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VR Mech’s Missing Link: The Phone in Your Pocket

Hackaday - 2 hours 37 minก่อน

In the process of making a homemade Mech Combat game that features robot-like piloted tanks capable of turning the cockpit independent of the direction of movement, [Florian] realized that while the concept was intuitive to humans, implementing it in a VR game had challenges. In short, when the body perceives movement but doesn’t feel the expected acceleration and momentum, motion sickness can result. A cockpit view that changes independently of forward motion exacerbates the issue.

To address this, [Florian] wanted to use a swivel chair to represent turning the Mech’s “hips”. This would control direction of travel and help provide important physical feedback. He was considering a hardware encoder for the chair when he realized he already had one in his pocket: his iPhone.

By making an HTML page that accesses the smartphone’s Orientation API, no app install was needed to send the phone’s orientation to his game via a WebSocket in Unity. He physically swivels his chair to steer and is free to look around using the VR headset, separate from the direction of travel. Want to try it for yourself? Get it from [Florian]’s GitHub repository.

A video is embedded below, but if you’re interested in details be sure to also check out [Florian]’s summary of insights and methods for avoiding motion sickness in a VR Mech cockpit.

This project incorporates a physical element into the VR environment, but there’s neat work being done in the other direction as well; how about spicing up your stationary bike with a VR headset and Google street view data?

Filed under: iphone hacks, Virtual Reality

Get Up Close to your Soldering with a Pi Zero Microscope

Hackaday - 5 hours 37 minก่อน

Do your Mark 1 Eyeballs no longer hold their own when it comes to fine work close up? Soldering can be a literal pain under such conditions, and even for the Elf-eyed among us, dealing with pads at a 0.4-mm pitch is probably best tackled with a little optical assistance. When the times comes for a little help, consider building a soldering microscope from a Pi Zero and a few bits and bobs from around the shop.

Affordable commercial soldering scopes aren’t terribly hard to come by, but [magkopian] decided to roll his own by taking advantage of the streaming capabilities of the Raspberry Pi platform, not to mention its affordability. This is a really simple hack — nothing is 3D-printed or custom milled. The stage base is a simple aluminum project box for heat resistance and extra weight, and the arm is a cheap plastic dial caliper. The PiCam is mounted to the sliding jaw of the caliper on a scrap of plastic ruler. The lens assembly of the camera needs to be hacked a little to change the focal length to work within 10 centimeters or so; alternatively, you could splurge and get a camera module with an adjustable lens. The Pi is set up for streaming, and your work area is presented in glorious, lag-free HDMI video.

Is [magkopian]’s scope going to give you the depth perception of a stereo microscope? Of course not. But for most jobs, it’ll probably be enough, and the fact that it can be built on the cheap makes it a great hack in our book.

Filed under: Raspberry Pi, tool hacks

Old Part Day: Voltage Controlled Filters

Hackaday - 8 hours 37 minก่อน

For thirty years, the classic synths of the late 70s and early 80s could not be reproduced. Part of the reason for this is market forces — the synth heads of the 80s didn’t want last year’s gear. The other part for the impossibility to build new versions of these synths was the lack of parts. Synths such as the Prophet 5, Fairlight CMI, and Korg Mono/Poly relied on voltage controlled filter ICs — the SSM2044 — that you can’t buy new anymore. If you can source a used one, be prepared to pay $30. New old stock costs about $100.

Now, these chips are being remade. A new hardware revision for this voltage controlled filter has been taped out by the original hardware designer, and these chips are being produced in huge quantities. Instead of $100 for a new old stock chip, this chip will cost about $1.60 in 1000 unit quantities.

The list of synths and music boxes sporting an SSM2044 reads like a Who’s Who of classic electronic music machines. E-Mu Drumulators, Korg polyphonic synths, Crumars, and even a Doepfer module use this chip in the filter section. The new chip — the SSI2144 — supposedly provides the same classic tone but adds a few improvements such as improved pin layouts, an SSOP package, and more consistent operation from device to device.

This news follows the somewhat recent trend of chip fabs digging into classic analog designs of the 70s, realizing the chips are being sold for big bucks on eBay, and releasing it makes sense to spin up a new production line. Last year, the Curtis CEM3340 voltage controlled oscillator was rereleased, giving the Oberheim OB, Roland SH and Jupiter, and the Memory Moog a new lease on life. These chips aren’t only meant to repair broken, vintage equipment; there are a few builders out there who are making new devices with these rereleased classic synths.


Filed under: hardware, musical hacks

Look at me with your Special Animatronic Eyes

Hackaday - 11 hours 38 minก่อน

Animatronics for movies is often about making something that works and is reliable in the short term. It doesn’t have to be pretty, it doesn’t have to last forever. [Corporate Sellout]  shows us the minimalist approach to building animatronics with this pair of special eyes.  These eyes move in both the pan and tilt. Usually, that means a gimbal style mount. Not in this case. The mechanical assembly consists of with popsicle sticks, ping-pong balls, film canisters and dental floss.

The frame for the eyes is made of simple popsicle sticks hot glued together. The eyes themselves are simple ping-pong balls. Arduino powered servos control the movement. The servos are connected to dental floss in a cable arrangement known as a pull-pull system. As each servo moves, one side of the arm pulls on a cable, while the other provides enough slack for the ping-pong ball to move.

Mounting the ping-pong balls is the genius part of this build. They simply sit in the open end of a couple of film canisters. the tension from the dental floss holds everything together. We’re sure it was a finicky setup to build, but once working, it’s reliable. Only a glue joint failure or stretch in the dental floss could cause issues.

There are plenty of approaches to Animatronic eyes. Check out the eyes in this Stargate Horus helmet, which just won our Sci-Fi contest. More recently we saw Gawkerbot, which uses a CD-ROM drive to provide motion for a creepy robot’s eyes.

Filed under: classic hacks, robots hacks

Acer Aspire Switch 3 Pro 2-in-1 with Apollo Lake CPU coming soon

Liliputing - 14 hours 22 minก่อน

Acer’s next 2-in-1 tablet may be cheaper than the Switch Alpha 12 the company released last summer. The Acer Aspire Switch 3 Pro has the same basic design, including the LiquidLoop fanless cooling system. But instead of Core i3, Core i5, or Core i7 chips, the new Switch 3 Pro is powered by an Intel […]

Acer Aspire Switch 3 Pro 2-in-1 with Apollo Lake CPU coming soon is a post from: Liliputing

Error: LP0 On

Hackaday - 14 hours 38 minก่อน

You don’t need fancy ICs and DACs to build a sound card for a PC. As [serdef]’s build over on hackaday.io shows, all you really need is a bunch of resistors. [serdef] built a clone of a sound card released for PC in the 80s, but with a few improvements. This mess of resistors features the best 8-bit sound you can get with a low-pass filter, volume divider, and a handy DB-25 connector.

The design of this LPT0 sound card is pretty much the same as when it was introduced to the world as the Covox Speech Thing. This ‘sound card’ was designed to clip onto the parallel port of a computer and send the 8-bit I/O of this port through a resistor ladder. Plug a pair of speakers into this thing, and you have a sound card that is completely made out of resistors. It was cheap, and in the demoscene it was popular.

There are a lot of amazing demos out there using this resistor DAC thing, and [serdef] has videos of his project playing a lot of them. You can check that out below.

Filed under: classic hacks

Xiaomi Mi Mix slim-bezel smartphone inspires knockoffs

Liliputing - 16 hours 53 minก่อน

Xiaomi’s Mi Mix is a striking looking smartphone with ceramic body, a big 6.4 inch display, and super-slim bezels on the top, right, and left sides. But while the Mi Mix is a premium phone that sells for over $500 in China, a number of other companies have drawn inspiration from the Mix design and unveiled […]

Xiaomi Mi Mix slim-bezel smartphone inspires knockoffs is a post from: Liliputing

Heavy Metal Detectors

Hackaday - 17 hours 38 minก่อน

Helsinki has a strong underground Heavy Metal scene, so what better way to show it off than to have listeners literally unearth the local sounds themselves with converted metal detectors that play, naturally, Metal? [Steve Maher] built these modified detectors and handed them to a bunch of participants who went on exploratory walks around the city. The tracks from local bands changed as the user moved from one concealed metallic object to the other to create the experience of discovering the hidden soundscape of the land. 

Because there was no writeup on the hardware, we contacted [Steve] ourselves, and here is what we learned.  [Luis Alejandro Olarte] helped out on the build that uses a Teensy 3.2 with an audio shield to play tracks from an SD card. The beeps that would normally help you find metallic objects are fed to the Teensy and control the volume of the output audio. The Teensy then loops through a 45 minute track that is only audible when metal is detected. This allows the audience to establish a connection between the metal as well as the music.

The video has [Steve Maher] talking about the concept and some of the walks organised under the project as part of Live Herring.

We think this is a great idea and can think of other variations on the theme. Using color sensors to play tracks and sounds that allow individuals with colour blindness or complete ocular disability to experience the hues in an auditory way? Red with loud music and sky-blue with the calm sound of a cool breeze. Adding a bit of haptic feedback could take this idea in so many directions.

If you’d rather DIY your own than modify one off the shelf, here’s an article on building your own metal detector.

Filed under: Microcontrollers, musical hacks

Deals of the Day (4-25-2017)

Liliputing - 18 hours 16 minก่อน

Need a 4K-ready media streamer and don’t want to spend a lot of money? Your best bets are usually the Xiaomi Mi Box,  Roku Premier, or Google Chromecast Ultra, all of which sell for $69. But right now Amazon is offering a refurbished Roku 4 for $10 less than that. Sure, this is a previous-gen model, but it’s […]

Deals of the Day (4-25-2017) is a post from: Liliputing

Hackaday Prize Entry: Brightenmacher

Hackaday - 19 hours 8 minก่อน

We have all at some point have made a flashlight. It used to be a staple of childhood electronics, the screw-in bulb in a holder, and a cycle lamp battery. If you were a particularly accomplished youthful hacker you might even have fitted a proper switch, otherwise, you probably made do with a bent paperclip and a drawing pin.

So you might think that flashlights offer no challenges, after all, how many ways can you connect a bulb or an LED to a battery? [Peter Fröhlich] though has a project that should put those thoughts out of your mind. It uses a power LED driven by a TI TPS61165 boost driver, with an ATTiny44 microcontroller providing control, battery sensing, and button interface. The result is a dimmable flashlight in a 3D printed case housing both control circuitry and a single 18650 cell which he sourced from a dead laptop. Suddenly that bent paperclip doesn’t cut it anymore.

The result is a flashlight that is the equal of any commercial offering, and quite possibly better than most of them. You can build one yourself, given that he’s published the physical files necessary, but probably because this is a work in progress there are as yet no software files.

We’ve featured a lot of flashlights over the years, but it’s fair to say they usually tend towards the more powerful. Back in 2015 we published a round-up of flashlight projects if it’s a subject that captures your interest.

The HackadayPrize2017 is Sponsored by:


Filed under: led hacks, The Hackaday Prize

Microsoft steps up push for Office 365 subscriptions over single-license Office installs

Liliputing - 19 hours 13 minก่อน

There are currently a few different ways to get your hands on Microsoft Office. There are home and business versions of Office. And make a one-time purchase to get a version of Office that you can install on a single PC or pay for an Office 365 subscription that lets you install the operating system on one […]

Microsoft steps up push for Office 365 subscriptions over single-license Office installs is a post from: Liliputing

#FreePCB via Twitter to 2 random RTs

dangerous prototype - 19 hours 55 minก่อน

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

Siglent SSA3032X Spectrum Analyzer review & experiments

dangerous prototype - 19 hours 58 minก่อน

Afroman did a review of the Siglent SSA3032X Spectrum.

More details at Afrotechmods tutorial page.

Ask Hackaday: What About the Diffusers?

Hackaday - 20 hours 37 minก่อน

Blinky LED projects: we just can’t get enough of them. But anyone who’s stared a WS2812 straight in the face knows that the secret sauce that takes a good LED project and makes it great is the diffuser. Without a diffuser, colors don’t blend and LEDs are just tiny, blinding points of light. The ideal diffuser scrambles the photons around and spreads them out between LED and your eye, so that you can’t tell exactly where they originated.

We’re going to try to pay the diffuser its due, and hopefully you’ll get some inspiration for your next project from scrolling through what we found. But this is an “Ask Hacakday”, so here’s the question up front: what awesome LED diffusion tricks are we missing, what’s your favorite, and why?

Diffusive Materials, Blending Colors

Look closely enough at an RGB LED and you’ll see three individual LED chips, not surprisingly in red, green, and blue. We all know this, and yet it’s still surprising how badly blended the colors can be, even from an LED unit like the WS2812, where the three diodes are ridiculously tiny and less than a millimeter apart. Somehow, even at desk-distance, you still get the feeling that you’re looking at a red LED and a blue LED instead of a blended magenta light source.

One approach is to use a diffusive material that has a rough enough surface that it scatters the light that passes through it. Diffusive materials include something “traditional” like frosted glass or acrylic, as seen in [Mike Szczys]’s 1 Pixel Pacman demo video or this classy linear RGB clock. Something like 50% transparent acrylic seems to be just about right. You can get a similar effect by sanding or tumbling a clear LED.

Then there are “oddball” diffusers. A drop of hot glue works pretty well, because it’s rarely crystal clear. Stranger still is polyester pillow stuffing. Lately, I’ve been experimenting with re-melting candles and entombing LEDs in paraffin wax — around 1 cm depth yields very uniform colors. I’ve also seen holes drilled in wooden cases, filled with epoxy, and sanded down.

You could always 3D print the case in a translucent material, so that the case is the diffuser. Or you can just hold up a sheet of paper or a cutout from a milk jug. These low-tech options work surprisingly well.

The main variables with diffusive materials is how transmissive the material is and how far away from the LED it’s located. Thicker, less transmissive materials tend to blur better but darken the LED more — sometimes a good thing. Locating the diffuser further away tends to mix colors better, but also blurs the points of light out, and can muddy up the image. Again, sometimes you want this effect, like in this wall panel, and sometimes you don’t, like in [Mike]’s Pacman. But the distance to the diffuser can be critical. Test it out well before designing the case.

Reflective Cavities, Shaping Light

Reflective cavities serve the same purpose as translucent material, but can be lighter weight if more difficult to construct. You can either add a diffuser sheet to the front of the cavity or not, as you wish. Both can be really nice effects. For instance, “Ecstatic Epiphany” by [Micah Elizabeth Scott] uses folded borders that bounce the LEDs off of a light-colored surface, and spread it around a little bit, to achieve both color mixing and some shaping. It works fine without any front cover.

Colossus” uses white foam-core dividers to make many individual reflective cavities, covered with two layers of white bed sheet as a front-surface diffuser. Within each cell, the colors are discrete and well mixed, for the perfect big-pixel effect. You could also use straws, toilet-paper tubes, or even soda bottles.

Photographer’s light boxes are also essentially diffuser cavities. We’ve shot many of our closeups in one that’s made of “vellum” art paper surrounding a wooden frame, but we recently upgraded to IKEA Trofast with optional LED lighting for nocturnal photo sessions. Most of the light coming through the translucent plastic ends up bouncing around inside, leaving very soft shadows and even illumination. It works better when driven by daylight. If you want to take this idea to the extreme, check out [Doog]’s model shooting rig. Note the clever use of underlit diffusive acrylic.

Nothing is stopping you from making interesting shapes out of the reflective cavities. Triangle-shaped reflective cells give [Micah Scott]’s “Triangle Attractor” and [Becky Stern]’s WiFi wall display their style. If triangles aren’t your thing, you can 3D-print the cavities in whatever shape you need, like these 16-segment displays.

Designing the diffusive cavity just right is an art more than a science. Generally speaking, the more reflective the walls, and the more volume they enclose, the better the color mixing is going to be. It’s definitely worth your time to experiment around with indirect illumination, where the light bounces first before leaving the box. Combining cavities with diffusive material front panels can yield some very subtle effects.

The Ask

Pshwew! That was a whirlwind tour of diffusing options, divided arbitrarily into categories of diffusive materials and cavities, with overlap. What did we miss? What’s your favorite LED diffusive effect?

Filed under: Ask Hackaday, led hacks, Skills

Samsung and LG smartphone displays with 4 curved edges under development?

Liliputing - อังคาร, 04/25/2017 - 23:35

Samsung’s Galaxy S8 smartphone features dual curved edges, with the display bending over the left and right sides of the display giving the phone a bezel-less design along its longest sides. But future smartphone displays might have curves along all four edges, enabling device makers to build phones with nearly nothing but screen on the […]

Samsung and LG smartphone displays with 4 curved edges under development? is a post from: Liliputing

Around the Globe on World Create Day

Hackaday - อังคาร, 04/25/2017 - 23:01

Last weekend was great for science and technology. While thousands of people took to the streets to protest anti-intellectualism, a few members of the Hackaday community dug their heels in, turned on the soldering iron, and actually did something about it. This was World Create Day, a community effort to come together and build something that matters. What did these people build? So much awesome stuff.

The Nest I/O in Karachi, Pakistan

The folks at The Nest I/O hackerspace in Karachi, Pakistan had a rather large meetup for World Create Day featuring the finest in laser cut, googly-eyed fighting robots. [Nasir Aziz] hosted a meetup at his favorite hackerspace for people to get together, discuss, and build something for the Hackaday Prize.

The highlight of the meetup was a discussion from EjaadTech, an industrial design firm that graduated from The Nest I/O accelerator. Among the projects invented during World Create Day were a ‘shopping helper drone’ and miniature fighting robots. Useful projects on one hand, awesome projects on the other, just like we like it.

MakerBay in Hong Kong A solar oven found at MakerBay

MakerBay is a hackerspace located smack in the middle of Hong Kong. Like most hackerspaces, finding a place was a problem, but the folks at MakerBay found something spectacular. They’re zoned industrial, and only a five-minute walk from a train station.

There are quite a few projects sitting around MakerBay including a solar oven that would be pretty dangerous if it were outdoors on a sunny day. Also on deck are prototypes of small sailing vessels with a flexible hull designed to track and contain oil spills.  Highlights of World Create Day include upcycled wood construction and a spontaneous piano interlude. I’m surprised I haven’t seen more hackerspaces with a piano; they’re effectively free if you have a truck and a place to store it.

BlenderLab in Lille

While the World Create Day event at the BlenderLab hackerspace in Lille, France didn’t set out to change the world with a project, they did manage to come up with a really neat digital hourglass. The body of this hourglass is made out of laser cut plywood, with the display made out of two LED matrices oriented at a 45-degree angle.

Hackaday NYC

[Zach Freedman] reveals his devious plotWhile World Create Day is a challenge for hackerspaces around the globe to come together and create something that solves a problem, that doesn’t mean there aren’t slightly more official events around the globe. Hackaday set up our own events in New York City, LA, and San Francisco.  The New York event was great thanks to our lovely East coast community manager [Shayna] and our hosts at Fat Cat Fab Lab.

[Zach Freedman], one of the regulars at our NYC meetups has an ulterior motive for getting the Fat Cat Fab Lab members to contribute their ideas to the Hackaday Prize: winning the Hackaday Prize would result in donating the winnings to the Fab Lab. It’s a brilliant and devious plot we very much recommend.

Tell us about your World Create Day

There were many more events going on around the globe last weekend, and we want to hear about how your World Create Day went. We’ll be covering more of the events of last weekend in the coming days, so make sure to add your pictures, stories, and links to the projects you started on your World Create Day event page on Hackaday.io. Event organizers are going to get some super awesome swag for making that effort.

The HackadayPrize2017 is Sponsored by:
Filed under: The Hackaday Prize

Whoops: Antivirus software Webroot bricks PCs by deleting Windows system files

Liliputing - อังคาร, 04/25/2017 - 22:44

Webroot provides security software for home and business users, and like most antivirus applications, the company’s software can identify and quarantine or delete potentially malicious files. Unfortunately on April 24th, a Webroot update mistakenly flagged hundreds of Windows system files as malware… causing many computers to stop working. The company says the bad virus definitions were […]

Whoops: Antivirus software Webroot bricks PCs by deleting Windows system files is a post from: Liliputing

An Analog Charge Pump Fabrication-Time Attack Compromises A Processor

Hackaday - อังคาร, 04/25/2017 - 22:00

We will all be used to malicious software, computers and operating systems compromised by viruses, worms, or Trojans. It has become a fact of life, and a whole industry of virus checking software exists to help users defend against it.

Underlying our concerns about malicious software is an assumption that the hardware is inviolate, the computer itself can not be inherently compromised. It’s a false one though, as it is perfectly possible for a processor or other integrated circuit to have a malicious function included in its fabrication. You might think that such functions would not be included by a reputable chip manufacturer, and you’d be right. Unfortunately though because the high cost of chip fabrication means that the semiconductor industry is a web of third-party fabrication houses, there are many opportunities during which extra components can be inserted before the chips are manufactured. University of Michigan researchers have produced a paper on the subject (PDF) detailing a particularly clever attack on a processor that minimizes the number of components required through clever use of a FET gate in a capacitive charge pump.

On-chip backdoors have to be physically stealthy, difficult to trigger accidentally, and easy to trigger by those in the know. Their designers will find a line that changes logic state rarely, and enact a counter on it such that when they trigger it to change state a certain number of times that would never happen accidentally, the exploit is triggered. In the past these counters have been traditional logic circuitry, an effective approach but one that leaves a significant footprint of extra components on the chip for which space must be found, and which can become obvious when the chip is inspected through a microscope.

The University of Michigan backdoor is not a counter but an analog charge pump. Every time its input is toggled, a small amount of charge is stored on the capacitor formed by the gate of a transistor, and eventually its voltage reaches a logic level such that an attack circuit can be triggered. They attached it to the divide-by-zero flag line of an OR1200 open-source processor, from which they could easily trigger it by repeatedly dividing by zero. The beauty of this circuit is both that it uses very few components so can hide more easily, and that the charge leaks away with time so it can not persist in a state likely to be accidentally triggered.

The best hardware hacks are those that are simple, novel, and push a device into doing something it would not otherwise have done. This one has all that, for which we take our hats off to the Michigan team.

If this subject interests you, you might like to take a look at a previous Hackaday Prize finalist: ChipWhisperer.

[Thanks to our colleague Jack via Wired]

Filed under: security hacks

Xiaomi’s in no hurry to launch smartphones in the US

Liliputing - อังคาร, 04/25/2017 - 21:26

Chinese company Xiaomi currently sells a popular line of entry-level, mid-range, and premium smartphones in about 30 markets around the world. But while the company sells a handful of products like headphones, speakers, batteries, and TV boxes in the US, the only way to buy a Xiaomi phone in the United States is to pick up […]

Xiaomi’s in no hurry to launch smartphones in the US is a post from: Liliputing

Different Differentials & The Pitfalls of the Easy Swap

Hackaday - อังคาร, 04/25/2017 - 21:01

I dig cars, and I do car stuff. I started fairly late in life, though, and I’m only just starting to get into the whole modification thing. Now, as far as automobiles go, you can pretty much do anything you set your mind to – engine swaps, drivetrain conversions, you name it – it’s been done. But such jobs require a high level of fabrication skill, automotive knowledge, and often a fully stocked machine shop to match. Those of us new to the scene tend to start a little bit smaller.

So where does one begin? Well, there’s a huge realm of mods that can be done that are generally referred to as “bolt-ons”. This centers around the idea that the install process of the modification is as simple as following a basic set of instructions to unbolt the old hardware and bolt in the upgraded parts. Those that have tread this ground before me will be chuckling at this point – so rarely is a bolt-on ever just a bolt-on. As follows, the journey of my Mazda’s differential upgrade will bear this out.

The car in question, currently known as the “Junkbox MX-5” until it starts running well enough to earn a real name. It somehow looks passable here, but in person I promise you, it looks awful.

It all started when I bought the car, back in December 2016. I’d just started writing for Hackaday and my humble Daihatsu had, unbeknownst to me, just breathed its last. I’d recently come to the realisation that I wasn’t getting any younger, and despite being obsessed with cars, I’d never actually owned a sports car or driven one in anger. It was time to change.

After realising all my favourite JDM metal was outside a budget I was comfortable spending, I settled on an automotive classic – I’d have a Mazda MX-5, known to the Americans as the Miata. It’s a Japanese take on the old British sportscar – a convertible roadster with an engine in the front, driving the rear wheels. I wanted the cheapest one I could find, and well – safe to say, I got it.

When I rolled up to buy the thing, it looked okay – some shabby paintwork, sure, but it drove great! It was a 1990 with the smaller 1.6 litre engine, and no performance parts to speak of, but I wanted a project anyway. I happily parted with $3000 and all was well, for about fifteen minutes. You see, on the way home, a terrible, awful noise began to emanate from the car’s drivetrain. My heart sank at rather a high rate of knots.

After limping home praying the thing wasn’t about to completely explode, I sprinted to the Internet for help.

“Weird deceleration noise”
“Scraping mx-5 deceleration”
“Miata drivetrain shuffling noise”

To my relief, thousands of people had exactly the same problem I did – a strange shuffling or scraping noise on deceleration in gear. To my exasperation, it wasn’t clear what the problem was – was it the differential, the gearbox – an exhaust heat shield? Eventually, I took a trip to a local MX-5 expert who indicated it was likely the gearbox or differential, but despite the noise it would probably be okay for another 50,000 km or so until I could get it fixed.

Now slightly more comfortable, I resolved to put up with the noise while I got on with real life. In the mean time, the car rewarded me with more trouble, like overheating – eventually solved by a radiator replacement you can watch in the video below.

I was very much getting my money’s worth out of this car, but I wasn’t worried. I’d bought this car expecting to upgrade virtually everything on it anyway, so I wasn’t too cut up about the worn out parts. After much research, I had decided that I wanted to upgrade to a limited-slip differential (LSD), which allows better torque distribution between the rear wheels for better grip and handling. Plus it helps you do mad skids. I settled on a 4.1 ratio unit from the more recent 1.8 litre cars, sourced from a wrecker a state over.

The Torsen LSD from a 1.8 litre MX-5, along with tailshaft & halfshafts with hubs attached. Apparently removing the halfshafts from the hubs is insanely difficult so I’m thankful the wrecker left them attached.

Now, I initially wasn’t too worried about the swap. The 1.8 litre LSD in itself isn’t a direct swap into a 1.6 litre car. However, if sourced with the tailshaft and halfshafts from a 1.8 litre car as well, everything should just bolt up. Sounds easy, right?

Well, that’s where the trouble starts. I’ve only been doing bigger mechanical jobs like this for a few months, but I was confident after reading a few tutorials that I could complete the job in just a few hours. But the tutorials I read assume a certain level of experience that I quickly learned I didn’t have.

First problem – tools! I’d happened across a great trolley jack and sourced some jackstands so I could get under the car. After getting everything set up, I slid under the car and prepared to start unbolting the differential mounts. Armed with a 3/8 inch ratchet I got in a cheap $50 toolkit, I was quickly disappointed. Drivetrain and suspension components are generally held on with very large fasteners, done up to a very high torque. We rounded off the 3/8 socket extension in the first five minutes, and called it a day while we waited for the hardware store to open.

This socket set was integral to getting the job done. A good set of tools will make your wrenching activities much more pleasurable.

The next day, I was back, armed with a tough new socket set. To say this transformed my experience is a total understatement. Suddenly, with a 300 mm extension and the 1/2 inch drive breaker bar, the nuts holding on the differential were no match for my raw strength. Instantly what felt like an impossible task seemed again to be a quick, one-day job. Until the next pitfall.

Things on cars get stuck a lot. Put a big bolt through a few parts, wang it up to 150 foot-pounds, and blast it with dirt and water for 27 years. Remove the bolt, and you might find it’s all still stuck together. As you’re trying to free things up, the initial instinct might be to reach for a hammer. But it’s not so easy –  sometimes it’s not obvious if you’re actually hitting the right thing. Other times, you’re on the ball, smack the part free – only to realise you’ve just put your screwdriver through a brake line. It often takes finesse, a cup of tea, and a quick question to the relevant forum or Facebook group to identify where one should place one’s hammer, and how hard one should swing it. On this job, there was confusion about a bushing that was holding the old differential on to the power plant frame – thankfully, the fine people of the Mazda MX-5 of Australia group confirmed I could bash away with impunity, and I did so.

A stubborn bushing. Hammer away, they said, and hammer I did.

Next problem was bolts. Despite ordering “everything” I needed to fit the diff to a 1.6 litre car, the wrecker had only supplied two nuts to go with the four bolts that attach the tailshaft to the differential. I suspect they might have been lost in transit, as everything was shipped loose. I wasn’t able to follow my initial plan of reusing the old nuts either – they were a smaller size. In the end, a last minute dash to the parts store netted me some slightly larger nuts that fit. It might sound strange to say that bolts are a problem, but you might be surprised. Automotive manufacturers generally use a higher grade of bolts than is typically available at the local hardware store, and in a much wider variety of thread pitches. Replacements are accessible at a specialty fastener distributor, but these all close at 5:00 PM and don’t open on weekends – cold comfort to the shadetree mechanic with a full-time job. I was thankfully saved by the auto parts store which did have the correct pitch nuts I needed on a Saturday, albeit at $7 for a pack of three. It was a better option than driving out to the wrecking yard to yank a single bolt off the nearest Mazda, though. With that solved, I felt confident I could finish the car that night.

The halfshaft, impudently refusing to seat fully in the differential. The green section should be fully flush up against the differential housing & seal.

I moved on to the next job – fitting the new halfshafts to the new differential. To my surprise, they didn’t just slide in. A quick search found that they required a heavy pounding with a stout hammer, so, after much wrestling with the shafts, which still had the hubs attached, I got the left one in. Buoyed by my new success, I was excited, and started immediately on the right, but to no avail. Repeated blows did nothing to force it in to its full depth. I once again begged the forums for insight, who all reported that it was difficult, but more hammering should do the job. At this point though, fatigue was setting in and I decided to finish up with a fresh mind and body in a few days.

Now armed with everything I needed, on the Monday, the work went quickly. A quick strike from the hammer seated the previously immovable half shaft. I didn’t stop to ask why. The differential was bolted up and filled with fluid, the powerplant frame aligned, and the transmission topped up with oil. I was excited – the car was close! All we had to do was refit the rear brakes and take it for a spin. The right side went together in a snap – I was well acquainted with the brakes by this point, having done an upgrade to the later model brakes when I found my car’s rear calipers were both non-functional.

It was dark by this point as we were working on the last wheel. For some reason the brakes just weren’t going together, and we kept fumbling around as we tried to take shortcuts, not wanting to disassemble the caliper any more than necessary to get it back together. Eventually, we realised the problem.

Yes, that brakepad is severely bent. I can only presume that it was due to incorrect fitment during the upgrade, but nonetheless. Not wanting to stop, we found a spare pad with the parts left over from the brake upgrade, and got halfway through putting everything back together until we realised the spare pad was the wrong type and it was all over. My three-hour differential upgrade was now going to bleed into a fourth day.

A good brake pad (top) versus the bent one (bottom). Note the highly irregular wear. The bent pad up against a rule. Colorized for clarity. I’m still not 100% sure how this happens on a single piston caliper.

By this point it was Wednesday, and armed with a new set of rear pads, I once again disassembled both rear brake assemblies and fitted everything up. I lazily adjusted the handbrake as, in several hours of trying, I’ve never been able to get it right despite following the proper instructions. I wasn’t surprised or that bothered when the handbrake largely failed to work.  With the wheels now back on, the car was gently lowered down off its stands, ready to drive.

To say I was nervous was an understatement. While it may be a “bolt-on” job, drivetrain components are more than capable of doing a lot of damage in the event something goes wrong. Reversing out of the driveway went well though, and there were no immediate catastrophic sounds as I drove the car to a friend’s extended driveway for testing. With the engine dialled up to 5,000 rpm, I dropped the clutch and to my delight, the car spun both rear wheels as expected – without flinging rotating metal components all over the place. The drive home further confirmed my success, with the awful scraping sounds now absent from my drivetrain.

I’m pretty darn pleased with the job, and can’t wait to test the car further at an upcoming skidpan day at the nearest racetrack. There’s still a long way to go, and I’m sure this won’t be the last part of the MX-5 to suddenly and unceremoniously fail on me. At the end of the day though, I managed to suffer through a “simple 3-hour bolt-on job”, even if it took me four days – and I’m all the more experienced for it.


Filed under: car hacks
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