High Voltage, Wood And Resin Result In Fractal Art

Wood burning, which goes by pyrography when it’s feeling fancy, has been an art form for centuries. [PapaJ06] puts a new twist on it by using a microwave oven transformer to generate fractal patterns in wood. We’ve seen these Lichtenberg figures before, but generally as electric discharges in acrylic sheets or crystal balls using multi-mega-electron volt accelerators. [PapaJ06]’s technique is considerably simpler and well within the reach of most would-be fractal artists, relying as it does on a transformer salvaged from a $20 Craigslist microwave.

But the extra twist that really brings the wow factor to the fractal patterns burned into the wood is the addition of some phosphorescent resin to fill the valleys carved by the electric discharge. [PapaJ06] carefully prepares the wood, fills the burns with glow powder mixed with epoxy resin, and finishes with a little sanding, linseed oil and polyurethane. The contrast between the charred and intact wood, and the way the resin fills the voids really brings out the fractal nature of the Lichtenberg figures.

[PapaJ06] doesn’t really show us too much about his process, but luckily [TheBackyardScientist] recently posted a video of his process for riding the lightning. Check it out after the break.

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The countertop in its natrual habitat: a van.

Cotton-Fiberglass Composite Makes Lightweight RV Countertops

You’ve seen fiber-reinforced-plastic before, no doubt, but perhaps never quite like in this video by [Whitburn Studio]: it’s still got the usual resin, but instead of glass or carbon fibers, he’s using printed Japanese cotton to create strong, lightweight and good looking parts for the interior of his RV– specifically the countertops.

The technique is very similar to the sort of moldless composite work Burt Rutan pioneered in aircraft use. The fiber-reinforced plastic is formed around a positive ‘buck’ that remains inside the final part, adding stiffness and some backing. Unlike Rutan’s designs, which used pure Styrofoam inside, [Whitburn] is using a sandwhich of two layers of thin ply (3.6 mm) with XPS foam in between. Adding plywood means you don’t need many layers of fiber– again, that’s a decorative cotton, here– to get a surface that won’t dent into the styrofoam when you drop a coffee cup on it.

Indeed, with the plywood providing much of the strength, he’s only using a single layer of cotton and a second of fiberglass– though the glass fibers are really there to protect the pretty print from oopsies while sanding, rather than for their mechanical properties, by the sounds of it. Everything is held together with clear epoxy resin, which also fills the weave of the fabrics. Multiple coats of that are required to get the smooth, shiny surface he shows off at the end, but all that sanding and buffing really pays off. That’s also where you have to be really careful to avoid oopsies– go through the cotton and you have to start over.

Aside from the aesthetics, since this is going in a vehicle the weight is an important consideration– the bigger of the two counters he makes, pictured here, weighs in at only 2.4 kg or 5.2 lb including the cutout covering the sink. That’s pretty good all things considered– a lot lighter than a cement countertop, or even one made of DIY resin tiles.

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Printing An Underwater Diving Helmet With Floating Air Supply

Old-school diving helmets are deceivingly simple, even if they are – as [Hyperspace Pirate] puts it in a recent video – essentially the equivalent of an upside-down bucket with an air hose supplying air into it. While working on a 3D-printed diving helmet, he therefore made sure to run through all the requisite calculations prior to testing out said diving helmet in his pool.

The 3D model for the diving helmet can be found over at Thingiverse if you too feel like getting wet, just make sure that you size it to fit your own head. In the video CAD (cardboard-aided design) was used to determine the rough bounding box for the head, but everyone’s head is of course different. The helmet was printed in ABS, with the sections glued together before being covered in fiberglass and epoxy resin. Note that polyester resin dissolves ABS, so don’t use that.

On the helmet is a 1/4″ SAE fitting for the air hose, with the air provided from an oil-less compressor that in the final iteration is strapped to a floatation device along with an inverter and batteries. Of note is that you do not want to use a gas-powered compressor, as it’ll happily use any CO2 and CO it exhausts to send down the air hose to your lungs. This would be bad, much as having vaporized oil ending up in your lungs would be bad.

Although in the video the system is only tested in a backyard pool, it should be able to handle depths of up to ten meters, assuming the compressor can supply at least 41 L/minute. With some compressor-side miniaturization and waterproofing, [Hyperspace Pirate] reckons it would work fine for some actual ocean exploration, which while we’re sure everyone is dying to see. Perhaps don’t try this one at home, kids.

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I, Integrated Circuit

In 1958, the American free-market economist Leonard E Read published his famous essay I, Pencil, in which he made his point about the interconnected nature of free market economics by following everything, and we mean Everything, that went into the manufacture of the humble writing instrument.

I thought about the essay last week when I wrote a piece about a new Chinese microcontroller with an integrated driver for small motors, because a commenter asked me why I was featuring a non-American part. As a Brit I remarked that it would look a bit silly were I were to only feature parts made in dear old Blighty — yes, we do still make some semiconductors! — and it made more sense to feature cool parts wherever I found them. But it left me musing about the nature of semiconductors, and whether it’s possible for any of them to truly only come from one country. So here follows a much more functional I, Chip than Read’s original, trying to work out just where your integrated circuit really comes from. It almost certainly takes great liberties with the details of the processes involved, but the countries of manufacture and extraction are accurate. Continue reading “I, Integrated Circuit”

Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

Does Carbon Fiber PLA Make Sense?

Carbon fiber (CF) has attained somewhat of a near-mystical appeal in consumer marketing, with it being praised for being stronger than steel while simultaneously being extremely lightweight. This mostly refers to weaved fibers combined with resin into a composite material that is used for everything from car bodies to bike frames. This CF look is so sexy that the typical carbon-fiber composite weave pattern and coloring have been added to products as a purely cosmetic accent.

More recently, chopped carbon fiber (CCF) has been added to the thermoplastics we extrude from our 3D printers. Despite lacking clear evidence of this providing material improvements, the same kind of mysticism persists here as well. Even as evidence emerges of poor integration of these chopped fibers into the thermoplastic matrix, the marketing claims continue unabated.

As with most things, there’s a right way and a wrong way to do it. A recent paper by Sameh Dabees et al. in Composites for example covered the CF surface modifications required for thermoplastic integration with CF.

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Repairing Brittle Plastic Retro Computer Cases

Using UV resin as glue for new case clips. (Credit: More Fun Making It, YouTube)
Using UV resin as glue for new case clips. (Credit: More Fun Making It, YouTube)

As computers like the venerable breadbox Commodore 64 age, their plastic doesn’t just turn increasing shades of yellow and brown, the ABS plastic also tends to get brittle. This is a problem that seems to plague many plastic cases and enclosures, but fortunately there are some ways to halt or even reverse the heavy toll of time, with the [More Fun Making It] YouTube channel exploring a number of methods, including UV-curable resin, PETG 3D-printed clips and silicone molds.

Aside from large-scale damage, screw posts tend to snap off a lot, either during shipping or when merely trying to open the case. The same is true for the clips around the edge of the C64 case, which rarely survive that long. Gluing a case clip back on with epoxy or such somewhat works, but is messy and not that durable.

Instead UV resin is used, together with newly printed clips in translucent PETG. The remnants of the old clips are removed, followed by the application of the resin. The clips are actually a modified version of a VIC-20 case clip design by [Ken Mills]. With the UV resin as glue, curing is almost instant with a UV lamp unlike the tedious process with epoxy.

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Pause Print, Add Hardware, And Enjoy Strength

3D Printing is great, but it is pretty much the worst way to make any given part– except that every other technique you could use to make that part is too slow and/or expensive, making the 3D print the best option. If only the prints were stiffer, stronger, more durable! [JanTech Engineering] feels your plight and has been hacking away with the M601 command to try embedding different sorts of hardware into his prints for up to 10x greater strength, as seen in the video embedded below.

It’s kind of a no-brainer, isn’t it? If the plastic is the weak point, maybe we could reinforce the plastic. Most concrete you see these days has rebar in it, and fiber-reinforced plastic is the only way most people will use resin for structural applications. So, how about FDM? Our printers have that handy M601 “pause print” command built in. By creatively building voids into your parts that you can add stronger materials, you get the best of all possible worlds: the exact 3D printed shape you wanted, plus the stiffness of, say, a pulltruded carbon-fiber rod.

[JanTech] examines several possible inserts, including the aforementioned carbon rods. He takes a second look at urethane foam, which we recently examined, and compares it with less-crushable sand, which might be a good choice when strength-to-weight isn’t an issue. He doesn’t try concrete mix, but we’ve seen that before, too. Various metal shapes are suggested — there are all sorts of brackets and bolts and baubles that can fit into your prints depending on their size — but the carbon rods do come out ahead on strength-to-weight, to nobody’s surprise.

You could do a forged carbon part with a printed mold to get that carbon stiffness, sure, but that’s more work, and you’ve got to handle epoxy resins that some of us have become sensitized to. Carbon rods and tubes are cheap and safer to work with, though be careful cutting them.

Finally, he tries machining custom metal insets with his CNC machine. It’s an interesting technique that’s hugely customizable, but it does require you to have a decent CNC available, and, at that point, you might want to just machine the part. Still, it’s an interesting hybrid technique we haven’t seen before.

Shoving stuff into 3D-printed plastic to make it a better composite object is a great idea and a time-honored tradition. What do you put into your prints? We’d love to know, and so would [Jan]. Leave a comment and let us know.

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