Hacker Straightens Own Teeth

So you say your wonky smile has you feeling a bit self-conscious? And that your parents didn’t sock away a king’s ransom for orthodontia? Well, if you have access to some fairly common fab-lab tools, and you have the guts to experiment on yourself, why not try hacking your smile with DIY braces?

First of all: just – don’t. Really. But if you’re curious about how [Amos Dudley] open-sourced his face, this is one to sink your teeth into. A little research showed [Amos] how conventional “invisible” braces work: a 3D model is made of your mouth, each tooth is isolated in the model, and a route from the current position to the desired position is plotted. Clear plastic trays that exert forces on the teeth are then 3D printed, and after a few months of nudging teeth around, you’ve got a new smile. [Amos] replicated this hideously expensive process by creating a cast of his teeth, laser scanning it, manipulating the teeth in 3D modeling software, and 3D printing a series of intermediate choppers. The prints were used to vacuum mold clear plastic trays, and with a little Dremel action they were ready to wear. After 16 weeks of night and day wear, the results are pretty amazing – a nicely aligned smile, and whiter teeth to boot, since the braces make great whitening trays.

Considering how badly this could have turned out, we’ve got to hand it to [Amos] for having the guts to try this. And maybe he’s onto something – after all, we’ve advocated for preemptive 3D scanning of our bodies recently, and what [Amos] did with this hack is a step beyond that.

[LupusMechanicus], thanks for the tip!

Machine Shop Soaps Are Good, Clean Learning Fun

At first glance, it’s easy to dismiss the creation of custom bath soaps as far outside the usual Hackaday subject matter, and we fully expect a torrent of “not a hack” derision in the comments. But to be able to build something from nothing, a hacker needs to be able to learn something from nothing, and there is plenty to learn from this hack.

On the face of it, [Gord] is just making kitschy custom bath soaps for branding and promotion. Cool soaps, to be sure, and the drop or two of motor oil and cutting fluid added to each batch give them a little machine shop flair. [Gord] experimented with different dyes and additives over multiple batches to come up with a soap that looked like machined aluminum; it turns out, though, that adding actual aluminum to a mixture containing lye is not a good idea. Inadvertent chemical reactions excepted, [Gord]’s soaps and custom wrappers came out great.

So where’s the hack? In stepping way outside his comfort zone of machining and metalwork, [Gord] exposed himself to new materials, new techniques, and new failure modes. He taught himself the basics of mold making and casting, how to deal with ultra-soft materials, the chemistry of the soap-making process, working out packaging and labeling issues, and how to deal with the problems that come from scaling up from prototype to production. It may have been “just soap”, but hacks favor the prepared mind.

Fail of the Week: Not All Mold Releases Release All Molds.

I’m writing a series of articles on resin casting as an extension to my experiences with the instructions found in the wonderful Guerrilla Guide. However, mistakes were made. Having run out of my usual mold release I went to a back-up jar that was lying around from a casting project long, long ago in a workshop far, far away.

Never much for readin’ the nutrition facts myself.

I’m refining a technique of making a mold the quick and dirty way. Everything was going well, the sprues looked good and the master released from the silicone. It was time to do the second half of the mold. As usual I applied a generous amount of mold release. Since it was the first time this mold was to be used I went ahead and did all the proper steps. Rubbing off the dried release and applying a few more coats just to be sure.

I was completely unaware that I was applying mold release designed for urethane molds only. In other words I thoroughly covered my silicone mold in silicone bonding agents. I remained unaware until trying to separate the halves of the mold and found them thoroughly joined. After going through the stages of grief I finally figured out where it all went wrong.

Oh well. I’m ordering some of my regular pick, Stoner A324, and that should do the trick. There’s also Mann- Ease Release 200. While having probably the best name a release agent can have, it doesn’t work as well and needs approximately 100 years to dry. After this setback I’d rather just, grudgingly, learn my lesson and order the correct thing.

I wonder if the smooth-on description can say URETHANE RUBBER a few more times.
Oh. Yes I see. Urethane… Urethane…

So now that we know the right way to fix this is to order the right product, is there a hack to get around it? Does anyone have a homebrew trick for release agent that can be used in a pinch? Leave your comments below.

An Introduction to Casting With Nuka Cola

There’s less than a month until the next Star Wars is released, and consequently a few weeks until amateur propmakers and cosplayers go insane fabricating their own lightsabers with lightsaber cross guards and rolling robots. Until then, Fallout is pretty cool and [Bill] is here to give us an introduction to prop making with one of the defining objects of this post-apocalyptic universe. He created a real life copy of a Nuka Cola bottle and created a great introduction to resin casting in the process.

As with all proper part making endeavours, this project began with getting reasonably accurate models of the object to be copied. In Fallout, we’re lucky enough to have a way to look at a specific object while zooming and spinning around it, giving [Bill] the basic shape. The size was rather easy as well: all bottlecaps are the same size, so [Bill] just scaled the model to that.

With the model created and the part printed out, assembled, and finished, it was time to create the mold. [Bill] used a two-part silicone mold for the basic shape. The actual casting was done by rolling around a little resin on the inside of the mold. There’s no need for a solid, bottle-shaped block of resin; bottles are hollow anyway.

There are a few neat tricks [Bill] has up his sleeve, including coating the inside of the mold with aluminum powder and using a vinyl cutter to get the labels and logos exactly right. The finished product turns out great, perfect for leaving in the Wasteland for 200 years until the Sole Survivor stumbles upon it.

Video below.

Continue reading “An Introduction to Casting With Nuka Cola”

3D Printed Eyeglasses, VR Lenses

[Florian] is hyped for Google Cardboard, Oculus Rifts, and other head mounted displays, and with that comes an interest in lenses. [Floian] wanted to know if it was possible to create these lenses with a 3D printer. Why would anyone want to do this when these lenses can be had from dozens of online retailers for a few dollars? The phrase, ‘because I can’ comes to mind.

The starting point for the lens was a CAD model, a 3D printer, and silicone mold material. Clear casting resin fills the mold, cures, and turns into a translucent lens-shaped blob. This is the process of creating all lenses, and by finely sanding, polishing, and buffing this lens with grits ranging from 200 to 7000, this bit of resin slowly takes on an optically clear shine.

Do these lenses work? Yes, and [Florian] managed to build a head mounted display that can hold an iPhone up to his face for viewing 3D images and movies. The next goal is printing prescription glasses, and [Florian] seems very close to achieving that dream.

The last time we saw home lens making was more than a year ago. Is anyone else dabbling in this dark art? Let us know in the comments below and send in a tip if you have a favorite lens hack in mind.

Hackaday Links: August 2, 2015

Over the last few years, Maker’s Asylum in Mumbai has grown from a garage to a very well stocked workspace with 140 members. They’re getting kicked out at the end of the month and they need some help. We just had a meetup at the Delhi branch of Maker’s Asylum, and these guys and gals are really cool.

Speaking of crowdfunding campaigns for hackerspaces, South Central Pennsylvania might be getting its own hackerspace. The 717 area code is a vast wasteland when it comes to anything anyone reading Hackaday would consider interesting, despite there being plenty of people who know their way around CNC machines, soldering irons, and welders. This needs to happen.

Need some help with Bluetooth standards? Tektronix has you covered with a gigantic poster of the physical layer. If only there were a repository of these handy, convenient reference posters.

Forgings and castings make for great YouTube videos, and this aluminum bell casting is no exception. There’s about 18 pounds of aluminum in there, which is pretty large as far as home casting goes.

Electronic Goldmine has an assortment of grab bags – spend a few dollars get a bag of chips, LEDs, diodes, or what have you. What’s in these grab bags? [alpha_ninja] found out. There’s some neat stuff in there, except for the ‘SMD Mixture’ bag.

Remember the found case molds for the Commodore 64C that became a Kickstarter? It’s happening again with the Amiga 1200. This is a new mold with a few interesting features that support the amazing amount of upgrades that have come out for this machine over the years. Being new molds, the price per piece is a little high, but that’s your lesson in manufacturing costs for the day.

Building A 20 Inch Disk Sander

A small disk sander is a useful and cheap addition to the shop. For about $100, you can buy a cheap combination 6″ disk/belt sander that’s extremely useful. The size and cost of power tools does not scale linearly, and if you want a big disk sander you might as well make your own.

The motor for this build is a 1kW single phase motor pulled from a floor polisher found in the trash. That’s enough to push a sanding disk around, but when you get to tools this large, you need a good base, good tilt mechanism, and everything should be extremely heavy.

This build meets all those requirements while still using mostly recycled components. The work table is actually made of three pieces of recycled aluminum epoxied together. Yes, you should cringe at this, but it actually makes a little bit of sense: thinner pieces can be cut on a table saw, and if you’re extremely careful during the glue-up, you can cut the mitre slot without a mill. This frame attaches to a frame made from aluminum extrusion and filled with a homebrew epoxy granite mix. Remember, heavy is better here.

In keeping with making a huge disk sander out of stuff pulled out of the trash, the trunnions and motor hub were cast out of aluminum melted in an old propane tank furnace. Once these were cleaned up, a disk was mounted on the hub and trued up in the most unsafe manner possible.

With a few additions including a machined mitre gauge, dust collector, and legs made out of wood that’s far too pretty for a simple shop tool, this huge assemblage of trash turned out to be a great sander. You can see a few videos of it below.

Continue reading “Building A 20 Inch Disk Sander”