What You See Is What You (Laser) Cut

June 28, 2015 by Mike Szczys 19 Comments

WYSIWYG editors revolutionized content management systems, will WYSIWYC interfaces do the same for laser cutters? Unlikely, but we still appreciate the concepts shown here. Chalkaat uses computer vision to trace lines drawn in ink with the cutting power of a laser.

At its core, you simply draw on your work piece with a colored marker and the camera system will ensure the laser traces this line exactly. There is even a proof of concept here for different behavior based on different line color, and the technique is not limited to white paper but can also identify and cut printed materials.

This is a spin on [Anirudh’s] first version which used computer vision with a projector to create a virtual interface for a laser cutter. This time around we can think of a few different uses for this. The obvious is the ability for anyone to use a laser cutter by drawing their designs by hand. Imagine introducing grade-school children to this type of technology by having them draw paper puppets and scenery in advance and have it cut in shop class for use in art projects.

A red arrow indicates cut line, but a pink arrow is used for indicating positioning on a work piece. The example shows a design from a cellphone etched next to a positioning marker. But we could see this used to position expensive things (like a Macbook) for etching. We also think the red marker could be used to make slight adjustments to cut pieces by scribing a work piece with the marker and having the laser cut it away.

This concept is a product of [Nitesh Kadyan] and [Anirudh Sharma] at the Fluid Interfaces group at the MIT Media Lab and is something we could see being built into future laser cutter models. What do you think?

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3D Printing Binaural Microphones

June 28, 2015 by Brian Benchoff 62 Comments

Binaural audio is probably the coolest thing you can listen to with a pair of headphones. Instead of just a single microphone, binaural recordings use two microphones, set inside an analog for a human head, to replicate exactly what you would hear if you were there.

The only way to record binaural audio is with fake plastic ears attached to a dummy head. Most of the famous microphone manufacturers have something like this, but with a 3D printer, anything is possible. [Carlos] created his own binaural microphone using a 3D printer and went through the trouble of creating a few audio demos. The results are weird, like [Carlos] is whispering into your ear.

The ears used in this microphone setup are taken from a Thingiverse project by [Jonathan March]. This model did not properly model the ear canal,and didn’t have any way to mask the sound from ear to ear; this is why the professional models also include a head. [Carlos] fixed these shortcomings and created a few 3D models that accurately model the human ear and head.

There’s also a simple stereo microphone amplifier for this project that is designed to fit right between the ears. This amplifier was designed in KiCAD, and the PCB is single sided. It’s not quite simple enough to assemble on a piece of stripboard, but [Carlos] did manage to manufacture it on some copper clad board in his mill.

The results? It sounds awesome. [Carlos] put together a demo of his microphone, link below, and it only works if you’re wearing headphones.

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Maker Faire Kansas City: Coming To Grips With The Mechanics Of Dexterity

June 28, 2015 by Kristina Panos 3 Comments

There is always a great variety of things to see and experience at the Kansas City Maker Faire. This is the fifth year for the event which is held at historic Union Station, a beautiful art deco train depot from a bygone era. With a multitude of booths and exhibits across two floors and a vast outdoor area, there is something for pretty much everyone. Often times, the interesting things are mobile conversation-starting creations. When we saw [Dan] walking around with a giant wooden contraption on his arm, we knew we must find out more about it.

The impetus for [Dan]’s project was his desire to pick up a soda can using a mechanical grip. He now believes this to have been a lofty goal, given the weight of a full can of the stuff. This prosthetic hand is made from wooden finger segments that are connected by small, continuous hinges. Each of [Dan]’s gloved fingers curls around a metal ring to control that digit’s large wooden analog. On the inside of the hand, sections of paracord run underneath strategically placed eye bolts on each finger segment and are tied off at the fingertips. A second set of eye bolts on the back of the hand anchor the network of rubber bands that provide resistance. Although he made it look easy to open and close the hand, [Dan] said that it’s pretty heavy to lug around and somewhat strenuous to use. Next time, he’ll probably go with foam or 3D-printed pieces.

2D Printed Tachometer For A Lathe

June 28, 2015 by Brian Benchoff 31 Comments

If you ever wanted a reason to have DC lighting pointed at the spinny part of your mill and lathe, [Bill] tells a great story. One day, he noticed the teeth on his lathe chuck would change color – red, then blue, then red. His conclusion was the fluorescent lights above his workbench was flashing, as fluorescent lights normally do.

Imagine if the teeth on [Bill]’s chuck weren’t painted. They would appear stationary. That’s usually a bad thing when one of the risks of using a lathe is ‘descalping.’ Buy an LED or incandescent work light for your shop.

This unique effect of blinking lights got [Bill] thinking, though. Could these fluorescent lights be used as a strobe light? Could it measure the RPM of the lathe?

And so began [Bill]’s quest for a 2D printed lathe tachometer. The first attempt was to wrap a piece of paper printed with evenly space numbers around the chuck. This did not work. The flash from his fluorescent bulb was too long, and the numbers were just a blur. He moved on to a maximum-contrast pattern those of us who had a ‘DJ phase’ might recognize immediately.

By printing out a piece of paper with alternating black and white bands, [Bill] was able to read off the RPM of his chuck with ease. That’s after he realized fluorescent lights blink twice per cycle, or 120 times a second. If you have a 3″ mini-lathe, [Bill] put the relevant files up, ready to be taped to a chuck.

Wirelessly Weighing Plants With The ESP8266

June 28, 2015 by Eric Evenchick 17 Comments

There’s a good number of hacks, and commercial products, for telling you when a plant needs watering. Most of them use an ADC to measure the resistance in the soil. As the soil’s moisture content drops, the resistance increases. High impedance, dead plant.

[squix]’s Thirsdee takes a different approach to plant health monitoring. Instead of measuring resistance, it simply weighs the plant. As the soil dries up, it gets lighter. By measuring the change in weight, the amount of water in the pot can be estimated.

Thirsdee uses a load cell to measure the weight. It’s read using an HX711 ADC, which is controlled by a NodeMCU. This development board is based on the ESP8266 chip. Since Thirsdee has WiFi, it can push notifications to your phone and log data on ThingSpeak. If you’re looking at the plant, an OLED shows you the current status of the plant. For us viewing from home, we can see a graph of [squix]’s plant drying out in real time.

[squix] provides us with a list of suppliers for the parts, and all the source code on Github.

Hackaday Prize Entry: Saving Water With The Vinduino

June 27, 2015 by Will Sweatman 9 Comments

[Reinier van der Lee] owns a vineyard in southern California – a state that is in a bit of a water crisis. [Reinier van der Lee] also owns an arduino and a soldering iron. He put together a project the reduces his water usage by 25%, and has moved it to open source land. It’s called the Vinduino.

Its operation is straight forward. You put a water sensor in the dirt. You turn on the water. When the water hits the sensor, you turn the water off. This was not, however, the most efficient method. The problem is by the time the sensor goes off, the soil is saturated to the point that the plant cannot take it all up, and water is wasted.

The problem was solved by using three sensors. The lowest most sensor is placed below the roots. So it should never go off. If it does, the plant is not taking in all the water, and you can reduce the output. The two sensors above it monitor the water as it transitions through the soil, so it knows when to decrease the water amount and watering cycle times.

Be sure to check out the project details. All code and build files are available on his github under the GNU General Public License 3.0

The 2015 Hackaday Prize is sponsored by:

Too Hot For Fido? Get Alerted!

June 27, 2015 by Mike Szczys 29 Comments

Meet project Oro, the temperature monitoring watchdog. Err… the watchdog monitoring temperature probe. Well, it’s both actually!

[Richard Deininger] built the project after having the AC system go down in his company’s server room. That environmental cooling is imperative if you don’t want your server hardware turned to slag. The idea is a separate piece of hardware that monitors the room temperature and will alert the on-call staff if it climbs too high. He was successful, and showing the hacked hardware around the office came up with a second idea: a temperature sensor for your car to ensure it’s not too hot for your dog.

Anyone who has a canine friend living with them knows you don’t utter the word “ride” out loud lest a barking, whimpering, whining frenzy ensue. But jingle those keys and they’ll be at the door in no time. During the summer you can still take them with you for short errands thanks to the peace of mind [Richard’s] build provides. It’s simply an Arduino, DHT22 temp/humidity probe, and a SIM900 GSM modem. Set your temperature threshold and you’ll get an alert if temperatures are climbing to unsafe levels for Fido.

While you have your tools out, we recommend building auto-watering and auto-feeding systems for the family pets. What’s that? You hate domesticated animals? There’s a hack you can use to chase them from your yard.