Analog Tank Driving Simulator Patrols A Tiny Physical Landscape

October 18, 2022 by Danie Conradie 30 Comments

How do you build a practical tank-driving simulator in the 1970s, when 3D computer-generated graphics are still just a fantasy of the future? If you’re a European tanker school, the solution is to use a large CNC machine to drive a camera around a miniature terrain model (German, translated). In the video after the break, [Tom Scott] takes it for a test drive.

The old computer was replaced with a Raspberry Pi — The original computer was replaced with a Raspberry Pi

Developed in France, the simulator provided a safer and more cost-effective way for teaching new trainees the basics of driving Centurion, Leopard 2, or Panzer 68 tanks. The trainee sits in a realistic “cockpit” mounted on a hydraulically-operated motion platform, with a TV screen in front of his face, which is connected to a camera mounted on a large gantry-style CNC platform.

The camera’s lens is mounted just above a pivoting metal foot which slides across the 12 m-long terrain model and sends its angle to the hydraulic system. It will even alter the tank’s handling based on its current position on the model to simulate different surfaces like dirt, snow, or asphalt.

The last of these systems remained in use until 2004 at the military training center in Thun, Switzerland, before being saved by the Swiss Military Museum from being scrapped. The original 70s computer, electronics, and hydraulics finally gave out, so the museum undertook a complete refurbishment of the system to return it to working order for museum visitors. It was kept as original as possible, but parts for the original computer could not be found, so it was replaced with a Raspberry Pi and custom interface board.

Over three decades, these simulators probably trained a few thousand tank drivers, and even with limited technology did an excellent job of preparing trainees for the real thing. Besides providing training for operators, drivers and pilots, simulators are also just plain fun. We’ve seen some impressive home built simulator including a A-10 Warthog, an F-15 sim built from an actual wreckage, and even a starship’s bridge.

Continue reading “Analog Tank Driving Simulator Patrols A Tiny Physical Landscape” →

An exploded diagram of the spot welder. Shown are the capacitor bank, trigger, 12 V relay, DC power input, power out, step up converter, voltmeter, industrial SCR module, and capacitor bank.

Hackaday Prize 2022: A Not-So-Smart Spot Welder

October 17, 2022 by Navarre Bartz 5 Comments

DIY spot welders often use high-powered components that can be a bit frightening, given the potential for dangerous malfunctions. [Wojciech “Adalbert” J.] designed his capacitive discharge spot welder to be safe, easy to build, and forego the microcontroller.

Many projects work great with just a single Li-ion cell, but when you need more power, you’ve got to start connecting more cells together into a battery. [Wojciech]’s spot welder is designed to be just powerful enough to weld nickel tabs onto a cell without any overkill. The capacitor bank uses nineteen Nichicon UBY 7500uF/35V capacitors, all wired in parallel using solder wick saturated with solder. They sit atop on a perfboard with metallicized holes to carry the high current.

[Wojciech] has detailed every step of building the welder, including changes to the off-the-shelf relay board and adding a potentiometer to the step-up converter board. The level of detail makes this seem like a good starting place if you’re hoping to hop into the world of DIY spot welders. Safe is always a relative term when dealing with high powered devices, so be careful if you do attempt this build!

DIY spot welders have graced these digital pages many times, including this one built with safety in mind, and this other one that was decidedly not.

Dumping An EMMC Chip With Many Bodge Wires

October 11, 2022 by Lewin Day 11 Comments

Sometimes, you know where the data you need is stored, you just don’t have a way to access it. In this case, [GetHypoxic] needed to rip data off an eMMC chip, salvaged out of a camera. With no desire to wait for an adapter to show up, it was time to bust out the bodge!

Once removed from the PCB, bodge wires were attached to the ball-grid array contacts on the bottom of the chip. Incredibly fine soldering was the order of the day to get these hooked up to the tiny pads, and we count 11 or 12 bodge wires in total. 1.8 volts was manually supplied to the eMMC chip, and it was directly wired up to the contacts of a built-in card reader out of an old laptop for reading.

Despite the rats-nest look of it all, and the yellow polyimide tape holding it together, [GetHypoxic] reported that it mounted successfully and got the job done. We’ve seen similar hacks before, too, wiring eMMC chips up to SD card adapters. It might look messy, but hey – it sure beats waiting for shipping!

Compensating For Your TVs Backlight

October 10, 2022 by Matthew Carlson 8 Comments

[Pekka Väänänen] has a Panasonic TV with a broken backlight that creates an uneven pink/green color. While it isn’t a huge deal for most films, black-and-white films tend to show the most effect. So, by modeling the distortion as a function, [Pekka] set out to find an inverse function that corrects the distortion before it gets to the TV.

However, the backlight doesn’t emit enough light for some colors, which means the blue and green channels need to be dimmed. As mentioned earlier, the distortion isn’t even, so the distortion needs to be captured and then calculated.

He took a few pictures with his phone, corrected the perspective, and applied a blur. The camera also has some distortion but works as a first approximation, but that isn’t something he covered here. Next, he set up a webcam and pointed it at the TV, trying to find good gain and offset values with a bit of Python.

Now it just becomes a problem of minimizing the per-pixel difference. Ultimately he just went for a random approach rather than an annealing or hill-climbing approach. Now that he had a function to apply, it was just a matter of adding a custom shader to his video player, which includes a live shader editor. He had to hack in support for an external texture, but he is kind enough to include the shader code and the patch in the article.

The result is excellent, and it’s a great use for an old TV. But perhaps, in some cases, it might be worth replacing the backlight entirely.

A bike computer sits on a wooden background. The back of the bike computer has a 3D printed attachment with two white translucent zip ties running through the back.

Repairing A Bike GPS With 3D Printing

October 7, 2022 by Navarre Bartz 10 Comments

We love hacks that keep gadgets out of the trash heap, and [Brieuc du Maugouër] has us covered with this 3D printable replacement mount he designed for his bike GPS.

One of the most frustrating ways a gadget can fail is when a small, but critical part of the device fails. [du Maugouër] combined a 3D printed back and four M2x6mm screws to make a robust new mount to replace the broken OEM mount on his handlebar-mounted GPS. Slots for zip tie mounting are included in case the replacement mount breaks before yet another replacement can be printed. Apparently [du Maugouër] agrees with Chief O’Brien that “in a crunch, I wouldn’t like to be caught without a second backup.” [Youtube]

It’s exciting that we’re finally in a time when 3D printed replacement parts are living up to their potential. This would be a lot easier if more manufacturers posted 3D printed design files instead of getting them pulled from 3D file platforms, but makers will find a way regardless of OEM approval.

We’ve covered a lot of bike hacks over the years including DIY Bike Computers and GPS Trackers. Do you have a project that keeps something from becoming trash or might save the world another way? There’s still time to enter the Save the World Wildcard round of the Hackaday Prize (closes October 16th).

A sliced digital file of a marker light enclosure. Background is a white and grey grid and object itself is a series of print path lines in red, orange, and green.

3D Printing Hard-To-Find Vintage Vehicle Parts

October 7, 2022 by Navarre Bartz 52 Comments

When I was growing up, my dad and I restored classic cars. Combing junkyards for the pieces we needed was a mixture of interesting and frustrating since there was always something you couldn’t find no matter how long you looked. [Emily Velasco] was frustrated by the high price of parts even when she was able to find them, so she decided to print them herself. She wrote an excellent tutorial about designing and 3D printing replica parts if you find yourself in a similar situation.

All four marker lights on [Velasco]’s 1982 Toyota pickup were on their way to plastic dust, and a full set would run her $160. Instead of shelling out a ton of cash for some tiny parts, she set out to replicate the marker lamps with her 3D printer. Using a cheap marker lamp replacement for a more popular model of pickup as a template, she was able to replace her marker lamps at a fraction of the cost of the options she found online. Continue reading “3D Printing Hard-To-Find Vintage Vehicle Parts” →

Fixing A 30-year Old Roland Bug

October 5, 2022 by Matthew Carlson 12 Comments

The Roland CM-500 is a digital synthesizer sound module released in 1991 that combines two incredibly powerful engines into one unit. However, in 2005 enthusiasts of the Roland MT-25 (one of the engines that went into the CM-500) noticed a difference between the vibrato rate on the MT-25 and the CM-500, rendering it less useful as now midi files would need to be adjusted before they sounded correct. Now thirty-something years later, there is a fix through the efforts of [Sergey Mikayev] and a fantastic writeup by [Cloudschatze].

They reached out to Roland Japan, who decided that since the device’s lifecycle had ended, no investigation was warranted. That led the community to start comparing the differences between the two systems. One noticeable difference was the change from an Intel 8098 to an 80C198. In theory, the latter is a superset of the former, but there are a few differences. First, the crystal frequency is divided by three rather than two, which means the period of the LFO would change even if the crystal stayed the same. Changing the 12 MHz crystal out for 8 MHz gave the LFO the correct period, but it broke the timings on the MIDI connection. However, this is just setting the serial baud rate divisor, which requires changing a few bytes.

Replace the ROM chip with a socket so you can slot your newly flashed PDIP-28 64kx8 ROM into a quick desoldering. Then swap the crystal, and you’ll have a machine that matches the MT-25 perfectly. The forum post has comparison audio files for your enjoyment. Finally, if you’re curious about other fixes requiring an inspiring amount of effort and dedication, here’s a game installer that was brought back from the dead by a determined hacker.