Self-Propelled Chainsaw Reduces Injuries

December 25, 2022 by Bryan Cockfield 30 Comments

[Advoko] is an expert at milling logs into various sizes of boards. He typically uses nothing but a chainsaw to enable him to mill on-site without needing to bring any large or expensive equipment. The only problem is that sometimes he gets a little carried away running his mill non-stop until he has enough lumber for whatever project he is building, which has led to some repetitive strain injuries. To enable him to continue to run his mill, he’s created this self-propelled chainsaw jig.

The creation of the self-propelled chainsaw was a little serendipitous. [Advoko] needed to mill a tree which had fallen on a slope, and he couldn’t move the large trunk before starting to mill. To avoid fatigue while pulling his chainsaw upwards, he devised a system of rubber belts that would help pull the weight of the chainsaw up the hill. Noticing that if the chainsaw could have been operated downhill, it would essentially pull itself along the cut, he set about building a carriage for the mill to hold the chainsaw in place while it semi-autonomously milled lumber for him.

The chainsaw jig isn’t fully autonomous; [Advoko] still needs to start and stop the chainsaw and set up the jig. It does have a number of safety features to prevent damage to the jig, the chainsaw, and himself too, and over a number of iterations of this device he has perfected it to the point where he can start it on a cut and then do other tasks such as move boards or set up other logs for cutting while it is running, saving him both time and reducing his risk of other repetitive strain injuries. If you don’t fully trust the automatic chainsaw jig, take a look at this one which requires a little more human effort but still significantly reduces the strain of milling a large log.

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I’ve Got Two Turntables And A Laser Engraver

November 27, 2022 by Bryan Cockfield 29 Comments

Digital media provides us with a lot of advantages. For something like recording and playing back music, digital copies don’t degrade, they can have arbitrarily high quality, and they can be played in a number of different ways including through digital streaming services. That being said, a number of people don’t feel like the digital experience is as faithful to the original sound as it could be and opt for analog methods instead. Creating analog copies of music is a much tougher matter though, as [Marco] demonstrates by using a laser engraver to produce vinyl records.

[Marco] started this month-long project by assembling and calibrating the laser engraver. It has fine enough resolution to encode analog data onto a piece of vinyl, but he had to create the software. The first step was to generate the audio sample, then process it through a filter to remove some of the unwanted frequencies. From there, the waveform gets made into a spiral, accounting for the changing speed of the needle on the record as it moves to the center. Then the data is finally ready to be sent to the laser engraver.

[Marco] did practice a few times using wood with excellent success before moving on to vinyl, and after some calibration of the laser engraver he has a nearly flawless 45 rpm record ready to hit the turntable. It’s an excellent watch if not for anything than seeing a working wood record. We’ve actually seen a similar project before (without the wood prototyping), and one to play records from an image, but it’s been quite a while.

Thanks to [ZioTibia81] for the tip!

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A Simple Stove, Built For Beans

October 14, 2022 by Bryan Cockfield 17 Comments

Sitting around a campfire or fireplace is an aesthetically pleasing experience in most situations, and can even provide some warmth. But unless you have a modern wood-burning appliance, it’s likely that most of the energy available in the biomass is escaping as un-burned vapors. Surprisingly, solving this problem is almost as easy as buying a can of beans at the store, and the result is a very efficient stove which can be used for heat in a pinch.

[Robert] is demonstrating this gasifier stove, not with beans but using both a can of peas and a larger can of potatoes. Various holes are drilled in each can in a specific pattern, and then the smaller pea can is fitted inside the larger potato can. Once a fire is going, the holes allow for air to flow in a way which traps the escaping un-burned vapors from the fuel and burns them as they flow through the contraption. No moving parts are required; this is all powered by the natural airflow that’s produced by the heat of the fire.

The result of a build like this is not only a stove which can extract a much higher percentage of the available fuel, but also quires much less fuel for a given amount of heat, and produces a much cleaner, less smokey fire. [Robert] also added a screen mantle which allows for this to be used more as a heat source, but similar builds can also be used just as effectively for cooking, too.

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Wooden You Like To Hear A CNC-Cut Phonograph Record?

June 17, 2022 by Dan Maloney 22 Comments

Say what you will about [Thomas Edison], but it’s hard to deny the genius of his self-proclaimed personal favorite invention: the phonograph. Capturing sound as physical patterns on a malleable medium was truly revolutionary, and the basic technology that served as the primary medium of recorded sound for more than a century and built several major industries is still alive and kicking today.

With so much technological history behind it, what’s the aspiring inventor to do when the urge to spin your own phonograph records strikes? Easy — cut them from wood with a CNC router. At least that’s how [alnwlsn] rolled after the “one-percent inspiration” hit him while cutting a PCB with his router. Reasoning that the tracks on the copper were probably about as fine as the groove on a record, he came up with some math to describe a fine-pitch spiral groove and overlay data from a sound file, and turn the whole thing into G-code.

For a suitable medium, he turned to the MDF spoil board used to ship PCB stencils, which after about three hours of milling resulted in a rather hairy-looking 78-RPM record. Surprisingly, the record worked fairly well on a wind-up Victrola. The spring-powered motor was a little weak for the heavy wooden record and needed a manual assist, but you can more or less clearly hear the 40-second recording. Even more surprising was how much better the recording sounded when the steel needle was replaced with a chunk of toothpick. You can check out the whole thing in the video below, and you’ll find the G-code generation scripts over on GitHub.

Is all this talk about reproducing music using wiggly lines confusing you? Woah, there, whippersnapper — check out [Jenny]’s primer for the MP3 generation for the background you need.

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Falling Down The Labyrinth With Wooden Microphone Design

May 17, 2022 by Dan Maloney 7 Comments

It used to be that when we featured one of [Frank Olson]’s DIY ribbon microphone builds, it was natural to focus on the fact that he was building them almost exclusively from wood. But despite how counterintuitive it may seem, and for as many comments as we get that his microphones shouldn’t work without metal in the ribbon motors, microphones like this wooden RCA Model 77 reproduction both look and sound great.

But ironically, this homage features a critical piece that’s actually not made of wood. The 77’s pickup pattern was cardioid, making for a directional mic that picked up sound best from the front, thanks to an acoustic labyrinth that increased the path length for incoming sound waves. [Frank]’s labyrinth was made from epoxy resin poured into a mold made from heavy paper, creating a cylinder with multiple parallel tunnels. The tops and bottoms of adjacent tunnels were connected together, creating an acoustic path over a meter long. The ribbon motor, as close to a duplicate of the original as possible using wood, sits atop the labyrinth block’s output underneath a wood veneer shell that does its best to imitate the classic pill-shaped windscreen of the original. The video below, which of course was narrated using the mic, shows its construction in detail.

If you want to check out [Frank]’s other wooden microphones, and you should, check out the beautiful Model 44 replica that looks ready for [Sinatra], or the Bk-5-like mics he whipped up for drum kit recording.

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Number Like It’s 1234 AD With This Cistercian Keypad

May 10, 2022 by Dan Maloney 14 Comments

Don’t feel bad if you don’t know what Cistercian numbers are. Unless you’re a monk of the Order of Cistercia, there’s really no reason for you to learn the cipher that stretches back to the 13th-century. But then again, there’s no reason not to use the number system to make this medieval-cool computer number pad.

If you haven’t been introduced to the Cistercian number system, it’s actually pretty clever. There are several forms of it, but the vertical form used here by [Tauno Erik] is based on a vertical stave with nine glyphs that can be attached to or adjacent to it. Each glyph stands for one of the nine numerals — one through nine only; there’s no need for a zero glyph. There are four quadrants around the stave — upper right, upper left, lower right, and lower left — and where the glyph lies determines the multiplier for the glyph. So, if you wanted to write the number “1234”, you’d overlay the following glyphs into a single symbol as shown.

[Tauno]’s Cistercian keypad, admittedly more of an art and history piece than a useful peripheral, somehow manages to look like it might have been on the desk of [Theodoric of York, Medieval Accountant]. Its case is laser-cut birch plywood, containing a custom PCB for the 20 keyboard switches and the Xiao RP2040 MCU that runs the show. Keycaps are custom made from what looks like oak combined with a 3D-printed part, similar to his previous wooden keycap macro pad. Each of the nine Cistercian glyphs is hand-carved into the keycaps, plus an imaginary glyph for zero, which wasn’t part of the system, as well as operators and symbols that might have baffled the medieval monks.

The native Cistercian system is limited to numbers between 1 and 9,999, so we’ll guess that the keypad just outputs the Arabic numeral corresponding to the Cistercian key pressed and doesn’t actually compose full Cistercian numbers. But the code to do that would be pretty easy, and the results pretty cool, if a bit confusing for users. Even if it’s just for looks, it’s still a cool project, and we doff the hood of our monkish robe to [Tauno] for this one.

Tree Forks As Natural Composite Joints In Architecture

May 6, 2022 by Jenny List 28 Comments

A problem facing architects when designing complex three-dimensional structures lies in their joints, which must be strong enough to take the loads and vector forces applied by the structure, yet light enough not to dominate it. Many efforts have been made to use generative design techniques or clever composites to fabricate them, but as Dezeen reports, a team at MIT are exploring an unexpected alternative in the form of naturally occurring tree forks.

The point at which a tree branch forks from its trunk is a natural composite material formed of an interlocking mesh of wood grain fibres. Timber processors discard these parts of the tree as they interfere with the production of smooth timber, but the same properties that make them support the weight of a branch are it seems perfect for the architects’ needs.

The clever part of the MIT team’s work lies in scanning and cataloguing a library of forks, allowing them to be matched from the database to vertices in an architectural design. The forks are subject to minimal machining before being incorporated into the structure, and to prove it the MIT folks have made a test structure. It’s not uncommon to see medieval barns or half-timbered houses using curved pieces of wood in their natural shapes, so it’s not surprising to see that this 21st century innovation isn’t an entirely new technique.