Isomorphic Keyboards With CV Out

July 13, 2019 by Brian Benchoff 6 Comments

A piano keyboard can be much more than a linear row of white keys and black keys. Over the history of the keyboard, different arrangement have been made, and in the late 19th century, the Janko keyboard was developed. This keyboard that was a series of buttons laid out on a hexagonal grid. The idea being that every scale in every key is fingered the same. Chords with large intervals are easier. It also looks cool.

To date, making a MIDI Janko keyboard (with CV out) was an exercise in buying a lot of buttons and programming a microcontroller. But this 3D print from [TomsJensen] adapts what is probably the most popular MIDI keyboard in production to a Janko layout.

We have seen something like this before with [John Moriarty] building a system that adapts a standard piano keyboard and any full-size MIDI controller into an isomorphic keyboard. However, if you want to play with modular synths you need a keyboard with CV out, the cheapest and most popular being the Arturia Keystep. That’s a smaller keyboard and requires a complete redesign.

This project is up on OnShape with the files up on Thingiverse should you want to print your own. Sure, it’s just a small modification to an already popular MIDI keyboard, but if you’ve got some plastic sitting around it would be great to try out.

3D Printing An Old-School Coherer

July 13, 2019 by Lewin Day 29 Comments

Coherers were devices used in some of the very earliest radio experiments in the 19th century. Consisting of a tube filled with metal filings with an electrode at each end, the coherer would begin to conduct when in the presence of radio frequency energy. Physically tapping the device would then loosen the filings again, and the device was once again ready to detect incoming signals. [hombremagnetico] has designed a basic 3D printed version of the device, and has been experimenting with it at home.

It’s a remarkably simple build, with the 3D printed components being a series of three brackets that combine to hold a small piece of plastic tube. This tube is filled with iron filings, and electrodes are inserted from either end. Super glue is used to seal the tube, and the coherer is complete.

The coherer can easily be tested by measuring the resistance between the two electrodes, and firing a piezo igniter near the tube. When the piezo igniter sparks, the coherer rapidly becomes conductive, and can be restored to a non-conductive state, or de-cohered, by tapping the tube.

Coherers and spark-gap sets are fun to experiment with, but be sure you have the proper approvals first. Video after the break.

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This Nerf Gun Is Terrifyingly Huge

July 11, 2019 by Lewin Day 10 Comments

Gatling guns were an early attempt at creating a rapid-firing weapon, and were popular amongst armies in the 19th century. Today, the basic design remains in use as a heavy weapon for putting many rounds downrange very quickly. [Ivan Miranda] decided that the Nerf world was missing a piece of the action, and got started on his own design (Youtube link, embedded below).

As per most [Ivan] builds, this one is a glorious pile of 3D printed parts turned into something functional and fun. It’s an ingenious design that’s more a Gatling in spirit than reality as it lacks the multiple barrels of the original, and it uses smart ducting to allow a single electric fan to both fire the foam Nerf balls as well as suck them in to reload the next shot. In testing, it achieved a muzzle velocity of 60 mph, firing at a rate of approximately 10 rounds/second. The presentation is great too, with plenty of cable wrap, meaty switches, and glowing lights to add to the aesthetic. There are even a couple of bright LED lamps on the front to help dazzle your targets into submission.

Once again, [Ivan]’s work is a great example of what is achievable with a 3D printer and smart design. His water jet drive ain’t bad, either. Video after the break.

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Enclosure Needs Labels? Make The 3D Printer Do It

July 8, 2019 by Donald Papp 18 Comments

Tool changing on 3D printers is hot right now, and it’s going to be really interesting to see the ideas that reliable tool changing lets people try out. One such idea is having the 3D printer use a marker to label the enclosure and buttons it just 3D printed.

The 3D print shown is an enclosure for a Pocket Operator by Teenage Engineering. [Marc Schömann] made the enclosure on Blackbox, a tool-changing 3D printer that he designed. The video below shows a pen holder drawing the labels directly onto the printed object. Pocket Operators may look like calculators, but they are clever electronic musical devices capable of producing real music. (The best way to learn about what they are and what they can do is to watch a tutorial video or two.)

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No Filament Needed In This Direct Extrusion 3D-Printer

July 8, 2019 by Dan Maloney 22 Comments

Ground plastic bits go in one end, finished 3D-prints come out the other. That’s the idea behind [HomoFaciens]’ latest build: a direct-extrusion 3D-printer. And like all of his builds, it’s made from scraps and bits most of us would throw out.

Pellet agitator is part of the extruder. All of this travels along with the print head.

Take the extrusion screw. Like the homemade rotary encoders [HomoFaciens] is known for, it appears at first glance that there’s no way it could work. An early version was just copper wire wrapped around a threaded rod inside a Teflon tube; turned by a stepper motor, the screw did a decent job of forcing finely ground PLA from a hopper into the hot end, itself just a simple aluminum block with holes drilled into it. That worked, albeit only with basically powdered PLA. Later versions of the extruder used a plain galvanized woodscrew soldered to the end of a threaded rod, which worked with chunkier plastic bits. Paddles stir up the granules in the hopper for an even flow into the extruder, and the video below shows impressive results. We also picked up a few tips, like using engine gasket paper and exhaust sealant to insulate a hot end. And the slip coupling, intended to retract the extruder screw slightly to reduce stringing, seems brilliant but needs more work to make it practical.

It’s far from perfect, but given the inputs it’s pretty amazing, and there’s something attractive about reusing all those failed prints. It reminds us a bit of the trash printer we featured recently, which is another way to stick it to the filament man. Continue reading “No Filament Needed In This Direct Extrusion 3D-Printer” →

3D Printed Buttons, Printed As A Single Unit

July 6, 2019 by Donald Papp 10 Comments

These nifty buttons come from [Marc Schömann], and they are intended to cover just about any kind of tact switches. The buttons, their cover, and the compliant bits that act as a spring can be 3D printed as a complete unit that requires no assembly, and can be used fresh off the print bed.

The design is still being developed, but those interested in playing with it can download the current model here. [Marc] printed this version in two colors, but that’s just to make how the buttons work easier to see. It also gave him an opportunity to test and tune the tool changer on his printer.

Tool changer, you say? Yes, indeed. The printer is the Blackbox, a open source, tool-changing 3D printer of [Marc]’s own design with its own Hackaday.io project page.

Embedded below is a video overview of the button design being prepped and printed on a Blackbox printer, with a tool change happening in the process. Tool changing is an attractive feature that many people including E3D have taken a swing at, and it’s always exciting to see it in action.

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E3D’s Love Letter To Toolchanging 3D Printers

July 4, 2019 by Sonya Vasquez 20 Comments

It’s been just over a year since E3D whetted our appetites for toolchanging printers. Now, with the impending release of their first toolchanging system, they’ve taken the best parts of their design and released them into the wild as open source. Head on over to Github for a complete solution to exchanging, locating, and parking tools on a 3D printer.

For anyone interested in fabricating the design, the files are in a format that you can almost re-zip and email to a manufacturer for quotes. As is, the repository offers STP-style CAD files, a complete set of dimensioned drawings, exploded views, and even a bill of materials. Taken as a whole, the system elegantly solves the classic problems that we’d encounter in toolchanging. Locking tools is done with a spring-based T-bar that swivels onto an wedge-shaped groove on the back of each tool plate. Locating tools is done so with a 3-groove kinematic coupling fabriacted from dowel pins. With these problems solved and presented so cleanly, these files become a path by which we can establish a common means for exchanging tools on 3D printer systems.

It’s worth asking: why develop an exceptional design and then release it for free? I’ll speculate that E3D has done an excellent job over the years establishing a well-recognized standard set of stock parts. Nearly every 3D printer builder is bound to have at least one spare V6 hotend sitting idle in a disassembled pool of former-3D-printers. With tool-changing positioned to become another step forward in the space of possibilities with 3D printing, setting the standard for tools early encourages the community to continue developing applications that lean on E3D’s ecosystem of parts.

In the last 30 years, 3D printing has transformed away from a patent-trolling duopoly to a community-friendly group of contributors that lean on each other’s shoulders with shared findings. It’s a kind gesture to the open-source community of machine builders to receive such a feature-complete mechanism. With that said, let’s start rolling the toolchanger hacks.