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| Sunday, April 18, 2004 |
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Sixteen months later to the day, comes another update. Much happened in 2003
to progress my coilgun's development (the homescale gun; the portable
one has seen no progress since June '02). This will be a long update.
Shortly after my last update in December 2002, I started my last semester of high school, the highlight of which was the Electricity and Magnetism portion of Physics. The course gave me what I needed to rework the equations in my EMF Simulator. Unfortunately, I could only do it on paper - I lost all the Java source files in a hasty reformat when switching to a new computer, and they weren't uploaded anywhere. I guess that's just fate. My Physics teacher saw my interest in the subject, and urged me to write a research abstract including applications other than as a weapon; the abstract was later published in the 2003 Journal of Student Research Abstracts. Okay, so good for me, I got something published. How does that advance the coilgun? Associated with the abstract was a "poster session" at Cal State Northridge in May, which for me meant a demonstration. That gave me the deadline I needed to get me working again. I wanted a solid, presentable device, so I tore apart what I had, got a lot more cardboard (my building base of choice) and started drawing out a new circuit. The pictures and project page show how it turned out, using my RIFA capacitor and a step-up circuit to charge at 340 volts. Now, I said this was a poster session, so I still needed a poster. Taking all the equations I had but never put to use, I simplified, approximated, and processed and ended up with my math-intensive poster. It was a hit at the poster session, I assure you. Jump to January, 2004. I'm starting my second quarter in college (University of California, Santa Barbara), taking my first programming class in Java, and in determining if it's possible to decompile the professor's example programs (I never did, really!), I realize I could also use such a decompiler to resurrect my Simulator Applet. And so I find one, and decompile the .class file that remained archived at the original site. Bingo, I can now resume work. Using the formulas from my poster, I tweaked and rewrote such that it would comply with what I had calculated. And this time, I uploaded the code to share and for safekeeping, but I didn't have the time or desire to update the site. Until now. Because I'm here at college, with no room to spare, I don't have my coilgun with me. I'm taking classes here over the first part of the summer, but I'll have a bigger space to work in then, so I might just bring my project back here to have something to do. If not, I'll be working on it as soon as I'm back home. |
| Wednesday, December 18, 2002 |
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You could have guessed by now that I've given up on my coilgun. This is not true! I haven't been working on it for a long time, but I haven't given up. My coilgun is in storage for the moment, but I've been thinking about it and I have a great new idea that I may try much later: the force on the projectile is directly proportional to the amount of iron in it, and because it's all iron, that means the mass. So as the mass increases, so does the force. However, acceleration is directly proportional to the force and inversely proportional to the mass, so this "decrease" exactly balances out the increase caused by mass. Now, if we make the coil the projectile, and surround the center of the barrel with an iron mass, then we're dealing with two masses: the one that increases the force can be varied and very large, while the mass of the projectile, which decreases the acceleration, can remain the same. I'll be trying this out not before March, but hopefully no later than August. I've also moved the site to my own server since I got Mac OS X 10.2 Server. My old site will remain as a mirror, but I can't guarantee updates. |
Sunday, August 25, 2002
As you can see from the hiatus from updates, I've been back
in school. On my free time I've been working on my EMF Simulator,
a preliminary version of which I've uploaded. It will calculate
the attraction on a projectile with a capacitor discharge system.
Soon to come: calculations for the changing inductance brought
on by the projectile, energy "stolen" from the circuit
by the accelerating projectile, and even an option to test with
an iron shell around the coil. The source code will be available
soon.
I've done very little work on my own coilguns. My portable
one is in storage until I get the time and resources to work
on it (I still haven't been able to find the right batteries
for my multimeter). My larger one is now in a cat litter box
so I can move it off my table every once in a while. I've put
a cardboard shelf over the top to hold the coil with barrel and
the switches. All the capacitors and charging circuits are below,
out of reach. I'll have pictures when I get around to uploading
them. I get my break in 2 months, so I might not be too active
until then.
| Sunday, August 25, 2002 |
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As you can see from the hiatus from updates, I've been back in school. On my free time I've been working on my EMF Simulator, a preliminary version of which I've uploaded. It will calculate the attraction on a projectile with a capacitor discharge system. Soon to come: calculations for the changing inductance brought on by the projectile, energy "stolen" from the circuit by the accelerating projectile, and even an option to test with an iron shell around the coil. The source code will be available soon. I've done very little work on my own coilguns. My portable one is in storage until I get the time and resources to work on it (I still haven't been able to find the right batteries for my multimeter). My larger one is now in a cat litter box so I can move it off my table every once in a while. I've put a cardboard shelf over the top to hold the coil with barrel and the switches. All the capacitors and charging circuits are below, out of reach. I'll have pictures when I get around to uploading them. I get my break in 2 months, so I might not be too active until then. |
Monday, June 17, 2002
Updated the RLC Calculator with new formulas
for better graphing, fixed HAPES (it had some minor problems),
and added a new applet: Kinetica. Also updated the Theory page
to keep everything separate. If you want two applets open at
the same time, try opening them in separate windows.
| Monday, June 17, 2002 |
| Updated the RLC Calculator with new formulas for better graphing, fixed HAPES (it had some minor problems), and added a new applet: Kinetica. Also updated the Theory page to keep everything separate. If you want two applets open at the same time, try opening them in separate windows. |
Sunday, June 9, 2002
Finished a useful Java calculator today. It's
on the Theory page.
| Sunday, June 9, 2002 |
| Finished a useful Java calculator today. It's on the Theory page. |
Saturday, June 8, 2002
I ordered six SCR's from Digikey on Monday.
They are rated at 70A continuous, 1000A surge for 8.3ms, 400v.
They should arrive this Monday. In the free time I had between
then and now, I involved myself in cooking on Tuesday and Wednesday,
then learned Java on Wednesday night, Thursday, and Friday. I've
uploaded a small applet that will graph the pulse created in
an RLC Circuit that should help you get a visual idea of the
current in your coil. The applet can be found in the Theory section.
| Saturday, June 8, 2002 |
| I ordered six SCR's from Digikey on Monday. They are rated at 70A continuous, 1000A surge for 8.3ms, 400v. They should arrive this Monday. In the free time I had between then and now, I involved myself in cooking on Tuesday and Wednesday, then learned Java on Wednesday night, Thursday, and Friday. I've uploaded a small applet that will graph the pulse created in an RLC Circuit that should help you get a visual idea of the current in your coil. The applet can be found in the Theory section. |
| Friday, May 31, 2002 |
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Wired together 15 of my 25 capacitors, but ran out of solder. I tested it first with only 3 capacitors and the projectile was able to penetrate a cardboard box. I tried again with all 15, but the suckback was too great - it only bounced off the box. I found that the optimum was 4. So I got my Dad to give me an advance on my birthday money, and I'll get some SCRs to use with this circuit (optically triggered). I found my digital camera, but not the computer cable. No worries, I have other ways to "develop" my pics. Took some great ones of my whole setup and the target box. I'm writing this at 12:38 am Thursday night (technically Friday), but because I don't have the pictures yet it won't get to you until Sunday night. I know I said I'd update sooner, but I couldn't bear the other camera, and without pictures I had nothing to update about. Wow, just fixed a lot of typos. I really have to stop updating in the middle of the night. It would be cool to get some little smilies too... |
| Monday, May 27, 2002 |
| I finally recieved my MECI package on Saturday after two and a half weeks. My mom almost flipped when she saw it, as it was packaged in a margarita box. I started winding my large coil with the 17 gauge wire I got, and I'm contemplating how to configure everything. I also realized, after a very electric ordeal, that my portable gun will absolutely need an SCR in order to function properly and reliably. |
| Sunday, May 19, 2002 |
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Redesigned my site from one page to several. Also created a title to add color and took some more pictures. No progress today on the coilgun, because I'm still awaiting my last two packages. I predict the AllElectronics package will arrive on Monday - they deliver from about 10 miles away. I ordered the MECI shipment on May 8th, and it still hasn't come. A visit to my Dad yesterday yielded a bag full of electronics junk, a light switch to use until I get a suitable SCR, and an old computer monitor. In a couple weekends he'll give me a bucket of broken power tools to sort through. Woohoo! |
Last updated: 4/18/04