Metal Forming With A 3D Printer

August 4, 2023 by 25 Comments

How do you use a 3D printer to bend metal? One way would be to take it to a machine shop and offer to trade the owner your printer for some time in their shop. A smarter way is to do like [Jaba 3D], and print dies using the printer. You can then use those dies in a press to make the shapes you want.

In the case of [Jaba], the Harbor Freight press uses a hydraulic cylinder to develop about 6 tons of pressure. We don’t think Harbor Freight carries this particular press, but for between $150 and $250, you can get a 12-20 ton press, and, of course, there are other suppliers, as well.

The target object, in this case, was an automotive bracket. The process of grabbing an image, converting it to an SVG, and then creating a 3D part has many uses. Apparently, PLA is sufficient for this purpose, although the print uses ten top and bottom layers along with 80% infill. That does make the prints take a long time.

As you might expect, the dies don’t last very long. In this case, they needed two shots, and they got them, but PLA is probably not the right material if you wanted to go for mass production.

Metal forming does occur at large scales, too. If you want to make your own press-forming tools, we have advice for you.

This Week In Security: Your Car’s Extended Warranty, Seizing The Fediverse, And Arm MTE

August 4, 2023 by 15 Comments

If you’ve answered as many spam calls as I have, you probably hear the warranty scam robocall in your sleep: “We’ve been trying to reach you about your car’s extended warranty.” That particular robocalling operation is about to run out of quarters, as the FCC has announced a nearly $300 million fine levied against that particular operation. The scammers had a list of 500 million phone numbers, and made over five billion calls in three months. Multiple laws were violated, including some really scummy behavior like spoofing employer caller ID, to try to convince people to pick up the call.

Now, that record-setting fine probably isn’t ever going to get paid. The group of companies on the hook for the amount don’t really exist in a meaningful way. The individuals behind the scams are Roy Cox and Aaron Jones, who have already been fined significant amounts and been banned from making telemarketing calls. Neither of those measures put an end to the problem, but going after Avid Telecom, the company that was providing telephone service, did finally put the scheme down.

Mastodon Data Scooped

There are some gotchas to Mastodon. Direct Messages aren’t end-to-end encrypted, your posts are publicly viewable, and if your server operator gets raided by law enforcement, your data gets caught up in the seizure.

The background here is the administrator of the server in question had an unrelated legal issue, and was raided by FBI agents while working on an issue with the Mastodon instance. As a result, when agents seized electronics as evidence, a database backup of the instance was grabbed too. While Mastodon posts are obviously public by design, there is some non-public data to be lost. IP addresses aren’t exactly out of reach of law enforcement, it’s still a bit of personal information that many of us like to avoid publishing. Then there’s hashed passwords. While it’s better than plaintext passwords, having your password hash out there just waiting to be brute-forced is a bit disheartening. But the one that really hurts is that Mastodon doesn’t have end-to-end encryption for private messages. Continue reading “This Week In Security: Your Car’s Extended Warranty, Seizing The Fediverse, And Arm MTE” →

Stack of Si3N4-LiNbO3 forming the integrated laser and integrated into test setup (d). (Credit: Snigirev et al., 2023)

Fast Adjustable Lasers Using Lithium Niobate Integrated Photonics

August 4, 2023 by 14 Comments

Making lasers smaller and more capable of rapidly alternating between frequencies, while remaining within a narrow band, is an essential part of bringing down the cost of technologies such as LiDAR and optical communication. Much of the challenge here lies understandably in finding the right materials that enable a laser which incorporates all of these properties.

A heterogeneous Si3N4–LiNbO3 chip as used in the study. (Credit: Snigirev et al., 2023)

Here a recent study by [Viacheslav Snigirev] and colleagues (press release) demonstrates how combining the properties of lithium niobate (LiNbO3) with those of silicon nitride (Si3N4) into a hybrid (Si3N4)–LiNbO3 wafer stack allows for an InP-based laser source to be modulated in the etched photonic circuitry to achieve the desired output properties.

Much of the modulation stability is achieved through laser self-injection locking via the microresonator structures on the hybrid chip. These provide optical back reflection that forces the laser diode to resonate at a specific frequency, providing the frequency lock. What enables the fast frequency tuning is that this is determined by the applied voltage on the microresonator structure via the formed electrodes.

With a LiDAR demonstration in the paper that uses one of these hybrid circuits it is demonstrated that the direct wafer bonding approach works well, and a number of optimization suggestions are provided. As with all of these studies, they build upon years of previous research as problems are found and solutions suggested and tested. It would seem that thin-film LiNbO3 structures are now finding some very useful applications in photonics.

(Heading image: Stack of Si3N4-LiNbO3 forming the integrated laser and integrated into test setup (d). (Credit: Snigirev et al., 2023) )

Odd Retrocomputer Had A Graphics Coprocessor

August 4, 2023 by 16 Comments

[Noel’s Retro Lab] scored an unusual 1980s vintage computer sold in Japan and Spain. The Seconinsa FM-7 appears to be a popular Fujitsu Japanese computer altered to fit the Spanish market. They seem to be pretty rare, at least in our part of the world. The outside appearance was very nice for the time, with a large keyboard and plenty of expansion ports. But the board has an unusual feature considering the era — dual CPUs. One 6809 executed your program, and another 6809 handled graphics output. You can see the machine in the video below.

There are two 32K ROMs, but the machine specifications claim only 48K. After dumping the ROMs, it turns out one of the ROMs has two copies of the same data. You can imagine they might not want to decode the entire address space. It could be that they needed 16K of space for other devices.

It wasn’t just the ROMs. The video RAM is pretty strange, too, as [Noel] explains. There are even some static RAMs the computer doesn’t claim. It appears these act as communication pipes between the two CPUs. In fact, it turns out that even the keyboard has its own 4-bit CPU, so the machine actually has a total of 3 CPUs!

This was a heavy-duty design for the time it was built. [Noel] wanted to fire it up, but he had to figure out the cables since the computer didn’t have any with it. Some clever repurposing of stock cables provided monochrome video output. Color display was a bit more complicated, but not impossible.

[Noel] winds the video up with some history of the companies behind the machine. The Spanish government wanted to use the FM-7 in the classroom, but the program failed to materialize. Want to see what it was like to program the thing? Here’s the Basic reference manual (in Spanish). Most of the documentation for the machine is either in Spanish or Japanese.

While this certainly is a rare computer, at least there’s a record of its existence. If you want to see what a Japanese computer looked like a few decades earlier, check out the FACOM 128B.

Continue reading “Odd Retrocomputer Had A Graphics Coprocessor” →

Apple III Slows Down To Smell The Roses

August 3, 2023 by 7 Comments

The most collectible items in the realm of vintage computers often weren’t the most popular of their era. Quite the opposite, in fact. Generally the more desireable systems were market failures when they first launched, and are now sought out because of a newly-appreciated quirk or simply because the fact that they weren’t widely accepted means there’s fewer of them. One of the retro computers falling into this category is the Apple III, which had fundamental hardware issues upon launch leading to a large recall and its overall commercial failure. [Ted] is trying to bring one of these devices back to life, though, by slowing its clock speed down to a crawl.

The CPU in these machines was a Synertek 6502 running at 1.8 MHz. With a machine that wouldn’t boot, though, [Ted] replaced it with his own MCL65+, a purpose-built accelerator card based on the 600 MHz Teensy 4.1 microcontroller in order to debug the motherboard. The first problem was found in a ROM chip which prevented the computer loading anything from memory, but his solution wouldn’t work at the system’s higher clock speeds. To solve that problem [Ted] disabled the higher clock speed in hardware, restricting the system to 1 MHz and allowing it to finally boot.

So far there haven’t been any issues running the computer at the slower speed, and it also helps keep the computer cooler and hopefully running longer as well, since the system won’t get as hot or unstable. This isn’t [Ted]’s first retrocomputing rodeo, either. His MCL chips have been featured in plenty of other computers like this Apple II which can run at a much faster rate than the original hardware thanks to the help of the modern microcontroller.

It’s Snake, In A QR Code, But Smaller

August 3, 2023 by 16 Comments

We’re not sure that many of you have recognised the need in your life for an x86 machine code program encoded into a QR code, but following on from someone else work [donno2048] has created a super-tiny Snake clone in assembly which comes in at only 85 bytes long. It fits far better in a QR code than the previous effort, but perhaps more useful is a web page demo which runs an in-browser DOS compatibility library. We followed the compilation instructions and got it running on our Manjaro installation, with the result of a somewhat unplayable but recognisable Snake, we’re guessing because it was written for a slower platform. The web version is more usable, and allows us to investigate its operation more thoroughly.

To achieve a working game in so little code is an impressive feat, and since we found different keys responded on machines with different keyboards we’re curious how it does its keyboard input. Also we think it has the Snake bug where turning back on yourself means instant game over. We would be interested to hear the views in the comments of readers who know something about x86 assembly, to help explain these points.

Force Feedback Steering Wheel Made From Power Drill

August 3, 2023 by 22 Comments

When it comes to controllers for racing games, there is perhaps no better option than a force feedback steering wheel. With a built-in motor to push against the wheel at exactly the right times, they can realistically mimic the behavior of a steering wheel from a real car. The only major downside is cost, with controllers often reaching many hundreds of dollars. [Jason] thought it shouldn’t be that hard to build one from a few spare parts though and went about building this prototype force feedback steering wheel for himself.

Sourcing the motor for the steering wheel wasn’t as straightforward as he thought originally. The first place he looked was an old printer, but the DC motor he scavenged from it didn’t have enough torque to make the controller behave realistically, so he turned to a high-torque motor from a battery-powered impact driver. This also has the benefit of coming along with a planetary gearbox as well, keeping the size down, as well as including its own high-current circuitry. The printer turned out to not be a total loss either, as the encoder from the printer was used to send position data about the steering wheel back to the racing game. Controlling the device is an Arduino, which performs double duty sending controller information from the steering wheel as well as receiving force feedback instructions from the game to drive the motor in the steering wheel. Continue reading “Force Feedback Steering Wheel Made From Power Drill” →