Treadmill Motor Belt Grinder

Turn Your New Years Resolution Into A Belt Grinder

February 12, 2017 by 17 Comments

We’re just over a month into the new year, and some people’s resolve on those exercise plans are already dwindling. There’s some good news though. That treadmill can be hacked into a nice belt grinder for your shop.

[Bob]’s treadmill belt grinder is based on a 2.5 horsepower motor he salvaged from a broken, donated treadmill. This motor needs 130 VDC to run, which is a bit of a challenge to generate. Fortunately, lots of treadmills seem to use the same MC-60 motor controller, which is compatible with this motor. Due to the widespread use of this controller, they can be found on eBay for about $30.

With the motor spinning, [Bob] built up a frame for the grinder, added rollers to hold the belt, and a spring based belt tensioner. The motor’s speed set point is controlled by a potentiometer, and the controller varies the power to keep a constant speed. Since the motor is capable of some serious RPM, a tachometer was added for feedback to prevent high-speed belt shredding.

The final result is a very professional looking tool for under $200. What would a grinder like this be used for? Knives of course! 2″ belt grinders are perfect for shaping and grinding knives and swords. In fact, you can see one in use in this sword hack.

Check out a video of the build after the break.

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3D Printed Rockets Are A Gas

February 12, 2017 by 26 Comments

We’ve probably all made matchstick rockets as kids. And around here anything that even vaguely looks like a rocket will get some imaginary flight time. But [austiwawa] is making some really cool 3D printed rockets that use common CO2 cartridges as a propellant. You can see them in action in the video below.

You might think just sticking a CO2 cylinder in a 3D printed jacket isn’t such a big deal, but [austiwawa] really went the extra mile. He read up on how to make the rocket stable (by manipulating the center of gravity versus the center of pressure) and explains what he had to do to get the rockets flying like you’d expect.

In addition, the launch tube is pretty interesting. A 3D printed part holds a sharp point and a spring. You lock the spring and when released it punches a clean hole in the propellant casing. The actual tube is a long piece of PVC pipe. From the video, it looks like these little rockets fly pretty high.

Judging from the video, the rocket body and launcher came from TinkerCAD. The way [austiwawa] put the fins on was both simple and clever.

Of course, you could also use Coke and propane, if you like. We’ve also seen some pretty cool setups with compressed air. Check out the rockets in action after the break,

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Blade Runner’s Voight-Kampff Test Gets Real

February 12, 2017 by 64 Comments

You’re in a desert, walking along in the sand when all of a sudden you look down and see a tortoise. It’s crawling toward you.

Any Sci-Fi fan knows this is a question from the iconic Voight-Kampff test, as made famous by the movie Blade Runner. Humans pass the test. Replicants fail and are “retired”. We may not have replicants just yet, but  [Tom Meehan] is building his own version of the Voight-Kampff machine. He’s entered it in the 2017 Hackaday Sci-Fi Contest.

The machine itself is an odd mix of 70’s and 80’s electronics with older technology. Three mini CRT displays, a sensor arm, and a bellows are some of the machine’s best-known features. [Tom] is starting with the sensor arm, an odd mix of belts and telescoping rods. He’s already got a manually operated prototype built. Add a motor, and one part of the machine is ready for action.

[Tom’s] version of the Voight-Kampff test isn’t going to be a just movie prop. He plans to add a sensor suite which will turn his machine something of a modern polygraph. A Non-contact Temperature sensor will measure blush response. Iris images will be captured by a Raspberry Pi NoIR camera. Pulse oxygen and galvanic skin response will also be captured by a separate hand module. All this data will be processed by a Raspberry Pi computer.

There’s quite a lot of work to be completed. Let’s hope for humanity’s sake that [Tom] gets it done before the contest deadline of March 6.

Cheap LCD TV Gets Cheaper Fix

February 12, 2017 by 34 Comments

Most hacks need some fair bit of skill and knowledge if you want to come out successful at the other end. Others, you just plunge in blindly with a “heck, it’s already broken so I can’t make it any worse” attitude. Throwing caution to the wind, you dive in, rip things up, and see if you can manage to catch the bull by the horns.

[Jim]’s cheap LCD TV, barely a few years old, died. It was purchased from the store whose blue polo-shirted cashiers can drive you nuts with their incessant questions. [Jim] just rolled up his sleeves and rather haphazardly managed to fix his TV while adding an extra feature along the way.

His initial check confirmed that the LCD panel worked. Using a flashlight, he could see that the panel was displaying video which meant it was the backlight that wasn’t working. Opening up the TV, he located the LED driver board whose output turned out to be zero volts. [Jim] happened to have a lot of WS2812B strips lying around, along with their power supplies and RGB color controllers. The obvious solution was to ditch the existing LEDs and power supply and use the WS2812B strips.

Surprisingly, the original backlight consisted of just 21 LEDs arranged in three rows. He ripped those out, put in the WS2812B strips, and taped the jumble of wires out of sight. After putting it back together, [Jim] was happy to see it worked, although the new strips were not as bright as the old ones, causing some uneven light bands. He solved this by adding a few more strips of LEDs. It took him a couple of hours to fix his TV, but by the end of it, he had a TV whose backlight could be adjusted to any color using the external color controllers — although we’re not too sure what good that would be.

Baofeng Handy Talkie Meets GNU Radio

February 11, 2017 by 9 Comments

There was a time when just about every ham had a pricey VHF or UHF transceiver in their vehicle or on their belt. It was great to talk to friends while driving. You could even make phone calls from anywhere thanks to automatic phone patches. In 1980 cell phones were uncommon, so making a call from your car was sure to get attention.

Today, ham radio gear isn’t as pricey thanks to a flood of imports from companies like Baofeng, Jingtong, and Anytone. While a handheld transceiver is more of an impulse buy, you don’t hear as much chat and phone calls, thanks to the widespread adoption of cell phones. Maybe that’s why [Bastian] had bought a cheap Baofeng radio but never used it.

He was working on a traffic light project and wanted to send an RF signal when the light changes. He realized the Baofeng radio was cheap and cheerful solution. He only needed a way to have the PC generate an audio signal to feed the radio. His answer was to design a UDP packet to audio flow graph in GNU Radio. GNU Radio then feeds the Baofeng. The radio’s built-in VOX function handles transmit switching. You can see a video demonstration, below.

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Nexus 5X Phone Resurrected By The Oven

February 11, 2017 by 67 Comments

Warranty shmarranty — toss the phone in the oven! There’s apparently a problem with the assembly of the Nexus 5X smartphones, and it looks like it is due to faulty BGA chip soldering. LG USA has had enough problems with the phone that they may not even have enough parts or new units to fix it, so they’re offering a refund. But we all know how it is to get attached to a device, right?

So [Alex] disassembled his beloved phone, pulled out the board in question, and gave it the XBox Red Ring Of Death treatment. He placed the board on some insulating aluminum foil, and baked it for six and a half minutes. Season with lemon and pepper, and serve! We’re honestly surprised that sticking the affected board into the oven at 195° C / 390° F for a few minutes would work at all. Isn’t that a low temperature for soldering, especially with a lead-free mix? Could it have been a problem with humidity after all? Continue reading “Nexus 5X Phone Resurrected By The Oven” →

Ping Pong Ball Improves The Google Daydream Controller

February 11, 2017 by 1 Comment

[Matteo] has just released a new installment of his Google Daydream VR controller hack, which we first covered last year (when he got it working with iOS). This time around he’s managed to forge a half Daydream, half PlayStation Move controller hybrid.

The original controller only managed a mere 3 DOF (Degrees of Freedom) using the internal accelerometer; although this conveyed rotational motion around the 3 axis, transitional information was completely lacking. [Matteo] resolves this by forming a simple positional marker out of a white LED enclosed in a standard ping pong ball; He tracks this setup using an iSight camera.

To gel everything together, he adds motion tracking to his already extensively developed software stack, which enables him to unshackle the Daydream controller from Android. He deciphers the Bluetooth packets and streams the sensory information straight to a web browser over a webSocket connection.

sf-stack

The results are quite impressive and the tracking is smooth. Not only does this add to the final goal of hacking his way towards a platform independent VR motion controller, he aptly gets some inspiration from Sony, extends Google’s hardware and even manages to use Apple’s webcam along the way. How’s that for carving passages between the walled gardens of consumer electronics?

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