypophosphite as the reducing agent.  A few other chemicals were added to the plating solution including sodium citrate (a complexing / chelating agent) and ammonium chloride (for pH adjustment & balance).  The solids were dissolved in water, forming a nice teal green aqueous nickel solution.  While the electroless plating solution is easily prepared, actually plating an object is bit more complicated as it involves more than just throwing the sample that you want plated into solution (which will lead to no result, unless your sample has a catalytically-active metal surface).

Teal green aqueous electroless nickel plating solution

What I learned from my venture into electroless plating is that surface preparation and activation are absolutely key to achieving success with this process.  The surface that you want to plate must be hydrophilic ("water-loving") and easily-wetted, which can be achieved by oxidizing the material.  I ended up dipping my 3D prints in concentrated sulfuric acid for a few seconds followed by a thorough rinse in water.  I believe my prints could have been oxidized a bit longer to achieve better results.  However, this being a preliminary investigation, the achieved results were a good test.  Following the surface preparation step, an activation step is required in which the surface of material is impregnated with essentially a catalytic seed metal atom from which nickel will crystallize and grow from the plating solution.  I used a very dilute aqueous solution of palladium chloride for this step.  Alternative activation solutions such as silver nitrate are also effective from what I've read as well.  After allowing the palladium solution to dry onto the surface of the plastic 3D print, the samples were finally ready to be lowered into the plating solution.  I did not suspend the models due to a lack of space and simply dropped them to the bottom of the heated solution.

The reaction proceeded very vigorously and appeared to get very hot.  I question whether the plating solution may be going out of control (thermal overrun) and precipitating all the nickel out of solution--the plating solution should theoretically be reusable over many cycles by plating only the catalytically activated surface of the 3D printed model that is lowered into solution.  This is something that will need to be examined more closely in the future.

Surface prep is key to a quality finish

Regardless, the 3D printed plastic models were allowed to plate for about an hour before being removed from the plating solution--revealing a rather lustrous and durable silver-colored metallic finish.  The texture of the model surface appears to be accentuated by the nickel coating and it seems that very smooth surfaces do not coat well (due to the metal plating being a mechanically-bonded material interaction / see owl in above photo) and may need to be roughened up or chemically etched to enhance nickel's adherence.  The nickel plated 3D prints feel very metallic (as should be expected) and look great too.  All-in-all, the electroless plating process shows a lot of potential for further optimization and application toward further surface treatment steps, such as chrome plating and more.

Wednesday, August 21, 2013

3D Printed Jewelry: Part Deux

I've deviated slightly from my original plan to print a pair of sunglasses, but I had a sudden inspiration to make another set of earrings (I still have lots of earring loops and parts to make several set pairs).  The latest design is also quite a step up in complexity from the previous simple "teardrop" shape covered in the previous post but was still fun to put together in 3D.

Official SC2 Tempest model

FastMatt's Tempest-inspired model design

The design and shape was loosely inspired from the Tempest flying unit in SC2 and because it was loosely inspired I took liberties in simplifying and generalizing the design for the intended application as a wearable earring.  Most notably, the tail end of the earring has a hollow post to inset an earring loop connection.  Additionally, the front of the earring also has a loop physically built into the design with the intention of hanging an as-of-yet-undecided "dangling model" representing a ball of lightning / energy.  The design is slightly modular in this sense.  

3 copies, 1 extra "just in case"

Two iterations were required, the first was scaled slightly too small causing some of the details and features to be lost due to the frailty of the miniature printed part.  The earrings were scaled up in size by about 25% and have come out nicely.  Both iterations (5 earrings in total) also had no failures as well which was really great.  The high print yield of the Form 1 is much appreciated.

Freshly-printed models on the build platform

The earrings will be extracted from their supports and attached to loops and after designing a 3D "energy ball"--that will be attached to the physical loop as well to yield the completed product.  The next issue will be to figure out what to do with the earrings (I'm no fashion model)...

Friday, August 9, 2013

Jewelry For The Masses

Nordstrom exclusive Lucite® earrings

As mentioned in the previous post, a friend recently inquired as to whether I could make some 3D printed jewelry--with the answer being, of course!  I received a link to a pair of earrings sold by Nordstrom--a set of Lucite® (aka Plexiglas®) earrings in the shape of an abstract teardrop, along with a request to replicate the design if possible.  Not being one to pass up a fun challenge, I accept the request and began the reproduction process.

Crude measurements

Without having a physical set of the earrings in front of me to accurately measure dimensions, I roughly gauged the earring's length based off a guesstimate of the length of the model's ear in the photo above and came up with a value of ~50 mm.  Thereafter, the first steps were to obtain the rough dimensional constraints of the teardrop shape (as seen above) so that everything could be drawn to scale in the CAD software.  Drawing the model in CAD was a learning process and took several iterative attempts to recreate the curved surfaces properly.  Once the general teardrop shape was created, a plan had to be devised with regard to how an earring loop would be attached to the top of the earring--in addition to needing to buy the earring "metal bits" as well.  This required making a trip to a local DIY jewelry craft shop, Fusion Beads, here in Seattle.  The trip was an interesting experience, and a little awkward as I had no idea was I looking for other than to describe the desired pieces as "metal earring bits that go through the ear," which I later learned are simply called "earring loops" which I properly referred to earlier.  After picking up the necessary supplies I discovered that the small eyelets that would inset into the teardrop had extremely narrow metal driving rods (~0.6 mm in diameter).  As far as I could recall, drill bits smaller than 1 mm in diameter don't practically exist.

However, instead of drilling into the top of the earring, the hole could simply be drawn into the CAD drawing and printed without requiring any modification.  Getting the holes to print properly required several iterations of changing the hole diameter and earring wall thickness.  A related minor issue that had to be overcome was that the 3D printed earrings had very small hole features which would fill with resin during printing and wouldn't get properly flushed out when cleaning the completed prints.  This proved to cause problems when trying to insert the eyelets into the earring bodies.

Freshly printed on the build platform

Regardless, after several trials, the earrings were successfully printed and the eyelets were inserted.  To prevent the eyelets from backing out, the driving rods of the eyelets were dipped in liquid resin, inserted into the earring body, and then the liquid resin was cured with a 405nm UV laser pointer which I happened to have laying around.  This method of sealing parts by manually curing the liquid resin with a handheld laser appears to be really effective.

Job complete

FastMatt exclusive Plastiq® earrings

Finally, the earrings were attached to earring loops and project was declared to be successfully completed.  Hopefully the future owner will get some good mileage out of them.

Freshly printed with supports

Freshly sanded

Also as mentioned previously, the full-scale Möbius bracelet was also completed, lightly sanded, and delivered to its happy new owner.

Hand delivering the goods

It seems like more 3D printed jewelry and accessories may be on the horizon in the future.  I recently designed a pair of sunglasses (on paper) and I'm thinking about fleshing out that project by prototyping a set if I can find the time.  Hopefully that will be one the next projects that I feature.