3D Print The Blasphemous Helicopter Part Known As A Jesus Nut

January 27, 2018 by Lewin Day 17 Comments

Today, when we say “Jesus nut”, we’re not referring to the people who spend their days proselytizing down at the mall. The term, likely spawned in the Vietnam war, refers to the main nut holding the rotors on to the mast of a helicopter which is in the shape of the Christian cross. If the “Jesus nut” was to fail, the rotors would detach from the craft, and there would be little for crews to do except to pray.

[Marius] was presented with a failed Jesus nut, though thankfully from an R/C helicopter, meaning there was no loss of life. A friend needed the part replaced for their FQ777 copter, so it was time to bust out the 3D printer and get to work.

The first step was to reconstruct the broken piece so it could be measured and then modeled in CAD software with the help of calipers to determine the original dimensions. What followed will be familiar to many 3D printing enthusiasts — a case of educated trial and error, experimenting with different filaments and print settings until a usable part was produced. [Marius] notes on the part’s Thingiverse page that they achieved the best print with an 0.2mm layer height, and printing two parts at once to allow the layers more time to cool during each pass. It was then a simple matter of tidying up the part with sandpaper and a drill bit before installing it on the vehicle.

[Marius] reports that the part was successful, being both strong enough to withstand the forces involved as well as having a fit that was just right to suit the rotor pin which needs to be able to turn freely within the Jesus nut. While they’re not always the right tool for the job, 3D printed replacement parts can sometimes surprise you. These prints that are used in repair work often don’t attract the same interest as printing cosplay armor, kinetic art, and low-poly Pokemon. But they quickly prove how transformative having a 3D printer, and the skills to use it, are. That’s why we’re running the Repairs You Can Print contest… take a few minutes to show off the really useful repairs you’ve pulled off with your 3D printer!

Win Big Prizes With Repairs You Can Print

January 16, 2018 by Brian Benchoff 58 Comments

Another month, another contest, and this time we’re looking for the best 3D printed repairs you’ve built.

The Repairs You Can Print Contest on Hackaday.io is a challenge to show off the real reason you bought a 3D printer. We want to see replacement parts, improved functionality, or a tool or jig that made a tough repair a snap. Think of this as the opposite of printing low poly Pokemon or Fallout armor. This is a contest to demonstrate the most utilitarian uses of a 3D printer. Whether you fixed your refrigerator, luggage, jet engine, vacuum cleaner, bike headlight, or anything else, we want to see how you did it!

The top twenty projects in the Repairs You Can Print contest will be rewarded with $100 in Tindie credit. That’s a Benjamin to spend on parts, upgrades, and components to take your next project to the next level!

Students and Organizations Can Win Big

The Best Student and Best Organization will win a Prusa i3 MK3!

This contest is open to everyone, but we’re also looking for the best projects to come from students and hackerspaces. We’ll be giving away two amazing 3D printers to the best Student entry and best Organization entry. These two top projects will be awarded an Original Prusa i3 MK3 with the Quad Material upgrade kit. This is one of the finest 3D printers you can buy right now, and we’re giving these away to the best student, hackerspaces, robotics club, or tool lending library.

If you have a project in mind, head on over to Hackaday.io and create a project demonstrating your 3D printed repair!

What is This Contest All About?

This contest is all about Repairs You Can Print, but what does that actually mean? Instead of printing Pokemon or plastic baubles on your desktop CNC machine, we’re looking for replacement parts. We’re looking for commercial, off the shelf items that were broken, but repaired with the help of a 3D printer. Is your repair good enough to show off as part of the contest? Yes! That’s the point, we want to see the clever repair jobs that people often don’t spend much time talking about because they just work.

Need some examples? Sure thing.

The underside of a vacuum cleaner

A 3D printed wheel for a broken vacuum cleaner

A while back, [Elliot Williams], one of the fantastic Hackaday Editors, had a broken vacuum cleaner. The wheels were crap, but luckily they were designed as a single part that snaps into a swivel socket. Over six or so years, the original wheels in this vacuum gave out, but a replacement part was quickly printed and stuffed into the socket. The new wheels have been going strong for a year now. That’s an entire year of use for a vacuum for five cents worth of plastic and an hour’s worth of printing time.

A 3D printed wheel on my luggage. The original was destroyed at either ORD or PHL.

Need another example? My suitcase was apparently dragged behind a luggage cart for miles at either ORD or PHL. When it arrived on the baggage carousel, one wheel was shredded, and the wheel mount was ground down to almost the axle. The rest of the bag was still good, and I just removed the old wheel, salvaged the bearings, and printed a new wheel out of PLA. This suitcase has now traveled 60,000 miles with a 3D printed wheel, and it’s only now looking worse for wear.

How To Get In On The Action

We’re looking for the best repairs, jigs, and tools you’ve ever printed. To get started, head on over to Hackaday.io, create a new project, and document your repair. The Repairs You Can Print contest will run from Tuesday, January 16th, 2018 through 12 PM PST Tuesday, February 20th, 2018. Here’s a handy count down timer for ‘ya.

LED Tree Brings Gravity To Christmas

January 10, 2018 by Kristina Panos 9 Comments

Here’s a fun entry into our coin cell challenge. The power source is the actuating force in [Frank]’s blinky LED Christmas tree, which takes advantage of the physical structure of coin cells and our old pal gravity to roll out some holiday cheer. Talk about forward voltage!

We love the concept, and the circuit couldn’t be more simple. A coin cell is released at the top of the tree and rolls down a series of angled foam board railings covered with 1/4″ copper tape. As the coin cell travels, the negative terminal shimmies along the face of the tree, which has corresponding ground rail tapes. There’s no microcontroller here—all that’s needed for blinks are breaks in the negative rail tape.

The challenging part of a project like this is the execution. Getting a coin cell to ride the rails without falling off required angle experimentation prior to and during the build. Now that it’s done, keeping the tree tilted back against the wall is key. [Frank] explored several options for returning the coin cell to the top using a camera motor and the gear assembly from an old inkjet, but for now, his six-year-old does the job without complaint. Check out his work ethic after the break.

Continue reading “LED Tree Brings Gravity To Christmas” →

BrewBuddy Is A Home Brewer’s Best Friend

January 8, 2018 by Kristina Panos 7 Comments

Whether coffee, tea, or beer is your jam, brewing is a delicate pas de deux of time and temperature. Proper brewing of any of these beverages can elevate the experience from average to amazing. With this in mind, [Marcelo] created a time and temperature tool to dial in his beer-brewing process.

BrewBuddy is a complex application-specific timer with an integrated thermometer. It lets him program time and temperature profiles for both the mashing process and the boiling process and store up to 10 steps for each. BrewBuddy doesn’t control the brewing temperature, but it does unify temperature-taking and time-marking into one convenient device that can last about 20 hours on a single CR2032.

The system is based on an STM32 and an LMT86 analog temperature sensor which has been modified to sit inside a stainless steel tube. There are four directional buttons to navigate through intuitive menus to set the desired times and temperatures. As each step completes, the status LED lights up and BrewBuddy waits for confirmation via button push before moving on to the next step. If there’s a problem, the timer can be paused and resumed using the up/down buttons. [Marcelo] is working to perfect the case design, but he already has the board files and firmware up on GitHub. Open up a cold one and check out the demo videos after the break.

After boiling and cooling comes fermentation, and that requires careful monitoring of the sugar content. Here’s a tool for that.

Continue reading “BrewBuddy Is A Home Brewer’s Best Friend” →

This Is The Last Weekend For The Coin Cell Challenge

January 6, 2018 by Brian Benchoff 6 Comments

This is it. This is the last weekend you’ll have to work on the most explosive battery-powered contest in recent memory. This is the Coin Cell Challenge, and it’s all ending this Monday. You have less than 48 hours to create the most amazing thing powered by a coin cell battery.

Joseph Primmer slapped a coin cell on a piezo and rickrolled a university

Right now, we’re looking at the entries to the Coin Cell Challenge, and there are some real gems here. Did you know the Rickroll Throwie maddeningly distributed around the dorms at Cornell is an entry? Yes, with just a coin cell, an ATtiny85, and a piezo, you can rickroll people for an entire year.

Need some more inspiration? Anthropomorphized pool noodles need love. CES is coming up next weekend, which means you too can get kicked out for life, just like Gizmodo reporters. The Northeast is suffering through a cold snap right now, so let’s try jumpstarting a car with a coin cell battery. There are a million and one things you can do with a coin cell battery, and we want to see what you can do with them.

The top twenty projects for this contest will each receive $100 in Tindie credit to pick up some fancy kits and cool gear. The three top winners will each receive a $500 cash prize. We’re looking for three things specifically — a Lifetime Award that keeps a project going longest, a Supernova Award that drains a coin cell in the blink of an eye, and a Heavy Lifting Award that demonstrates what shouldn’t be possible with a simple coin cell.

This is your last weekend to submit a project, and the contest ends Monday afternoon, Pacific time. Enter now!

Take The Coin Cell Challenge This Weekend!

December 29, 2017 by Mike Szczys 7 Comments

The year is drawing to a close, and we have a weekend project for you to while away the remaining hours. Take the Coin Cell Challenge!

The point of the challenge is to do something interesting with a coin cell. That’s it! It’s a challenge that can be as simple or as involved as you want. Low power is where it’s at these days, so if you’ve never used the hardware sleep modes in your favorite microcontroller, that would make an excellent challenge entry. Show us what you’re able to do with short wake periods, and talk about when and why that wake happens. Or go a completely different route and build your own cell!

[Ben Krasnow] makes the most of a tiny power source

The top twenty entries will each receive a $100 Tindie credit so they can score some excellent gear. Three top winners in some special areas who will each be awarded a $500 cash prize. We’re looking for something interesting that demonstrates longest life (Lifetime Award), something that burns through that coin cell as if it’s going out of style (Supernova Award), and something that fills us with disbelief (Heavy Lifting Award) because it shouldn’t be possible with “just a coin cell”.

One of our biggest inspirations for this contest was [Ben Krasnow] who managed to squeeze enough juice out of a miniscule coin cell to power his Flashing Light Prize entry, only because he reduced internal resistance by heating the cell with an air gun (here’s the Hackaday coverage of that project). And [Elliot Williams] wrote a great guide on what kind of juice you can expect to get out of a cell. Take these to heart and do something interesting this weekend. Enter now!

Environmentally Aware Jewelry Gets Attention

December 27, 2017 by Tom Nardi 5 Comments

We didn’t include a “Most Ornate” category in this year’s Coin Cell Challenge, but if we had, the environmentally reactive jewelry created by [Maxim Krentovskiy] would certainly be the one to beat. Combining traditional jewelry materials with an Arduino-compatible microcontroller, RGB LEDs, and environmental sensors; the pieces are able to glow and change color based on environmental factors. Sort of like a “mood ring” for the microcontroller generation.

[Maxim] originally looked for a turn-key solution for his reactive jewelry project, but found that everything out there wasn’t quite what he was looking for. It was all either too big or too complicated. His list of requirements was relatively short and existing MCU boards were simply designed for more than what he needed.

On his 30 x 30 mm PCB [Maxim] has included the bare essentials to get an environmentally aware wearable up and running. Alongside the ATtiny85 MCU is a handful of RGB LEDs (with expansion capability to add more), as well as analog light and temperature sensors. With data from the sensors, the ATtiny85 can come up with different colors and blink frequencies for the LEDs, ranging from a randomized light show to a useful interpretation of the local environment.

It’s not much of a stretch to imagine practical applications for this technology. Consider a bracelet that starts flashing red when the wearer’s body temperature gets too high. Making assistive technology visually appealing is always a challenge, and there’s undoubtedly a market for pieces of jewelry that can communicate a person’s physical condition even when they themselves may be unable to.

Form or function, life saving or complete novelty, there’s still time to enter your own project in the 2017 Coin Cell Challenge.