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The Hacklet #6 – Lasers

Hacklet 6

This week’s Hacklet is all about lasers, which have been shining a monochromatic light for hackers since 1960. The first working laser was demonstrated by [Theodore Maiman], who was a hacker / maker himself, having learned circuits in his father’s home electronics lab. It’s no surprise that lasers have been hugely popular in the hacker community ever since.

laserwelder[Maiman’s] first laser was pumped with flash tubes, which is similar to the YAG laser in [macona’s] project to restore a laser welder. He’s gotten his hands on a 1985 model 400W Lumonics laser welder. This welder was originally bought by Tektronix to weld titanium CRT flanges. Time moved on, and the welder was sold to [macona’s] company, who used it until the Anorad control system died. There was an effort to bring it up to date with new servos and an OpenCNC control system, but the job was never finished. This laser sat for 12 years before [macona] bought it, and now he’s bringing it back to life with LinuxCNC. The project is off to a blazing start, as he already has the laser outputting about 200 Watts.

d0c96d91On the slightly lower power side of things we have [ThunderSqueak’s] 5mW visible red (650nm) laser. [ThunderSqueak] needed an alignment laser with decent focusing optics for her other projects. She mounted a module in a plastic case and added a switch. A quick build, but it’s paying dividends on some of her bigger projects – like her Low Cost CO2 Laser Build, which we featured on the blog back in May.

 

la-cutter

[phil] used buildlog 2.x as the inspiration for his Simple DIY laser cutter. The laser power comes from a low cost K40 laser tube and head. His frame is aluminum extrusion covered with Dibond, an aluminum composite material used in outdoor signs. Locomotion comes from NEMA 17 stepper motors. Many of [phil’s] parts are machined from HDPE plastic, though it looks like they could be 3D printed as well. We bet this one will be a real workhorse when it’s done.

 

la-cutter2[ebrithil] is working on a combo laser engraver/PCB etcher which will use a solid state laser module. His layout is the standard gantry system seen on many other mills and 3D printers. Dual steppers on the Y axis increase avoid the need for a central belt. His Z axis was donated by an old DVD drive. It has enough power to lift a pen, and should be plenty accurate for focusing duty. He’s already run a couple of great tests with a low power violet laser and glow in the dark material.

openexposer[Mario] is creating an incredibly versitile laser tool in his OpenExposer, which can do everything from stereolithography 3D printing to making music as a laser harp. The genius here is [Mario’s] reuse of laser printer parts. Every laser printer uses the same basic setup: a laser, a scanning mirror, and optics to stretch the beam out to a full page width. [Mario] is already getting some great prints from OpenExposer. This project is one to watch in The Hackaday Prize.

ramenspec[fl@C@] is digging into the physics side of things with his DIY 3D Printable RaspberryPi Raman Spectrometer. Raman Spectrometers are usually incredibly expensive pieces of requirement which can tell us which elements make up a given material sample. [fl@C@’s] laser is a 532nm 150mW laser, which bounces through a dizzying array of mirrors and lenses. The resulting data is crunched by a Raspberry Pi to give a full spectrographic analysis. [fl@C@’s] entered his project in The Hackaday Prize, and we featured his bio back in June.

That’s it for this week’s Hacklet, until next week, don’t just sit around wondering why aren’t lasers doing cool stuff. Make it happen, and post it up on Hackaday.io!

 

XOXO For The OCXO

HPocxo

[Kerry Wong] recently got himself a frequency counter. Not just any counter, a classic Hewlett-Packard 5350B Microwave Counter. This baby will go 10Hz all the way up to 20GHz with only one input shift. A true fan of Hackaday Prize judge [Dave Jones], [Kerry] didn’t turn it on, he took it apart. In the process, he gave us some great pictures of late 80’s vintage HP iron.

Everything seemed to be in relatively good working order, with the exception of the oven indicator, which never turned off. The 5350B had three time bases available: a Thermally Compensated Crystal Oscillator (TCXO),  an Oven Controlled Crystal Oscillator (OCXO), and a high stability OCXO. [Kerry’s] 5350B had option 001, the OCXO. Considering it was only a $750 USD upgrade to the 5350B’s $5500 USD base price, it’s not surprising that many 5350B’s in the wild have this option.

[Kerry] checked the wattage of his 5350B, and determined that it pulled about 27 watts at power up and stayed there. If the OCXO was working, wattage would have dropped after about 10 minutes when the oven came up to temperature. Time to tear open an oven!

Armed with a copy of the 5350B service manual from HP’s website, [Kerry] opened up his OCXO. The Darlington transistors used as heaters were fine. The control circuit was fine. The problem turned out to be a simple thermal fuse. The service manual recommended jumping out the fuse for testing. With the fuse jumped, the oven came to life. One more piece of classic (and still very useful) test equipment brought back to full operation.

[via Dangerous Prototypes]

The Old Ping-Pong Ball Levitation Trick

pingpongLev

[Jacob] has put a slightly new twist on the levitating ball trick with his ping-pong ball levitation machine. We’ve all seen magnetic levitation systems before. Here on Hackaday, [Caleb] built a Portal gun which levitated a Companion Cube. Rather than go the magnetic route, [Jacob] levitated a ping-pong ball on a cushion of air.

Now, it would be possible to cheat here, anyone who’s seen a demonstration of Bernoulli’s principle knows that the ball will remain stable in a stream of air. [Jacob] proves that his system is actually working by levitating ping-pong balls with different weights.

A Parallax Ping style ultrasonic sensor measures the distance between the top of the rig and the levitating ball. If the ball gets above a set distance, [Jacob’s] chipKit based processor throttles down his fans. If the ball gets too low, the fans are throttled up. A software based Proportional Integral Derivative (PID) loop keeps the system under control. A graph of the ball distance vs fan speed is displayed on an Android tablet connected to the controller via USB.

When [Jacob] switches a heavy ball for a light one, the lighter ball is pushed beyond the pre-programmed height. The controller responds by reducing the fan speed and the ball falls back. Who said you can’t do anything good with a box of corn dogs?

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Pocket Calculator Emulates Pocket Calculator

msp430 Calc Emu

[Chris] has built a pocket calculator that emulates… a pocket calculator. Two pocket calculators, in fact. Inspired by [Ken Shirriff’s] incredible reverse engineering of the Sinclair scientific calculator, [Chris] decided to bring [Ken’s] Sinclair and TI Datamath 2500II simulators to the physical world.

Both of these classic 70’s calculators are based on the TMS0805 processor. The 0805 ran with 320 11-bit words of ROM and only three storage registers. Sinclair’s [Nigel Searle] performed the real hack by implementing scientific calculator operations on a chip designed to be a four function calculator.

[Chris] decided to keep everything in the family by using a Texas Instruments msp430 microcontroller for emulation. He adapted [Ken’s] simulator code to run on a MSP430G2452. 256 bytes of RAM and a whopping 8KB of flash made things almost too easy.[Chris’] includes ROMs for both the TI and the Sinclair calculators. The TI Datamath ROM is default, but by holding the 7 key down during boot, the Sinclair ROM is loaded. The silk screen includes key icons for both calculators, as well as some Doge-inspired wisdom on the back.

All joking aside, these really are amazing little calculators. Children of the 60’s and 70’s will be taken back when they see the LEDs flash as the emulated TMS0805 performs algorithmic arithmetic. [Chris’] code is up on Github. While he hasn’t released gerbers yet, he does have images of his PCB layout on the 43oh.com forums.

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[Tymkrs] Tombstone Guitar Amplifier

tymkrsTombstone

[Atdiy and Whisker], the team behind [The Tymkrs] YouTube channel, are at it again with a tombstone guitar amp project.(YouTube playlist link) Their amp began life as a Philco Tombstone radio which had seen better days. By the time [Tymkrs] got their hands on it, it was just a shell of its former self, as someone had already stripped all the electronics.

The amplifier itself is a disused Leslie tube amp [Tymkrs] had on hand. An LM386 serves as the pre-amp, making this a hybrid solid and vacuum state machine.

The tombstone speaker is especially interesting. [Tymkrs] went with an electrodynamic field coil speaker. Field coil speakers have no magnets, instead using a high voltage (approx 90V DC) coil to create a magnetic field for the voice coil to push against. This sort of speaker was commonplace in the 1930’s, as large magnets couldn’t be made lightweight enough to be used in a speaker. As magnet technology improved, permanent magnets became a staple in speakers.

[Tymkrs] paid special attention to the finish of the amplifier. They brought the tired old radio back to a high shine, then added a Metropolis inspired overlay from aged copper-clad board. The result is an amp that looks great and sounds great!

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Automatic Audio Leveling Circuit Makes Scanning More Fun

alan-scope1

[Alan’s] friend came to him with a problem. He loved listening to his scanner, but hated the volume differences between stations. Some transmitters would be very low volume, others would nearly blow his speakers. To solve the problem, [Alan] built up a quick automatic leveling circuit (YouTube link) from parts he had around the lab.

[Alan’s] calan-scope2ircuit isn’t new, he states right in the video that various audio limiting, compressing, and automatic gain control circuits have been passed around the internet for years. What he’s brought to the table is his usual flair for explaining the circuits’ operation, with plenty of examples using the oscilloscope. (For those that don’t know, when [Alan] isn’t building circuits for fun, he’s an RF applications engineer at Tektronix).

Alan’s circuit is essentially an attenuator. It takes speaker level audio in (exactly what you’d have in a desktop scanner) and outputs a limited signal at about 50mv peak to peak, which is enough to drive an auxiliary amplifier. The attenuator is made up of a resistor and a pair of 1N34A Germanium diodes. The more bias current applied to the diodes, the more they will attenuate the main audio signal. The diode bias current is created by a transistor-based peak detector circuit driven off the main audio signal.
But don’t just take our word for it, watch the video after the break.

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Hacklet #5 – Hackerspaces And DIY Laptops

sector67

Did you know that Hackaday.io has a hackerspace index? That’s right, you can enter your local hackerspace’s info, pictures, videos, and social media links. Members and crew can link their hackaday.io profiles and drop comments about their latest projects.

The map up at the top of the hackerspace index’s page is interactive too – zoom in on your country and local area to see any spaces nearby. It’s like one-stop shopping for awesome. Well, except that this awesome is free.

It really is great to see all the pictures of spaces large and small. Some of the most stunning shots are from c-base, in Berlin, Germany. Founded in 1995, the c-base crew have created an incredible space. Take a look at the workstation in the photo. Is it Steampunk? Matrix-punk? Heck no, that’s 100% c-base.

c-base

 

Do It Yourself Laptops

You don’t have to be Bunnie Huang to build your own laptop. All it takes is some time, ingenuity,and a good hot glue gun.

opentech-laptop

Our first laptop is actually inspired by Bunnie’s Novena. The OpenTech-Laptop uses two binders as it’s shell, but inside hides some decent computing power. [OpenTech] used a miniITX motherboard with an ATOM N2800 CPU. The screen came from an old laptop (long live matte 4:3 screens!) [OpenTech] even hand wired a Low Voltage Differential Signaling (LVDS) cable so the motherboard can push those pixels. A wireless keyboard, hard drive, and speakers round out the build. [OpenTech] is still looking for a portable power solution.Why not follow Bunnie’s lead and grab some R/C Plane LiPo batteries, [OpenTech]?

minibsd

Next up is a MiniBSD laptop computer created by [Jaromir]. MiniBSD is based on RetroBSD, a PIC32 based BSD single board computer. Rather than use a premade platform like the Fubarino, [Jaromir] laid out his own board with everything he wanted – a microSD socket, SDRAM, real-time clock, and all the trimmings. He then added a graphical LCD, a LiPo battery, and a sweet retro keyboard from an old Czech computer company called Tesla. [Jaromir’s] next task is a 3D printed case. The only problem is the case is 2cm wider than his current printer’s bed!

http://hackaday.io/project/1559-Laptop-pi

You didn’t think we’d leave the Raspberry Pi out, now did you? Laptop-pi is [Bram’s] project to convert an old DVD player (remember those?) into a Pi Laptop. Not only did [Bram] build a QWERTY keyboard from scratch on perfboard, he also hacked together an on-screen keyboard so he can type with just a D-pad. He’s currently fighting with a dodgy audio amp, but we’re sure that’s just a temporary setback. We think Laptop-pi will be a killer portable for retro gaming!

 

That’s it for this week’s Hacklet, stay tuned for next week when we bring you more of what’s happening at Hackaday.io!