DIY Long Distance Laser Telescope Does Some Damage

Here’s a DIY laser rifle which can explode a balloon at around 150 feet (45 meters) as well as some angry chemicals at a similar distance. Since there are plenty of videos of lasers doing that at around a meter, why shouldn’t doing so farther away be easy? Despite what many expect, laser beams don’t remain as straight lines forever. All light diverges over a distance. This makes it hard to create a laser which can do damage from more than around a meter and is why most demonstrations on YouTube are that distance or less.

Galilean telescope and laser idea[Styropyro’s] handheld, DIY laser rifle, or Laser Telescope Blaster as he calls it, works for long distances. His solution lies in some surprising physics: the larger the diameter of the beam, the more slowly it will diverge. So he used the opposite of a Galilean telescope to take the small beam of his 405-nanometer laser and increase its diameter. His best result was to explode a balloon at 150 feet (45 meters).

He did run into another issue first though. Anyone who’s tried to keep a camera aimed at a target through a telephoto lens while holding the camera in their hands knows that even a tiny movement will throw the camera off target. For a laser beam to sufficiently heat up the balloon in order to make it explode, the beam has to stay on it for a short period of time. But at a long distance, small movements of his rifle made the beam wander. Putting the rifle on a tripod fixed that. In the video below you can see him work through his design and these issues to finally get his big success.

We can guess what spurred on this interest in long-distance laser rifles. Back in July, a Chinese company made bold claims to building one which could do damage at 800 meters.

Continue reading “DIY Long Distance Laser Telescope Does Some Damage”

Catch a Rising Star with Arduino

Space is big. Really big. Yet on TV and movies, enemy spacecraft routinely wind up meeting at roughly the same spot and, miraculously, in the same orientation. If you’ve ever tried to find something smaller than the moon in a telescope, you’ll appreciate that it isn’t that easy. There are plenty of tricks for locating objects ranging from expensive computerized scopes with motors to mounting a phone with Google Sky or a similar program to your telescope. [DentDentArthurDent] didn’t use a phone. He used an Arduino with an outboard GPS module.

You still have to move the scope yourself, but the GPS means you know your location and the time to a high degree of accuracy. Before you start an observing session, you simply point the telescope at Polaris to calibrate the algorithm, a process which in the northern hemisphere is pretty easy.

Continue reading “Catch a Rising Star with Arduino”

Pi Zero Gives Telescope Hands Free Focus

It seems like [Jason Bowling] never gets tired of finding new ways to combine the Raspberry Pi with his love of the cosmos. This time he’s come up with a very straightforward way of focusing his Celestron 127SLT with everyone’s favorite Linux SBC. He found the focus mechanism on the scope to be a bit fiddly, and operating it by hand was becoming a chore. With the Pi Zero and a stepper motor, he’s now able to focus the telescope with more accuracy and repeatability than clumsy human fingers will be able to replicate.

On this particular type of telescope, the focus knob is a small knob on the back of the scope (rather than on the eyepiece), which just so happens to be the perfect size to slide a 15mm bore pulley over. With a pulley on the focus knob, he just needed to mount a stepper motor with matching toothed pulley next to it and find a small enough belt to link them together. Through the magic of Amazon and McMaster-Carr he was able to find all the parts without having to make anything himself, beyond the bent piece of aluminum he’s using as a stepper mount.

To control the stepper, [Jason] is using an EasyDriver connected up to the Pi’s GPIO, which along with a 5V regulator (which appears to be a UBEC from the RC world) is held in a tidy weather proof box mounted to the telescope’s tripod. The regulator is necessary because the whole setup is powered by a 12V portable “jump start” battery pack for portability. Handy when you’re stargazing in the middle of a field somewhere.

[Jason] promises a future blog post where he details how he used Flask to create a web-based control for the hardware, which we’ll be keeping an eye out for. In the meantime, he reports that his automated focus system is working perfectly and keeps the image stable in the eyepiece even while moving (something he was never able to do by hand).

Last year this same scope had a Raspberry Pi camera mounted to it to deliver some very impressive pictures without breaking the bank. We’re interested in seeing how [Jason] ties these systems together going forward.

Astro Cat: Raspberry Pi Telescope Controller

When somebody tackles an engineering problem, there are two possible paths: they can throw together a quick and dirty fix that fits their needs (the classic “hack”, as it were), or they can go the extra mile to develop a well documented solution that helps the community as a whole. We cover it all here at Hackaday, but we’ve certainly got a soft spot for the latter approach, even if some may feel it falls into the dreaded territory of “Not A Hack”.

When [Gary Preston] wanted to control his telescope and astrophotography hardware, he took the second path in a big way. Over the course of several posts on his blog, [Gary] walks us though the creation of his open source Raspberry Pi add-on board that controls a laundry list of sensors and optical gear. Just don’t call it a HAT, while it may look the part, [Gary] is very specific that it does not officially meet the HAT specifications put out by the Raspberry Pi Foundation.

Even if you aren’t terribly interested in peering into the infinite void above, the extremely detailed write-up [Gary] has done contains tons of multidisciplinary information that you may find useful. From showing how to modify the Pi’s boot configuration to enable true hardware UART (by default, the Pi 3 ties it up with Bluetooth) and level shifting it with a ST3232 to a breakdown of the mistakes he made in his PCB layout, there’s plenty to learn.

Astro CAT is a completely open source project, with the hardware side released under the CERN Open Hardware License v1.2, and the INDI driver component is available under the GPL v3.

If this looks a bit daunting for your first stab at astrophotography with the Raspberry Pi, fear not. We’ve covered builds which can get you up and running no matter what your budget or experience level is.

A Giant Magellan Telescope Needs Giant Mirrors

The Giant Magellan Telescope doesn’t seem so giant in the renderings, until you see how the mirrors are made.

The telescope will require seven total mirrors each 27 feet (8.4 meters) in diameter for a total combined diameter of 24.5 meters. Half of an Olympic size pool’s length. A little over four times the diameter of the James Webb Space Telescope.

According to the website, the mirrors are cast at the University of Arizona mirror lab and take four years each to make. They’re made from blocks of Japanese glass laid out in a giant oven. The whole process of casting the glass takes a year, from laying it out to the months of cooling, it’s a painstaking process.

Once the cooling is done there’s another three years of polishing to get the mirror just right. If you’ve ever had to set up a metal block for precision machining on a mill, you might have an idea of why this takes so long. Especially if you make that block a few tons of glass and the surface has to be ground to micron tolerances. A lot of clever engineering went into this, including, no joke, a custom grinding tool full of silly putty. Though, at its core it’s not much different from smaller lens making processes.

The telescope is expected to be finished in 2024, for more information on the mirror process there’s a nice article here.

Hackaday Links: 👻 🎃 Spooky Edition, 2017

A few links posts ago, we wrote something about a company selling huge LED panels on eBay, ten panels for $50. Those panels are gone now, but a few lucky hackers got their hands on some cool hardware. Now there’s a project to reverse engineer these Barco NX-4 LED panels. Who’s going to be the first to figure out how to drive these things? Doesn’t matter — it’s a group project and we’re all made richer by the contributions of others.

Prague is getting a new hackerspace.

A year and a half ago, a $79 3D printer popped up on Kickstarter. I said I would eat a hat if it shipped by next year. Seeing as how it’s basically November, and they’re not selling a $79 printer anymore — it’s $99 — this might go down as one of my rare defeats, with an asterisk, of course. I’m going to go source some very large fruit roll-ups and do this at Supercon. Thanks, [Larry].

Speaking of bets, this week Amazon introduced the most idiotic thing ever invented. It’s called Amazon Key. It’s an electronic lock (dumb), connected to the Internet (dumber), so you let strangers into your house to deliver packages (dumbest). CCC is in a few months, so I don’t know if Amazon Key will be hacked by then, but I’m pretty confident this will be broken by March.

The Lulzbot Taz is one of the best printers on the market, and it is exceptionally Open Source. The Taz is also a great printer for low-volume production. It was only a matter of time until someone built this. The Twoolhead is a parallel extruder for the Taz 6. Instead of one extruder and nozzle, it’s two, and instead of printing one object at a time, it prints two. Of course it limits the build volume of the printer, but if you need smaller parts faster, this is the way to go.

Hey, did you hear? Hackaday is having a conference the weekend after next. This year, we’re opening up the doors a day early and having a party at the Evil Overlord’s offices. Tickets are free for Supercon attendees, so register here.

At CES this year, we caught wind of one of the coolest advances in backyard astronomy in decades. The eVscope is ‘astrophotography in the eyepiece’, and it’s basically a CCD, a ton of magic image processing, and a small display, all mounted inside a telescope. Point the scope at a nebula, and instead of seeing a blurry smudge, you’ll see tendrils and filaments of interstellar gas in almost real-time. Now the eVscope is on Kickstarter. It’s a 4.5 inch almost-Newtonian (the eyepiece is decoupled from the light path, so I don’t even know how telescope nomenclature works in this case), an OLED display, and a 10-hour battery life.

Is the fidget spinner fad over? Oh, we hope not. A technology is only perfected after it has been made obsolete. Case in point? We can play phonographs with lasers. The internal combustion engine will be obsolete in automobiles in twenty years, but track times will continue going down for forty. Fidget spinners may be dead, but now you can program them with JavaScript. What a time to be alive!

Audio tomphoolery even an idiot tech blogger can see through! I received a press kit for a USB DAC this week that included the line, “…low drop out voltage regulators running at 3.3 V, meaning the 5 V USB limit is well preserved.” Yes, because you’re running your system at 3.3 V, you won’t draw too much current from a USB port. That’s how it works, right?

[Peter Sripol] is building an ultralight in his basement. The last few weeks of his YouTube channel have been the must-watch videos of the season. He’s glassed the wings, installed all the hardware (correctly), and now he has the motors and props mounted. This is an electric ultralight, so he’s using a pair of ‘150 cc’ motors from HobbyKing. No, that’s not displacement, it’s just a replacement for a 150 cc gas engine. On a few YouTube Live streams, [Peter] did what was effectively a high-speed taxi test that got out of hand. It flew. Doing that at night was probably not the best idea, but we’re looking forward to the videos of the flight tests.

World’s Largest Telescope Stopped by LED

Earlier this year a simple indicator LED brought the Keck 1 telescope, a 370 tons mass, to a halting stop. How exactly did an LED do this? Simple: it did nothing.

As it so happens, [Andrew Cooper] was just about the leave the summit of Mauna Kea (in Hawaii) when his radio instructed him otherwise: there was an issue. Upon returning, [Andrew] was met by a room of scientists and summit supervisors. “Yeah, this was not good, why are they all looking at me? Oh, h%#*!” The rotor wasn’t moving the telescope, and “no rotator equals no science data.” After being briefed on the problem, [Andrew] got to work. Was it a mechanical issue? No: manual mode worked quite fine, also indicating that the amplifiers and limit switches are functional as well.

Jumping from chip to chip, [Andrew] came across an odd voltage: 9.36V. In the CMOS [Andrew] was investigating, this voltage should have High (15V) or Low (0v) and nowhere in between. Judging by the 9.36V [Andrew] decided to replace the driving IC. One DS3632 later, nothing had changed. Well, maybe is one of the loads pulling the line low? With only two choices, [Andrew] eliminated that possibility quickly. Likely feeling as if he was running out of proverbial rope, [Andrew] remembered something important: “the DS3236 driving this circuit is an open collector output, it needs a pull-up to go high.”

Reviewing the schematic, [Andrew] identified the DS3236’s pull-up: an LED and its current limiting resistor. While the carbon composition resistor was “armageddon proof,” [Andrew] was suspicious of the LED. “Nick, can you get me a 5k resistor from the lab?” Hold the resistor on the pins of the chip and the amplifiers immediately enabled.

[Andrew] summarizes things quite well: “yes… One of the world’s largest telescopes, 370 tons of steel and glass, was brought to a halt because of a bad indicator LED”. It stopped things by doing nothing, or rather, by not turning on.

We love it when we get troubleshooting stories, and if you share our interest in problem-solving, check out this broken power supply troubleshooting or learn what could go wrong with I2C.

Edit: Keck 1 is one of the largest optical telescopes in the world. Thanks to [Josh] for noticing our error.