Injection Molding IPhone Cases From Trash

February 7, 2018 by Tom Nardi 27 Comments

We imagine you’ve heard this already, but waste plastic is a problem for the environment. We wrap nearly everything we buy, eat, or drink in plastic packaging, and yet very little of it ends up getting recycled. Worse, it doesn’t take a huge industrial process to melt down a lot of this plastic and reuse it, you can do it at home if you were so inclined. So why aren’t there more localized projects to turn all this plastic trash into usable items?

That the question that [Precious Plastic] asks, and by providing a centralized resource for individuals and communities looking to get into the plastic recycling game, they hope to put a dent in the worldwide plastic crisis. One of their latest projects is showing how plastic trash can be turned into functional iPhone cases with small-scale injection molding.

The video after the break goes into intricate detail about the process involved in creating the 3D CAD files necessary to make the injection molds. Even if you don’t plan on recycling milk jugs at home, the information and tips covered in the video are extremely helpful if you’ve ever contemplated having something injection molded. The video even demonstrates a neat feature in SolidWorks that lets you simulate how molten plastic will move through your mold to help check for problem areas.

Once you’ve designed your mold on the computer, you need to turn it into a physical object. If you’ve got a CNC capable of milling aluminum then you’re all set, but if not, you’ll need to outsource it. [Precious Plastic] found somebody to mill the molds through 3DHubs, though they mention in the video that asking around at local machine shops isn’t a bad idea either.

With the mold completed, all that’s left is to bolt the two sides together and inject the liquid plastic. Here [Precious Plastic] shows off a rather interesting approach where they attach the mold to a contraption that allows them to inject plastic with human power. Probably not something you’d want to do if you’re trying to make thousands of these cases, but it does show that you don’t necessarily need a high tech production facility to make good-looking injection molded parts.

This project reminds us of the tiles made of HDPE plastic with nothing more exotic than what you’d find in the average kitchen. Projects like these really drive home the idea that with the right hardware individuals can turn trash into usable products.

Continue reading “Injection Molding IPhone Cases From Trash” →

Make A Better, Spring-Loaded SMT Tape Strip Holder

January 19, 2018 by Donald Papp 6 Comments

Every so often, a project is worth some extra work to see if the idea can go any further. [JohnSL] has been busy doing exactly that with his spring-loaded SMT tape holder project. Having done the original with 3D printing, he has been working on designing for injection molding. This isn’t a motorized feeder, it’s still a manual tool but it is an improvement over the usual workshop expedient method of just sticking segments of tape down to the desktop. Tape is fed into the holders from one end and spring tension holds the tape firm while a small slot allows the cover tape to be guided backward after peeling. As anyone who has used cut segments of tape to manually deal with SMT parts knows, small vibrations — like those that come from peeling off the clear cover — can cause the smaller components to jump around and out of their pockets, and any length of peeled cover gets awkward quickly.

The design allows for multiple holders to mount side-by-side.

In [JohnSL]’s design, all SMT tapes sit at an even height regardless of size or tape thickness. A central support pushes up from the bottom with tension coming from a spring pulling sideways; the central support is forced upward by cams and presses against the bottom surface of the tape. As a result, the SMT tape gets supported from below with even tension and the whole assembly maintains a narrow profile suitable for stacking multiple holders side by side. The CAD files are available online along with a McMaster-Carr part number for the specific spring he used.

After working out the kinks on 3D printed prototypes, [JohnSL] decided to see if it would be feasible to design an injection molded version and made a video outlining the process, embedded below.

Continue reading “Make A Better, Spring-Loaded SMT Tape Strip Holder” →

DIY Injection Mold Design For The Home Shop

November 11, 2017 by Dan Maloney 30 Comments

3D printing is great for prototyping, and not bad for limited runs of parts. Unfortunately though it really doesn’t scale well beyond a few pieces, so when you’re ready for the mass market you will need to think about injection molding your parts. But something like that has to be farmed out, right? Maybe not, if you know a thing or two about designing your own injection molds.

The video below comes from [Dave Hakkens] by way of his Precious Plastic project, whose mission it is to put the means of plastic recycling into the hands of individuals, rather than relying on municipal programs. We’ve covered their work before, and it looks like they’ve come quite a way to realizing that dream. This tutorial by [Dave]’s colleague [Jerry] covers the basic elements of injection mold design, starting with 3D modeling in Solidworks. [Jerry] points out the limitations of a DIY injection molding effort, including how the thickness of parts relates to injection pressure. Also important are features like gentle curves to reduce machining effort, leaving proper draft angles on sprues, and designing the part to ease release from the mold. [Jerry] and [Dave] farmed out the machining of this mold, but there’s no reason a fairly complex mold couldn’t be produced by the home gamer.

When you’re done learning about mold design, you’ll be itching to build your own injection mold machine. Precious Plastic’s tutorial looks dead simple, but this machine looks a little more capable. And why CNC your molds when you can just 3D print them?

Continue reading “DIY Injection Mold Design For The Home Shop” →

Designing Products With Injection Molding In Mind

June 5, 2017 by Bob Baddeley 18 Comments

3D printing is a technique we’ve all been using for ages at home, or via Shapeways, but if you are designing a product, 3D printing will only get you so far. It’s crude, slow, expensive, and has lots of limitations. While it’s great for the prototyping stage, ultimately products manufactured in volume will be manufactured using another method, and most likely it will be injection molding. Knowing how to design a part for injection molding means you can start prototyping with 3D printing, confident that you’ll be able to move to a mold without major changes to the design.

The 2017 Hackaday Prize includes a $30,000 prize for Best Product as we seek products that not only show a great idea, but are designed for manufacturing and have thought through what it takes to get them into the hands of the users. Some of the entries seem to be keenly aware of the challenges associated with moving from prototyping to production. Here are some examples of best practices when prototyping with future injection molding in mind.

Continue reading “Designing Products With Injection Molding In Mind” →

Hackaday Links: March 19, 2017

March 19, 2017 by Brian Benchoff 6 Comments

This is from the Daily Fail, but a working Apple I is going up on the auction block. It’s expected to bring in $317,693 USD. In other news, we’re going to be at the Vintage Computer Festival East at the end of the month. There is usually an Apple I there.

The most popular crowdfunding campaign of the month is Lego tape. It’s an adhesive-backed tape with studs on the top, allowing you to clip Lego pieces into place. How easy would this be to create at home? It’s really just a silicon mold and some 3M stickytape. Anyone up for a home casting challenge?

You guys know the Hackaday Overlords have a Design Lab, right? What’s a Design Lab? It’s a place filled with tools where we allow residents to come in for free, build stuff, give them training, and let them keep all their IP. It’s like a hardware accelerator, but focused on Open Source hardware. It is our gift to the community and we ask nothing in return. But that’s not important right now. We’re doing shots.

2017 will be the first year Maker Faire will have three flagship faires. New York is a given, as is the Bay Area. and A few weeks ago, Chicago grabbed the third flagship faire. If you’ve already bought tickets and scheduled your trip, terrible news: the Chicago Maker Faire has been postponed until late fall.

Flip clocks are cool. What’s a flip clock? The clock in Groundhog Day, or a bunch of flaps, gears, and a synchronous motor that displays the time. You know what’s not cool about flip clocks? They’re usually stuffed in horrible 70s plastic enclosures painted Harvest Gold or Avacado. [bentanme] found a flip clock and stuffed it in a glass jar. It’s kept in place by a few 3D printed parts that ingeniously keep the clock from moving around while still allowing you to see the gears. Neat.

Tools Of The Trade — Injection Molding

November 4, 2016 by Bob Baddeley 34 Comments

Having finished the Tools of the Trade series on circuit board assembly, let’s look at some of the common methods for doing enclosures. First, and possibly the most common, is injection molding. This is the process of taking hot plastic, squirting it through a small hole and into a cavity, letting it cool, and then removing the hardened plastic formed in the shape of the cavity.

The machine itself has three major parts; the hopper, the screw, and the mold. The hopper is where the plastic pellets are dumped in. These pellets are tiny flecks of plastic, and if the product is to be colored there will be colorant pellets added at some ratio. The hopper will also usually have a dehumidifier attached to it to remove as much water from the pellets as possible. Water screws up the process because it vaporizes and creates little air bubbles.

Next the plastic flecks go into one end of the screw. The screw’s job is to turn slowly, forcing the plastic into ever smaller channels as it goes through a heating element, mixing the melted plastic with the colorant and getting consistent coloring, temperature, and ever increasing pressure. By the time the plastic is coming out the other end of the screw, and with the assistance of a hydraulic jack, it can be at hundreds of tons of pressure.

Finally, the plastic enters the mold, where it flows through channels into the empty cavity, and allowed to sit briefly to cool. The mold then separates and ejector pins push the part out of the cavity.

Continue reading “Tools Of The Trade — Injection Molding” →

Hackaday Retro Edition: A New Commodore 64 Case

March 11, 2015 by Brian Benchoff 73 Comments

Some time in the 80s, the plastic injection molds for the Commodore 64C, the Commodore 128, and the Plus/4 were shipped from somewhere in Asia to the great Commodore Mother Brain in West Chester, Pennsylvania. These molds had already produced a million or two cases, but there were some issues with production – too much waste, or something like that. A mechanical engineer took a look at the molds, sent out some recommendations, and moved the 2500 pound molds to a corner of the building.

For some time after a gray day in April, 1994 these molds sat in a West Chester, Pennsylvania warehouse until they were sold off. They made their way to a plastics manufacturer around Dallas, Texas where they sat for twenty years. All things must pass, sometimes several times, and this plastics manufacturer closed down, contacted an auctioneer, and began to sell off some of their equipment.

The hero of our story, [Dallas Moore], owns a small business, buying and selling everything from Barbie dolls to antiques. He found an ad for an auction at a plastics manufacturing plant in the newspaper, and figuring he could find something interesting, headed out to the auction preview.

The auctioneer at this liquidation sale asked [Dallas] what he did, and mentioned there was something pretty cool tucked away in a warehouse full of hardened steel molds. Something about molds for old computers. These were the molds for the Commodore 64C, Commodore 128, and the Commodore Plus/4. A literal crucible of computing history, stacked on a pallet and up for sale.

The auctioneer said one of his friends was interested in the molds, and thought they would make a neat coffee table. Something about this struck [Dallas] the wrong way and for the entire drive home he thought about someone taking history and turning it in to a piece of furniture. He decided to buy these molds and lugged the three 2500 pound pieces of hardened steel to his shop. Not wanting to let a good piece of history go to waste, he contacted another plastics manufacturer, planned a run of a thousand or so Commodore 64C cases in red, white, and blue. [Dallas] is funding the whole production run through Kickstarter.

To me, this is one of the greatest retrocomputing successes in recent memory. There will always be someone putting SD cards in old computers, getting them on the Internet (and especially pointed towards our retro edition), and cloning complete systems in FPGAs. This, though, is a clear example of someone recognizing the historical importance of several thousand pounds of steel, realizing there’s a market out there, and doing the leg work to remanufacture these pieces of history.

I put in my $45 for a red one, and I tipped off [Bil Herd], designer of the C128 and Plus/4, to this Kickstarter. He’s been talking with [Dallas], there I’m sure he’ll chime in on the comments with some retellings of Commodore battle stories.

If it arrives in time, I’ll be bringing my limited-edition red 64C case to the Vintage Computer Festival in Wall, NJ April 17-19. That’s a plug for the event. If you’re in the area, you should come.

EDIT: [Dallas] has a different story of where the molds came from.