Pool Temperature Monitor Mollifies Fortunate But Frustrated Children

May 2, 2021 by Kristina Panos 25 Comments

Who needs the city pool when you can party in the private pool over at Grandma and Grandpa’s house? No need to wait until Memorial Day weekend when it hits 90° F in the first week of May. But how can you placate grandchildren who want to know each and every day if it’s finally time to go swimming, and the pool itself is miles away? Although grandparents probably love to hear from you more often there’s no need to bother them with hourly phone calls. You just have to build a floating, remote pool temperature monitor which broadcasts every 30 minutes to an Adafruit MagTag sitting at kid’s eye level on the refrigerator.

Between the cost of commercial pool temperature monitors and all the reviews that mention iffy Wi-Fi connections, it sounds like [Blake] is better off rolling his own solution. Inside the floating part is an ESP32, a DS18B temperature sensor, and a 18650 cell. Most of the body is PVC, except for the 3D-printed torus that holds some foam for buoyancy. A handful of BBs in the bottom keep the thing pointed upright. For now, it shows the water temperature, but [Blake]’s ultimate goal is to show the air temperature as well.

Maybe it’s still too cold to swim, but the sun shines brightly most days. Why not harness its energy to heat up the water?

Two-Player PVC Racing Rig Plays Daytona USA

May 1, 2021 by Lewin Day 9 Comments

SEGA’s Daytona USA is that big orange arcade racing machine you remember from the 90s that still seems to hang on in cinemas and pizza joints worldwide. Its controls may be floaty and physics unrealistic, but it’s probably the one racing game that almost everyone has played at one point or other. [Tom Tilley] decided to build a PVC racing rig for the game during his travels in Thailand.

As a bonus, the lightweight rigs can be broken up and transported easily by scooter.

PVC pipe is used to whip up the frames for the budget simulator, inside which each player sits. Different sizes of PVC pipe and various adapters are used to create a basic steering wheel, to which a potentiometer is attached, while the centering mechanism is simply a rubber band. The pedals are built similarly and fitted with microswitches. The build relies on a cheap USB gamepad that mimics the typical PlayStation Dual Shock design, with the pot and switches wired in place of the existing thumbstick and buttons. A computer running the PC version of Daytona USA is then used to complete the setup, along with a projector for split-screen fun.

It’s certainly not a high-end simulator by any means, but for the price of some pipes and cheap controllers, [Tom] was able to create a two-player racing rig for a fraction of the cost to hire the real arcade machine for a weekend. The kids that playtested the system certainly seemed to have a good time, as well. We’ve seen similar low-tech builds before, too – with impressive results. Video after the break.

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PVC Pipes Play “Popcorn” Perfectly

February 22, 2021 by Kristina Panos 16 Comments

There are all sorts of fun ways to make music with empty jugs and other things that resonate with a popping sound when poked with a finger. Should you ever get stuck on that proverbial desert island, you can entertain yourself by making cheerful, staccato music with nothing but a fingertip and the inside of your cheek. At the very least, it will keep your spirits up until you can fashion an ocarina from a coconut.

[Nicolas Bras] loves to make homemade instruments. When he saw all the scrap pieces of perfectly finger-sized PVC tubing piling up around the workshop, he decided to make an instrument specifically to play the effervescent synth tune “Popcorn”. (Video, embedded below.) He plays it by plugging and quickly unplugging wood-capped pipes with his fingers, and using another PVC tube to blow across the tops of them to fill out the orchestration.

[Nicolas] started by making a two-octave chromatic scale with 25 pipes ranging from C4 to C6. He kept building on it from there in both directions, ultimately ending up with a poppin’ 68-note pipe organ that sounds fantastic. If you’re interested in getting the sound samples, [Nicolas] has those and the instrument plans available through Patreon.

Be sure to check out the build and demo video below — it’s a joy to see it come together, and the whole thing clocks in under six minutes. Take our word for it and don’t jump to the “Popcorn” cover, because the build-up is necessary for maximum enjoyment.

Hungry for more “Popcorn”? Here’s a robotic glockenspiel busting out a striking cover.

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Air Cannon Serves Up A Blast Of Ferrocerium Sparks

October 15, 2020 by Dan Maloney 25 Comments

OK, looks like we have a new way to entertain the kids and wreak havoc in the neighborhood, if this spark-shooting ferrocerium cannon is as easy to build as it looks.

This one comes to us by well-known purveyor of eyebrow-singing projects [NightHawkInLight], whose propane torch never seems to get a break. The idea here is a large scale version of an apparently popular trick where the “flints” from lighters, which are actually rods of ferrocerium, an aptly named alloy of iron and cerium, are heated to a nearly molten state and dropped onto a hard surface. The molten alloy thence explodes in a shower of sparks, to the mirth and merriment of those in attendance.

[NightHawkInLight]’s version of the trick scales everything up. Rather than lighter flints, he uses ferrocerium rods from firestarters of the type used for camping. The rod is stuffed into a barrel formed from steel brake line which is connected to the output of a PVC air chamber. His ominpresent propane torch is attached in such a way as the flame plays upon the loaded pyrophoric plug, heating it to a molten state before the air is released from the chamber. The massive display of sparks seen in the video below is pretty impressive, but we’re getting tired of gender reveal parties and forest fires. We just hope he had fire extinguishers on hand.

Seriously, be careful with stuff like this. [NightHawkInLight] has a lot of experience working with these kinds of projects, from his plasma-propelled soda bottles to making synthetic rubies with an arc welder. We’re sure he wouldn’t want to see anyone get hurt.

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Hack A Folding Bike To Help You Catch Some Pike

August 3, 2020 by Kristina Panos 7 Comments

For many of us, this whole pandemic thing has produced some unexpected upsides. One of [George Turvey]’s was finding a nice new scenic route to work that goes by a lake with bike trails. [George] thought it might be nice to go fishing after work, and use a folding bike to cover a lot of ground while looking for good spots on the shore. There was just one problem — riding a bike while transporting tackle is awkward.

The bike comes with a front mount that’s meant to hold the special bags they make, so that became square one for designing a rod and tackle holder. Then [George] had to weigh the pros and cons of additive vs. subtractive methods for prototyping the holder, or at least the connection between it and the mount on the bike.

Milling won out, at least for the initial proof of concept, and result is a modular mock-up that combines a milled Kydex connector and tackle box holder with a double-barrel PVC rod holder. This way, [George] had a prototype in a fraction of the time it would have taken to design and print it. Cast your line past the break to see how fast [George] can switch gears into fishing mode.

3D printing definitely has a place in the fishing world. How else are you gonna design your own lures?

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Converted Car Lets Toddlers Tool Around

February 10, 2020 by Kristina Panos 9 Comments

A few years ago, a professor at the University of Delaware started a project called Go Baby Go. It’s designed to bring fun and affordable mobility to small children with disabilities. The idea is to modify Power Wheels cars to make them easier for disabled kids to operate, and to teach as many people as possible how to do it in the process. The [South Eugene Robotics Team] is taking this a step further by replacing the steering wheel with a joystick that controls two motors with an Arduino Nano.

In the first instance you replace the foot pedal with a push button. The plans also call for a PVC frame, a high-backed seat, and a seat belt to make it safer. The end result is a fun ride the kid can control themselves that functions a lot like a power wheelchair, but is much more affordable. It has the added bonus of being a fun conversation piece for the other kids instead of a weird scary thing.

They also replace the front wheels with 5″ casters, because being able to spin around in circles is awesome. Their project shows how to do the entire conversion in great detail, starting with a standard ride-on car that comes with some assembly required. Motor past the break to check out a short demo with an extremely happy child tooling around in a fire truck.

If these kids get too wild, they’re gonna need traction control for these things.

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