From Fail To Wail: Guitar Picks Made From 3D Printed Waste

Between failed prints and iterative designs that need a few attempts before you nail them down, a certain amount of wasted material is essentially unavoidable when 3D printing. The good news is that PLA is a bioplastic and can be broken down via industrial composting, but even still, any method that allows you to reuse this material at home is worth taking a look at.

In a recent video, [Noah Zeck] details one potential use for your scrap plastic by turning his failed 3D prints into guitar picks. The idea here could really be applied to anything you can make out of thin plastic sheeting, but the fact that you can easily and cheaply produce picks with a commercially available punch makes this application particularly appealing.

The first step in this process is about as low-tech as it gets: wrap your scrap printed parts in rags, and beat them with a sledge hammer. This breaks them up into smaller and more manageable pieces, which is important for the next step. If the parts are small enough and you’ve got a decently powerful blender you don’t mind devoting to plastic recycling, we imagine that would make short work of this step as well.

Once suitably pulverized, [Noah] puts the plastic on a piece of glass and gets it warmed up with a heat gun. PLA has a fairly low glass transition temperature, so it shouldn’t take much time to soften. Then he puts a second piece of glass on top and squeezes them together to get a thin, flat sheet of plastic. Once cooled, he punches his guitar picks out of the sheet, with bonus points if the colors swirled around into interesting patterns. If you’re not musically inclined, we’ve seen a very similar method used to produce colorful floor tiles.

Continue reading “From Fail To Wail: Guitar Picks Made From 3D Printed Waste”

Hacking Broken Plastic Parts Without A 3D Printer

We’ve all encountered the odd plastic part that is broken and unobtainable. Sure, 3D printers can print big replacement parts, but sometimes you just need to rebuild a very specific piece. [AkBkukU] shows off a technique for doing just that using a process you could almost call manual 3D printing. We’ve seen baking soda used to cure cyanoacrylate glue before, but this technique uses it to build layers of glue that are apparently quite solid.

There’s quite a bit of nuance in the video below, but the basic idea is to put a pile of soda on one side of a piece of tin foil and a glob of glue. You dip the part in glue and then into the soda. Each time you get a little thicker layer of glue.

Afterward, you’ll have to file and otherwise shape the new part, but the fact that it can survive being filed should tell you something. We were reminded of how some people use epoxy to form repair parts and then machine them to the exact shape needed. At the very end of the video he builds up layers on a part he can’t dip. Did it work? Watch it and see.

In addition to the manual 3D printing technique, he demonstrates using baking soda to cure repairs on a knurled knob from an old clock radio. That’s a bit more conventional, but if you haven’t seen it done before, it is nearly miraculous.

Glue is amazing. We’ve seen hot glue do injection molding. There are many more types out there, too.

Continue reading “Hacking Broken Plastic Parts Without A 3D Printer”

CNC Machine Rolls Up An Axis To Machine PVC Pipe

Whether it’s wood, metal, plastic, or otherwise, when it comes to obtaining materials for your builds, you have two choices: buy new stock, or scrounge what you can. Fresh virgin materials are often easier to work with, but it’s satisfying to get useful stock from unexpected sources.

This CNC router for PVC pipe is a great example of harvesting materials from an unusual source. [Christophe Machet] undertook his “Pipeline Project” specifically to explore what can be made from large-diameter PVC pipe, of the type commonly used for sewers and other drains. It’s basically a standard – albeit large-format – three-axis CNC router with one axis wrapped into a cylinder. The pipe is slipped around a sacrificial mandrel and loaded into the machine, where it rotates under what looks like a piece of truss from an antenna tower. The spindle seems a bit small, but it obviously gets the job done; luckily the truss has the strength and stiffness to carry a much bigger spindle if that becomes necessary in the future.

The video below shows the machine carving up parts for some lovely chairs. [Christophe] tells us that some manual post-forming with a heat gun is required for features like the arms of the chairs, but we could see automating that step too. We like the look of the pieces that come off this machine, and how [Christophe] saw a way to adapt one axis for cylindrical work. He submitted this project for the 2019 Hackaday Prize; have you submitted your entry yet?

Continue reading “CNC Machine Rolls Up An Axis To Machine PVC Pipe”

Repurposed Plastic Protects PCBs

An errant wire snipping across the wrong electrical pins spells the release of your magic smoke. Even if you are lucky, stray parts are the root of boundless malfunctions from disruptive to deadly. [TheRainHarvester] shares his trick for covering an Arduino Nano with some scrap plastic most of us have sitting in the recycling bin. The video is also after the break. He calls this potting, but we would argue it is a custom-made cover.

The hack is to cut a bit of plastic from food container lids, often HDPE or plastic #2. Trim a piece of it a tad larger than your unprotected board, and find a way to hold it in place so you can blast it with a heat gun. When we try this at one of our Hackaday remote labs and apply a dab of hot glue between the board and some green plastic it works well. The video suggests a metal jig which would be logical when making more than one. YouTube commenter and tip submitter [Keith o] suggests a vacuum former for a tighter fit, and we wouldn’t mind seeing custom window cutouts for access to critical board segments such as DIP switches or trimmers.

We understand why shorted wires are a problem, especially when you daisy-chain three power supplies as happened in one of [TheRainHarvester]’s previous videos.

Continue reading “Repurposed Plastic Protects PCBs”

Innovative Bird Feeder Design Recycles Recycling’s Garbage

Recycling beverage cartons isn’t 100% efficient. The process yields some unusable garbage as a byproduct. Why? Because containers like juice boxes are mostly paper, but also contain plastic and aluminum. The recycling process recovers the paper fibers for re-use, but what’s left after that is a mixture of plastic rejects and other bits that aren’t good for anything other than an incinerator or a landfill. Until now, anyway!

It turns out it is in fact possible to turn such reject material into a product that can be injection-molded, as shown here with [Stefan Lugtigheid]’s SAM bird feeder design. The feeder is not just made from 100% recycled materials, it’s made from the garbageĀ of the recycling process — material that would otherwise be considered worthless. Even better, the feeder design has only the one piece. The two halves are identical, which reduces part count and simplifies assembly.

[Stefan] makes it clear that the process isn’t without its quirks. Just because it can be injection-molded doesn’t mean it works or acts the same as regular plastic. Nevertheless, the SAM birdfeeder demonstrates that it can definitely be put to practical use. We’ve seen creative reprocessing of PET bottles and sheet stock made from 3D printed trash, but recycling the garbage that comes from recycling drink cartons is some next-level stuff, for sure.

Making Microfluidics Simpler With Shrinky Dinks

It’s as if the go-to analogy these days for anything technical is, “It’s like a series of tubes.” Explanations thus based work better for some things than others, and even when the comparison is apt from a physics standpoint it often breaks down in the details. With microfluidics, the analogy is perfect because it literally is a series of tubes, which properly arranged and filled with liquids or gasses can perform some of the same control functions that electronics can, and some that it can’t.

But exploring microfluidics can be tough, what with the need to machine tiny passages for fluids to flow. Luckily, [Justin] has turned the process into child’s play with these microfluidic elements made from Shrinky Dinks. For those unfamiliar with this product, which was advertised incessantly on Saturday morning cartoon shows, Shrinky Dinks are just sheets of polystyrene film that can be decorated with markers. When placed in a low oven, the film shrinks about three times in length and width while expanding to about nine times its pre-shrunk thickness. [Justin] capitalized on this by CNC machining fine grooves into the film which become deeper after shrinking. Microfluidics circuits can be built up from multiple layers. The video below shows a mixer and a simple cell sorter, as well as a Tesla valve, which is a little like a diode.

We find [Justin]’s Shrinky Dink microfluidics intriguing and can’t wait to see what kind of useful devices he comes up with. He’s got a lot going on, though, from spider-powered beer to desktop radio telescopes. And we wonder how this technique might help with his CNC-machined microstrip bandpass filters.

Continue reading “Making Microfluidics Simpler With Shrinky Dinks”

Plastics: Acrylic

If anything ends up on the beds of hobbyist-grade laser cutters more often than birch plywood, it’s probably sheets of acrylic. There’s something strangely satisfying about watching a laser beam trace over a sheet of the crystal-clear stuff, vaporizing a hairs-breadth line while it goes, and (hopefully) leaving a flame-polished cut in its wake.

Acrylic, more properly known as poly(methyl methacrylate) or PMMA, is a wonder material that helped win a war before being developed for peacetime use. It has some interesting chemistry and properties that position it well for use in the home shop as everything from simple enclosures to laser-cut parts like gears and sprockets.

Continue reading “Plastics: Acrylic”