This Soap Dispenser Will Crush Your Germs

July 17, 2020 by Sharon Lin 12 Comments

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.

Model of the soap dispenser made in Fusion 360

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.

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Time Bandit Clock Hits The Aesthetic Jackpot

July 6, 2020 by Kristina Panos 11 Comments

When was the last time you looked forward to looking at a clock? Not to find out the time per se — like gee, maybe it’s beer o’ clock already — but waited with bated breath to gaze upon a particular clock? Never? We don’t blame you, but only because you haven’t seen this fruit machine clock in action yet.

Every 60 seconds, the reels start spinning like some little man inside pulled the lever on a slot machine (or fruit machine, as they’re called across the pond). The reels slow down and stop one by one, left to right, settling on the four digits of time in 24-hour mode. Imagine the suspense of coming to see what time it is just as the reels start spinning!

[timebanditclock] grew this fruit machine out of old-school discrete logic beautifully applied to stripboard. Each of the reels has a DIY binary encoder that uses IR transmit/receive pairs to generate a binary word. These four binary words are compared to a binary clock module using comparators.

We think this is an amazing concept already, but then [timebanditclock] worked overtime by doing it all in discrete logic. Spin past the break to see a demo and stick around for the build video.

Want a challenging clock build that’s a little less challenging? Maybe it’s time to try circuit sculpture.

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Automatic Planet Finder Is Out Of This World

June 5, 2020 by Kristina Panos 5 Comments

When the world is on your shoulders, it can be relaxing to remember that we’re just hairless monkeys hurtling through space on a big rock alongside a lot of other rocks. If you find yourself wondering where exactly the other major rocks are instead of worrying, we think that’s a good sign.

Wherever [snowbiscuit] lives, there’s a large planet finder in a public square somewhere that stopped locating rocks a long time ago. Hungry to watch such a thing in action, [snowbiscuit] built a great-looking tabletop version that uses the Horizontal Coordinate System to locate planets. Inside is a Raspberry Pi 3, which queries NASA for azimuth and altitude data and combines that data with a predetermined north reading to point out whatever planet was selected by spinning the printed telescope on top. The telescope itself is non-working, and returns to north after a few seconds to wait for input.

This project is wide open for remixing if you want to make your own. As lovely as it is now, designing around a slip ring would eliminate all those long wires and make it more sleek. Take a peek after the break.

Don’t stop your desktop space toy collection there — build an ISS-tracking lamp to go with it.

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Tarot Machine Flips Through Fate’s Rolodex

May 29, 2020 by Kristina Panos 8 Comments

Were tarot card readers deemed non-essential in your part of the world (and do you think they saw it coming?) More than ever, we all need diversions that are for entertainment purposes only. And what better basis for entertainment than a mystical fortune-telling robot that can read your tarot cards?

This fantastic-looking ‘bot stands on the shoulders of [Scott Bezak]’s trailblazing method for easy DIY split-flap displays. Push the rather inviting-looking button on the top, and the flaps start flipping around to find your fortune. Once the fates have aligned, a thermal printer on the front spits out an image of your card along with an interpretation.

It’s obvious that [i_mozy] put quite a lot of effort into this slick machine, and we think the stickers look especially great. All the details of physical tarot card readings are accounted for, including a random number to decide the card’s position, and LEDs to represent the card’s element. Suspend your disbelief and check out the demo/promo video after the break.

Split-flap displays are a great choice no matter what you want to show. We’ve seen them used to display everything from the weather to the current Spotify track.

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No Corners Were Cut On This Arduino Circle Cutter

May 8, 2020 by Tom Nardi 9 Comments

Hackers always have their eye out for a good deal, so when [Gadget Reboot] saw a good price on square stickers he had to pull the trigger. There was just one problem: his logo is a circle. He could have rectified the problem with a pair of scissors on a lazy afternoon, but we think building an elaborate circle cutting machine was a much better use of his time.

But this project isn’t just for the Giotto wannabes. Even if you don’t find yourself in need of an infinite supply of perfect paper circles, the video after the break provides an excellent case study in getting stepper motors to do your bidding; whatever that might be. [Gadget Reboot] walks the viewer through the design and construction of a dual stepper motor controller that could be used for a multitude of tasks.

With an onboard Arduino Pro Micro, OLED display, and rotary encoder, this controller just needs some custom software to make your CNC dreams come true. [Gadget Reboot] is even using low-cost optical endstops in this build, which are a great non-contact way of making sure your machine doesn’t go out of bounds. That’s particularly important when the machine happens to be wielding a razor blade.

If you’re a thoroughly modern hardware hacker who prefers using a web browser to twiddling knobs, then perhaps you’d be interested in the WiFi enabled stepper motor controller we covered recently.

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Watch The Day Inch Along With A Tape Measure Clock

April 27, 2020 by Kristina Panos 24 Comments

If we asked you to rattle off all the tools at your own personal disposal, you’d probably leave your timepieces off the list. But we say clocks are definitely tools — cool tools that come in countless forms and give meaning to endless days.

A clock form we hadn’t considered was that of an actual tool. So we were immeasurably delighted to see [scealux]’s clock made from a measuring tape. At least, the time-telling part of the clock is made from a measuring tape. The case isn’t really from a tape measure — it’s entirely printed, Bondo’d, sanded, and painted so well that it’s quite easy to mistake it for the real thing.

Tightly packed inside this piece of functional art is an Arduino Nano and a DS3231 precision RTC module, which we think is fitting for a tool-based clock. The Nano fetches the time and drives a stepper motor that just barely fits inside. There’s just enough tape wound around the printed hub to measure out the time in increments of one hour per inch. Take 1/16″ or so and watch the demo and brief walk-through video after the break.

Not all tools are sharp, and not all clocks are meant to be precise. Here’s a clock for the times that gives you the gist.

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From The MacGyver Files: Using A Stepper Motor As An Encoder

April 8, 2020 by Al Williams 27 Comments

It isn’t hard to imagine a scenario where you are stuck at home all day with nothing to do and certain items are in short supply. Sure, bathroom tissue gets all the press, but try buying some flour or a freezer and see how far you get. Plus online shopping has given up on next day delivery for the duration. Not hard to imagine at all. Now suppose your latest self-quarantine project needs a rotary shaft encoder. Not having one, what do you do? If you are [Tech Build] you go all MacGyver on an old printer and pull out a stepper motor.

How does a stepper motor turn into an encoder? Well, that’s the MacGyver part. We are not big fans of the physical circuit diagrams, but it looks like [Tech Build] borrowed (with credit) from an earlier post and that one has a proper schematic.

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