A Single-Digit-Micrometer Thickness Wood Speaker

Researchers have created an audio speaker using ultra-thin wood film. The new material demonstrates high tensile strength and increased Young’s modulus, as well as acoustic properties contributing to higher resonance frequency and greater displacement amplitude compared to a commercial polypropylene diaphragm in an audio speaker.

Typically, acoustic membranes have to remain very thin (on the micron scale) and robust in order to allow for a highly sensitive frequency response and vibrational amplitude. Materials made from plastic, metal, ceramic, and carbon have been used by engineers and physicists in an attempt to enhance the quality of sound. While plastic thin films are most commonly manufactured, they have a pretty bad impact on the environment. Meanwhile, metal, ceramic, and carbon-based materials are more expensive and less attractive to manufacturers as a result.

Cellulose-based materials have been making an entrance in acoustics research with their environmentally friendly nature and natural wooden structure. Materials like bagasse, wood fibers, chitin, cotton, bacterial cellulose, and lignocellulose are all contenders for effective alternatives to parts currently produced from plastics.

The process for building the ultra-thin film involved removing lignin and hemicellulose from balsa wood, resulting in a highly porous material. The result is hot pressed for a thickness reduction of 97%. The cellulose nano-fibers remain oriented but more densely packed compared to natural wood. In addition, the fibers required higher energy to be pulled apart while remaining flexible and foldable.

At one point in time, plastics seemed to be the hottest new material, but perhaps wood is making a comeback?

[Thanks Qes for the tip!]

Harmonic Analyzer Does It With Cranks And Gears

Before graphic calculators and microcomputers, plotting functions were generally achieved by hand. However, there were mechanical graphing tools, too. With the help of a laser cutter, it’s even possible to make your own!

The build in question is nicknamed the Harmonic Analyzer. It can be used to draw functions created by adding sine waves, a la the Fourier series. While a true Fourier series is the sum of an infinite number of sine waves, this mechanical contraption settles on just 5.

This is achieved through the use of a crank driving a series of gears. The x-axis gearing pans the notepad from left to right. The function gearing has a series of gears for each of the 5 sinewaves, which work with levers to set the magnitude of the coefficients for each component of the function. These levers are then hooked up to a spring system, which adds the outputs of each sine wave together. This spring adder then controls the y-axis motion of the pen, which draws the function on paper.

It’s a great example of the capabilities of mechanical computing, even if it’s unlikely to ever run Quake. Other DIY mechanical computers we’ve seen include the Digi-Comp I and a wildly complex Differential Analyzer. Video after the break.

Continue reading “Harmonic Analyzer Does It With Cranks And Gears”

3D Printer Meets CNC Router To Make Wood Prints

We’ve seen plenty of plywood 3D printers before; after all, many early hobbyist machines were made from laser-cut plywood. But this plywood 3D-printer isn’t made from plywood – it prints plywood. Well, sort of.

Yes, we know – that’s not plywood the printer is using, but rather particleboard, the same material that fills the flatpack warehouse of every IKEA store. And calling it a printer is a bit of a stretch, too. This creation, by [Shane Whigton] and his Formlabs Hackathon team, is more of a hybrid additive-subtractive CNC machine. A gantry-mounted router carves each layer of the print from a fresh square of material – which could just as easily be plywood as particleboard. Once a layer is cut, the gantry applies glue to it, puts a fresh sheet of material on top, and clamps it down tight. The router then carves the next layer, and so on up the stack. The layer height is limited to the thickness of the material – a nominal 3/4″ (19 mm) in this case – and there’s a remarkable amount of waste, but that’s not really the point. Check out the printer in action and the resulting giant Benchy in the video below.

Seeing all that particleboard dust and glue got us thinking: what about a 3D-printer that extrudes a paste of sawdust mixed with glue? We imagine that would be a bit like those giant printers that extrude concrete to build houses.
Continue reading “3D Printer Meets CNC Router To Make Wood Prints”

Project Egress: The Hinges

A door’s hinges are arguably its most important pieces. After all, a door without hinges is just, well, a wall. Or a bulkhead, if we’re talking about a hingeless hatch on a spacecraft.

And so the assignment for creating hinges for Progress Egress, the celebration of the 50th anniversary of the Apollo 11 landing by creating a replica of the command module hatch, went to [Jimmy DiResta]. The hinges were complex linkages that were designed to not only handle the 225 pound (102 kg) hatch on the launch pad, but to allow extended extravehicular activity (EVA) while en route to the Moon. [Jimmy], a multimedia maker, is just as likely to turn metal as he is to work in wood, and his hinges are a study of 1960s aerospace engineering rendered in ipe, and extremely hard and dense tropical hardwood, and brass.

[Jimmy]’s build started with a full-size 3D-printed model of the hinge, a move that paid off as the prints acted both as templates for machining the wood components and as test jigs to make sure everything would articulate properly. Sheet brass was bent and soldered into the hinge brackets, while brass rod stock was turned on the lathe to simulate the hydraulic cylinder hinge stays of the original. The dark ipe and the brass work really well together, and should go nicely with [Fran Blanche]’s walnut and brass latch on the assembled hatch.

With [Adam Savage]’s final assembly of all the parts scheduled for Thursday the 18th, we’re down to the wire on this celebration of both Apollo and the maker movement that was at least in part born from it.

Note: the assembly started at 11:00 Eastern time, and there’s a live stream at https://airandspace.si.edu/events/project-egress-build.

Continue reading “Project Egress: The Hinges”

JigFab Makes Woodworking Easier

Woodworking is an age-old craft that requires creativity and skill to get the best results. Experienced hands get the best results, while the new builder may struggle to confidently produce even basic pieces. JigFab is here to level the playing field somewhat.

Much of the skill in woodworking comes with mastering the various joints and techniques required to hold a piece together. Cutting these joints often requires specialized tools and equipment – ideally, some sort of jig. These jigs can be difficult to build in themselves, and that’s where JigFab shines.

The workflow is straightforward and quite modern. A piece is designed in Autodesk Fusion 360. Various joints can then be defined in the model between individual parts. JigFab then generates a series of laser cut constraints that can be used with power tools to easily and accurately cut the necessary parts to build the final piece.

It’s an impressive technology which could rapidly speed the workflow of anyone experimenting with woodwork and design. There’s even smart choices, like having a toolkit of standard predefined elements that reduce laser cutting time when producing new constraints. If you’re eager to get stuck in to woodwork, but don’t know where to start, don’t worry – we’ve got a primer for that. Video after the break.

Continue reading “JigFab Makes Woodworking Easier”

Printing On Wood, With An Inkjet

As a little experiment in desktop printing, because you can make a desk out of wood, [BlueFlower] modified a standard inkjet printer to print on wood. This is not an electronics mod by any means; this is still a printer that’s plugged into a USB port, does all the fancy printer firmware stuff, tells you to refill the yellow ink cartridge when you only want to print black, and all the other things that inkjet printer firmware will do. This is a mechanical mod. By taking apart the belts and rails and mounting them to a new frame, [BlueFlower] was able to open up the printer so a moving bed holding a board could be moved through the mechanics.

While the printer itself looks a little janky, you can’t argue with results. The prints look good, and should hold up well with a bit of finish. There’s a height adjustment for different thicknesses of stock, and if you’re exceptionally clever, you might be able to put a six-foot-long board through this thing. You can check out a video of this direct to wood printer in action below.

Continue reading “Printing On Wood, With An Inkjet”

Home-Brew CNC Router Mills A Wooden Mouse

First off, we’ll admit that there no real practical reason for wanting a wooden mouse – unless of course the cellulose rodent in question is the one that kicked it all off in “The Mother of All Demos” fifty years ago. Simply putting a shell around the guts of a standard wireless optical mouse is just flexing, but we’re OK with that.

That said, [Jim Krum]’s design shows some impressive skills, both in the design of the mouse and the build quality of his machine. Starting with what looks like a block of white oak, [Jim] hogs out the rough shape of the upper shell and then refines it with a small ball-end mill before flipping it over to carve the other side. His registration seems spot on, because everything matches up well and the shell comes out to be only a few millimeters thick. The bottom plate gets the same treatment to create the complex shape needed to support the mouse guts and a battery holder. He even milled a little battery compartment cover. He used a contrasting dark wood for the scroll wheel and a decorative band to hold the top and bottom together and finished it with a light coat of sealer.

It’s a great look, and functional too as the video below reveals. We’ve seen a few other fancy mice before, like this wood and aluminum model or even one that would look at home on [Charles Babbage]’s desk.

Continue reading “Home-Brew CNC Router Mills A Wooden Mouse”