LeanPipe

Building Things With Lean Pipe

Sometimes you just want to build something quickly and easily. Maybe you just need a basic structure for your actual project, or perhaps you want to be able to easily modify the design. Maybe you don’t have access to many fancy tools to build a solid, lightweight structure. Another possibility is that you want to be able to break down your structure and move it at a later date. In cases like these, you might want to consider using lean pipe.

Lean pipe is kind of like K’NEX for adults. It’s made up of metal pipe and specialized fittings. If you’ve ever worked with PVC pipe before then this may sound familiar. The difference is lean pipe is stronger and designed specifically for building sturdy structures. The fixtures designed for use with lean pipe are much easier to work with than PVC pipe. With PVC pipe, it seems like you never have the exact right fitting and you have to build your own adapters, quickly increasing the cost of the design.

A typical lean pipe fitting will either slide over the end of a section of pipe, or wrap around it somewhere in the middle. An adjustment screw can then be tightened to clamp the fitting in place around the sections of pipe. The video below does a good job demonstrating the different possibilities with fittings. The primary issue with this material is that you might not be able to find it at your local hardware store. Luckily, a quick Internet search will turn up a number of online purchasing options.

So what can you build with this stuff? Cody has been building himself computer desks with an industrial look. He first starts out with the frame design. This is the part that’s made from the lean pipe. Once the frame is completed he just needs to work on the wood surfaces. All he really needs to do is cut the wood to shape and then finish it to look nice. It then lays in place and can be bolted down for extra security. Continue reading “Building Things With Lean Pipe”

How To Weigh An Eyelash

So you’re a boxer, and you’re weighing in just 80 micrograms too much for your usual weight class. How many eyelashes do you need to pluck out to get back in the ring? Or maybe you’re following the newest diet fad, “microcooking”, and a recipe calls for 750 micrograms of sugar, and you need to know how many grains that is. You need a microgram scale.

OK, we can’t really come up with a good reason to weigh an eyelash, except to say that you did. Anyway, not one but two separate YouTube videos show you how to build a microgram balance out of the mechanism in a panel meter. You know, the kind with the swinging pointer that they used to use before digital?

Panel meters are essentially an electromagnet on a spring in the field of a permanent magnet (a galvanometer). When no current flows through the electromagnet, the spring pulls the needle far left. As you push current through the electromagnet, it is attracted to the fixed permanent magnet, fighting the spring, and tugs the pointer over to the right. More current equals more pull.

Continue reading “How To Weigh An Eyelash”

The Modular Bench Power Supply To Rule Them All

Right now, [The Big One] is using an ATX power supply as a bench power supply for all his electronics projects. It works, but it’s not ideal. The next step up from a power supply from an old computer is, in order, one of those Chinese deals on Amazon, a used HP supply, or for the very cool people among us, building your own. [The Big One] is very, very cool and he’s building the modular bench supply to rule them all.

This is not your $100 china special power supply that [The Big One] would have to buy again in a few months. Inside this massive power supply is a massive transformer and rectifier that fans out to multiple power supply modules. The modules themselves will be based on an OPA548 that will be able to supply up to 3A with current limiting.

Each of these channels will be controlled by an ATMega32u4, with all the fancy stuff you’d expect from the ultimate supply; USB for setting voltage, current, and logging data, a nice LCD character display, and it’s surprisingly cheap; just about $100 for the transformer, and about $50 for each module.

It’s shaping up to be a great build, and with all the features, a power supply that would also make a great kit. If you have any input you’d like [The Big One] to hear, let him know on the project page.

A wood router with automated height adjustment

A Router Table With Height Control

The wood router is a versatile power tool which can be picked up at a low price. Nicer router setups are mounted underneath a table, with the cutting head poking through. This makes it easier and safer to work with the tool.

[Paul] combined his interest in electronics and woodworking by making a router table with automated controls [translation]. The neat part of this build is the automated height control, which ensures accurate cutting depth.

The router is mounted to a threaded rod, which allows it to be moved up and down by a motor. A low cost L298 motor driver provides the power to the motor, which is controlled by an Arduino Uno. A VCNL4020 based sensor board is used to measure distance and accurately set the router height. This tiny proximity sensor looks like a nifty chip, providing distance measurements up to 200 mm and an ambient light sensor in one package.

The routing table has an LCD display and buttons, allowing the user to dial in their desired height. The entire thing was built using recycled bits and well under $100 in new parts.

Robo-Wire-Snips Clip 1k Segments

Quick, you need 1000 pieces of wire of the same length, what do you do? The disappointing answer is to put on the miniseries masterpiece Frank Herbert’s Dune and get to work snipping those bits by hand. We usually clamp a scrap piece of molding protruding perpendicular to the bench to use as a length guide in these cases.

The more exciting answer is to build a robot to do it for you. There’s no way you can build the robot faster than you could cut the wire… unless you have admirable rapid prototyping skills like [Eberhard]. He strapped together a barebones machine from two motors, and one switch in no time. Pretty amazing!

Wire coming off the spool feeds through two guides held by a third-hand. The outfeed length depends entirely on timing; two slices of wine cork drive the wire which passes through the open jaws of a wire snip. Those snips are hot-glued in place, with a motor winding up a strip connected to the other handle in order to make the cut. The only feedback is a limit switch when the snip is fully open.

It is entirely possible to get even less advanced. Here’s the same concept without the limiting switch. We appreciate the eloquence of the snipper squeeze method on that one. But for the most part we think you’ll be interested in one that goes about stripping the wire ends as well as cutting to length.

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Altoids Tin Network Analyzer

Network Analyzers are frequently used for measuring filters, making them extremely valuable for building radios and general mucking about with RF. They are, however, extremely expensive. You can, however, build one in an Altoids tin with an Arduino Nano, a small screen, and an AD9850 frequency synthesis module picked up on eBay.

The basic idea behind a network analyzer is to feed a frequency into a device, and measure the amplitude coming out of the device, and plot this relationship over a frequency. [Bill Meara] has been a human network analyzer before, changing frequencies and plotting the output of devices under test by hand. [DuWayne] (KV4QB) build a device to automate the entire process.

The block diagram is easy enough – an AD9850 sends a signal to the device, and this is measured by the Arduino with a small amplifier. The signal is measured again when it comes back from the device under test, and all this is plotted on a small display. Simple, and [DuWayne] is getting some very good readings with a lowpass filter and crystal filter made on a small solderless breadboard.

Watt Meter Build Walks You Through Power Measurement Basics

You almost never hear of a DC Watt Meter – one just does some mental math with Volts and Amps at the back of one’s head. An AC Watt Meter, on the other hand, can by pretty useful on any workbench. This handy DIY Digital AC Watt Meter not only has an impressive 30A current range, but is designed in a hand-held form factor, making it easy to carry around.

The design from Electro-Labs provides build instructions for the hardware, as well as the software for the PIC micro-controller at its heart. A detailed description walks you through the schematic’s various blocks, and there’s also some basics of AC power measurement thrown in for good measure. The schematic and board layout are done using SolaPCB – a Windows only free EDA tool which we haven’t heard about until now. A full BoM and the PIC code round off the build. On the hardware side, the unit uses MCP3202 12 bit ADC converters with SPI interface, making it easy to hook them up to the micro-controller. A simple resistive divider for voltage and an ACS-712  Hall Effect-Based Linear Current Sensor IC are the main sense elements. Phase calculations are done by the micro-controller. The importance of isolation is not overlooked, using opto-isolators to keep the digital section away from the analog. The board outline looks like it has been designed to fit some off-the-shelf hand-held plastic enclosure (if you can’t find one, whip one up from a 3D printer).

Although the design is for 230V~250V range, it can easily be modified for 110V use by changing a few parts. Swap the transformer, change the Resistive voltage divider values, maybe some DC level shifting, and you’re good to go. The one feature that would be a nice upgrade to this meter would be Energy measurements, besides just Power. For an inside look at how traditional energy meters work, head over to this video where [Ben Krasnow] explains KiloWatt Hour Meters