[Tom Sachs] Builds His Own Space Program


Born in the mid 60’s, [Tom Sachs] has always been fascinated with space, especially the Apollo program. Just like every kid of his generation, [Tom] imagined himself in Neil Armstrong’s and Buzz Aldrin’s boots, gazing over the lunar surface. He never gave up that dream, and years later as a successful modern artist, he built his own space program.

[Tom Sachs] is a master of bricolage . Taken from the French word for tinkering, Wikipedia defines bricolage as “… the construction or creation of a work from a diverse range of things that happen to be available, or a work created by such a process.”  The term could also describe the junkbox procurement methods we use on many of our own projects.

sachs-lunar-landerBoth [Tom's] 2007 lunar program and his 2012 Mars program featured his astonishing lunar lander. Built from plywood, found items, and junk, the lander literally made us do a double take the first time we saw it. The attention to detail is incredible. At first glance one could mistake this for a simulator built by NASA themselves. After a few seconds the custom touches start to jump out, such as a “Thank You” garbage door from a fast food restaurant, or a bar stocked with tequila and vodka. The lander’s tools are not just for show either, as the gallery opens with a simulated space mission, which could best be described as a mix of art, improv, and an epic game of make-believe for adults.

[Tom's] installations also include mission control, which in his Mars piece consisted of a dizzying array of screens, controls and an 80’s boombox. Dressed in the white shirt, thin tie, and horn rimmed glasses we’ve come to associate with NASA engineers of the 60’s, this is where [Tom] works. He truly is the engineer of this mission.

Editor’s Note [Tom] and the entire hacker community at large have a chance to go to space by entering The Hackaday Prize!

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Light Pen Draws on LED Matrix


Who needs a 1920×1080 OLED display when you can have an 8×8 matrix of LED goodness? That’s the question [Kathy] asked when she built this LED matrix light pen project. It looks simple enough – a 64-LED matrix illuminates as the pen draws shapes. But how does the circuit know which LED is under the pen? Good old fashioned matrix scanning is the answer. Only one LED is lit up at any time.

[Kathy] used a pair of 74LS138 3-to-8 line decoders to scan the matrix. The active low outputs on the ‘138 would be perfect for a common cathode matrix. Of course [Kathy] only had a common anode matrix, so 8 PNP transistors were pressed into service as inverters.

The pen itself is a phototransistor. [Kathy] originally tried a CdS photoresistor, but found it was a bit too slow for matrix scanning. An LM358 op-amp is used to get the signal up to a reasonable level for an Arduino Uno to detect.

The result is impressive for such a simple design. We’d love to see someone use this platform as the start of an epic snake game.

Droning On: PID Controllers and Bullet Connectors

droning-on-hill Not all drones are multirotors – Posing in our title photo are Maynard Hill and Cyrus Abdollahi. Maynard’s plane, TAM5 aka The Spirit of Butts Farm, is the smallest aircraft to make a transatlantic flight (YouTube link). Retracing the path of Alcock and Brown from Newfoundland to Ireland, the 6 pound (dry weight) model made the trip in just under 39 hours. All this happened in 2003, and was the cap on a lifetime of achievements for Hill. These are the types of pursuits that will be banned in the USA if the FAA restrictions go into effect.

Flight Controllers

Quite a few of you thought the Naze32 was left out of last column’s flight controller roundup. I hear you loud and clear! I’ll add the Naze to the controllers which will be tested on The Hackaday Testbed. The hard part is finding the darn things! I currently have an Acro Naze32 on its way to Droning On HQ.  If I can find a full version, I’ll add that.

PID Controllers Deep Dive

I’ve gotten a few questions on Proportional Integral Derivative (PID) controllers, so it is worth diving in a bit deeper to explain what a PID controller is. PID controllers are often found in process controls managing parameters like temperature, humidity, or product flow rate. The algorithm was initially designed in the late 1800’s as a method of controlling the helm of large naval ships. In fixed wing drones, PID keeps the plane’s wings level and on course. In multicopters, PID loops control heading, but they also provide the stable flight which allows the quadcopter to fly in the first place. A full explanation of PID loops would be beyond the scope of a single article, but let’s try a 10,000 foot explanation.

pidP: This is the “Present” parameter. P Has the most influence on the behavior of the aircraft.  If the wind blows your quadcopter from level flight into a 30 degree right bank, P is the term which will immediately take action to level the quad out. If the P value is too high, The quadcopter will overshoot level flight and start banking the other way. In fact, way too high a P value can cause a quadcopter to shake as it oscillates or “hunts” for level. Too Low a P value? the quadcopter will be very slow to react, and may never quite reach level flight again.

I: This the “Past” parameter. The I term dampens the overshoot and oscillations of the P term, and avoids the tendency of P to settle above or below the set point. Just like with P, too high an I term can lead to oscillation.

D: This is the “Future” parameter, and has the smallest impact on the behavior of the aircraft. In fact, some flight controllers leave it out entirely.  If P and I are approaching a set point too quickly, overshoot is likely to occur. D slows things down before the overshoot happens.

So why do multicopter pilots dread PID tuning?  Quite simply, it’s a tedious process. Couple a new pilot and an unproven aircraft with un-tuned PID values, and you have a recipe for frustration – and broken propellers. Things get even more complex when you consider the fact that there are at least 3 sets of PID variables to be tuned – Pitch, Roll, and Yaw. Some flight controllers now support multiple PID values depending on the style of flight. Want your plane or multicopter to fly around like a hotrod? You need a totally different set of PID values than a docile trainer craft. Rolf Bakke (KapteinKUK himself) made a video illustrating how multicopters behave when tuning PID values. You can easily see how a quad can go from “drunk” to “angry bee” with just a few value tweaks. All this is coming together with The Hackaday Testbed, which will help me in posting a few PID tuning videos of my own.

Hackaday Testbed Update

As for the testbed itself, it’s nearly complete! You can follow the progress on my Hackaday Projects Page. Most of the assembly has been relatively straightforward.   though of course there are always a few snags. It seems I always forget something when ordering up parts for coils-bada build. In this case it was 2.5mm banana plugs and motor mounting screws.

The Hobbyking motors attach to the frame with 3mm screws. The problem is that there really is no way to know how long the screws should be until you have the motors, mounting plates and drone frame on hand. I have a bunch of 3mm screws of various lengths, and thankfully there were enough screws of the correct length to mount the motors. Murphy is always at my side, as I accidentally grabbed a screw that was 1mm too long and, you guessed it, screwed right into the windings of the motor. Doh! Thankfully I had spares.

bullet-solderBullet connectors can be a real pain to solder. There are some jigs out there which help, but I’ve always found myself going back to the old “helping hands” alligator clips. Bullets tend to use lower gauge wire than we’re used to with regular electronics. 14, 12, even 8 gauge wires are used on R/C aircraft. A low power soldering iron with a surface mount tip just won’t cut it. Those irons just doesn’t have the thermal mass to get the connectors up to soldering temperature. This is one of those places where a decent 40 watt or better Weller iron (yes, the kind that plugs right in the wall) can be a godsend. I’m using an Metcal iron here, with a wide flat tip.

bullet-solder-2Bare bullet connectors and alligator clips can also create a problem – the metal clips create even more thermal mass. Years back an old-timer showed me a trick to handle this. Slip a piece of silicone R/C plane fuel tubing on the bullet, and then clip the helping hands onto the tube. The tube will act as insulation between the bullet and the clip. Silicone can easily withstand the temperatures of soldering. I’ve also used the silicone tube on the jaws themselves – though eventually the jaws will cut the soft tubing.

That’s about it for this edition Droning on! Until next time, keep ‘em flying!

Title photo credit Cyrus Abdollahi.

Hackaday Reader [David] Wins a Camera from Make and Nikon


Make the shot fixed[David Schwarz] whipped up this moving time-lapse camera rig and won himself a sweet Nikon setup. You might remember our post about the Nikon Make:The Shot Challenge. [David] saw our post, and started thinking about what he wanted to enter. Like a true engineer, he finally came up with his idea with just 3 days left in the contest.

[David] wanted to build a moving time-lapse rig, but he didn’t have the aluminum extrusion rails typically used to build one. He did have some strong rope though, as well as a beefy DC motor with a built-in encoder. [David] mounted a very wide gear on the shaft of the motor, then looped the rope around the gear and two idler pulleys to ensure the gear would have a good bite on the rope. The motor is controlled by an Arduino, which also monitors the encoder to make sure the carriage doesn’t move too far between shots.

[6__pulley_systemDavid] built and tested his rig over a weekend. On Monday morning, he gave the rig its first run. The video came out pretty good, but he knew he could get a better shot. That’s when Murphy struck. The motor and controller on his rig decided to give up the ghost. With the contest deadline less than 24 hours away, [David] burned the midnight oil and replaced his motor and controller.

Tuesday morning, [David] pulled out his trump card – a trip to Tally Lake in Montana, USA. The equipment worked perfectly, and nature was cooperating too. The trees, lake, and the shadows on the mountains in the background made for an incredible shot. Once the time-lapse photos were in the can, [David] rushed home, stitched and stabilized the resulting video. He submitted his winning entry with just 2 hours to spare.

Click past the break for more on [David's] time-lapse rig, and to see his final video.

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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.



[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


[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


[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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