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.

Continue reading “Plasma Cutter On The Cheap Reviewed” →

3D Printing A Cassette Is Good Retro Fun

April 15, 2024 by 10 Comments

The cassette is one of the coolest music formats ever, in that you could chuck them about with abandon and they’d usually still work. [Chris Borge] recently decided to see if he could recreate these plastic audio packages himself, with great success.

He kicked off his project by printing some examples of an open source cassette model he found online. The model was nicely accurate to the original Compact Cassette design, but wasn’t exactly optimized for 3D printing. It required a great deal of support material and wasn’t easy to customize.

[Chris] ended up splitting the model into multiple components, which could then be assembled with glue later. He then set about customizing the cassette shells with Minecraft artwork. Details of the artwork are baked into the model at varying heights just 1/10th of the total layer height. This makes it easy to designate which sections should be printed with which filament during his multi-colored print. And yet, because the height difference is below a full layer height, the details all end up on the same layer to avoid any ugly gaps between the sections. From there, it’s a simple matter of transferring over the mechanical parts from an existing cassette tape to make the final thing work.

It’s a neat trick, and the final results are impressive. [Chris] was able to create multicolored cassettes that look great. It’s one of the better uses we’ve seen for a multi-colored printer. This would be an epic way to customize a mixtape for a friend!

We’ve seen some great 3D printed cassettes before, too, like these retro reel-to-reel lookalikes.

Continue reading “3D Printing A Cassette Is Good Retro Fun” →

Logic Analyzers: Decoding And Monitoring

April 15, 2024 by 8 Comments

Last time, we looked into using a logic analyzer to decode SPI signals of LCD displays, which can help us reuse LCD screens from proprietary systems, or port LCD driver code from one platform to another! If you are to do that, however, you might find a bottleneck – typically, you need to capture a whole bunch of data and then go through it, comparing bytes one by one, which is quite slow. If you have tinkered with Pulseview, you probably have already found an option to export decoded data – all you need to do is right-click on the decoder output and you’ll be presented with a bunch of options to export it. Here’s what you will find:

2521888-2521888 I²C: Address/data: Start
2521896-2521947 I²C: Address/data: Address write: 22
2521947-2521954 I²C: Address/data: Write
2521955-2521962 I²C: Address/data: ACK
2521962-2522020 I²C: Address/data: Data write: 01
2522021-2522028 I²C: Address/data: ACK
2522030-2522030 I²C: Address/data: Start repeat
2522038-2522089 I²C: Address/data: Address read: 22
2522089-2522096 I²C: Address/data: Read
2522096-2522103 I²C: Address/data: ACK
2522104-2522162 I²C: Address/data: Data read: 91
2522162-2522169 I²C: Address/data: NACK
2522172-2522172 I²C: Address/data: Stop

Whether on the screen or in an exported file, the decoder output is not terribly readable – depending on the kind of interface you’re sniffing, be it I2C, UART or SPI, you will get five to ten lines of decoder output for every byte transferred. If you’re getting large amounts of data from your logic analyzer and you want to actually understand what’s happening, this quickly will become a problem – not to mention that scrolling through the Pulseview window is not a comfortable experience.

The above output could look like this: 0x22: read 0x01 ( DEV_ID) = 0x91 (0b10010001). Yet, it doesn’t, and I want to show you how to correct this injustice. Today, we supercharge Pulseview with a few external scripts, and I’ll show you how to transfer large amounts of Sigrok decoder output data into beautiful human-readable transaction printouts. While we’re at it, let’s also check out commandline sigrok, avoiding the Pulseview UI altogether – with sigrok-cli, you can easily create a lightweight program that runs in the background and saves all captured data into a text file, or shows it on a screen in realtime! Continue reading “Logic Analyzers: Decoding And Monitoring” →

Remembering Peter Higgs And The Gravity Of His Contributions To Physics

April 15, 2024 by 9 Comments

There are probably very few people on this globe who at some point in time haven’t heard the term ‘Higgs Boson’  zip past, along with the term ‘God Particle’. As during the 2010s the scientists at CERN were trying to find evidence for the existence of this scalar boson and with it evidence for the existence of the Higgs field that according to the Standard Model gives mass to gauge bosons like photons, this effort got communicated in the international media and elsewhere in a variety of ways.

Along with this media frenzy, the physicist after whom the Higgs boson was named also gained more fame, despite Peter Higgs already having been a well-known presence in the scientific community for decades by that time until his retirement in 1996. With Peter Higgs’ recent death after a brief illness at the age of 94, we are saying farewell to one of the big names in physics. Even if not a household name like Einstein and Stephen Hawking, the photogenic hunt for the Higgs boson ended up highlighting a story that began in the 1960s with a series of papers.

Continue reading “Remembering Peter Higgs And The Gravity Of His Contributions To Physics” →

Waveform Generator Teardown Is Nearly Empty

April 15, 2024 by 26 Comments

We always enjoy [Kerry Wong]’s insightful teardowns, and recently, he opened up a UTG1042X arbitrary waveform generator. Getting inside was a bit of a challenge since there were no visible screws. Turns out, they were under some stickers. We always dislike that because it is very difficult to get the unit to go back together.

Once open, the case reveals it is almost completely empty. The back panel has a power supply, and the front panel has all the working circuitry. The box seems to be for holding the foot and preventing the device from getting lost on your bench.

The power supply is unremarkable. There are a few odd output voltages. The main board is a bit more interesting, especially after removing the heat sink. There are two channels, but the board isn’t laid out, with a lot of segregation between the two channels. That makes sense with the output sections clustered together and the digital section with the CPU, FPGA, and the DAC in close proximity.

The other side of the board connects to a very simple display board. It would be interesting to compare this to a circa-1980s AWG, which would have been far more complicated.

Making a waveform generator with a microprocessor and a DAC isn’t hard. The hard part is the output stages and maximizing the operating speed.

Continue reading “Waveform Generator Teardown Is Nearly Empty” →

Voice Control For A Vintage Heathkit Radio

April 14, 2024 by 6 Comments

Most modern ham rigs have a voice activated transmission (VOX) mode, although we don’t know many people who use it often. When a transmitter is in VOX mode, it starts transmitting when you talk, and then, when you pause for a second or two, the transmitter turns off. Many old ham transmitters, though, didn’t support VOX, so Heathkit sold the VX-1 “electronic voice control” to add VOX to older transmitters. [Jeff Tranter] shows us inside a clean-looking unit.

These devices were sold from 1958 to 1960 and used tubes and a selenium rectifier. The device is connected between the microphone and the transmitter. It also sat between the receiver and the speaker to mute audio while transmitting. The original unit had a screw terminal to connect to the outside world, and some of the screws had live line voltage on them. The unit [Jeff] examines is modified to have phono jacks along with a few other repairs.

The wiring looks like a tube radio. Tubes are above the chassis, and point-to-point wiring is underneath. There is also an unusual sealed selenium rectifier. [Jeff] shows how the device works using just a receiver. A few minor repairs were needed.

If you are interested in getting your ham license, most modern radios support VOX out of the box — no rhyme intended. We do, however, love that old Heathkit gear.

Continue reading “Voice Control For A Vintage Heathkit Radio” →

Porting Modern Windows Applications To Windows 95

April 14, 2024 by 82 Comments

Windows 95 was an amazing operating system that would forever transform the world of home computing, setting the standard for user interaction on a desktop and quite possibly was the OS which had the longest queue of people lining up on launch day to snag a boxed copy. This raises the question of why we still don’t write software for this amazing OS, because ignoring the minor quibbles of ‘security patches’ and ‘modern hardware compatibility’, it’s still has pretty much the same Win32 API as supported in Windows 11, plus it doesn’t even spy on you, or show you ads. This line of reasoning led [MattKC] recently to look at easy ways to port modern applications to Windows 95.

In the video, the available options are ticked off, starting with straight Win32 API. Of course, nobody writes for the Win32 API for fun or to improve their mental well-being, and frameworks like WxWidgets and QuteQt have dropped support for Windows 9x and generally anything pre-Win2k for years now. The easiest option therefore might be Microsoft’s .NET framework, which in its (still supported) 2.0 iteration actually supports Windows 98 SE, or basically within spitting distance of running it on the original Win95.

Continue reading “Porting Modern Windows Applications To Windows 95” →