Weather Word Clock Warns You Of Impending Winter

November 8, 2015 by James Hobson 3 Comments

Word clocks are pretty popular “artsy” ways of telling time, but [doktorinjh] wanted to try something a little different. So instead of showing the time — it shows the weather.

He’s using an Arduino Yun to access the Weather Underground API for data and then sends the data out to a grid of 100 individually addressable RGB LEDs — NeoPixels to be precise. The LEDs are overlayed with a laser cut acrylic sheet with various words and weather icons to allow for a pretty specific depiction of current (or future) weather conditions.

The frame is made out of colonial style molding and since it’s a weather clock, he turned the grid of LEDs into a rainbow effect, because, why not?

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Are You Telling Me You Built A Lexus…Out Of Cardboard?

November 1, 2015 by George Graves 32 Comments

So, you want a new Lexus? Well then download yourself a free car, and cut it out on a laser. Add some glue, and bingo, you have yourself a fancy new ride. We’ll, not really.

Sure, this promo video is just a publicity stunt from Toyota (News flash: Your fancy Lexus is actually a Toyota) but we have to hand it to them, it worked. It’s basically 1700 individually shaped, laser cut cardboard cross-sections that are painstakingly stacked and glued together. What we like about this is the technique – that is making a 3D object from 2D.

Using 2D parts to create 3D shapes is nothing new. Most people’s first experience with this technique is with building model airplanes. Instead of cardboard, balsa wood sheets are cut into profiles and connected with stringers to form the shape of a plane. It turns out to be a very efficient way of making 3D structures when you only have 2D materials to work with. And with 3D software now in the hands of the masses, it’s never been a better time to try your hand at building in 3D. For a great example, see this carbon-fiber guitar made using Autodesks free 123D Make software. And don’t limit yourself to parallel layers, you can generate all sorts of shapes including furniture with the free and open source Sketch-Chair software. Which will come in handy, because you’ll most likely need a place to sit while you’re waiting for your new cardboard car to finish printing.

[via CNN]

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Wii-Motified Laser Cutter Refocuses For Contoured Cutting

November 1, 2015 by Sonya Vasquez 11 Comments

Still laser cutting all of your parts in 2D? Not the folks over at [Just Add Sharks]. With a few lines of code and an in-tact Wii-Mote, they’ve managed to rig their laser cutter to dynamically refocus based on the height of the material.

The hack is cleanly executed by placing the Wii-Mote both at a known fixed distance-and-angle and within line-of-sight of the focused beam. Thankfully, the image-processing is already done onboard by the Wii-Mote’s image sensor, which simply returns the (x,y) coordinates of the four brightest IR points in view. As the beam moves over the material, the dot moves up or down in the camera’s field-of-view, triggering a refocus of the laser as it cuts. Given that the z-axis table needs to readjust with the contour, the folks at [Just Add Sharks] have slowed down the cutting speed. Finally, it’s worth noting that the Wii-Mote was designed to detect IR LEDs, not a 10600-nanometer laser beam, but we suspect that the Wii-Mote is receiving colors produced by the fluorescing material itself, not the beam. Nevertheless, the result is exactly the same–a dynamically refocusing laser!

Now that [Glowforge] has released a continuously-refocusing laser cutter implemented with stereoscopic cameras, it’s great to see the community following in their footsteps with a DIY endeavor. See the whole system in action after the break!

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Mass Effect Rubber Band Gun A Beauty To Be-holster

October 31, 2015 by Sonya Vasquez 6 Comments

This Halloween, crafting most of your props and replicas wont be as easy as hitting “print.” This Mass Effect M-6 Carnifex Rubber Band Gun is the exception, though, and it’s all thanks to the detailed efforts of [eggfooyoung]. Like many others in childhood, [eggfooyoung] dreamed of sporting his own rubber-band gun. Year’s later, he’s made that dream a reality, and one for many others as well.

Mechanically, rubber-band guns, especially semi-automatic ones, are a finely tuned escapade into complex levers and joints. [eggfooyoung] took it upon himself to learn from the best in the craft, in this case, YouTube user [RBGuns] who has posted designes for numerous rubber band weapons. Overall, the M-6 Carnifex is a triumph of shared knowledge, as it’s an iteration of [RBGun’s] M9 build. [eggfooyoung’s] documentation is also everything we’d love to see in a weekend project: design files [PDF], detailed pictures documenting the step-by-step gluing process, and resources to dig more deeply into building your own rubber band guns.

Light Speed: It’s Not Just A Good Idea

October 6, 2015 by Al Williams 31 Comments

[Kerry Wong] took apart a PM2L color analyzer (a piece of photography darkroom gear) and found a photomultiplier tube (PMT) inside. PMTs are excellent at detecting very small amounts of light, but they also have a very fast response time compared to other common detection methods. [Kerry] decided to use the tube to measure the speed of light.

There are several common methods to indirectly measure the speed of light by relating frequency to wavelength (for example, using microwave ovens and marshmallows). However, measuring it directly is difficult because of the scale involved. In only a microsecond, light travels almost 1000 feet (986 feet or 299.8 meters).

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Neato Botvac LiDAR Repair Includes Juicy Pics And A Tool Hack

September 28, 2015 by Brandon Dunson 4 Comments

It seems second nature to us and it’s one of the ways we hackers are different from the larger population… sometimes we absolutely insist on buying something that is already broken. Which is where we join [Anton] as he reverse engineers, debugs, and repairs a broken Neato Botvac’s LiDAR system all in the name of having clean floors at a fraction of the cost.

Now keep your head on a swivel ’cause along the way [Anton] has the all-too familiar point in his repair where he puts the original project on hold while he makes a specialized tool he needs to finish the job. It’s hard to tell which is more impressive: turning a laptop webcam into a camera capable of clearly viewing bond wires and (wait for it!) where they are attached on the Silicon, or that he (yeah, we were making a comparison…member?) went straight back to solving the original problem. [Anton] did split this project into two separate blog posts, the first one is linked above and it’s not until the second post that he fixes the original problem. Perhaps there was a bit of scope creep, which was the reason for the separate blog entries? At any rate, [Anton] does a great job documenting the process along with what he calls some ‘juicy pictures’ and you can see a few of them after the break.

It’s been a while since we’ve seen a Neato hack (there’s pun in there somewhere, commenters below us will surely wipe the floor with it). LiDar on the other hand has been covered more recently in a Police LiDAR Tear Down and another post relating more directly to [Anton’s] repair.

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Drawbacks Of Laser Cut Delrin–and How To Slip Around Them

September 22, 2015 by Sonya Vasquez 34 Comments

Welcome back to part II in this ensemble of techniques with laser-cut Delrin. Thanks for many of the great insights along the way in the comments. In this guide, I’d like to go over some of the more immediate kinks that come to mind when getting started with this material.

Sourcing Delrin Sheets

When it comes to shopping, there are a variety of suppliers to choose from, but there are a few key words and thoughts to keep in mind.

Names

First, Delrin, is the “brand name” that refers to the Acetal homopolymer. Variants may also be labeled, acetal or acetal homopolymer. Delrin’s natural color is a soft white, but dyes can take it into a range of other colors. Black and white are, by far, the most common, though.

Tolerances

In the previous guide, all of the examples were cut from a small range of sheet thicknesses (0.0625[in], 0.09375[in], and .125[in]) sourced from OnlineMetals. As the thickness of the sheet increases, the tolerances on the thickness rating will also become more loose. You might buy a .125[in] plate and find it to be .124[in] in some places and .126[in] in others. If you purchase a .250[in] sheet, however, you’ll find that it may vary as much as .126[in] oversize though!

Buy it Flat

Despite McMaster-Carr being my go-to solution for one-off prototypes where rapid build iterations trump BOM cost, I don’t recommend purchasing Delrin from them as their sheets don’t have a flatness rating and often gets shipped bent in (oddly sized) boxes. (Seriously, has anyone else gotten a few oddly-sized parts in a gigantic McMaster-box before?)

Internal Stresses

Extruded Delrin has internal stresses built up inside of the sheet. There are a variety of reasons why this could be the case, but my biggest hunch is that the extrusion process at the factory results in different parts of the sheets solidifying at different times as the sheet cools, possibly causing some parts of the sheet to tighten from the cooling before other gooier sections have yet to finish cooling. What this means for you is that as your part gets lased out of the sheet, you’re, in a sense, relieving that stress. As a result, the part that you cut–especially for thin sheets–may come out of the laser cutter slightly warped.

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