I started laying down some ideas I had about why I'd entered this instructable into various contests as part of another step, but then I realized how much I'd written, so I transplanted everything here. Enjoy!
1. 4th Epilog Challenge
"Be sure to tell us what you'll do with the Zing if you win!"
What would I do if I won a laser cutter? What wouldn'
As the captain of my high school's science team who is responsible for managing building events, I can see dozens of ways in which our school could use this device. Not only will it allow us to assemble balsa wood structures with never before seen precision, but it will also significantly reduce the time it takes and thus the number of structures we can test before we take one to an event. Usually, due to the time it takes to cut and measure everything by hand, we can only make one or two structures in time for an event, which means that if a design flaw shows up once we're done building, there's little we can do to correct it. Not anymore with the Zing!
We also build other complex things like musical instruments and Rube Goldberg devices that require precision parts to work smoothly. While duct tape and glue work to a certain extent, we've always ended up with something that falls apart on the last day or doesn't work the right way when we demonstrate it. Using computer-designed mechanical components rather than "those pieces of scrap wood we found in [redacted]'s basement", we'll be able to make our stuff work right.
But enough about what this device could do for my team in terms of the competitive advantage it gives us, given that this laser will be available to anyone I know who asks (tools are shared among the team, and this is tool like any other), the real question to ask is not what I will do, but what will the dozens of people who will get to play with it too will do. All of my teammates are just about as passionate about science as I am and just as willing to tinker around and build something cool. Some of them even have instructables accounts and I'm sure they'll be dying to write up what they've made once they've made it. I know that sounded a bit cheesy, but I really hope to make it the truth.
Ok, ok... I realize I've somewhat of avoided the central focus of the question, "what will I
do?", so here's a quick list of some stalled projects that could really use a kick in the behind from a laser cutter/engraver:
- Tube amplifier
After finding a trashed 1950s tube type television set in unserviceable condition about a year and a half ago, I did the only sensible thing I could and gutted it for parts to build a tube amp. Interestingly enough, this particular television used a 5AQ5 output tube and an 8FQ7 deflection oscillator. Why is that important? Well, as it turns out, the 5AQ5 is electrically identical to the held-in-high-esteem 6V6 output tube and the 8FQ7 is the same as the famous 12AX7. Both of these tubes are commonly used in high end audio and instrument amplification.
Once I realized that I was holding the key ingredients to a pretty darn good amplifier, I designed a circuit with what parts I had (my original drawing from ninth grade is attached) and got to work. Unfortunately, I didn't have any suitable output transformer, so I used something scavenged from a transistor amplifier that was (obviously) horribly mismatched to the output tube I was using. I also quickly learned that the 5AQ5 tube I had was leaky by the faint blue glow it emitted during operation. Nonetheless, it worked
The reason I didn't pursue this project was my inability to build a proper enclosure for the amplifier. With the tools I had (and have), there's just no good way for me to punch precision holes in aluminum to mount transformers, tube sockets, screws, etc. (the last time I tried to use my dremel to make a square mounting hole in an aluminum project box was a disaster. It worked, but I ended up with jagged, uneven cuts and scratches all over the place; acceptable for that project, but not for an amplifier).
That's where the laser cutter comes in.
Using the Zing laser cutting system, I would easily be able to make cuts in the thin sheet of aluminum that I plan to mount everything onto and this would allow me to pursue my project without having to worry about the impossible nightmare that doing everything by hand would create. I would also be able to engrave professional-looking labels and switch mounting holes.
Given that the 5AQ5 an 8FQ7 tubes are actually nonstandard versions of already "worthless" tv tubes (the standard versions are the 6AQ5 and 6FQ7), they are extremely cheap, especially when compared to even the most inexpensive 6V6 and 12AX7 variants ($5 per tube versus $30 or more per tube). This means that a high quality stereo tube amplifier using these tubes could probably be built for $150 or less (my estimate including output and power transformers) and that it would rival the performance of systems costing many times that price. I think this is an exciting project that just needs a little touch of laser to get it going again!
- Analog computer
I'm currently working on a fully functional opamp-based analog computer that would be able to solve complex systems of differential equations that might not have analytic solutions. I became interested in analog computers when I read the Heathkit EC-1 Analog Computer Kit manual i found here
. It used 9 vacuum tube-based opamps to solve relatively simple DEs, but with modern technology, I could easily increase that number to as many as I want; I plan on making it a modular unit. Of course, instead of having a whole box full of vacuum tubes
for each unit, there will only be a few ICs per module.
I already tested my ability to make a simple analog computer by building a rudimentary 2 opamp computer that solves the equation of motion of a harmonic oscillator. All that remains to be done is more testing with more opamps, construction of the individual integrators/multipliers/adders/other operators, and construction of an enclosure. Since I plan on demonstrating this at my school and college, I want it to look as professional as possible. With my level of metalworking ability, however, the best I could do would be a mess. With a laser cutter, I would be able to machine a really nice enclosure that I could use for years.
- Homebuilt oscilloscope
With the success of this project, I am currently building a version 2 cathode ray tube with a more advanced electron gun design that will produce a more focused electron beam and direct it at a phosphor screen. Then, using magnetic deflection coils and a simple sweep generator and vertical amplifier, I'll be able to make my own oscilloscope from scratch. Combined with my planned analog computer, it would make for a true 1950s computing experience!
However, to hold the homebuilt cathode ray tube in the enclosure will require precision metalwork that I do not currently have to tools for. With a laser cutter, I would be able to use a computer to design an enclosure and electron tube mount that would allow me to demonstrate my analog computer/cathode ray tube wherever I need to. In the future, I also plan to improve the oscilloscope to make it into a simple television set. The electronics are not too complex, and Jon Stanley designed a circuit that he used to display television images on his oscilloscope
If this project will be successful, then I think I might just be the first amateur to ever build their own television from scratch and from commonly available parts. Some others have made their own simple televisions using already manufactured cathode ray tubes, but none so far with homemade tubes. This project is still a long way from completion, but it is
possible in the relatively near future.
- Tesla coil control panel and interrupter
Apart from allowing me to machine professional-looking enclosures/control panels for my Tesla coils and external controllers like audio modulators and interrupters, the Zing laser cutter will also allow me to make the precision parts I need to put my newest mid-size DRSSTC together.
Unfortunately, with the tools I have, there is no way for me to make the precision cuts I need in order to make a good, clean-looking primary support system. My project is currently stuck with a fully wound secondary, assembled toroid, built and painted enclosure, tested half bridge and primary capacitor, but no primary coll.
2. Green Living & Technology Challenge
Experiments involving particle accelerators, vacuum systems, and high voltages often require expensive or esoteric equipment and professional assembly, but not this one!
I've been wanting to build my own fusor or small-scale accelerator for years now, but I just didn't have the money to buy parts and supplies for even a bare minimum steel or Pyrex vacuum chamber (easily several hundred dollars). However, after visiting Robert Hunt's site, teralab, and reading about how he used custom glass vacuum envelopes to perform a variety of experiments (including building his own vacuum tube triode!), I realized that a professional-grade vacuum chamber was not necessary to get started with some of those projects I've been inclined towards for years.
Unfortunately, scientific glass blowing is not quite as easy as Mr.Hunt makes it seem and proper equipment can be rare and difficult to procure (there's not too much demand for it anymore; after all, do most physicists blow their own glass vacuum chambers these days? I didn't think so =/). That's where the glass bottle comes into play. Once I watched this "5 minute fusor" video, I realized that if glass bottles and 5 minute epoxy are strong enough to hold up to a pretty decent vacuum, then maybe I wouldn't need one of those fancy custom machined steel chambers with $100 CF flanges stuck in at every possible angle that I had been dreaming of to perform some basic experiments. Thus, the wine bottle CRT was born. Other experimenters confirmed that this was possible (link, link).
This is the reason I would consider this to be a "green" project. Instead of using a large, expensive steel contraption, I used a wine bottle. Instead of using a lab grade adjustable high voltage power supply, I recycled a transformer from an old neon sign and a high voltage diode from a trashed microwave.
Sorry, it seems like some of my links were deleted for unknown reasons. I'll try to get them back as soon as I figure out what went wrong!