Current Sink Keeps The Smoke In

One of the most versatile tools on anyone’s work bench, at least as far as electrical projects are concerned, is a power supply. Often we build our own, but after we’ve cobbled together some banana jacks with a computer’s PSU or dead-bug soldered a LM317 voltage regulator to a wall wart, how will that power supply perform? Since it’s not desirable to use a power supply that’ll let the smoke out of everything it powers (or itself, for that matter) a constant current sink, or load, can help determine the operating limits of the power supply.

[electrobob] built this particular current sink from parts he had lying around. The theory of a constant current sink is relatively straightforward so it’s easily possible to build one from parts out of the junk drawer, provided you can find a few transistors, fuses, an op amp, and some heat sinks. The full set of schematics that [electrobob] designed can be found on his main project page. He’s also gone a step further with this build as well, since he shorted out his first prototype and destroyed some of the transistors. But, using a few extra transistors in his design also improves the safety and performance of the load, so it’s a win-win.

This constant current load also has the added feature of being able to interface with a waveform generator (an Analog Discovery, specifically) and as a result can connect and disconnect the load quickly. If you aren’t in need of an industrial-grade constant current sink and you have some spare parts lying around, this would be a great one to have around the work bench.

A Water Jet Cutter From A Cheap Pressure Washer

We’ve become used to CNC mills and 3D printers becoming staples of our workshops, and thanks to the wonders of international trade even a modest laser cutter is not beyond the reach of most experimenters. But there is one tool that has so far evaded all but either commercial operations or the extremely well-heeled, the water cutter. These machines use a high-pressure water jet, usually carrying a stream of abrasive particles, to cut through the material placed beneath them. From our perspective they are interesting in that they can cut metal, something not normally possible with the laser cutters within our reach.

A water cutter is something you might think would be impossible for an experimenter to make for themself, but [Applied Science] is on hand to disprove that notion. He’s taken a cheap pressure washer, and modified it to produce a much higher water pressure for a water cutting head.

His very detailed description of the modifications makes for an extremely interesting watch, and we’ve placed the video below the break. The higher pressure is achieved by modifying the washer’s pressure on-off switch with a newly-machined sleeve and a stronger spring. The description of how the washer switch works is interesting in itself. Then we are treated to a complete teardown of a water cutting head, with abrasive feed, tungsten carbide tube, and ruby nozzle. This last component is surprisingly cheap. He then gives us a run-down of its design, particularly with respect to choosing the size of the orifices to match the pump. Finally we take a look at his abrasive feed system, and the plastic funnel he uses to keep water flow back out of his hopper.

For now the cutter is static, but his obvious next step is to bring it to some form of CNC table. If this project brings water cutting one step closer to the masses, we can’t wait!

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Nitro Powered Rotary Tool

We really don’t know if the world needs it but we’re sure glad [johnnyq90] took the time to build one. We’re talking about a nitro powered rotary tool. Based on a Kyosho GX-12 nitro engine, commonly used in R/C cars, [johnnyq90] machines almost all other parts in his shop to make a really cool ‘Nitro-Dremel’. But success didn’t come at the first try.

The first prototype was made using a COX 049 engine but the lack of proper lubrication cause damage to the crankshaft. Because of this setback, [johnnyq90] swaps it out with a O.S Max 10 Aero engine he had lying around in the shop. That didn’t work out so well as the engine was quite hard to start. On the third try he finally decided to use the 2.1 cc Kyosho GX-12 engine to power up his 20.000 rpm tool. As noisy as one would expect and, from the videos it seems quite powerful too as it easily pierces through an aluminium block, cuts steel like a breeze, and breezes through other less demanding feats.

But [johnnyq90] is no stranger to nitro engines nor to Hackaday. In the past he built, among other things, a nitro powered cordless drill and showed impressive feats of machining in a micro version of a Tesla turbine. We wonder what’s next…. a nitro powered tattoo gun perhaps?

In the 20 minute video after the break, we enjoy watching the construction of the ‘Nitro-Dremel’, as well as other parts from two previously failed prototypes:

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Making an Inexpensive DRO

[Andrew] wanted a digital readout (DRO) for his mini lathe and mini mill, but found that buying even one DRO cost as much as either of his machines. The solution? You guessed it, he built his own for cheap, using inexpensive digital calipers purchased off eBay.

The DRO he created features a touch screen with a menu system running on an LPCXpresso, while smaller OLED screens serve as labels for the 7-segment displays to the right. The DRO switches back and forth between the lathe and mill, and while the software isn’t done, [Andrew] hopes to be able to transfer measurements from one machine to the other.

In a very sweet touch, [Andrew] hacked cheap digital calipers to provide measurements for each axis, where they provide a resolution of 0.01mm. There are six daughter boards, one for each caliper, and each has a PIC that converts from serial to I2C, freeing the main firmware from dealing with six separate data streams.

The DRO doesn’t have a case, [Andrew] has it positioned out of chip-range from either machine.

A previous DRO we featured in 2012 used an Android tablet as its display.

Hack Your Hot Air Station

It used to be hot air soldering gear was exotic, but not anymore. There are plenty of relatively inexpensive choices. Many of these appear to be the same despite having different brand names and model numbers. One that is common and inexpensive is the 858D. These run about $50. [Gabse] has one and decided to upgrade it using some open source controller hardware and software. There wasn’t a complete guide, so he created one himself.

According to the original GitHub page, the controller will work with the Youyue-858D and any clones. However, there are others like the Atten 858D that use a different controller. In addition, there have been several variants. [Gabse’s] guide is for the latest version. Information on other versions and brands might be on this discussion board thread.

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[Bre Pettis] Buys Other Machine Co.

Other Machine Co., manufacturer of the very capable and very cool OtherMill Pro CNC machine, has been acquired by [Bre Pettis], former CEO of MakerBot. Under the terms of the acquisition, current CEO of Other Machine Co, Dr. Danielle Applestone, will remain in charge of the company.

We have a love affair with the OtherMill here at Hackaday. We have a few of them kicking around the Design Lab, and they’re great. Six mil traces are possible, and the OtherMill is a very reliable machine. We’ve taken a look at the OtherMill manufacturing process and liked what we saw, and we’ve invited [Danielle Applestone] to talk about the quest for the highest precision per dollar.

Of course, the newsworthy item for this, ‘rich guy buys a company’ story is who acquired the company. [Pettis] is most famous for being one-third of the original MakerBot team, a position that netted him about $130 Million after Stratasys acquired MakerBot. Stratasys’ acquisition of MakerBot has made a lot of people angry and has been widely regarded as a bad move. The history of MakerBot is not written yet, but the general consensus is that [Pettis] only played a very limited role in the downfall of MakerBot and desktop 3D printing as a whole.

Since leaving MakerBot for greener pastures, [Pettis] has put his money to work; he’s also an investor in the laser cutter startup Glowforge. While Glowforge has seen its share of troubles including a ridiculous policy on field-replaceable laser tubes, and perpetual delays for production units, Glowforge will be shipping soon. It’s unclear how the Glowforge will ultimately be received. But [Pettis’] continues to put his money where his mouth is (and into hardware startups) with this acquisition of Other Machine Co..

The Textile Bench

What’s on your bench? Mine’s mostly filled with electronic test equipment, soldering kit, and computers. I’m an electronic engineer by trade when I’m not writing for Hackaday, so that’s hardly surprising. Perhaps yours is like mine, or maybe you’ve added a 3D printer to the mix, a bunch of woodworking tools, or maybe power tools.

So that’s my bench. But is it my only bench? On the other side of the room from the electronics bench is a sturdy folding dining table that houses the tools and supplies of my other bench. I’m probably not alone in having more than one bench for different activities, indeed like many of you I also have a messy bench elsewhere for dismantling parts of 1960s cars, or making clay ovens.

My textile bench, with a selection of the equipment used on it.
My textile bench, with a selection of the equipment used on it.

The other bench in question though is not for messy work, in fact the diametric opposite. This is my textile bench, and it houses the various sewing machines and other equipment that allow me to tackle all sorts of projects involving fabric. On it I’ve made, modified, and repaired all sorts of clothing, I’ve made not-very-successful kites, passable sandals, and adventurous tent designs among countless other projects.

Some of you might wonder why my textile bench is Hackaday fodder, after all it’s probably safe to assume that few readers have ever considered fabricating their own taffeta ball gown. But to concentrate only on one aspect of textile work misses the point, because the potential is there for so much cross-over between these different threads of the maker world. So I’m going to take you through my textile bench and introduce you to its main tools. With luck this will demystify some of them, and maybe encourage you to have a go.

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