Making Custom Curved Mirrors At Home

July 16, 2021 by Tom Nardi 8 Comments

Generally speaking, creating custom mirrors is a complex task that involves a lot of careful grinding, and isn’t something to be taken lightly if you need precision results. Just ask the folks who provided NASA with a wonky mirror for the Hubble. But assuming you’re not working on an orbital space telescope (or even a ground based one, for that matter), [volzo] has recently documented some techniques for producing single and double curved mirrors of reasonable quality using common workshop tools.

The first step is finding something that’s a bit easier to work with than glass. After testing various reflective materials such as PVC foil and painted PETG sheets by comparing the reflections of projected test patterns, [volzo] found that laminated polystyrene gave the most accurate results. If you just want to make a simple bent mirror, he shows how you can pop one of these sheets on a CNC router, make the appropriate cuts, and fold them into shape.

That part might seem a bit obvious, but what about a more complex shape? Here, [volzo] points to how the thin sheets of polystyrene also lend themselves to vacuum forming. As demonstrated in the video below, all it takes is a 3D printed plug and some basic equipment to rapidly produce mirrors in arbitrary shapes.

Now obviously the optical properties of such mirrors will leave something to be desired, but depending on your application, that might not be such a big deal. As examples [volzo] shows off a few projects using these custom mirrors, such as a tabletop camera that captures both sides of the table simultaneously and a circular projector. Laminated polystyrene could potentially even be used to create low-cost variable mirrors.

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Teardown: RADICA I-Racer

May 26, 2021 by Tom Nardi 3 Comments

Long before the Oculus Rift and HTC Vive came along, some of the biggest names in gaming tried to develop practical stereoscopic displays. These early attempts at virtual reality (VR) were hindered by the technical limitations of their time, and most never progressed beyond the prototype stage. Of the ones that did make it to retail shelves, none managed to stick around for very long. The best known example is Nintendo’s Virtual Boy, which ended up being a financial disaster upon its release in 1995 and some regard as the gaming giant’s greatest blunder.

Despite these public failures, Radica still felt compelled to throw their hat into the ring. Best known for their line of relatively simplistic LCD handheld games, the company produced several rudimentary stereoscopic stand-alone titles in the late 1990s to try and cash in on the VR fad. Among the later entries in this series was 1999’s NASCAR i-Racer, which at least externally, looks quite a bit like modern VR headset.

Featuring a head-mounted stereoscopic display, a handheld controller, force feedback, and integrated headphones, you’d certainly be forgiven for thinking the i-Racer was ahead of its time. But its reliance on the primitive LCD technology that put Radica on the map, combined with the need to keep the game as cheap as possible, keeps the experience planted firmly in the 1990s. But perhaps there’s something we can do about that.

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Air-Assist Analysis Reveals Most Effective — And Quietest — Methods

May 9, 2021 by Dan Maloney 19 Comments

If there’s one thing that continues to impress us about the Hackaday community as the years roll by, it’s the willingness to share what we’ve learned with each other. Not every discovery will be news to everyone, and everything won’t be helpful or even interesting to everyone, but the mere act of sharing on the off chance that it’ll help someone else is really what sets the hardware hacking world apart.

Case in point: this in-depth analysis of laser cutter air-assist methods. Undertaken by [David Tucker], this project reads more like a lab writeup than a build log, because well, that’s pretty much what it is. For those not into laser cutters, an air assist is just a steady flow of air to blow smoke and cutting residue away from the beam path and optics of a laser cutter. It’s simple, but critical; without it, smoke can obscure and reflect the laser beam, foul lenses and mirrors, and severely degrade cut quality.

To see what air-assist methods work best, [David] looked at four different air pumps and compressors, along with a simple fan. Each of these methods was compared to a control of cuts made without air assist. The test was simple: a series of parallel lines cut into particle board with the beam focused on the surface at 80% power, with the cut speed slowly decreasing. It turned out that any air-assist was better than nothing, with the conspicuous exception of using just a fan, which made things worse. Helpfully, [David] included measurements of the noise levels of the compressors he tested, and found there’s no advantage to using an ear-splitting shop compressor over a quieter aquarium air pump. Plus, the aquarium pumps are cheap — always a bonus.

Not sure how to get up to speed with lasers? Laser Cutting 101 might be a great place to start.

Precision Optics Hack Chat With Jeroen Vleggaar Of Huygens Optics

November 30, 2020 by Dan Maloney 4 Comments

Join us on Wednesday, December 2nd at noon Pacific for the Precision Optics Hack Chat with Jeroen Vleggaar!

We sometimes take for granted one of the foundational elements of our technological world: optics. There are high-quality lenses, mirrors, filters, and other precision optical components in just about everything these days, from the smartphones in our pockets to the cameras that loom over us from every streetlight and doorway. And even in those few devices that don’t incorporate any optical components directly, you can bet that the ability to refract, reflect, collimate, or otherwise manipulate light was key to creating the electronics inside it.

The ability to control light with precision is by no means a new development in our technological history, though. People have been creating high-quality optics for centuries, and the methods used to make optics these days would look very familiar to them. Precision optical surfaces can be constructed by almost anyone with simple hand tools and a good amount of time and patience, and those components can then be used to construct instruments that can explore the universe wither on the micro or macro scale.

Jeroen Vleggaar, know better as Huygens Optics on YouTube, will drop by the Hack Chat to talk about the world of precision optics. If you haven’t seen his videos, you’re missing out!

When not conducting optical experiments such as variable surface mirrors and precision spirit levels, or explaining the Double Slit Experiment, Jeroen consults on optical processes and designs. In this Hack Chat, we’ll talk about how precision optical surfaces are manufactured, what you can do to get started grinding your own lenses and mirrors, and learn a little about how these components are measured and used.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, December 2 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

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Skylight In Any Room

October 4, 2020 by Brian McEvoy 41 Comments

Despite a glut of introvert memes, humans need sunlight. If vitamin D isn’t your concern, the sun is a powerful heater, and it helps plants grow. Sadly for [mime], their house is not positioned well to capture all those yummy sunbeams. Luckily for us, their entry into the 2020 Hackaday Prize is their sun-tracking apparatus that redirects those powerful rays throughout the house. It uses a couple of mirrors to redirect the light around their shed and into the house. For those who work in a dim office, no amount of work is too great for a peek of natural sunlight.

Movie spoiler alert: We saw this trick in the 1985 movie Legend and it was enough to vanquish the Lord of Darkness.

This project started in 2014 and sat on hiatus for more than five years, but it is back and prime for improvements fueled by half-a-decade of experience. The parts that aren’t likely to change are the threaded struts that adjust the positioning mirror’s angle, the driving motors, and power circuitry. Their first plan was to build a solar-powered controller with an Arduino, DC motors, and sun telemetry data, but now they’re leaning toward stepper motors and a computer in the house with a long cable. They are a finalist this year, so we will keep our eyes peeled for further development.

Mirror, Mirror, On Your Cam, Show Us What You’ve Drawn By Hand

September 19, 2020 by Brian McEvoy 10 Comments

Working and learning from home may be the new norm, and if IKEA shelves are any indication, folks are tricking out their home office with furniture, gadgets, and squishy chairs. While teleconferencing has proven to be an invaluable tool, paper documents aren’t going down with out a fight.

Unfortunately dedicated document cameras require significant space and monies, so they’re impractical if you only share once in a while. [John Umekubo] didn’t want students and teachers hobbled by the same costs and inconveniences, so he modeled a mirror holder that slides over a laptop’s webcam and directs the view downward.

[John]’s adventures started with a Twitter post, as seen below, but the responses were so encouraging that he published his design on Thingiverse for everyone. There’s also a version that can be laser cut out of cardboard, though we imagine a pair of scissors would work in a pinch. He admits there’s already a consumer model, but wasn’t planning to sell them anyway. Like us, he wants to get people to share their work.

We recently covered a simpler version of the same idea in use at Northwestern University, and we’ve seen a similar hack that gives a split-screen effect to sketch and maintain eye contact. If you want to share the view in your room, we have a Raspberry Pi streaming option that’s worth checking out.

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Mirror Turns Webcam Into Document Camera

September 17, 2020 by Elliot Williams 12 Comments

This is one of those so-simple-I-wish-I-invented-it hacks. Professor [Michael Peshkin] is teaching his engineering students remotely. While he has a nice second camera that he can use to transmit whatever he doodles on paper, most of his students just have the single webcam built into their laptops.

The solution is to put a mirror in front of the laptop cam, and flip the image left-to-right in software. They use Zoom, which has a mirror mode. Done.

The trick is making a nice frame. [Michael] has bent one out of wire, but suggests that a mirror compact works about as well in a pinch. It’s super important that his students can ask him questions backed up by drawings, and this reduces the startup cost to nearly nothing, making it universally useful.

[Prof. Peshkin] is not a stranger to mirror-based pedagogical hacks. Seven years ago, he showed us how to make a transparent whiteboard for video lectures, and it blew up on Hackaday. Since then, there are hundreds or thousands of Lightboards in the wild. We hope this idea catches on as well!