Automatic etcher...pretty cool!

[rockgardenlove]

So the other day I was getting tired of agitating my PC boards by hand, so I came up with something that I think is pretty cool.  I have an old dead 12" speaker, the problem being that somebody bumped it, and the cone got all messed up, so it was left outside throughout the winter, and now the cone is really terrible.  But anyways, I cut little notches in the cone, and made a spot for my PCB etching tray to sit securely.  Now get your board, and etchant, and put it in that tray, and then place the tray in the little notches you cut in the speaker.  Now go find something that puts out alot of bass, and hook the audio source up to the speaker.  I personally just recorded myself with a bass making various thuds, and I hook the speaker up to my computer and loop the sound source.  Leave it like that, and in 20 mins or so, the board is all done, without having touched it alt all!

[KORGULL]

That's cool. With a function generator you could set it to a frequency that produces maximum, steady vibration. I've been experimenting with vibrating water in a container over a speaker to see how the vibational patterns change at different frequencies. At certain frequencies the water really gets jumping. You just need a small amplifier circuit to run the function generator's signal through.

[Unbeliever]

If you use a bigger container of water, put your head in it and send to the speaker a signal with the right resonant frequency your head will explode.

[wampcat1]

If you use a bigger container of water, put your head in it and send to the speaker a signal with the right resonant frequency your head will explode.

I shudder to think that *someone* will try that!! 

[rockgardenlove]

Your head would explode?

[Unbeliever]

Your head would explode?

[gez]

[davebungo]

I know that years ago, when I was an apprentice, we used to clean boards in a VAT of Arklone L (not a very nice solvent), but the cleaning was encouraged with ultrasonic waves.  Perhaps if you stepped up the frequency a lot, it may improve the etching process?

[markm]

 
Think I'll stick with the "old-fashioned" method of just swishing it around every few minutes.
Besides, the thought of anyone's head explode is frightening
reminds me of the Scanners flick
   MarkM

[rockgardenlove]

Uh so, if you hit just the right resonance with the speaker, would your board explode!?

[gez]

Uh so, if you hit just the right resonance with the speaker, would your board explode!?

I suppose anything will explode at resonant frequency given the right amount of energy, but that's the clincher...the only thing that's likely to happen to your head if you stick it in a tank with a speaker in it is....er, your hair will get wet.

You might get ear ache too...

[Paul Marossy]

LOL That's funny! 

[magicdog]

Best to try and avoid the 7Hz region of the spectrum (might prove difficult to generate anyway) but that would shake you into oblivion...

[Transmogrifox]

First, I must give my kudos to rockgardenlove.  That's one of the coolest things I've heard of.  Good way to put useles junk to a good use.  I put the last board I etched into a ziploc freezer bag and set in in my lap while I rocked on the rocking chair.  Just about have to take up knitting if I do very many boards like this.  The ratted out speaker sounds like a good way to do this.

The other idea I had was to get a number of boards ready in ziploc bags with etchant solution, and throw them in the back of my pickup on the way to work.

Best to try and avoid the 7Hz region of the spectrum (might prove difficult to generate anyway) but that would shake you into oblivion...

This is the resonant frequency of the stomach.  If you are running a large concert, and put something in the system to rumble the mains at 6 or 7 Hz, then you'll make everybody simultaneously vomit.  This means that, with an amp/speaker combo of good low bass response, you could conceivably get sick of your ring modulator (literally).

[Floyd Pepper]

Watch those sub woofers...

"Ifrasound: Very low frequency sound generators could be tuned to incapacitate humans, causing disorientation, nausea, vomiting or bowel spasms."
http://www.authorsden.com/visit/viewarticle.asp?AuthorID=8395&id=11681

"...incremental effects from discomfort to death"
http://www.acoustics.org/press/137th/altmann.html

Ouch!

[Satch12879]

You know, as much as I think the Mythbusters from TV are unscientific douchebags, they did kinda prove that that whole using sound to make someone lose their bowels thing doesn't work.  EM works far better at causing disorientation and mental disruptions anyway.

And if you did excite your mellon with the exact resonant freqency, I doubt it'd explode.  Plus you've got all that damping to contend with from your brain matter, cerebral fluid, skin, fat, muscle, etc.

[RaceDriver205]

Yeah, fraid that Satch is right. Resonance doesn't nessesarily culminate in an explosion.
In helicopters the pilots wear special helmets, which stops their heads resonating with the propellers or the engine (I forget which). This causes imparing of vision and would not be very comfortable.

[Transmogrifox]

Yeah, fraid that Satch is right. Resonance doesn't nessesarily culminate in an explosion.
In helicopters the pilots wear special helmets, which stops their heads resonating with the propellers or the engine (I forget which). This causes imparing of vision and would not be very comfortable.

Not sure if "afraid" is the word to use. I'm grateful Satch is right.  Can you  imagine some prankster making a bunch of people at a rock concert crap their pants?

It looks like from the second article posted by floyd, that it was a little more reliable source than the first.  This article pretty well covered the bases in showing how much power it would take to produce the said effects of low frequency acoustic waves.  In the end the article showed that the military's research of acoustic weapons probably won't amount to much since it requires too much power to be effective at any appreciable range.

It's still a funny thought.  Now I''ve pulled this thread totally OT.  Etching stompbox boards with an old speaker...I'll have to try that if I ever get my hands on a trashed old speaker.

[rhodes]

i cann't wait for 20 mins. I can etch in less than 5 mins. in heated ferric chloride. Try to boil ferric chloride in a test tube and the job is done to less than 2 mins.

[RaceDriver205]

Not sure if "afraid" is the word to use. I'm grateful Satch is right.  Can you  imagine some prankster making a bunch of people at a rock concert crap their pants?

Oh, that effect. Yeah, that ones possible. I believe that Tesla (the legend) did research into low frequency vibration of the human body. It was apparently very relaxing, but it was relaxing to the bowels as well, and you can guess the consequences.

Hey what does OT mean?