Annealing Plastic For Stronger Prints

Much fuss has been made over the strength of 3D printed parts. These parts are obviously stronger in one direction than another, and post processing can increase that strength. What we’re lacking is real data. Luckily, [Justin Lam] has just the thing for us: he’s tested annealed printed plastics, and the results are encouraging.

The current research of annealing 3D printed parts is a lot like metallurgy. If you put a printed part under low heat — below the plastic’s glass transition temperature — larger crystals of plastic are formed. This research is direct from the Society of Plastics Engineers, and we’re assuming they know more about material science than your average joe. These findings measured the crystallinity of a sample in relation to both heat and time, and the results were promising. Plastic parts annealed at a lower temperature can attain the same crystallinity, and therefore the same strength, if they’re annealed for a longer time. The solution is simple: low and slow is the best way to do this, which sounds a lot like sous vide.

A while back, [Justin] built a sous vide controller for the latest cooking fad. The idea behind a sous vide controller is to heat food in a water bath at a lower temperature, but for a longer time. The result here is the most tender steaks you’ll ever have, and also stronger 3D printed parts. In his test, [Justin] printed several rectangular samples of PLA, set the temperature to 70°C, and walked away for a few hours. The samples annealed in the water bath were either cooled quickly or slowly. The test protocol also included measuring the strength in relation to layer height. The test jig consisted of a bathroom scale, a drill press, and a slot head screwdriver bit.

Although the test protocol is slightly questionable, the results are clear: annealing works, but only if the part is printed at a low layer height. However, parts with larger layer heights had a higher maximum stress. Is this helpful for the home prototyper? That depends. The consensus seems to be that if you’re at the mechanical limits of a 3D printed part, you might want to think about more traditional manufacturing. That’s just common sense, but there’s always room to push the envelope of 3D printing.

CPLD-Based Synchronization of Multiple Software Defined Radios

Forgive the click bait headline, but the latest work from [Marco Bartolucci] and [José A. del Peral-Rosado] is really great. They’re using multiple HackRFs, synchronized together, with hybrid positioning algorithms to derive more precise localization accuracy. (PDF)

Like all SDRs, the HackRF can be used to solve positioning problems using WIFi, Bluetooth, 3G, 4G, and GNSS. Multiple receivers can also be used, but this requires synchronization for time-based or frequency-based ranging. [Bartolucci] and [Peral-Rosado] present a novel solution for synchronizing these HackRFs using a few convenient ports available on the board, a bit of CPLD hacking, and a GNSS receiver with a 1 pps output.

This is technically two hacks in one, the first being a sort of master and slave setup between two HackRFs. Using the Xilinx XC2C64A CPLD on board the HackRF, [Bartolucci] and [Peral-Rosado] effectively chain two devices together. The synchronization error is below one sampling period, and more than two HackRFs can be chained together with the SYNC_IN port of each connected together in parallel. Read more about it in their pull request to the HackRF codebase.

This simplest technique will not work if the HackRF receivers must be separated, which brings us to the second hack. [Bartolucci] and [Peral-Rosado] present another option in that case: using the 1 pps output of a GNNS receiver for the synchronization pulse. As long as both HackRFs can see the sky, they can act as one. Very cool!

Internet of Hungry Hungry Things

The Hippopotamus is the most dangerous large animal in Africa. The Internet of Things will kill us all. What do you get when you combine the two? Hungry hungry. [Mike] took the classic game Hungry Hungry Hippos and turned it into an amazing and amusing Internet of Things device with voice recognition and machine vision.

Hungry Hungry Hippos is a child’s (board?) game designed to teach children the virtue of gluttony. The board is surrounded by four lever-actuated plastic hippopotami, and the object of the game is to mash a lever and collect marbles in the mouths of these piggish pachyderms. [Mike] automated this game with four servos connected to these levers, with each servo controlled by a W65C265SXB single board computer. Yes, this project has code written in 6502 assembly.

Taking this a step further, [Mike] is using a Playstation 3 camera connected to a netbook for image processing. When the camera detects a marble in front of a particular hippo, that hippo becomes hungry hungry. Autoplaying Hungry Hungry Hippos. What a fantastic time to be alive.

The Internet of things connectivity? [Mike] also made these hippos controllable via Amazon’s Alexa with the help of an Electric Imp. To activate the blue hippo, all [Mike] needs to say is, “Alexa, tell game that blue hippo needs to eat.” It’s an Internet of Things computer vision AI hippopotamus. We all knew technology was eating us alive, but we never thought technology was hungry hungry.

You can check out [Mike]’s demo videos below.

Continue reading “Internet of Hungry Hungry Things”

Friday Hack Chat: Electronics Design And Naming A Puppy

For one reason or another, Hackaday has an extended family of ridiculously capable contributors. One of the most illustrious is [Bil Herd], Commodore refugee, electronic engineer, medic, and all-around awesome guy. He’ll be joining us over on this Friday for a Hack Chat on Electronics Design.

This Friday, we’re hosting a Hack Chat with [Bil]. If you want to talk Commodore, this is the guy. If you want to talk about PLAs and programmable digital logic, this is the guy. If you want to know how to build a system from scratch in just a few months, [Bil]’s your man. [Bil] has decades of experience and his design work was produced by the millions. You’ll rarely come across someone with as much experience, and he’ll be in our Hack Chat this Friday.

[Bil] has a long career in electronics design, beginning with fixing CB radios and televisions back when fixing TVs was still a thing. Eventually, he worked his way up the engineering ladder at Commodore Business Machines where he designed the Commodore TED machines and the amazing Commodore 128.

After surviving Commodore, [Bil] has worked at a trauma center in Camden, NJ, flown with medics in the Army, and eventually came over to Hackaday where he produces videos from subjects ranging from direct digital synthesis, programmable logic, active filters, and how CMOS actually works. Basically, if it involves electronics, [Bil] knows what’s up.

Oh, as an added bonus, we get to name a puppy this week. [Bil] got a new puppy and it needs a name. Send in your suggestions!

Here’s How To Take Part:

join-hack-chatOur Hack Chats are live community events on the Hack Chat group messaging. This hack chat will take place at noon Pacific time on Friday, June 16th. Confused about where and when ‘noon’ is? Here’s a time and date converter!

Log into, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about

brdMaker, a DIY Pick and Place Machine

A small, desktop pick and place machine has obvious applications for hackerspaces, small companies, and even home labs. However, despite multiple efforts, no one has come up with a solution that’s both better and cheaper than buying a used, obsolete pick and place machine. [Mika]’s brdMaker is yet another attempt at a desktop chipshooter, and while the prototype isn’t done yet, it’s a fantastic build that might soon be found in your local electronics lab.

The easy part of any pick and place machine is a Cartesian frame. This has been done over and over again by the 3D printing and CNC communities, and the brdMaker is no exception. [Mika]’s robot is a 600 by 600 mm CNC frame powered by NEMA 23 motors. So far, so good.

The tricky part of a pick and place machine is working with the fiddly bits. This means feeders and machine vision. There are several different options for feeders including a ‘drag’ feeder that uses the vacuum nozzle tip to move a reel of parts along, and a slightly more complicated but vastly more professional feeder. A machine needs to see the parts it’s putting down, so [Mika] is using two cameras. One of these cameras is mounted on the toolhead and looks surprisingly similar to a USB microscope. The other camera is mounted in the frame of the machine to look at the bottom of a part. This camera uses 96 LEDs to illuminate the component and find its orientation.

[Mika]’s brdMaker still has a long way to go, but there are indications the market is ready for a cheap, easy to use desktop pick and place machine. The Chipsetter, an exquisitely designed pick and place machine revealed at last year’s NY Maker Faire had an unsuccessful Kickstarter, but they’re still chugging along.

Hackaday Prize Entry: Internet of Fidget Spinners

We just closed out the Internet of Useful Things round of the Hackaday Prize, which means we’re neck deep in judging projects to move onto the final round this fall. Last week, everyone on was busy getting their four project logs and illustrations ready for the last call in this round of the Hackaday Prize. These projects are the best of what the Internet of Things has to offer because this is the Internet of Useful things.

We’re not sure how [Matthias]’ project will rank. It’s an Internet of Things fidget spinner. Yeah, we know, but there are some interesting engineering challenges in building an Internet-connected fidget spinner.

This is a PoV fidget spinner, which means the leading edges of this tricorn spinner are bedazzled with APA102 LEDs. Persistence-of-vision toys are as old as Hackaday, and the entire idea of a fidget spinner is to spin, so this at least makes sense.

These PoV LEDs are driven by an ESP8285, or an ESP8266 with onboard Flash. This is probably the smallest wireless microcontroller you can find, an important consideration for such a small build. Power comes from a tiny LiPo, and additional peripherals include an accelerometer to measure wobble and an optical switch to measure the rotation speed.

These electronics are fairly standard, and wouldn’t look out of place in any other project in The Hackaday Prize. The trick here is mechanical. [Matthias] needs to mount a skateboard bearing to a PCB, and no one has any idea how he’s going to do that. A fidget spinner should be well-balanced, and again [Matthias] is running into a problem. Has anyone here ever done mass and density calculations on PCBs and lithium cells? Is it possible to 3D print conformal counterweights? Has science gone too far?

Will the Internet of Things PoV Fidget Spinner make it to the finals round of The Hackaday Prize? We’ll need to wait a week or so to find out. One thing is for certain, though: you’re going to see this on AliBaba before September.

A Universal USB To Quadrature Encoder

Computer mice existed long before the Mac, and most of the old 8-bit computers had some software that could use a mouse. These mice had balls and quadrature encoders. While converters to turn these old mice into USB devices exist, going the other way isn’t so common. [Simon] has developed the answer to that problem in the form of SmallyMouse2. It turns a USB mouse into something that can be used with the BBC Micro, Acorn Master, Acorn Archimedes, Amiga, Atari ST and more.

The design of the SmallyMouse2 uses an AT90USB microcontroller that supports USB device and host mode, and allows for a few GPIOs. This microcontroller effectively converts a USB mouse into a BBC Micro user port AMX mouse, generic quadrature mouse, and a 10-pin expansion header. The firmware uses the LUFA USB stack, a common choice for these weird USB to retrocomputer projects.

The project is completely Open Source, and all the files to replicate this project from the KiCad project to the firmware are available on [Simon]’s GitHub. If you have one of these classic retrocomputers sitting in your attic, it might be a good time to check if you still have the mouse. If not, this is the perfect project to delve into to the classic GUIs of yesteryear.