A diagram showing an LED on the left, a lever-style plumbing valve in the center, and an Arduino Uno on the right.

Plumbing Valves As Heavy Duty Analog Inputs

October 24, 2022 by Navarre Bartz 36 Comments

Input devices that can handle rough and tumble environments aren’t nearly as varied as their more fragile siblings. [Alastair Aitchison] has devised a brilliant way of detecting inputs from plumbing valves that opens up another option. (YouTube) [via Arduino Blog]

While [Aitchison] could’ve run the plumbing valves with water inside and detected flow, he decided the more elegant solution would be to use photosensors and an LED to simplify the system. This avoids the added cost of a pump and flow sensors as well as the questionable proposition of mixing electronics and water. By analyzing the change in light intensity as the valve closes or opens, you can take input for a range of values or set a threshold for an on/off condition.

[Aitchison] designed these for an escape room, but we can see them being great for museums, amusement parks, or even for (train) simulators. He says one of the main reasons he picked plumbing valves was for their aesthetics. Industrial switches and arcade buttons have their place, but certainly aren’t the best fit in some situations, especially if you’re going for a period feel. Plus, since the sensor itself doesn’t have any moving parts, these analog inputs will be easy to repair should anything happen to the valve itself.

If you’re looking for more unusual inputs, check out the winners of our Odd Inputs and Peculiar Peripherals contest or this typewriter that runs Linux.

Continue reading “Plumbing Valves As Heavy Duty Analog Inputs” →

Custom Controller Ups Heat Pump Efficiency

March 25, 2022 by Bryan Cockfield 59 Comments

Heat Pumps are an extremely efficient way to maintain climate control in a building. Unlike traditional air conditioners, heat pumps can also effectively work in reverse to warm a home in winter as well as cool it in summer; with up to five times the efficiency of energy use as a traditional electric heater. Even with those tremendous gains in performance, there are still some ways to improve on them as [Martin] shows us with some modifications he made to his heat pump system.

This specific heat pump is being employed not for climate control but for water heating, which sees similar improvements in efficiency over a standard water heater. The problem with [Martin]’s was that even then it was simply running much too often. After sleuthing the energy losses and trying a number of things including a one-way valve on the heating water plumbing to prevent siphoning, he eventually found that the heat pump was ramping up to maximum temperature once per day even if the water tank was already hot. By building a custom master controller for the heat pump which includes some timing relays, the heat pump only runs up to its maximum temperature once per week.

While there are some concerns with Legionnaire’s bacteria if the system is not maintained properly, this modification still meets all of Australia’s stringent building code requirements. His build is more of an investigative journey into a more complex piece of machinery, and his efforts net him a max energy usage of around 1 kWh per day which is 50% more efficient than it was when it was first installed. If you’re looking to investigate more into heat pumps, take a look at this DIY Arduino-controlled mini heat pump.

Continue reading “Custom Controller Ups Heat Pump Efficiency” →

Portable Pizza Oven Has Temperature Level Over 900

January 24, 2022 by Bryan Cockfield 36 Comments

While it’s possible to make pizza from scratch at home right down to the dough itself, it’ll be a struggle to replicate the taste and exquisite mouthfeel without a pizza oven. Pizzas cook best at temperatures well over the 260°C/500°F limit on most household ovens while pizza ovens can typically get much hotter than that. Most of us won’t have the resources to put a commercial grade wood-fired brick oven in our homes, but the next best thing is this portable pizza oven from [Andrew W].

The build starts with some sheet metal to form the outer and inner covers for the oven. [Andrew] has found with some testing that a curved shape seems to produce the best results, so the sheet metal goes through rollers to get its shape before being welded together. With the oven’s rough shape completed, he fabricates two different burners. One sits at the back of the oven with its own diffuser to keep the oven as hot as possible and the other sits underneath a cordierite stone to heat from the bottom. Both are fed gas from custom copper plumbing and when it fires up it reaches temperatures hot enough that it can cook a pizza in just a few minutes. With some foldable legs the oven also ends up being fairly portable, and its small size means that it can heat up faster than a conventional oven too.

This is [Andrew]’s third prototype oven, and it seems like he has the recipe perfected. In fact, we featured one of his previous versions almost two years ago and are excited to see the progress he’s made in this build. The only downside to having something like this would be the potential health implications of always being able to make delicious pizzas, but that is a risk we’d be willing to take.

Continue reading “Portable Pizza Oven Has Temperature Level Over 900” →

The Miracle Of Injection Molding: How Does It Work?

December 17, 2017 by Bryan Cockfield 18 Comments

Pretty much any household item nowadays has an involved, extremely well-thought-out manufacturing method to it, whether it’s a sheet of paper, an electrical outlet, a can of tuna, or even the house itself. Some of the stories of how these objects came to be are compelling, though, as one of the recent videos from [This Old Tony] shows as he takes a deep dive into a $5 ball valve, and uses it to talk about all of the cool things you can do with injection molding.

Injection molding is the process of casting molten plastic into more useful pieces of plastic. In this case it’s a plumbing valve which might seem simple on the surface, but turns out to be much more involved. These ball valves are extremely reliable but have a very small price tag, meaning that a lot of engineering must have gone into their design. What is unearthed in the video is that injection molding allows parts to be cast into the molds of other parts, and the means by which those parts don’t all melt together, and how seals can be created within the part itself. All of this happens with a minimal number of parts and zero interaction from a human, or from any robot that isn’t the injection mold itself.

The video goes into exceptional detail on these valves specifically but also expounds on various techniques in injection molding. Similar to the recognition the seemingly modest aluminum can deserves, the injection molded ball valve deserves a similar amount of respect. While [This Old Tony] usually focuses on metalworking, he often tackles other interesting topics like this and this video is definitely worth checking out.

Continue reading “The Miracle Of Injection Molding: How Does It Work?” →

Honey, When Did We Get An Indoor Pool?

May 1, 2017 by Jamie Navarro 47 Comments

Is it too much to ask for a home to have a little ‘smart’ built-in? If you’ve ever woken up (or come home) to your dwelling being flooded, you’ll know how terrible it feels, how long it can take to recover from, and how stressful it can be. Yeah, it’s happened to us before, so we really feel for [David Schneider]. He woke up one Sunday morning to a whole lot of water in his house. The inlet valve for his washing machine somehow got stuck in the open position after putting a load of laundry in the previous night.

[David] took progressively complex measures to prevent a broken water feed flood from happening in the future. First, he lined the entire floor of his laundry closet with a steel tray. OK, that’s a good start but won’t prevent another disaster unless it is caught very quickly. How about a simple audible water alarm? That’s good and all if you’re home, but what if you’re not?

Next, he installed a valve with a mechanical timer on the water line for the washing machine which closes automatically after 2 hours of being opened. Much better, but what about all the other thirsty appliances around the house? After searching online a little, he found plenty of whole house systems that would work for him, but there were 2 problems with these. First, most were network-based and he didn’t want to IoT-ify his house’s water system. Second, they were overpriced.

Of course the solution was to put together his own system! First, he purchased a few mostly inexpensive things — a wireless alarm, some water sensors, and a motorized ball valve. Then he collected the last few things he needed from what he had on hand around the house, and got to work connecting the 4 LEDs on the alarm to 4 analog input pins on his Arduino. Next, he added a relay between the Arduino and the motorized ball valve.

If a sensor detects water, it tells the alarm about it (wirelessly), which triggers the Arduino to energize a relay that is connected to the motorized ball valve, causing it to shut off the main water line for the entire house. Disaster averted! Sure, it’s a fairly simple hack, but it works, meets his requirements, and now he sleeps better at night knowing he won’t wake up (or come home) to an indoor swimming pool.

It’s surprising that we haven’t seen more hacks like this given it’s such a common problem. The closest thing we can remember is an overflow sensor for an aquarium. If homes came standard with a water main shutoff system, it would remove a stressful event from our lives and maybe even lower our insurance premium.

Simple Devices Protecting Our Water System

November 17, 2015 by Richard Baguley 39 Comments

We are all used to turning on the faucet and having clean, drinkable water on demand. But think about what happens afterwards in your home: that water is used to wash dishes or water lawns and many other uses that render it undrinkable. What stops this nasty water from flowing back into your pipes and out of your kitchen faucet? A backflow preventer. This simple, but vital, part of your plumbing turns your water pipes into one-way systems that give out clean, drinkable water. This isn’t just about making your water taste nice: backflow preventers protect your water supply from things like brain-eating amoeba and E Coli that could kill.

Continue reading “Simple Devices Protecting Our Water System” →

Wet Spill Vacuum Cleaner Attachment

June 13, 2013 by Mike Szczys 45 Comments

wet-spill-vacuum-attachment

You’ve got to hand it to [Lou], not only does he know how to build simple items, he also knows how to sell their worth. Here’s a wet spill vacuum cleaner attachment which you can build on the cheap. A picture of the final product fails to have the same impact as his video showing its use in cleaning up a simulated cat disgorging from the carpet.

From the picture we’re sure you’ve already figured out how it work. The air and damp matter come in one side and are dropped into the jar as the air is sucked out the other. [Lou] suggests raiding your recycling bin for the jar. The intake and outflow are both pieces from a PVC P-trap intended for a sink drain. They have a threaded flange which keeps the part from pulling all the way through the 1.5″ holes drilled in the lid.

This is going to work best with a high-flow shop vacuum. So while you’ve got the tools out, why not build a dust separator as well?

Continue reading “Wet Spill Vacuum Cleaner Attachment” →