Homemade Bulletproof Glass, Built And Tested

January 28, 2016 by Dan Maloney 35 Comments

Hackers tend to stash away lots of stuff that seems useless, right up until it saves the day. This includes not just junk in our parts bin but brains full of tips and tricks for the shop. With that in mind, you might want to file away a few of the tips in [AvE]’s video of how he made bulletproof glass for a rainy day.

By his own admission, [AvE]’s video is a little disjointed, and the topic of the bulletproof glass is only covered at the beginning and again briefly at the end. Most of the video concerns the machining of a stout stand for the glass for testing on the range. There’s plenty to learn from the machining, though, and [AvE] is always good for a laugh, so the video is worth a watch. The bulletproof glass itself is part of a long-term project that [AvE] is releasing first to his Patreon patrons – a ridiculously over-built flashlight dubbed “The Midnight Sun”. His first two tries at laminating the Lexan discs were less that optimal, as both brands of cyanoacrylate glue clouded the polycarbonate. Stay tuned to the end of the video for the secret of welding Lexan together into an optically clear sandwich.

As for testing under fire, [AvE] sent the rig off to buddy [TAOFLEDERMAUS] for the hot lead treatment. The video after the break shows that the glass is indeed bulletproof, as long as the bullet in question is a .22LR. Not so much for the 9mm, though – that was a clear punch-through. Still, pretty impressive performance for homebrew.

If you want something that can stop an arrow, there’s a lot of materials science to be learned from the ancient Greeks.

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CD Execution Chamber Sends Old Discs Off With A Bang

July 10, 2015 by Dan Maloney 22 Comments

Welded steel safety cage? Check! Polycarbonate blast shield? Check! Vacuum cleaner motor wired to an inviting red button? Double check! Stack of CDs to dispose of as destructively as possible? [Firas Sirriyeh] has got you covered with his CD Terminator 1.0.

While [Firas’s] build log is a little short on descriptive text, there’s really no need for it. His pictures tell the tale. The combination media shredder and interactive performance art piece is a stoutly constructed affair, which you’d want anything capable of flinging razor-sharp plastic and Mylar shrapnel to be. [Firas] has displayed his CD execution chamber at the Jerusalem Mini Maker Fair 2015 (in Hebrew; English link) and the Musara Mix Festival where the must-see video after the break was shot (mildly NSFW language). Some CDs give up the ghost very quickly, but one held out for a remarkable long time before finally exploding; you can see it flexing and warping in a way that almost appears to be slow-motion.

For those who’d rather not fuss with all that bothersome safety, there’s always this automatic CD launcher to play with.

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Fabricating Your Own Backpack Straps For Unorthodox Uses

July 25, 2012 by Mike Szczys 14 Comments

Back in the 1980’s there was a movie cliché that the person with the largest boombox on their shoulder was always the coolest. It’s obvious to us that [Tim Gremalm] thinks that’s silly. Why be uncomfortable carrying something like that on your shoulder when you can strap a much larger object to your back? He’s working on a mammoth speaker enclosure which can be carried around, but he needed a set of backpack straps to make it happen.

This thing is going to be adding some serious weight to his body, so he also whipped up the padded waist belt seen above. For fabric he reused an Ikea couch cover. The material is made to survive a lot of pulling and stretching. For padding he used what he calls ‘floor mop’. It looks like it might be microfiber mop cloth be we can’t really be sure. With ten layers of the mop encased in the couch cover he finish off each strap by sewing it to some nylon webbing.

After the break you can see a picture of [Tim] modelling the huge polycarbonate speaker enclosure for which these backpack and waist straps were made. This project has many posts associated with it so if you’re interested in seeing more you can use this project tag link.

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3D Printing With Nylon For A More Useful Objects

May 22, 2012 by Brian Benchoff 34 Comments

[taulman] over on Instructables has been working on his own version of a 3D printer. Unlike the usual PLA or ABS filament all the RepRaps and Makerbots use, this printer uses nylon to make parts with very interesting properties.

Most extrusion printers are designed to print with ABS (a very hard plastic that melts around 220-230° C) or PLA (a somewhat softer plastic that melts at about 180° C). [taulman] is using Nylon 6, a very slippery and bendable plastic that melts around 320° C (about 600 degrees Fahrenheit). He’s doing this with a hot end of his own design and a ‘spiky’ extruder bolt that allows high-temperature thermoplastics to be extruded into any shape imaginable.

For the longest time, the 3D printer community has been using low-temperature thermoplastics such as PLA and ABS. There are obvious benefits to these materials: it’s pretty easy to source a spool of filament, and the low melting point of these plastics makes building a printer easier and safer. Now that [taulman] has the high-temperature plastic nut cracked, he’s moving on to easily-machiniable Delrin and transparent Polycarbonate. Very cool, and hopefully in a year’s time we’ll have a choice of what material to run in our printers.

After the break, there are a few videos [taulman] put up showing his printer at work and the properties of his 3D printed objects. It looks like [taulman] can print objects that are impossible on any other 3D printer we’ve seen; the flexible iPhone case probably couldn’t be made on any other DIY machine.

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Share A Light-up LED Heart With Your Valentine

February 14, 2012 by Brian Benchoff 5 Comments

It’s not roses or jewelry, but we hope [Erik]’s light-up USB heart will be appreciated by his significant other. When the two heart pieces come in contact with each other, each side lights up.

[Erik] started his build by cutting two half-heart shaped pieces out of polycarbonate. After drilling a few holes for LEDs and wires, magnets and reed switches were installed along the ‘broken’ side of the heart. Whenever the hearts come in contact with each other, the magnets trip the reed switches and light up both sides of the heart.

There is USB flash drive embedded in each heart half is loaded with a portable Dropbox. When the USB drive is plugged into a computer, the dropbox steps into action and synchronizes the photo album stored in each heart half. No matter how far apart they are, [Erik] and his SO can share pictures through their glowing LED hearts. Not to come off as a hopeless romantic, but this sounds like something we’d like for Valentine’s day. We’re hoping [Erik]’s SO thinks that as well.

Printing With Clear Polycarbonate

December 30, 2011 by Brian Benchoff 13 Comments

Those of us with 3D printers have had two major choices when selecting a material to print with – ABS, a very hard plastic, and PLA, a more brittle plastic with a lower melting point. [Alex] and [Luke] have been experimenting with printing polycarbonate and creating clear crystalline objects on a standard 3D printer.

The first foray into printing polycarbonate didn’t go so well for [Luke]. Objects came out looking very milky and there was a bit of popping during filament extrusion. The guys solved this problem by putting the polycarbonate filament in a food dehydrator overnight to get rid of the moisture. Polycarbonate has a higher melting temperature than other plastics – around 260 degrees Celsius – which can cause some problems with Teflon insulators in the hot ends of extruders. The guys didn’t have any problems with fumes, though.

If you’ve ever wanted to print something clear, it looks like it’s now possible. Check out the video after the break to see a Makerbot Thing-O-Matic printing with clear polycarbonate.

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Using Polycarbonate Filament With A RepRap

September 30, 2011 by Mike Szczys 19 Comments

[Rich] couldn’t find any instances where RepRap owners had used polycarbonate as a 3D printing source material. He’s filled that knowledge gap by running multiple polycarbonate printing tests. Polycarbonate is a plastic that is highly resistant to shattering yet it’s still rather soft. With enough effort it can be bent and stretched, but it’s fairly difficult to break the material.

The test spool of polycarbonate was special ordered for this project. [Rich] sourced 1.6mm filament since 3mm material would have been difficult to spool. It melts at a temperature range of 280-300 degrees Celsius, which he reaches with a hot-end extruder design. The printed material comes out a bit cloudy, which may be due to the heating process itself, or due to extruder reversals (he’s not quite sure what’s causing it). But as you can see above and in the video after the break, it’s certainly a viable printing medium.

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