Possibly The Cheapest Way To Film In Bullet Time

April 30, 2024 by 19 Comments

When The Matrix hit the cinemas back in 1999 it started a minor revolution with its use of so-called “Bullet time” — a freeze-frame technique in which the action could move round a momentarily frozen subject. It’s filmed using an array of cameras in an arc, something which was pretty expensive back then but is now within the reach of almost anyone. Just how cheaply bullet time can be filmed is shown by [3DSage], who turned nine toy cameras into a budget bullet time rig.

The cameras themselves are what you might expect for the princely sum of nine dollars, but as he points out, their low-resolution video has a certain charm. Some iteration was required to produce the rig without fouling their flip-out screens, and he found that the video quality was far better than their still image quality. But eventually he was able to extract the required array of frames and stitch them together with a video interpolator for the required effect. His cat is a handsome creature from any angle, we can now reveal.

The video below the break has all the details, and while we couldn’t spot quite the same camera he used on our local version of the online shop he used, there seem to be plenty of similar cheap devices should you wish to try it for yourself. Either way, this cost much less than the previous budget bullet time contender.

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Solar Panel Keeps Cheap Digital Calipers Powered Up

April 20, 2024 by 40 Comments

There’s no doubt that cheap digital calipers are useful, especially when designing 3D-printed parts. Unfortunately, cheap digital calipers are also cheap, and tend to burn through batteries quickly. Sure, you can remove the battery when you’re done using them, but that’s for suckers — winners turn to solar power to keep their calipers always at the ready.

[Johan]’s solar upgrade begins with, unsurprisingly, a solar cell, one that just fits on the back of his digital calipers. Like most of these cheap calipers, this one is powered by a single 1.5 V LR44 button cell, while the polycrystalline solar cell is rated for 5 V, so [Johan] used a red LED as a crude voltage regulator. He also added a stack of fourteen 100 μF SMD capacitors soldered together in parallel. The 1206 devices form a 1,400 μF block that’s smaller than the original button cell so that everything fits in the vacated battery compartment. It’s pretty slick.

Given their agreeable price point, digital calipers are a tempting target for hacking. We’ve seen a ton of them, from accessibility add-ons to WiFi connectivity and even repurposing them for use as DROs. Ever wonder how these things work? We’ve looked at that, too.

Bad Experiences With A Cheap Wind Turbine

April 20, 2024 by 44 Comments

If you’ve got a property with some outdoor space and plenty of wind, you might consider throwing up a windmill to generate some electricity. Indeed, [The Broject List] did just that. Only, his experience was a negative one, having purchased a cheap windmill online. He’s warning off others from suffering the same way by explaining what was so bad about the product he bought.

The windmill in question was described as a “VEVOR Windturbine”, which set him back around 100 euros, and claimed to be capable of producing 600 watts at 12 volts. He starts by showing how similar turbines pop up for sale all over the Internet, with wildly inflated specs that have no relation to reality. Some sellers even charge over 500 euros for the same basic device.

He then demonstrates the turbine operating at wind speeds of approximately 50 km/h. The output is dismal, a finding also shared by a number of other YouTube channels out there. Examining the construction of the wind turbine’s actual generator, he determines that it’s nowhere near capable of generating 600 watts. He notes the poorly-manufactured rotor and aluminium coils as particular disappointments. He concludes it could maybe generate 5 watts at most.

Sadly, it’s easy to fall into this trap when buying online. That’s where it pays to do your research before laying down your hard-earned cash. Continue reading “Bad Experiences With A Cheap Wind Turbine” →

A red 3D-printed Raspberry Pi-based document scanner

Raspberry Pi Scanner Digitizes On The Cheap

April 17, 2024 by 29 Comments

It’s pretty important in 2024 to be able digitize documents quickly and easily without necessarily having to stop by the local library or buy an all-in-one printer. While there are plenty of commercial solutions out there, [Caelestis Cosplay] has created a simple document scanner that takes documents, as [Caelestis Cosplay] puts it, from papers to pixels.

The build is probably what you’re expecting — it’s essentially a Raspberry Pi (in this case a 4B), a V2 Pi camera, and a handful of custom 3D-printed parts. [Caelestis Cosplay] says they had never designed anything for printing before, and we think it looks great. There’s also a buzzer to indicate that the scan is starting (one beep) or has completed (two beeps), a ‘ready’ indicator, and a ‘working’ indicator.

Everything you’d need to build your own is available over on Instructables, including document scanner and controller scripts. Be sure to check it out in action after the break, and see it quickly scan in a document and put it on a thumb drive.

Looking for a 3D scanner? Check out the OpenScan project.

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Plasma Cutter On The Cheap Reviewed

April 15, 2024 by 24 Comments

If you have a well-equipped shop, it isn’t unusual to have a welder. Stick welders have become a commodity and even some that use shield gas are cheap if you don’t count buying the bottle of gas. But plasma cutters are still a bit pricey. Can you get one from China for under $300? Yes. Do you want one that cheap? [Metal Massacre Fab Shop] answers that question in the video below.

First impressions count, and having plasma misspelled on the unit (plasme) isn’t promising. The instructions were unclear, and some of the fittings didn’t make him happy, so he replaced them with some he had on hand. He also added some pipe tape to stop any leaking.

The first test was a piece of quarter-inch steel at 35 amps. The machine itself is rated to 50 amps. Sparks ensued, and with a little boost in amperage, it made a fair-looking cut. At 50 amps, it was time to try a thicker workpiece. It made the cut, although it wasn’t beautiful. The leaking regulator and the fact that he can’t run the compressor simultaneously as the cutter didn’t help.

From the look of it, for light duty, this would be workable with a little practice and maybe some new fittings. Unsurprisingly, it probably isn’t as capable as a professional unit. Still could be very handy to have.

It is possible to convert a welder into a plasma cutter. A handheld unit like this probably won’t benefit from a Sharpie.

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Do You Trust Your Cheap Fuses?

April 11, 2024 by 34 Comments

When a fuse is fitted in a power rail, it gives the peace of mind that the circuit is protected. But in the case of some cheap unbranded fuses of the type that come in kits from the usual online suppliers that trust can be illusory, as they fail to meet the required specification.

[Andreas Spiess] has used just these fuses for protection for years as no doubt have many of you, so it was something of a shock for him to discover that sometimes they don’t make the grade. He’s taken a look at the issue for himself, and come up with an accessible way to test your fuses if you have any of those cheap ones.

It’s an interesting journey into the way fuses work, as we’re reminded that the value written on the fuse isn’t the current at which it blows but the maximum it’s intended to take. The specification for fuses should have a graph showing how quickly one should blow at what currents above that level, and the worry was that this time would be simply too long for the cheap ones.

In the video below the break, he looks at the various set-ups required to test a fuse, and instead of a bank of large power supplies, he came up with a circuit involving an 18650 cell and three one ohm resistors in parallel. The resulting 1/3 ohm resistor should pass in the region of 10 A when connected across the 18650, so with a 5 A fuse in that circuit and a storage ‘scope he’s able to quickly test a few candidates. He found that the cheap fuses he had were slower to blow than a Bosch part but weren’t as worrisome as he’d at first thought. If you have any of these parts, maybe you should take a look at them too?

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Heating Mars On The Cheap

April 8, 2024 by 78 Comments

Mars is fairly attractive as a potential future home for humanity. It’s solid, with firm land underfoot. It’s able to hang on to a little atmosphere, which is more than you can say about the moon. It’s even got a day/night cycle remarkably close to our own. The only problem is it’s too darn cold, and there’s not a lot of oxygen to breathe, either.

Terraforming is the concept of fixing problems like these on a planet-wide scale. Forget living in domes—let’s just make the whole thing habitable!

That’s a huge task, so much current work involves exploring just what we could achieve with today’s technology. In the case of Mars, [Casey Handmer] doesn’t have a plan to terraform the whole planet. But he does suggest we could potentially achieve significant warming of the Red Planet for $10 billion in just 10 years. Continue reading “Heating Mars On The Cheap” →