Misc Hacks

4137 Articles

Finely Machined Valve Controls Miniature RC Hydraulics

August 28, 2019 by 4 Comments

Hydraulic components are the industrial power transmission version of LEGO. Pumps, cylinders, valves – pretty much everything is standardized, and fitting out a working system is a matter of picking the right parts and just plumbing everything together. That’s fine if you want to build an excavator or a dump truck, but what if you want to scale things down?

Miniature hydraulic systems need miniature components, of which this homebrew hydraulic valve made by [TinC33] is a great example. (Video embedded below.) If you’re curious about why anyone would need these, check out the tiny hydraulic cylinders he built a while back, wherein you’ll learn that miniature RC snowplows are a thing. The video below starts with a brief but clear explanation about how hydraulic circuits work, as well as an explanation of the rotary dual-action proportional valve he designed. All the parts are machined by hand in the lathe from aluminum and brass stock. The machining operations are worth watching, but if you’re not into such things, skip to final assembly and testing at 13:44. The valve works well, providing very fine control of the cylinder and excellent load holding, and there’s not a leak to be seen. Impressive.

[TinC33] finishes the video with a tease of a design for multiple valves in a single body. That one looks like it might be an interesting machining challenge, and one we’d love to see.

Thanks to [mgsouth] for the tip.

Lead Former Makes LED Cubes A Little Easier To Build

August 25, 2019 by 8 Comments

There’s no doubting the allure of a nicely crafted LED cube; likewise, there’s no doubting that they can be a tremendous pain to build. After all, the amount of work scales as the cube of the number of LEDs you want each side to have, and let’s face it – with LED cubes, the bigger, the better. What to do about all that tedious lead forming?

[TylerTimoJ]’s solution is a custom-designed lead-forming tool, and we have to say we’re mighty impressed by it. His LED cubes use discrete RGB LEDs, the kind with four leads, each suspended in space by soldering them to wires. For the neat appearance needed to make such a circuit sculpture work, the leads must be trimmed and bent at just the right angles, a tedious job indeed when done by hand. His tool has servo-controlled jaws that grip the leads, with solenoid-actuated lead formers coming in from below to bend each lead just the right amount. The lead former, along with its companion trimmer, obviously went through a lot of iterations before [TylerTimoJ] got everything right, but we’d say being able to process thousands of LEDs without all the tedium is probably worth the effort.

We’re looking forward to the huge LED cubes this tool will enable. Perhaps this CNC wire bender and an automated wire cutter would come in handy for the supporting wires?

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Feeding Chickens, With Style

August 23, 2019 by 8 Comments

Ah, the joys of domestic animals. Often adorable, occasionally useful, they’re universally unable to care for themselves in the slightest. That’s part of the bargain though; we take over responsibility for their upkeep and they repay us with whatever it is they do best. Unless the animal in question is a cat, of course – they have their own terms and conditions.

Chickens, though, are very useful indeed. Give them food and water and they give you delicious, nutritious, high-quality protein. Feeding them every day can be a chore, though, unless you automate the task. This Twitch-enabled robotic chicken feeder may be overkill for that simple use case, but as [Sean Hodgins] tell it, there’s a method to all the hardware he threw at this build. That would include a custom-welded steel frame holding a solar panel and batteries, a huge LED matrix display, a Raspberry Pi and camera, and of course, food dispensers. Those are of the kind once used to dispense candy or gum for a coin or two in the grocery; retooled with 3D-printed parts, the dispensers now eject a small scoop of feed whenever someone watching a Twitch stream decides to donate to the farm that’s hosting the system. You can see the build below in detail, or just pop over to Sweet Farm to check out the live feed and gawk at some chickens.

It’s an impressive bit of work on [Sean]’s part for sure, and we did notice how he used his HCC rapid prototyping module to speed up development. Still, we’re not convinced there will be many donations at $10 a pop. Then again, dropping donations to the micropayment level may lead to overfed chickens, and that’s not a good thing.

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Automatic Rewinder Makes Kite Retrieval A Breeze

August 21, 2019 by 26 Comments

So you’ve built a fine kite, taken it to the beach, and let it ride the wind aloft on a spool of line. Eventually it has to come down, and the process of reeling all that line that was so easily paid out is likely a bigger chore than you care to face. What to do?

If you’re like [Matt Bilsky], the answer is simple: build a motorized kite reel to bring it back in painlessly. Of course what’s simple in conception is often difficult to execute, and as the second video below shows, [Matt] went through an extensive design and prototype phase before starting to create parts. Basic questions had to be answered, such as how much torque would be needed to reel in the kite, and what were the dimensions of a standard kite string reel. With that information and a cardboard prototype in hand, the guts of a cordless drill joined a bunch of 3D-printed parts to form the running gear. We really liked the research that went into the self-reversing screw used to evenly wind the string across the spool; who knew that someone could do a doctoral dissertation on yarn-winding? Check out the “Reeler-Inner” in action in the first, much shorter video below.

With some extra power left from the original drill battery, [Matt] feature-crept a bit with the USB charger port and voltmeter, but who can blame him? Personally, we’d have included a counter to keep track of how much line is fed out; something like this printer filament counter might work, as long as you can keep the sand out of it.

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Get Ready For Games Night With 3D Catan

August 20, 2019 by 13 Comments

Settlers of Catan is a staple for boardgaming aficionados. Some fans like to express themselves by building a custom set of their own, and [Maclsk] is no different. Enter 3D Catan!

The models for the various pieces were designed in Blender, a great open source 3D modelling program. They were then printed on an Anycubic i3 Mega, taking about 80 hours and using 700 grams of PLA filament. With 116 game pieces, there was plenty of filing and sanding to do.

With this completed, it was then time for paint. [Maclsk] shows off a strong understanding of model painting fundamentals, from dry brushing to using PVA glue to give water elements a glossy sheen. If you’re new to the techniques, sit down with your local Warhammer players – they’ll be more than able to point you in the right direction.

Overall, it’s a great build that really pops on the gaming table. We’ve seen other die-hard Catan fans come out with their own builds, too. Video after the break.

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A Real All-In-One Printer Should Have A Computer In It, Too

August 16, 2019 by 14 Comments

With printers generally being cheaper to replace than re-ink, there are plenty of cast-offs around to play with. They’re a great source for parts, but they’re also tempting targets for repurposing for entirely new uses. Sure, you could make a printer into a planter, but slightly more useful is this computer built into a printer that still prints.

This build is [Mason Stooksbury]’s earlier and admittedly useless laptop-in-a-printer build, which we covered a few months back. It’s easy to see where he got his inspiration, since the donor printer’s flip-up lid is a natural for mounting a display, and the capacious, glass-topped scanner bed made a great place to show off the hybrid machine’s guts. But having a printer that doesn’t print didn’t sit well with [Mason], so Comprinter II was born. This one follows the same basic approach, with a Toshiba Netbook stuffed into an H-P ENVY all-in-one. The laptop’s screen was liberated and installed in the printer’s lid, the motherboard went into the scanner bay along with a fair number of LEDs. This killed the scanner but left the printer operational, after relocating a power brick that was causing a paper jam error.

[Mason]’s Comprinter II might not be the next must-have item, but it certainly outranks the original Comprinter on the utility spectrum. Uselessness has a charm of its own, though; from a 3D-printed rotary dial number pad to a useless book scanner, keep the pointless projects coming, please.

Bike-Mounted Synthetic-Aperture Radar Makes Detailed Images

August 15, 2019 by 20 Comments

Synthetic-aperture radar, in which a moving radar is used to simulate a very large antenna and obtain high-resolution images, is typically not the stuff of hobbyists. Nobody told that to [Henrik Forstén], though, and so we’ve got this bicycle-mounted synthetic-aperture radar project to marvel over as a result.

Neither the electronics nor the math involved in making SAR work is trivial, so [Henrik]’s comprehensive write-up is invaluable to understanding what’s going on. First step: build a 6-GHz frequency modulated-continuous wave (FMCW) radar, a project that [Henrik] undertook some time back that really knocked our socks off. His FMCW set is good enough to resolve human-scale objects at about 100 meters.

Moving the radar and capturing data along a path are the next steps and are pretty simple, but figuring out what to do with the data is anything but. [Henrik] goes into great detail about the SAR algorithm he used, called Omega-K, a routine that makes use of the Fast Fourier Transform which he implemented for a GPU using Tensor Flow. We usually see that for neural net applications, but the code turned out remarkably detailed 2D scans of a parking lot he rode through with the bike-mounted radar. [Henrik] added an auto-focus routine as well, and you can clearly see each parked car, light pole, and distant building within range of the radar.

We find it pretty amazing what [Henrik] was able to accomplish with relatively low-budget equipment. Synthetic-aperture radar has a lot of applications, and we’d love to see this refined and developed further.

[via r/electronics]