Genaille’s Rods: When Paint Sticks Do Math

April 26, 2022 by Ryan Flowers 2 Comments

What is a hacker, if not somebody who comes up with solutions that other just don’t see? All the pieces may be in place, but it takes that one special person to view the pieces as greater than the sum of their parts. As [Chris Staecker] explains in the video below the break, Henri Genaille was one such person.

When French mathematician Edouard Lucas (himself well known for calculating the longest prime number found by hand) posed a mathematical problem at the French Academy, a French railway engineer named Henri Genaille developed the rods we’re discussing now.

Genaille’s Rods are designed to perform multiplication. But rather than require computation by the user, the rods would simply need to be laid out in the correct order. The solution could readily be found by just following the lines in the correct pattern. This might sound a lot like cheating, and that’s exactly what it is. No manual math needed to be done. Genaille also created rods for doing long division, which we’re sure were every bit as enthralling as the multiplication rods. Demonstrations of both are included in the video below.

While Genaille’s Rods have gone the way of the slide rule, we can’t help but wonder how many engineers and scientists carried around a set of marked up wooden sticks in their pocket protector.

If designing and building manual mathematical machines is something that you think really adds up to a good time, check out this post on how to design and build your own circular slide rule!

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SMT Part Counter Aims To Ease Taking Inventory

April 20, 2022 by Donald Papp 16 Comments

[Nick Poole] has an interesting idea for a new tool, one that has the simple goal of making accurate part counts of SMT reels as easy as pulling tape through a device. That device is the BeanCounter, an upcoming small handheld unit of his own design that counts parts as quickly as one can pull tape through a slot. The device is powered by a CR2032 cell and and works with 8 mm wide tapes up to 2 mm in height, which [Nick] says covers most 0805 or smaller sized parts, as well as things like SOT-23 transistors.

Why would one want to make such a task easier? Two compelling reasons for such a tool include: taking inventory of parts on partial reels or cut tape, and creating segments that contain a known number of parts.

The first is handy for obvious reasons, and the second is useful for things like creating kits. In fact, the usefulness of this tool for creating tape segments of fixed length is perhaps not obvious to anyone who hasn’t done it by hand. Sure, one can measure SMT tape with a ruler or a reference mark to yield a segment containing a fixed number of parts, but that involves a lot of handling and doesn’t scale up very well. In fact, the hassle of cutting tape segments accurately and repeatedly is a common pain point, so making the job easier has value.

If you looked at the photos and suspected that the big, 7-segment numeric display is done with clever PCB fabrication options (making segments by shining LEDs through PCB layers, a trick we always like to see) you’re not alone. After all, [Nick] has a lot of experience in getting clever with board fabrication, and eagle-eyed readers may even suspect that the reset and setup buttons on the edge of the tool are created by using flex PCB segments as switches. Want the nitty-gritty details? Visit the GitHub repository for the project and see it all for yourself at the CAD level.

Bring Precision To The Woodshop With An Electronic Router Lift

April 20, 2022 by Dan Maloney 13 Comments

One of the knocks that woodworkers get from the metalworking crowd is that their chosen material is a bit… compliant. Measurements only need to be within a 1/16th of an inch or so, or about a millimeter, depending on which side of the Atlantic you’re on. And if you’re off a bit? No worries, that’s what sandpaper is for.

This electronic router lift is intended to close the precision gap and make woodworking a bit less subjective. [GavinL]’s build instructions are clearly aimed at woodworkers who haven’t dabbled in the world of Arduinos and stepper motors, and he does an admirable job of addressing the hesitancy this group might feel when tackling such a build. Luckily, a lot of the mechanical side of this project can be addressed with a commercially available router lift, which attaches to a table-mounted plunge router and allows fine adjustment of the cutting tool’s height from above the table.

What’s left is to add a NEMA 23 stepper to drive the router lift, plus an Arduino to control it. [GavinL] came up with some nice features, like a rapid jog control, a fine adjustment encoder, and the ability to send the tool all the way up or all the way down quickly. Another really nice touch is the contact sensor, which is a pair of magnetic probes that attach temporarily to the tool and a height gauge to indicate touch-off. Check the video below to see it all in action.

One quibble we have with [GavinL]’s setup is the amount of dust that the stepper will be subjected to. He might need to switch out to a dustproof stepper sooner rather than later. Even so, we think he did a great job bridging the gap between mechatronics and woodworking — something that [Matthias Wandel] has been doing great work on, too.

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Custom-Fit Small Shop Crane Lightens The Load

April 19, 2022 by Dan Maloney 13 Comments

On the shortlist of workshop luxuries, we’d bet a lot of hackers would include an overhead crane. Having the ability to lift heavy loads safely and easily opens up a world of new projects, and puts the shop into an entirely different class of capabilities.

As with many of us, [Jornt] works in a shop with significant space constraints, so the jib crane he built had to be a custom job. Fabricated completely from steel tube, the build started with fabricating a mast to support the crane and squeezing it into a small slot in some existing shelves in the shop, which somehow didn’t catch on fire despite being welded in situ. A lot of custom parts went into the slewing gear that mounts the jib, itself a stick-built space frame that had to accommodate a pitched ceiling. A double row of tubing along the bottom of the jib allows a trolley carrying a 500 kg electric winch to run along it, providing a work envelope that looks like it covers the majority of the shop. And hats off for the safety yellow and black paint job — very industrial.

From the look of the tests in the video below, the crane is more than up to the task of lifting engines and other heavy loads in the shop. That should prove handy if [Jornt] tackles another build like his no-compromises DIY lathe again.

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Gridfinity: 3D Printed Super Quick Tool Storage And Retrieval

April 18, 2022 by Dave Rowntree 32 Comments

Our favourite cyborg [Zack Freedman] has been stumbling over a common problem many of us will be all too familiar with — that of tool storage and the optimal retrieval thereof. His solution is the Gridfinity: A modular workshop organisation system.

Never chase your pen around on the desk again

In [Zack]’s words, the perfect workshop has tools and materials arranged in the following way: (a) every item has a dedicated home within reach of where you’ll use it. (b) items are exposed and in position for instant grabification. (c) the storage system shields you from accidents like spills and injuries. (d) it is effortless to setup and easy to put back and rearrange. An instant-access storage solution such as the Gridfinity is designed not to help you store more stuff, but finish more projects. The idea is very simple — display your stuff so that you can quickly find what you need and get back to the project as quickly as possible. We think these aims are pretty spot on!

From an implementation perspective, the system consists of a 3D printed base plate with a grid structure. It is angled internally so storage bins drop in, but are not easy to knock out. Storage units drop into the grid in various sizes and orientations, such that everything is contained within the grid’s outer boundary, so the whole assembly will fit inside a drawer with ease. Small part storage bins have a curved inner surface enabling one to easily scoop out a part when required. A partial lid on the top allows them to be stacked vertically if required.

Super-quick access to fully sorted stock – no more searching

Whilst the system is work in progress, there are still about a hundred different storage units, for anything from 3D printer nozzles to racks for tweezers. Implemented as parameterised models in Fusion360, it is easy to tweak existing models for your stuff, or create totally new ones, from the supplied templates.

No discussion of tool organisation would be complete without first considering the king of tool organisation [Adam Savage], the principle of first order retrieval is a strong one. For a more in-your-face solution, you could go down the pegboard-on-wheels route, or perhaps if you’re less mobile and in a tight squeeze, then get comfortable with the French cleat and build something full custom right into the walls. Whatever solution you come up with, do share it with us!

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An unfastened piece of pipe in a drill press, rotating away

Drill Press Piece Fastening 101

April 17, 2022 by Arya Voronova 16 Comments

What are the options you have for securing your workpiece to the drill press table? [Rex Krueger] shows us that there’s plenty, and you ought to know about them. He goes through the disadvantages of the usual C-clamps, and shows options like the regular drill press vice and a heavy-duty version that even provides a workpiece tilting mechanism, and points out small niceties like the V-grooves on the clamps helping work with round stock. For larger pieces, he recommends an underappreciated option — woodworkers’ wooden handscrew clamps, which pair surprisingly well with a drill press. Then, he talks about the hold-down drill press clamps, a favourite of his, especially when it comes to flat sheets of stock like sheet metal or plastic.

As a bonus for those of us dealing with round stock, he shows a V-block he’s made for drilling into its side, and round stock clamp, made by carefully drilling a pair of wooden hand screw clamps, for when you need to drill into a dowel from its top. The ten-minute video is a must watch for anyone not up to speed on their drill press piece fastening knowledge, and helps you improve your drilling game without having skin in it.

We’ve covered a few ingenious and unconventional drill piece fastening options before, from this wise held down by repurposed bicycle quick-release parts, to an electromagnetic wise that left our readers with mixed opinions.

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A handheld device to measure electromagnetic fields

Measuring Electromagnetic Fields With Just An Arduino And A Piece Of Wire

April 17, 2022 by Robin Kearey 9 Comments

Electromagnetic interference problems can be a real headache to debug. If you need to prove what causes your WiFi to slow down or your digital TV signal to drop, then the ability to measure electromagnetic fields (EMF) can be a big help. Professional equipment is often very expensive, but building an EMF detector yourself is not even that difficult: just take a look at Arduino expert [Mirko Pavleski]’s convenient hand-held electromagnetic field detector.

The basic idea is quite simple: connect an antenna directly to an Arduino’s analog input and visualize the signal that it measures. Because the input of an ADC is high impedance, it is very sensitive to any stray currents that are picked up by the antenna. So sensitive in fact, that a resistor of a few mega-Ohms to ground is required to keep the sensor from triggering on any random kind of noise. [Mirko] made that resistance adjustable with a few knobs and switches so that the detector can be used in both quiet and noisy environments.

Making the whole device work reliably was an interesting exercise in electromagnetic engineering: in the first few iterations, the detector would trigger off its own LEDs and buzzer, trapping itself in a never-ending loop. [Mirko] solved this by encasing the Arduino inside a closed, grounded metal box with only the required wires sticking out. The antenna’s design was largely based on trial-and-error; the current setup with a 7 cm x 3 cm piece of aluminium sheet seemed to work well.

While this is not a calibrated professional-grade instrument, it should come in handy to find sources of interference, or even simply to locate hidden power cables. You can view this as a more advanced version of [Mirko]’s Junk Box EMF Detector; if you have a second Arduino lying around, you can use that one to generate interference instead. Continue reading “Measuring Electromagnetic Fields With Just An Arduino And A Piece Of Wire” →