3D Printed Battery Pack Keeps Old Drill Spinning

January 29, 2018 by Tom Nardi 12 Comments

The greatest enemy of proprietary hardware and components is time. Eventually, that little adapter cable or oddball battery pack isn’t going to be available anymore, and you’re stuck with a device that you can’t use. That’s precisely what happened to [Larry G] when the now antiquated 7.2V NiCd batteries used by his cordless drill became too hard to track down. The drill was still in great shape and worked fine, but he couldn’t power the thing. Rather than toss a working tool, he decided to 3D print his own battery pack.

The 3D modeling on the battery pack is impeccable

He could have just swapped new cells into his old pack, but if you’re going to go through all that trouble, why not improve on things a little? Rather than the NiCd batteries used by the original pack, this new pack is designed around readily available AA NiMH batteries. For the light repairs and craft work he usually gets himself into, he figures these batteries should be fine. Plus he already had them on hand, and as we all know, that’s half the battle when putting a project together.

Interestingly, the original battery pack was wired in such a way that it provided two voltages. In older tools such as this one, this would be used for rudimentary speed control. Depending on which speed setting the drill is on, it would either connect to 4 or 6 cells in the original pack. [Larry] didn’t want to get involved with the extra wiring and never used the dual speeds anyway, so his pack only offers the maximum speed setting. Though he does mention that it may be possible to do PWM speed control in the battery itself via a 555 timer if he feels like revisiting the project.

[Larry] tells us the pack itself was rendered completely from scratch, using only the original battery pack and trial-and-error to get the fit perfect. He reused the side-mounted release buttons to save time, but otherwise everything is 3D printed in PETG for its strength and chemical resistance.

This is an entry in Hackaday’s

Repairs You Can Print contest

The twenty best projects will receive $100 in Tindie credit, and for the best projects by a Student or Organization, we’ve got two brand-new Prusa i3 MK3 printers. With a printer like that, you’ll be breaking stuff around the house just to have an excuse to make replacement parts.

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!

Students Hack An Unusual Violin

January 26, 2018 by Al Williams 18 Comments

[Sean Riley] is a violinist who had a problem. He wanted to play one particular piece, but he couldn’t. It wasn’t that he lacked the skill — he a doctoral student at the University of Texas and has two degrees in violin performance from The Julliard School. The problem was that “The Dharma at Big Sur” by [John Adams] is made for an instrument with six strings, while most violins only have four. So he did what any of us would do. He stopped by the local hackerspace and fabricated one. You can hear (and see) [Sean] performing with the instrument in the video, below.

The University of Texas operates “The Foundry” which is a hackerspace with all the usual items: laser cutters, 3D printers, and the like. It is open to all their students and staff. [Sean] needed some help with the engineering, and was lucky to find a mechanical engineering senior, [Daniel Goodwin], working at The Foundry.

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Printed It: Rubber Band PCB Vise

January 24, 2018 by Tom Nardi 31 Comments

If you’ve ever worked on a small PCB, you know how much of a hassle it can be to hold on to the thing. It’s almost as if they weren’t designed to be held in the grubby mitts of a human. As designs have become miniaturized over time, PCBs are often so fragile and festooned with components that tossing them into the alligator clips of the classic soldering “third hand” can damage them. The proper tool for this job is a dedicated PCB vise, which is like a normal bench vise except it doesn’t crank down very hard and usually has plastic pads on the jaws to protect the board.

Only problem with a PCB vise is, like many cool tools and gadgets out there, not everybody owns one. Unless you’re doing regular PCB fabrication, you might not take the plunge and buy one either. So what’s a hacker on a budget to do when they’ve got fiddly little PCBs that need attention?

Luckily for us, we live in a world where you can press a button and have a magical robot on your desktop build things for you. Online model repositories like Thingiverse and YouMagine are full of designs for printable PCB vises, all you have to do is pick one. After looking through a number of them I eventually decided on a model designed by [Delph27] on Thingiverse, which I think has a couple of compelling features and more than deserves the few meters of filament it will take to add to your bench.

Of course the best part of all of this is that you can customize and improve the designs you download, which is what I’m about to do with this PCB vise!

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Making Prints More Resilient With Fibre-Filled Filament

January 23, 2018 by James Hobson 14 Comments

For all that we love 3D printers, sometimes the final print doesn’t turn out as durable as we might want it to be.

Aiming to mimic the properties of natural structures such as wood, bone, and shells, a research team lead by [Jennifer A. Lewis] at Harvard John A. Paulson School of Engineering and Applied Sciences’ Lewis Lab have developed a new combined filament and printing technique which they call rotational 3D printing.

Minuscule fibres are mixed in with the epoxy filament and their controlled orientation within the print can reinforce the overall structure or specific points that will undergo constant stresses. To do so the print head is fitted with a stepper motor, and its precisely programmed spin controls the weaving of the fibres into the print. The team suggests that they would be able to adapt this tech to many different 3D printing methods and materials, as well as use different materials and printed patterns to focus on thermal, electrical, or optical properties.

Be it adding carbon nano-tubes or enlisting the expertise of spiders to refine our printed materials, we’re looking forward to the future of ever stronger prints. However, that doesn’t mean that existing methods are entirely lacking in endurance.

[Thanks for the tip, Qes!]

3D Printed Desk Harnesses The Power Of Fusion 360 And McMaster-Carr

January 23, 2018 by Dan Maloney 36 Comments

Black pipe furniture is all the rage now, and for good reason — it has a nice industrial aesthetic, it’s sturdy, and the threaded fittings make it a snap to put together. But if you’ve priced out the fittings lately, you know that it’s far from cheap, so being able to 3D-print your own black pipe fittings can make desks and tables a lot more affordable.

Cheapness comes at a price, of course, and [Vladimir Mariano] takes pains to point out that his desk is a light-duty piece that would likely not stand up to heavy use. But since the flange fittings used to connect the plywood top to the legs and as feet would cost about $64 all by themselves from the local home center, printing them made sense. Together with custom pieces to mount stretchers between the legs, the 3D-printed parts made for a decently sturdy base.

But the end product isn’t the main point of the video below. Thanks to the ability to browse the McMaster-Carr catalog from within Fusion 360, [Mariano] was able to seamlessly import the CAD model of a suitable iron flange and quickly modify it to his needs. The power of this feature is hard to overstate; you can literally browse through a catalog of engineered parts and print usable replicas instantly. Sure, it’s not made of metal, but it’s a huge boon to designers to be able to see how the final product would look, especially in the prototyping phase of a project.

Not familiar with McMaster-Carr? It’s an engineer’s online playground, and we covered the ins and outs of doing business with McMaster a while back.

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ESP8266 Beacon Announces Your Arrival

January 21, 2018 by Tom Nardi 68 Comments

It used to be people were happy enough to just have to push a button in their car and have the garage door open. But pushing a button means you have to use your hands, like it’s a baby toy or something. We’re living in the 21st century, surely there must be a better way! Well, if you’ve got a home automation system setup and a spare ESP8266 laying around, [aderusha] may have your solution with MQTTCarPresence.

The theory of operation here is very clever. The ESP8266 is powered via the in-dash USB port, which turns on and off with the engine. When the engine is started, the ESP8266 is powered up and immediately connects to the WiFi network and pushes an MQTT message to Home Assistant. When Home Assistant gets the notification that the ESP8266 has connected, it opens the garage door.

When [aderusha] drives out of the garage and away from the house, the ESP8266 loses connection to the network, and Home Assistant closes the door. The same principle works when he comes home: as the car approaches the house it connects to the network and the garage door opens, and when the engine is shut off in the garage, the door closes again.

The hardware side of the setup is really just a WeMos D1 mini Pro board, though he’s added an external antenna to make sure the signal gets picked up when the vehicle is rolling up. He’s also designed a very slick 3D printed case to keep it all together in a neat little package.

We’ve covered automated entry systems based on the ESP8266 before, though usually the ESP stays at home. Be sure to check out the awesome series [Elliot Williams] has on the wonders of MQTT if you’re looking to setup your own automation system.