Not Just a Floor Wax but an Embossing Powder!

The embossing process used in the creation of some of your fancier wedding invitations and business cards is an interesting one. It’s often called thermography or thermographic printing. Slow-drying, wet ink is applied to a substrate. The ink is dusted with a thermoplastic polymer called embossing powder, and a heat source raises the ink while drying it.

Commercial embossing powder costs about $10 an ounce. As [Ken] discovered, its manufacture is quite closed-source to boot. He set about creating his own embossing powder, and succeeded with a combination of commonly available floor finish and distilled white vinegar. A standard-sized bottle of floor finish yielded about four ounces of homemade embossing powder.

How does this work? The floor finish is an acrylic-based stable emulsion. Adding vinegar destabilizes the emulsion, decreasing its pH and setting the polymer free.  It’s a fairly fast process, which you can see in the second video that accompanies [Ken]’s write up. From there, it’s mostly a matter of straining the material, letting it dry, and pulverizing the coarse matter into powder. In the first video, [Ken] performs a comparison test of Ranger, a commercial powder, and his own concoction.

For a completely different take on home embossing, check out this soda-can-turned-keepsake-box.

Smarter-than-wood Saw Blade Makes Perfect Foldable Joints

[Andrew Klein] knows the pain of building drawers from plywood. It can be a pain to get all of the pieces measured and cut just right. Then you have to line them up, glue them together, and clamp them perfectly. It’s time-consuming and frustrating. Then one day it hit him that he might be able to make the whole process much easier using a custom saw blade.

The the video below, [Andrew] does a great job explaining how the concept works using a piece of paper. The trick is that the plywood must be cut in a very specific shape. This shape results in the plywood just barely being held together, almost as if it’s hinged. The resulting groove can then be filled with wood glue, and the plywood is folded over on itself. This folding process leaves no gaps in the wood and results in a strong joint. Luckily this special shape can be cut with a specialized saw blade.

This new process removes the requirement of having five separate pieces for a drawer. Instead, only four cuts are needed on a single piece of square plywood. The corners are then removed with a razor blade and all four sides are folded up and into place. [Andrew] shows that his prototype blade needs a little bit of work, but he’s so hopeful that this new invention will be useful to others. Continue reading “Smarter-than-wood Saw Blade Makes Perfect Foldable Joints”

Hacking the United States Postal Service (Kinda)

The United States Postal Service (USPS) is fixture of American life with its roots going back to colonial times. It operates the largest civilian vehicle fleet in the world, delivering about half a billion pieces of mail a day. As with any system of that size it’s always interesting to peek and poke at to see how it works. Unfortunately, it’s not as fun to hack as the phone system once was, but that didn’t stop some hackers pranksters from giving it a go.

So how do you “hack” the mail? Simple, by testing its own rules. The folks at [Improbable Research] did just that and some of the results were interesting enough that we thought we would share them with you. They started with testing valuable items to see how honest USPS employees would be. First they attached a $20 bill to a post card. Yep, it showed up just 4 days later, and the money was still there. So they decided to see if sentimental items, that normally would be refused by the postal service, might skate through.  They were able to send both an un-boxed single rose, and a human tooth (in a clear plastic box) without issue. Both arrived just fine, despite the rule that human remains are not allowed to be shipped via USPS.  We’ll let you read some of the other items they tried.

So the next time you’re in Hawaii, forget about sending that generic, boring post card back home. Instead, slap some stamps on a coconut to let your friends know exactly how much fun you’re having.

With that said, we wouldn’t be doing our job looking out for our readers if we didn’t mention that before you try anything too outlandish, you can be fined for abuse of the postal system, even as a recipient. There was a fair amount of fallout when those guys sent a camera through the mail. Have fun, but not at someone else’s expense.

Xilinx Borrows Code For Their Own Devices

Back in 2012, [tmbinc] discovered a neat little undocumented feature in the Xilinx ISE: the ability to use TCP/IP instead of JTAG cables. [tmbinc] was working on an Open Hardware USB analyzer and discovered the nearly undocumented Xilinx Virtual Cable, a single ‘shift’ command that opens up a TCP connection and sends JTAG data out to another computer on the network. It’s extraordinarily useful, [tmbinc] wrote a daemon for this tool, and everything was right with the world.

Yesterday, [tmbinc] discovered the Xilinx Virtual Cable again, this time in one of Xilinx’s Github repos. The code was extraordinarily familiar, and looking closer at a few of the revisions, he saw it was very similar to code he had written three years ago.

The offending revision in the Xilinx repo is nearly identical to [tmbinc]’s Xilinx Virtual Cable Driver daemon. Variable names are the same, the variables are declared in the same order, and apart from whitespace, code conventions are the same. This is not to say someone at Xilinx stole code from [tmbinc], but if this were a computer science lab, there would be an academic disciplinary hearing. What’s worse, Xilinx plastered their copyright notice at the top of the code.

In an issue [tmbinc] raised, he said he was flattered, but clarified that his code was developed entirely from scratch. He believes the Xilinx code was derived from his own code written three years ago. Since [tmbinc]’s code was uploaded without a license, it defaulted to All Rights Reserved. This does not bode well for the Xilinx legal department.

In any event, you really, really have to wonder what Xilinx’s internal documentation looks like if a random person on the Internet can discover a barely-documented protocol, write a daemon, put it on the Internet, and have someone at Xilinx use that code.

Thanks to the anonymous tipster for sending this into the Hackaday tip jar.

Learning Logic Gates With Dominos

Even though most of us know logic gates like the back of our hands, we just found this awesome explanation video you can use to teach kids in a very fun way — Using nothing but dominoes.

Produced by [Numberphile], our host sets up various “circuits” using dominoes to explain all the various logic gates. Some of the patterns are a bit tricky to setup since you actually have to set up timing based on the spacing of the dominoes — makes us wonder how many bloopers there were!

But don’t take our word for it, it’s well worth a watch after the break.

Continue reading “Learning Logic Gates With Dominos”

School Kids Build Ontario Power Generation System Model

The STEAMLabs community makerspace teamed up with a grade 6 class from Vocal Music Academy, a public elementary school in downtown Toronto, to create a working model of the Ontario Power System. It pulls XML files and displays the live power generation mix from renewable and other sources on a 3D printed display on RGB LED strips. Arduino coding on a Spark Core provides the brains.

The kids learned HTML, CSS and Javascript to build a web interface to send commands to the Spark and explain how the system works. Their project was accepted as an exhibition at the TIFF DigiPlaySpace. The kids presented their project to adults and other kids at the event. STEAMLabs has also published a free, open source Internet of Things teaching kit to enable other educators to make projects with Internet brains.

STEAMLabs is currently crowd-funding a new makerspace in Toronto. They’re almost there, a few hundred dollars short of their target, with a couple of days to go. Help them help kids and adults make amazing things! When Hackaday visited Toronto recently, [Andy Forest] dropped in to show off this project. Projects like these which let kids become creators of technology, rather than mere consumers, is one of the best ways to get them hooked to hacking from an early age.

Continue reading “School Kids Build Ontario Power Generation System Model”

Bitten By PCB Defects

If you’ve ordered PCBs from Seeed Studio, ITead, DirtyPCB, or another board house in China, you’ve probably noticed that neat little 100% e-test option available on the order form. If you select this, the board house will throw your PCBs in a machine that will poke a pin in every pad to make sure all the connections are good. Less work for you, right? As [Andy] found out, not always. He was bitten by a manufacturing defect that sheds some light on what that e-test actually is, and the capabilities of what these Chinese board houses can do.

Most of [Andy]’s project have a lot of surface mount components, and when he receives his boards, he notices a few pin pricks on each and every pad. This is from a flying lead machine; a robotic continuity checker that makes sure all the relevant pads are electrically isolated from each other.

One of [Andy]’s recent projects is an entirely through-hole design. Apparently these robotic meters don’t test through-hole pads; it’s significantly harder to measure the continuity of a hole rather than a pad, apparently. After assembling one of these boards, he noticed a problem where one of the GPIOs was permanently high. The offending trace was found underneath a DIP socket, in precisely the worst possible place it could be.

If [Andy] had inspected the board beforehand, this problem would have been avoided. He says it was a relatively simple board with big traces and wide spaces and he didn’t think a manufacturing defect was possible. He was wrong, and now we have a warning. We thank him for that.