RSSMake: Projects
Intern's Corner: Naked piezo pickup for Cigar Box Guitar
Every other week, MAKE's awesome interns tell about the projects they're building in the Make: Labs, the trouble they've gotten into, and what they'll make next.
By Meara O'Reilly, projects intern
I've been working on winding coils and testing out a cool new electromagnetic guitar pickup for the upcoming issue of MAKE, so I thought I'd share a modification I did a while ago on the old piezoelectric pickup that was featured on the quick and easy Cigar Box Guitar in MAKE Volume 04.
Here's the piezo buzzer used for a pickup in MAKE's original Cigar Box Guitar, still encased in black plastic.
Piezoelectric transducer discs often come in protective plastic casings, but they're actually much more sensitive without them! I've spent many an hour with needlenose pliers cracking them open like steamed lobsters to get at the ceramic and metal underneath, and I've found the difference in amplification to be definitely worth it.
The original design had the plastic-encased piezo element (a piezo buzzer) inside the cigar box, and it worked fine, but I've learned that it works even better without the plastic case.
One of our old CBGs even had the piezo buzzer mounted directly under the strings, sort of propping them up into alignment with the fretboard, in order to show off the pickup. This was failing for two reasons: first, the point of contact was too broad, causing a buzzing sound as the strings hit the long, flat surface of the plastic, and second, because the piezo disc was oriented at the bottom of the plastic casing, it was protected from some of the most important vibrating bodies on the guitar -- the strings!
I decided to build something where a narrower contact point (or bridge) could directly conduct the vibration from the strings to the disc.
Here's my modified piezo pickup, naked, in direct contact with the bridge, and sounding great.
I cut a small block of balsa wood (about the width of the fretboard and long enough for the disc to rest comfortably upon) to prop up the whole setup. I placed placed the piezo on top of this balsa base, then cut a small piece of a wooden barbeque skewer we had lying around and placed that on top of the piezo as a bridge.
The strings, once wound on, will normally hold the bridge in place (in fact, many types of acoustic guitars have some sort of free-standing bridge like this), but for extra security, I cut both of the rounded ends off a popsicle stick and glued them flush with the balsa block to provide a sort of "baby gate" for the skewer, to keep it from rolling too much.
Voilà! The smaller contact point, applied directly to the piezo disc and held in place by the strings, conveys the string sound wonderfully.
What pickup modifications have you discovered?
Posted by Keith Hammond |
Feb 24, 2010 09:35 AM
Intern's Corner, MAKE Projects, Mods, Music |
Permalink
| Comments (1)
|
Suggest a Site
Make: Projects - Label-etching a glass bottle
My Make: Projects - Bottle cutting post has proven to be one of the most popular of the series. So here's a short follow-up revealing a simple trick I discovered for etching designs on glass bottles using the bottle's label as a built-in resist.
Read more
Posted by Sean Michael Ragan |
Feb 13, 2010 06:03 PM
Chemistry, DIY Projects, Green, MAKE Projects |
Permalink
| Comments (0)
|
Suggest a Site
Flashback: Caught in the Act
This week's Flashback, from the pages of MAKE Volume 15, shows how authors Jim Moir and Ken Lange devised a camera setup to auto-trigger photos of the critters who came to visit their backyards in the dead of night. Judging from the multitude of pictures they've gathered over the years, there is no shortage of wildlife variety in their neighborhood. Check it out to build your own and see what's lurking behind your house. You can also still pick up a back issue of Volume 15, the Music issue, over in the Maker Shed.
Caught in the Act
By Jim Moir and Ken Lange
Ever wonder what's getting into your garage at night, eating your cat food in the backyard, or coming by your tent when you're camping? Now you can find out. With a digital camera, flash, and triggering mechanism, you'll be able to see exactly which critters are prowling at 3 a.m.
Although there are some challenges to overcome, we've discovered that there are plenty of solutions to develop a remote wildlife photography system that meets your needs and budget. Film cameras were used in the past, but clearly digital cameras bring this hobby to a new level by eliminating the expense, time, and effort that comes with film.
MATERIALS
Digital camera We prefer the Kodak DC-290 and discuss its benefits in this article.
Infrared (IR) detector or motion sensor
Camera flash
Power supply
What Does It Take to Do This?
Our challenge was to choose a camera system that can stay awake for long periods (most shut down after a few minutes to conserve battery power) and to rig a method for sensing the animal and triggering the shutter remotely. We also needed a flash capable of illuminating an area large enough to capture pictures of what tripped the camera. Finally, we needed power reserves big enough to run the camera, the external flash, and the animal-sensing trigger mechanism for several days.
What Camera to Use?
We evaluated the 2 typical camera types -- point-and-shoot and SLR -- to capture our wildlife images. Both have advantages and disadvantages. Point-and-shoot cameras are inexpensive but need a lot of modifications to work. SLRs have more features but can be pricey.
We chose a third path and used the Kodak DC-290. This modestly priced camera was an excellent choice, with a respectable 3.3-megapixel picture and many programmable features not available in most point-and-shoot cameras. This enabled us to make the system work without extensive hacking, and at the same time kept the total system to a reasonable cost. While this camera is no longer in production, it is regularly available on eBay for $50 to $150 (depending on condition, accessories, and demand).
Read more
Posted by Goli Mohammadi |
Feb 10, 2010 06:00 PM
MAKE Projects, Photography |
Permalink
| Comments (1)
|
Suggest a Site
Flashback: The Florence Siphon Arabica Brewing & Extraction Apparatus
I thought I was really into coffee until I met John Edgar Park, host of Make: television, contributing writer to Make: Online, and author of several MAKE magazine articles. John takes his coffee seriously. Seriously. Case in point was when he devised and wrote a how-to for his Florence Siphon Brewing and Extraction Apparatus for MAKE Volume 17, our Lost Knowledge issue. This apparatus is sure to raise eyebrows (and spirits) next time you invite someone to your workshop for a cup of blessed joe. Check out the whole project in this week's Flashback, and pick up a back issue of MAKE 17 over in the Maker Shed.
Make your own mad-scientist coffee machine.
By J. Edgar Park II
Aboard the dirigible Aeroship Phaedrus, two men are seated at a table in the onboard Laboratory:
"Doctor Liepold, would you kindly prescribe something to lift my depressed spirits?"
"Why of course, Captain Heffernan. What is it that ails you?"
"My mind feels sluggish and there is still much work to be done before daylight. I am drawing up charts for the expedition."
"Ah, yes, I have just the thing. Sit a moment while I extract the invigorants from these wondrous beans."
"Very good, thank you. What is that strange device, Herr Doktor?"
"I call it the Florence Siphon. It is an arabica brewing and extraction apparatus. Allow me to demonstrate. First, I fill this boiling flask with a quantity of pure spring water. It is a vessel of my own devising that can withstand great heat and pressure. I heat the flask, which causes the water to vaporize, passing through this tube here, through a filter, and into the beaker to my left. Here, the water commingles with precisely roasted and ground fruit of Coffea arabica. I give the slurry a rapid stirring to fully saturate the grounds, then wait.
"As my boiling flask cools, a vacuum is created, causing the very atmosphere of the Earth to push the liquid through the filter, leaving the grounds and all unsavory particulate matter behind. Thus the liquid, now filled with essences, oils, solubles, flavors, and vital invigorants, is returned to the flask. Allow me to unstopper it and pour you a dose."
"Doctor! You have outdone yourself! I feel revitalized by this most miraculous potion."
The vacuum siphon coffee brewing method dates back to the 1840s. It produces some of the cleanest, smoothest-tasting coffee of any method. Commercial vacuum pots are available, but I wanted to heighten the drama of vacuum brewing by taking it into the realm of the mad scientist's lab. Thus the Florence Siphon was born!
After studying original patent drawings and existing devices, I identified these key features:
• Water is heated in a boiling flask that has a tube leading to a second vessel containing ground coffee.
• The tube must have a filter, to allow the water to flow through but not the grounds.
• The filter must be submerged during brewing, so as to maintain a seal with the boiling flask.
• The second vessel must be accessible for stirring the slurry.
• The boiling flask must be large enough to create a sufficient vacuum as it cools to "pull" the coffee back through.
One drawback to early vacuum brewers was the constant danger of exploding glass. Today, we have plenty of high-quality borosilicate glassware that's up to the task — it just happens to be found in the lab, not the kitchen.
Filtration was another challenge. I tinkered with a few options (including an unfortunate foray into shower heads) before arriving at an inverted thistle tube. This is a type of bulbed funnel that's easy to cover with filter cloth. (Thanks to Dr. Jim Callan from Avogadro's Lab Supply for this suggestion.)
I assembled my funnel, stopper, tubing, filter, and a beaker for the grounds. I filled my flask with preheated water (small burners can take a while to boil 500ml), poured 38g of medium-ground coffee into the beaker, donned my goggles, and lit the burner.
The water began to bubble quickly, and soon went straight up the glass tube and over to the grounds. After about a minute, the flask was nearly empty and I extinguished the flame. At this point, there was an abundance of expanded water vapor (steam) inside the flask, which prevented the water from returning.
I stirred up the slurry with a stick and then waited with great excitement. Would the siphon be able to draw the coffee back up? At just about the 2-minute mark, I saw the gorgeous brown liquid begin its ascent. This is due to the vacuum created by the cooling and contraction of water vapor in the boiling flask. It was tentative at first, but as the boiling flask continued to cool, the coffee started to move quickly up the tube, over and then back down to the flask below. Within another 20 seconds, the journey was complete: 420ml of coffee made it back, leaving 80ml of water behind with the grounds.
I removed the stopper and poured myself a cup. It was perfect! Smooth, bright, clear, and clean. Vacuum coffee is a step above a French press, and leagues above drip. Plus, when you brew with the Florence Siphon you get to don your lab coat and cackle maniacally. What more could you want from a cup of coffee?
Here's how to build your own Florence Siphon.
Read more
Posted by Goli Mohammadi |
Feb 3, 2010 06:00 PM
Chemistry, MAKE Projects |
Permalink
| Comments (5)
|
Suggest a Site
Make: Projects - Periodic table elements collection cabinet
Every chemist (and arguably every scientist, and arguably everyone else in the world), whether amateur or professional, should have an elements collection. Theodore Gray has written eloquently about the hows and wherefores of collecting the chemical elements, so I won't belabor the point here other than to say: chemistry has been called the central science, and arguably, chemistry's greatest achievement has been the discovery of the chemical elements, the realization of the periodicity of their properties and its implications for atomic structure, and the isolation of each of those elements in its pure or "standard" state. Collecting the individual elements lets you participate in that incredible story in a way that no amount of book-learnin' ever will.
Read more
Posted by Sean Michael Ragan |
Jan 24, 2010 07:00 PM
Chemistry, MAKE Projects, Science |
Permalink
| Comments (2)
|
Suggest a Site
Featured Projects
Explore more Make: Projects
