A Home Made Air Pump From PVC Pipe

April 28, 2017 by 14 Comments

If you need a supply of low pressure air – let’s say enough pressure to ensure a constant supply but not enough to describe as “Compressed air” with a straight face – what do you do? Many people will reach for an aquarium pump, after all that represents a readily available and relatively inexpensive source of bubbles.

But not [truebassB], instead he built his own air pump from first principles (YouTube, embedded below) using PVC pipe. It’s a straightforward design in which the cylinder is a length of pipe with a disc of flat PVC glued to its end, and the piston is fabricated from a short piece of the same tube with a section cut out to reduce its diameter. An adequate seal is achieved using a piece of rubber cut from an inner tube, and the gudgeon pin is cut from a piece of wire. The connecting rod is another longer piece of wire, and the crank is a wooden disc with an offset hole. Power comes from a DC motor taken from a dead power tool. A couple of ball check valves are used for air input and output.

The resulting pump isn’t the prettiest of pumps, and it could probably do with a bit of balancing as it rattles somewhat. But it’s a pump, and it obviously cost next-to-nothing, so that in our eyes makes it a neat build. He’s posted a video of the build which we’ve placed below the break.

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Air-Powered Wheelchair Goes Like The Wind

April 28, 2017 by 53 Comments

Electric wheelchairs are responsible for giving back independence to a great many people the world over. They do have their limitations, however, including long recharge times and a general aversion to large amounts of water. Being weatherproof is one thing, but taking one to a waterpark is another thing entirely. Fear not, for The University of Pittsburgh has the answer: the air-powered wheelchair.

Known as the PneuMobility project, the chair relies on a couple of compressed air tanks as a power source. They appear to be a of composite construction, which would cut down on weight significantly and help reduce risk of injury in the case of a failure. The air is passed through a system of valves to a special compressed air motor, allowing the user to control the direction of travel. Unfortunately details on the drive system are scant — we’d love to know more about the design of the drivetrain! Reportedly a lot of the components come from the local hardware store, though we haven’t seen a whole lot of compressed air drive motors on the racks of Home Depot/Bunnings/et al.

Range for the wheelchairs is listed as about 1/3 of an electric wheelchair but recharging compressed air takes minutes, not hours. Developed by the university’s Human Engineering Research Laboratories, the wheelchair isn’t just a one off. There are plans to supply ten of the machines to the Morgan’s Wonderland amusement park to enable wheelchair users to share in the fun of the water park.

We’ve seen some great wheelchair hacks in the past, too – like this chair built specifically for the sand dunes! Video after the break.

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KFC Winged Aircraft Actually Flies

April 14, 2017 by 41 Comments

[PeterSripol] has made an RC model airplane but instead of using normal wings he decided to try getting it to fly  using some KFC chicken buckets instead. Two KFC buckets in the place of wings were attached to a motor which spins the buckets up to speed. With a little help from the Magnus effect this creates lift.

Many different configurations were tried to get this contraption off the ground. They eventually settled on a dual prop setup, each spinning counter to each other for forward momentum. This helped to negate the gyroscopic effect of the spinning buckets producing the lift. After many failed build-then-fly attempts they finally got it in the air. It works, albeit not to well, but it did fly and was controllable. Perhaps with a few more adjustments and a bit of trial and error someone could build a really unique RC plane using this concept.

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Ask Hackaday: How Does This Air Particle Sensor Work?

April 11, 2017 by 18 Comments

The hardware coming out of [Dr. Peter Jansen]’s lab is the craziest stuff you can imagine. He’s built a CT scanner out of plywood, and an MRI machine out of many, many turns of enamel wire. Perhaps his best-known build is his Tricorder – a real, all-sensing device with permission from the estate of [Gene Roddenberry] to use the name. [Peter]’s tricorder was one of the finalists for the first Hackaday Prize, but that doesn’t mean he’s stopped working on it. Sensors are always getting better, and by sometime in the 23rd century, he’ll be able to fit a neutrino detector inside a tiny hand-held device.

One of the new sensors [Peter] is working with is the MAX30105 air particle sensor. The marketing materials for this chip say it’s designed for smoke detectors and fire alarms, but this is really one of the smallest dust and particle sensors on the market. If you want a handheld device that detects dust, this should be the chip you’re looking at.

Unfortunately, Maxim is being very, very tight-lipped about how this particle sensor works. There is a way to get access to raw particle counts and the underlying algorithms, and Maxim is more than willing to sell those algorithms through a third-party distributor. That’s simply not how we do things around here, so [Peter] is looking for someone with a fancy particle sensor to collect a few hours of data so he can build a driver for this chip.

Here’s what we know about the MAX30105 air particle sensor. There are three LEDs inside this chip (red, IR, and green), and an optical sensor underneath a piece of glass. The chip drives the LEDs, light reflects off smoke particles, and enters the optical sensor. From there, magic algorithms turn this into a number corresponding to a particle count. [Peter]’s hackaday.io log for this project has tons of data, math, and statistics on the data that comes out of this sensor. He’s also built a test rig to compare this sensor with other particle sensors (the DSM501A and Sharp sensors). The data from the Maxim sensor looks good, but it’s not good enough for a Tricorder. This is where you, o reader of Hackaday, come in.

[Peter] is looking for someone with access to a fancy particle sensor to collect a few hours worth of data with this Maxim sensor in a test rig. Once that’s done, a few statistical tests should be enough to verify the work done so far and build a driver for this sensor. Then, [Peter] will be able to play around with this sensor and hopefully make a very cheap but very accurate air particle sensor that should be hanging on the wall of your shop.

Build Your Own High Power Air Cannon Out Of PVC

April 7, 2017 by 41 Comments

[NightHawkInLight] a.k.a. [Ben] recently built an awesome high power air cannon out of PVC pipe. PVC air cannons are great, and everyone should build one of these at some point in their life, but what really makes this build exceptional is the valve. [Ben] created a piston valve for this cannon that can be built with parts sourced from your local home supply store. Anyone can build this thing, and everyone should.

Instead of using a ball valve or other such contrivance to dump air directly from a reservoir into the chamber of this PVC air cannon, [Ben] is using a much more clever design. This is a barrel sealing PVC air cannon, with a moving piston sealed against a rubber hose clamp in the barrel. Adding air through the fill valve moves the piston forward, allowing air to leak into the reservoir. The air supply is then disconnected, and the trigger released causing the piston to move backward. This releases all the air in the reservoir into the barrel instantaneously, resulting in faster ping pong balls and potatoes.

The original trigger for this high power PVC air cannon used a simple ball valve for the trigger. [Ben] didn’t like this solution – it was hard to open and somewhat unergonomic. The ball valve trigger has since been replaced with a valve from a sprinkler system, giving this high power PVC air cannon a fancy brass trigger. It looks awesome, and can kill a watermelon from twenty yards. What more could you want in a high power PVC air cannon?

You can check out the videos for this build – including a guide for the clever piston valve – below.

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Hackaday Prize Entry: Modular Instrumentation For Aircraft

April 5, 2017 by 18 Comments

Parts, tools, and components for aviation and aerospace are sold in ‘Aviation Monetary Units’ (AMU). Right now, the conversion factor from USD to AMU is about 1000 to 1. This stuff is expensive, but there is a small portion of the flying community that prides itself on not breaking the bank every time something needs to be replaced. Theses are often the microlight, ultralight, and experimental aircraft enthusiasts. Steam gauges are becoming obsolete and expensive to repair, and you’re not going to throw a 15 AMU Garmin G500 in an ultralight that only costs 10 AMU.

To solve this problem, [Rene] is turning to sensors, displays, and microcontrollers that are cheap and readily available to build modular aviation instruments.

As with all aviation gear, the first question that springs to mind is, ‘what will the FAA think about this?’. [Rene] is in South Africa, so the answer is, ‘nothing’. If a few American pilots decide to build one of these, that’ll fly too; these are instruments designed for non-type-certified aircraft. That’s not to say there are no rules for what goes into these aircraft, but the paperwork is much easier.

Right now, the design goals for [Rene]’s instruments is under 0.1 AMU per module, robust, RF shielded, with engine monitoring, fuel management, heading, air and ground speed, altitude, attitude, and all the other gauges that make flying easy. He’s using a CAN bus for all of these modules, and in the process slowly dragging the state of the art of ultralight aviation into the 1990s. It’s fantastic work, and we can’t wait to see some of these modules in the air.

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The Altair Shield

March 14, 2017 by 24 Comments

From PDPs to Connection Machines, the Hackaday crowd are big fans of blinkenlights. While this project isn’t an old CPU, RAM, ROM, and an S-100 bus wrapped up in a fancy enclosure, it is a great recreation of the Altair 8800, the historic kit computer that supposedly launched the microcomputer revolution.

[Justin] says his project is just another Altair 8800 clone, but this one is cut down to the size of an Arduino shield. This is in stark contrast to other Altair recreations, whether they are modern PCs stuffed in an old case, modern replicas, or a board that has the same functionality using chunky toggle switches.

On board [Justin]’s pocket-sized Altair are a few LEDs, some DIP switches, and an octet of spring-loaded dual throw switches that wouldn’t look out of place in a 40-year old computer.

This shield targets the Arduino Due rather than the Mega, but only because the Due performs better running an Altair simulation. Everything is there, and a serial terminal is available ready to run BASIC or any other ancient OS.