When it comes to cleaning your hands, [Arnov Sharma] is not messing around. He built an automatic soap dispenser using ultrasonic sensors, a stepper motor for activating the pump, and 3D printed components for housing a bottle of soap – a spectacular display of over-engineering. At least he won’t be needing to stand in line at the supermarket for motion detection soap dispensers anytime soon.
Initially, he had the idea to build the dispenser using a common servo motor-based method. This would involve activating motors to push down on the plunger for the soap bottle to dispense soap. Instead, he for a different approach that ended up being fairly straightforward in theory, although the execution is pretty involved.
He started off by 3D printing the compartment where the soap bottle would sit and the structural support for the Z-axis rail that would be pushing down on the soap bottle. It’s similar to the type of linear actuator you might find in a 3D printer or PCB mill, where a motor controls a rotating screw that moves the carriage across a belt. (We presume the linear rail came first, and the ultrasonic soap dispenser second.)
In this build, there are two additional rods added to help support the lever pressing down on the soap dispenser.
The setup is controlled by an Arduino, which triggers the movement from the linear actuator if it receives a signal from an ultrasonic sensor. He’s added the model files and Arduino code for other makers curious about building a similar project. Check out his video for the soap dispenser in action – the stepper motor definitely makes for a much more powerful plunge than you might expect.
Blowing bubbles is a pastime enjoyed by young and old alike. The pleasant motion and swirling colors of the bubbles can be remarkably relaxing. With the right tools and techniques, it’s possible to take striking photos of these soap film phenomena, and that’s exactly what [Eric] and [Travis] did.
After beginning with a robotic arm and a computer fan blowing bubbles, the project moved towards a simple stepper motor setup. A thin frame is lowered into a solution of soapy water, then brought back up by the stepper motor. The resulting soap film is held in front of a black background and carefully lit with a softbox light.
Lens selection is critical for this sort of work – in this case, a TS-E 50mm Macro f/2.8 lens was the order of the day. [Eric] shares other tips for taking great shots, such as adding sugar to the solution to make the soap film last longer, and using a modified speaker to help “paint” the surface of the films.
The resulting images are beautiful examples of the art, showing vibrant colors from the interference patterns created by the light. [Eric] has done a great job of clearly documenting the development process and the final results, making it possible for others to recreate the project elsewhere.
If you’ve been hanging out here at Hackaday for awhile, you’ve certainly seen projects that were based around the concept of putting a miniature computer inside the carcass of some other piece of electronics. In fact at this point it’s something of a running joke, certainly we must have seen an Arduino or Raspberry Pi shoehorned into every type of consumer gadget ever built by this point. But if you thought this would be another example of that common trope by the headline, you might be in for something of a surprise.
[zapta] didn’t put an Arduino inside this GOJO LTX-7 soap dispenser, it was already in there to begin with. That’s right, apparently we’ve hit the point that even cheap soap dispensers are now running on programmable microcontrollers. While we can’t blame those of you who are no doubt groaning and/or rolling their eyes thanks to this particular case of computational gluttony, it does mean we’re able to report with a straight face something which frankly would have passed as an April Fool’s joke in previous years: the development of an open source soap dispensing firmware.
So how does one upload a new Arduino sketch to their GOJO soap dispenser? It’s not like the thing has a USB port on the side for convenient hacking. As explained by [zapta], it involves stripping the dispenser all the way down until the electronics board is free, and then adding in a programming header to make subsequent firmware fiddling a bit easier. Writing a new firmware to the ATTiny48 powered board will require an external ISP (the Atmel AVRISP MKII was used for this hack, though any should work), but it’s otherwise pretty painless.
[zapta] has done an excellent job documenting the different components on the board, and reverse engineered enough of the critical aspects (such as the motor controller and proximity sensor) to write a new open source firmware which can be flashed to the GOJO LTX-7. Beyond allowing you to “Open Source All the Things”, using this new firmware does have some practical advantage in that you can configure how much soap is dispensed per activation. Going further, we’d be exceptionally interested in hearing about anyone who manages to come up with a firmware that enables some hitherto impossible soap dispensing trickery.
His write-up is a pretty fun read, walking through his process, including an oscilloscope measurement showing how the capacitors’ voltage drops from 5.26 V to 3.5 V when the trigger is pressed, and interestingly, slowly recovers until it’s released a second later, when it then rises back to 4.5 V. He’s even included how he worked out of the panel’s maximum power point (MPP), which is what he was doing when the kids were first lured away to blow soap bubbles. But we’re sure Hackaday readers aren’t as easily distracted.
The resulting Solar Powered Bubble Blaster works quite well. At a starting voltage of 5.23 V, it runs for 15 seconds and then takes only a minute to recharge. Charged batteries would have had a longer runtime but take longer to recharge, an important point when trying to keep kids interested. See it in action in the video below.
Post an animation on Reddit of a workable machine that looks neat and does something cool and the next day someone will have built it. That’s what happened when [The-Big-Ship] uploaded an animation of a clever bubble making machine — though we had to look twice to convince ourselves that it wasn’t real. The next day [Over_Engineered_2] posted a video of his working one.
We often hear that you need precision CAD software such as Solidworks and AutoCAD to design a functional machine but the animation was done using Cinema 4D, used for films such as Iron Man 3 and Tron: Legacy. This shows that you can at least get a reassurance that the basic mechanics will fit and move together without having to design precision parts.
That’s not to say that reality didn’t interfere with implementing it though. In [Over_Engineered_2]’s video below he points out that the bigger ring of the original animation didn’t work with his small motor and propeller, and had to switch to the smaller ring. Also, note that the ring needed guide rails on the sides to keep it from twisting, something a real world ignoring animation can get away without. Check out the videos below to see the two in action.
At first glance, it’s easy to dismiss the creation of custom bath soaps as far outside the usual Hackaday subject matter, and we fully expect a torrent of “not a hack” derision in the comments. But to be able to build something from nothing, a hacker needs to be able to learn something from nothing, and there is plenty to learn from this hack.
On the face of it, [Gord] is just making kitschy custom bath soaps for branding and promotion. Cool soaps, to be sure, and the drop or two of motor oil and cutting fluid added to each batch give them a little machine shop flair. [Gord] experimented with different dyes and additives over multiple batches to come up with a soap that looked like machined aluminum; it turns out, though, that adding actual aluminum to a mixture containing lye is not a good idea. Inadvertent chemical reactions excepted, [Gord]’s soaps and custom wrappers came out great.
So where’s the hack? In stepping way outside his comfort zone of machining and metalwork, [Gord] exposed himself to new materials, new techniques, and new failure modes. He taught himself the basics of mold making and casting, how to deal with ultra-soft materials, the chemistry of the soap-making process, working out packaging and labeling issues, and how to deal with the problems that come from scaling up from prototype to production. It may have been “just soap”, but hacks favor the prepared mind.
Kickstarter started out as a platform for group buys, low-volume manufacturing, and a place to fund projects that would otherwise go unfinished. It would be naive of anyone to think this would last forever, and since these humble beginnings, we’re well into Peak Kickstarter. Now, Kickstarter, Indiegogo, and every other crowdfunding platform is just another mouthpiece for product launches, and just another strategy for anyone who needs or wants money, but has never heard of a business loan.
Of course there will be some shady businesses trying to cash in on the Kickstarter craze, and over the last few years we’ve done our best to point out the bad ones. Finding every terrible Kickstarter is several full-time jobs, but we’ve done our best to weed out these shining examples of the worst. Following up on these failed projects is something we have been neglecting, but no longer.
Below are some of the most outrageous Kickstarters and crowdfunding campaigns we’ve run across, and the current status of these failed entrepreneurial endeavors.