Repairing a Vintage Hohner Harmonica Case

My Grandfather bought a Hohner Chromonika while serving in World War II (ironically, a German brand). When I was a child I had my own little blues harp, and seeing that I had an interest in it, he gave me his harmonica, in a lovely finger-jointed wood box.

Being a child at the time, I was a bit rough on the whole kit, and the box ended up broken with a couple of the pieces lost. I took the time recently to fabricate new finger-jointed pieces, and attach a new pair of hinges. Here's how the build went:



The Harmonica Case and the blank I cut from scrap stock.



I used the dremel to cut out the finger joints, after scrolling the existing joints on the box. Some adjustments were necessary to get a tight fit.



The joints were attached with wood glue, and clamped for drying.



I jacked these hinges off a box that I hardly use. They're pretty weathered, and a decent fit.





I'm happy with the results, and glad I was able to try this detail work with the dremel.

Scrap Wood Shelves Featured in Stop Motion Animation

Last week, my classmate Will Jennings and I created this whimsical stop motion video at ITP using my scrapwood shelves, and their assorted corresponding knick-knacks. We created it using IStopMotion, which is a fantastic program if you're looking to do that sort of thing. Enjoy!

Pez ZomBie from William Jennings on Vimeo.

"Ohm Sweet Ohm" Decorative Plaque

A while back I received a plaque saying "Home is Where Your Story Begins." It was just a bit too kitschy and corny for display in our home, but I didn't want a gift to go to waste, so I re-imagined it with a geeky twist.

"Ohm Sweet Ohm" - complete with the Omega symbol and a lightning bolt is much more our style. I made it by masking over the entire plaque and then cutting out the letters with an x-acto, making an adhesive stencil. Hit it with some silver spraypaint (boy do I love spraypaint) and voila - geektastic!

Recycling Plastic Bags into Childrens' Blocks

I learned about the method of "stewing" plastic bags from this instructable a while back, and decided to try it for myself.  In short, it's done by placing the bags in canola oil, in which they acquire a gummy consistency, suitable for molding into rigid pieces. I decided to make some childrens' blocks out of it. As far as I know the plastic is all #2 HDPE which I assume is safe for children. Can anyone shed some light on this? (don't worry I wouldn't give this to kids until I'm absolutely sure).

The swirly, marbled patterns have potential, although just mixing all the different colors together make it ugly as sin. Perhaps in the future I'll use various color schemes and they'll come out nicer.

On further thought, what basically gets created from this process is plastic lumber . Perhaps I can hang onto all my #2 plastic and slowly make enough plastic bricks to build a house. :) or even better, raid the bins on recycling day and live within other peoples' waste. Oh the possibilities....

Check out build pics at my flickr page.

How To Rewire Roland DS90 Speakers (For Humanities Students)

After so many years of literary analysis and myriad other right-brained ventures, I've become quite sluggish in mathematical type analyses. So, when I accidentally blew the internal amplifiers on my Roland DS90 desktop monitors, it took six years of procrastination before I finally opened them up and converted them to passive speakers.

Wiring in series and parallel I could understand, but when it got into the heady world of impedance and frequency crossovers, my brain started to swirl. I'll try to give the condensed version of how I figured it all out.

First, these monitors have two speakers, one standard for all frequencies, and one tweeter for only high frequencies.

A "crossover" is a speaker wired in parallel that has it's frequency limited by wiring in one or more capacitors.

I found out the "crossover frequency" of my speakers, then checked out this site to calculate the proper capacitance

Then it was a matter of rummaging through my junked circuit boards to find the right capacitors. That same site I linked to has a nifty little calculator that tells you how many farad you get when wiring the capacitors in different series or parallel combinations.

Now for the build pics:

The monitors with their butts ripped off.

The capacitors wired in: 2 10 microfarad caps in series, and 1 2.2 microfarad cap in parallel = 7.2 microfarad

Hacking the input: After I went all Om Nom Nom on the preamp circuit board...

I used the existing RCA input jack, and kept the rest of the amplifier guts intact, guessing that their physical presence has an effect on the overall sound of the monitors.

What's it Worth to You?

     One of my favorite quotes is, "You tell me 'Looks like someone has too much time on their hands,' but all I hear is 'I don't know what it feels like to be creative.'"
     Every day we experience a conscious state taking up what Clay Shirky calls cognitive surplus. In two nights' worth of TV time (watching the NBA finals game 1 last night, and a TV movie this night) I've organized all of my loose hardware: nuts, bolts, nails, screws, washers, and whatever else I might dive into for inspiration from time to time.
     One on side, I paid less attention to what I was watching on the tube. But how much attentions do we really pay to the act of watching television anyway?

     Now the tip: sorting hardware is a devious task when you feel like you've gotten so much accomplished, but it's really just because you sorted the big stuff first. Then it's a marathon of drudgery and fine motor exercise. When you're down to a handful of fluff and the tiniest of pieces, I suggest throwing it all in a tin can, going outside, and burning it from a safe distance with a splash of accelerant (isopropyl, gasoline, kero, what have you...).