The Ruben's Tube worked wonderfully at the event last night! No glitches, perfect behavior -- though it did blow out twice. We had some wind, and I was pushing the bass for good effect.
All in all, it seemed to be popular, and I had a number of great conversations both before and after with technically minded people.
I also met the guys doing the effigy at Flipside, so that's good! Once school is behind me (just a few weeks... argh!) I'll spend some time with them at the warehouse and we can finalize the arrangements.
Of the various conversations (why are there small holes and big holes? {better re-ignition behavior and less pressure loss), Why the flare at this end {I couldn't find a smaller end plug so I adapted}, and so on... technical trivia) there was one audio enthusiast (or perhaps engineer) whose name I do not remember (actually I don't remember any names! sorry folks) had a very interesting idea.
Basically, a mechanical band-pass filter upstream of the gas injection, acting as a one-way valve to the tube. Simple to build; holes in a barrier, with flexible flaps over them that seal in response to backpressure; the size of the holes would need to be tuned, though, for optimal behavior at my preferred frequencies (whatever those end up being). Anyway, a pressure pulse would drive gas into the tube, but on the pull-back the valve would close up preventing me sucking air into the tube and blowing out the flame.
It would be difficult to add this now, with everything sealed up, so I may have to make a new tube sometime to test it. Or, after the show, I may try to tear down and re-build a tube to test the theory.
It was fun to be amongst fellow mad scientists and enthusiasts! I am so looking forward to being part of the geek community again.
My tazers worked fine on the 12-volt wall-wart. But when I wired them to the 12-volt lead-acid battery.... sparks! Smoke! Broken.
I guess I needed that current-limiting resistor after all.
I have one functional tazer left, but I think I'll move to plan-B and build a high-voltage igniter some other way... from scratch, or maybe from a more durable (e.g. 12-volt) device. More research is needed.
Tomorrow, April 12th, I am doing a demo of my Ruben's Tube at the April DorkBot (7PM, Cafe Mundi@1704 east 5th)! Just one of the 4, to simplify setup. I did a test run last night at a friend's house, found a few wrinkles (the tazer burnout, forgot a power cord), but generally had success on a nearly-empty tank.
I'll do more tests tonight, and carefully bag up my cables and stuff so I'll have _everything_ tomorrow. I also need to note the more interesting frequencies on the signal generator, and test my new external mixer (feeding the signal generator into the Mac was not working well).
During last night's test, three of the four channels on the amplifier were working beautifully, but one was not giving me any signal. Then, after 5 or 10 minutes of operation, the dead channel came to life. Mysterious.
I'm going to buy some better cables today. I don't trust all of my cables.
Also, finished the article on the hot-glue web gun and sent the text to my editor (who still seems to be on vacation; come back Mark! I want feedback!).
Took Monday off to do homework... on the hard CS class; foolish me, took a "project" class; foolish me, chose an "interesting" project. Both translate into more work than I want to do.
Soon. Soon. Will be done soon.
Well, just saw the Sawbones, and I'm now scheduled for a sleep study. I finally got sick of my inability to concentrate (I'm functioning at a very low level at work, compared to my usual) and I've been hearing the praise of my friends for their sleep apnea treatments, so I'll give it a whirl. If it's not that, it's allergies.. or diet.. or lifestyle.. or psychological factors.. such as overwork.. or.. or... We'll see.
Lessee, about 5 weeks of school left, max, unless things go wrong.
I've got a few articles to write for a leading magazine (non-fiction, but still). More on this once it hits the shelves!
I also want to write a custom story for a new steampunk magazine; a new magazine, maybe it's easier to get in? But I need a good steamy idea, and I need it polished by April 15! We'll see. With my trouble concentrating, it will be tough.
Theh Ruben's Tubes are moving along apace; I have the tubes mostly built now, and the electrical ignitors (repurposed tazers) are almost done, the wiring harnesses mostly assembled. Testing to occur this weekend, if anyone wants to drop by Saturday evening to see!
Okay, off to build some electronic fireflies and maybe do a run for the hot-glue web shooter...