Laser-Cut Lamp With Magic Switch

March 18, 2016 by 25 Comments

This laser-cut lamp is an awesome example of what you can do with a laser cutter and a bit of creativity. It was completely laser cut and features no fasteners, except for a bit of glue.

[PaisleyGarbage] has been making lamps for a while now and had the concept for this one early on. After rendering a model of it on the computer, he decided it was finally time to try making it. It wasn’t quite as easy as he thought it’d be, but the challenges along the way only help you to learn when doing a project like this.

He laser cut alternating strips of wood and acrylic to create the unique sandwiched light look of the final product. Instead of using fasteners or anything, he even slid the pieces together on acrylic dowels keeping the design as minimalist and clean as possible. But the part we really like is the magnetic switch.

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Live From The Midwest RepRap Festival

March 18, 2016 by 22 Comments

It’s time once again for the world’s premier DIY 3D printer event, the 2016 Midwest RepRap Festival.

The 2016 Midwest RepRap festival is a yearly celebration of blue tape, aqua net, and tangled strands of 3D printer filament held at the Elkhart county fairgrounds in Goshen, Indiana. This year, the fairgrounds has fiber Internet, and we have a Dropcam. This can only mean one thing: live streaming from the best 3D printer convention on the planet.

The livestream is down because MRRF is over

This stream should be active the entire weekend, with the requisite breaks for sleep and to take the entire crew to the Chinese buffet down the street. Of course, if you’re in the area, you’re more than welcome to stop by. Registration is free, although a small donation would be appreciated.

The schedule for the event is as follows:

  • Friday: now until 10pm Eastern
  • Saturday: 10am to 6pm Eastern
  • Sunday: 10am to 3pm Eastern

The (incomplete) list of speakers (which might be livestreamed) is as follows:

  • E-Nable 3D printed prosthetics
  • B3 Innovations From MRRF to retail
  • IMade3D STEM + Jellybox
  • MakerOS Make Money with 3D Printing
  • J. Conway 3D Printer Adaptive Scanning Technologies

Hacking The Raspberry Pi WiFi Antenna For More DB

March 18, 2016 by 38 Comments

I’ve been testing out the Raspberry Pi 3, and one thing I have found is that the WiFi antenna that was added in this new model is not especially good: the Pi has trouble connecting to my WiFi network in places that other devices have no issues. That’s not surprising, because the antenna on the Pi 3 is tiny: mounted right next to the display connector, it is just a few millimeters wide. [Ward] at DorkbotPDX agrees, so he decided to look into adding a better antenna by adding an external connector.

He tried two approaches: replacing the antenna with a tail connector, and adding a U.FL connector to the unused solder pads on the board. Both require some delicate soldering work, so they aren’t approached lightly. Replacing the antenna with an external connector produced a significant increase in signal output, which should equate with more range for the WiFi connection.

It is also interesting to note that the Pi 3 has solder pads on the board to add an external antenna connector, but that they are not used. Plus, one of the solder pads is covered by solder mask. Using these is the second approach that [Ward] used, soldering on a U.FL connector and connecting that to a small rubber duckie antenna. Again, this proved more efficient, increasing the power output of the antenna significantly.

NOTE: This hack definitely falls into “Don’t try this at home” territory. Messing with antennas voids the warranty and FCC certification for the Pi, and can cause all sorts of signal-related unpleasantness if you aren’t careful.

Beyond Measure: Instrumentation Amplifiers

March 18, 2016 by 35 Comments

In the first article about measurement systems we looked at sensors as a way to bring data into a measurement system. I explained that a sensor measures physical quantities which are turned into a voltage with a variable conversion element such as a resistor bridge. There will always be noise in any system, and an operational amplifier (op-amp) can be used to remove some of that noise. The example we considered used an op-amp in a differential configuration that removes any disturbance signal that is common to both inputs of the op-amp.

But that single application of an op-amp is just skimming the surface of the process of bringing a real-world measurement of a physical quantity into a digital system. Often, you’ll need to do more work on the signal before it’s ready for sampling with a digital-to-analog converter. Signal conditioning with amplifiers is a deep and rich topic, so let me make it clear that that this article will not cover every aspect of designing and implementing a measurement system. Instead, I’m aiming to get you started without getting too technical and math-y. Let’s just relax and ponder amplifiers without getting lost in detail. Doesn’t that sound nice?

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Home Made 8mm Digitizer

March 18, 2016 by 24 Comments

The 8mm film look is making a comeback, but distributing it is an issue. [Heikki Hietala] wanted an easy way to digitally capture the 8mm movies he made. So, he built an 8mm digitizer from an Arduino, a cheap Canon camera and the guts of an old 8mm film camera. When you throw in a few 3D printed components and some odd electronics, you get an impressive build that captures 8mm film with impressive speed and quality.

This build started with a Canon Ixus 5 camera running CHDK (the Canon Hack Development Kit) to lock the settings down. This points at the film strip through a macro lens so each frame of the strip fills the frame. An Arduino then triggers the camera to take a photo using a USB cable. The same Arduino also controls a motor that winds the film and triggers the film gate from the camera that he salvaged. By reversing the function and triggering it with a servo motor, he can easily blank off the edges of the frame so no stray light shining through the film material causes any problems. Once the camera has captured every frame on the strip, he feeds the captured images into Blender, which processes them and spits out the final movie.

This is a very impressive build overall. [Heikki] has obviously put a lot of thought into it, and the whole thing looks like it runs very efficiently and quickly. The captured video looks great, as you can see from this sample. The decision to use a salvaged film gate was a smart one: there is no point in reinventing the wheel if engineers of previous generations have solved the problem. Kudos to [Heikki] for also documenting the process in a lot of detail: he has produced a 5-part series on his blog that shows how and why he made the decisions he did. This series goes over the overall view of the project, using CHDK to control the camera, 3D printing parts, wiring the Arduino and writing the code that controls the system.

This sits nicely alongside the 8mm to video camera hack that we wrote about recently. This one doesn’t involve taking apart the camera (except for the sacrificial one that supplied the gate), and you still get that wonderfully grainy, jumpy look of 8mm film.

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What Lies Beneath: The First Transatlantic Communications Cables

March 18, 2016 by 81 Comments

For some reason, communications and power infrastructure fascinates me, especially the long-haul lines that move power and data over huge distances. There’s something about the scale of these projects that really gets to me, whether it’s a high-tension line marching across the countryside or a cell tower on some remote mountain peak. I recently wrote about infrastructure with a field guide that outlines some of the equipment you can spot on utility poles. But the poles and wires all have to end at the shore. Naturally we have to wonder about the history of the utilities you can’t see – the ones that run under the sea.

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SATA Cable Replaces DC Motor Brushes As Macgyver Looks On

March 18, 2016 by 21 Comments

[dmalhar] was digging around in his bins for motors and found one with missing brushes. Being resourceful (and not able to find another motor), he managed to tear apart a SATA cable and form the pins into brushes with just the right amount of spring. Yes, this looks like a cheap motor, but in the moment of necessity availability wins, and this hack is truly commendable. If he had used a paperclip, MacGyver would have been proud, but the SATA cable pins make us proud.

Normally the brushes of DC motors are made with a graphite or some other material which provides a small amount of resistance so that when the motor is spinning the brushes will provide a gradual shift of current from one commutator to the next. Also, the softness of the carbon makes the brush wear down instead of the commutator, and in large motors the brushes are replaceable. In cheap motors the engineers design the brush material around the expected lifetime of the product. In [dmalhar’s] case, the motor just got its lifetime extended by a while.