External Buffer Boosts 3D Printer Filament Splicing On The Palette 2

July 21, 2019 by Tom Nardi 15 Comments

There was a time when most of us thought the next logical step for desktop 3D printing was to add additional extruders and hotends, allowing the machine to print in multiple colors or materials. Unfortunately such arrangements quickly become ungainly, and even with just two extruders, calibration can be a nightmare. Because of this, development has been trending towards systems that use just one hotend and simply alternate the filament being fed into it. But such systems have their own problems.

Arguably the biggest issue is how long it takes to switch filaments. The Palette 2 uses a physical buffer of spliced filament to try and keep ahead of the printer, but as [Kurt Skauen] demonstrates, there are considerable performance gains to be had by building a bigger buffer. He says there’s still some calibration issues to contend with, but judging by the video after the break, we’d say he is certainly on the right track.

The buffer is necessary to give the spliced filament time to cool and bond before being fed into the printer, but as currently designed, the machine simply can’t store enough of it to keep up with high print speeds. The stock buffer area holds 125mm worth of spliced filament, but the modification [Kurt] has designed adds a whopping 280mm on top of that to reach more than three times the stock capacity.

He’s successfully tested printing at speeds as high as 200mm/s with his upgraded buffer, a big improvement over what he was seeing with the original buffer area. This despite the fact that Mosaic (the company that produces the Palette) claim the original buffer size was already more than sufficient. It seems we’ve found ourselves in the middle of a debate between Mosaic and some very vocal members of the community, and while we don’t want to take sides, it’s hard to ignore [Kurt]’s findings.

Want to make your own? [Kurt] has released all the information necessary for others to duplicate his work, including the STLs for all printed parts and a list of the bearings, springs, and fasteners you’ll need to put it together. It looks like a fairly large undertaking, but with the potential for such a considerable speed boost, we don’t doubt others will be willing to take the plunge. One person who printed and assembled an earlier version of the buffer upgrade reports their print speeds with a 0.8 mm nozzle have more than doubled.

The Palette has come a long way from we first saw it in 2016, and since then, Prusa has thrown their orange hat into the ring with their own filament-switching upgrade. Neither machine is without its niggling issues, but they’re still probably our best shot at taking desktop 3D printing to the next level.

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3D Printed Snap Gun For Automatic Lock Picking

July 17, 2019 by Pat Whetman 31 Comments

At a far flung, wind blown, outpost of Hackaday, we were watching a spy film with a bottle of suitably cheap Russian vodka when suddenly a blonde triple agent presented a fascinating looking gadget to a lock and proceeded to unpick it automatically. We all know very well that we should not believe everything we see on TV, but this one stuck.

Now, for us at least, fantasy became a reality as [Peterthinks] makes public his 3D printed lock picker – perfect for the budding CIA agent. Of course, the Russians have probably been using these kind of gadgets for much longer and their YouTube videos are much better, but to build one’s own machine takes it one step to the left of center.

The device works by manually flicking the spring (rubber band) loaded side switch which then toggles the picking tang up and down whilst simultaneously using another tang to gently prime the opening rotator.

The size of the device makes it perfect to carry around in a back pocket, waiting for the chance to become a hero in the local supermarket car park when somebody inevitably locks their keys in their car, or even use it in your day job as a secret agent. Just make sure you have your CIA, MI6 or KGB credentials to hand in case you get searched by the cops or they might think you were just a casual burglar. Diplomatic immunity, or a ‘license to pick’ would also be useful, if you can get one.

As mentioned earlier, [Peter’s] video is not the best one to explain lock picking, but he definitely gets the prize for stealth. His videos are below the break.

In the meantime, all we need now are some 3D printed tangs.

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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” →