I posted a build report the other week about part of my kid's school science project - a tremolo build. (http://www.madbeanpedals.com/forum/index.php?topic=25928.0)
Here's the rest of the project - he has built a tremolo using a motor, spring, container, and liquid sloshing around. There was much science done testing different liquids, and in the end 'Pine-o-clean' was chosen as the tremolo liquid of choice.
It has two configurations with the container upright wobbling, or horizontal being bounced back and forwards in a pipe. Amazingly (well, to me anyway) this works out as an almost sine wave tremolo and a square wave, respectively.
The tremolo has a bit of randomness to it... sometimes the waves come in groups of two or three close together, then with a bit of a gap. It's a pretty cool sound.
Example of the waveform coming out of this thing:
(http://graybloomfield.com/guitar/wp-content/uploads/2017/07/trem-1024x352.jpg)
He also played around with a solenoid instead of the motor, but that bit isn't finished yet.
The 'guts':
(http://graybloomfield.com/guitar/wp-content/uploads/2017/07/IMG_1764-1024x765.jpg)
A 30 second video of it working:
http://graybloomfield.com/guitar/2017/07/30/liquid-tremolo/img_1758/ (http://graybloomfield.com/guitar/2017/07/30/liquid-tremolo/img_1758/)
And a 5 minute video if you want more 'science':
http://graybloomfield.com/guitar/2017/07/30/liquid-tremolo/science2017-480/ (http://graybloomfield.com/guitar/2017/07/30/liquid-tremolo/science2017-480/)
this is all sorts of cool. Very creative!
So, basically the liquid sloshing is changing the resistance between two poles and shunting some signal to ground? Or just straight up attenuating the signal?
Looks like it was a lot fun. Great memories
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That's awesome!
Awesome. The extra science video was also very good.
I've bookmarked this to look at carefully when I can spend time on it and enjoy. I'd love to do some modified version of this with my daughter sometime. She is always asking to help with my projects.
That's so cool 8)
Surfin wth the Alien! 8)
Very cool project
Quote from: nzCdog on July 30, 2017, 02:13:00 PM
Surfin wth the Alien! 8)
Very cool project
Well picked. That's the song he's learning at the moment. :)
Quote from: somnif on July 30, 2017, 04:33:18 AM
So, basically the liquid sloshing is changing the resistance between two poles and shunting some signal to ground? Or just straight up attenuating the signal?
Yep, the liquid shorts between signal and ground. What amazed me is that it wasn't necessarily an on/off effect. It had definite ramping on and off, depending on the angles of the wires and liquid movement.
I was also surprised that tap water is a pretty crap conductor for these purposes. Salt water was much better. Pine-o-clean was the bomb.
Quote from: mjg on July 30, 2017, 03:03:44 PM
Quote from: somnif on July 30, 2017, 04:33:18 AM
So, basically the liquid sloshing is changing the resistance between two poles and shunting some signal to ground? Or just straight up attenuating the signal?
Yep, the liquid shorts between signal and ground. What amazed me is that it wasn't necessarily an on/off effect. It had definite ramping on and off, depending on the angles of the wires and liquid movement.
I was also surprised that tap water is a pretty crap conductor for these purposes. Salt water was much better. Pine-o-clean was the bomb.
Resistance is a function of distance! Grab a glas of water and stick your DMM leads in 1cm apart and check the resistance (Pure water is 18.2M/cm, My "filtered" water is about 1M, my tap water is like 20k and tastes like pool run-off). Then move them closer, then further apart. By sloshing you're changing the liquid distance between the two poles, so variable resistance.
Very cool project.
Lol... Our tap water was about 500k with the leads 1cm apart.
from memory, whiskey was pretty bad at conducting too. I got to drink most of the test subjects. Not the cleaning products though. :P
Gold medal stuff here. Jack White will probably try and buy this from you at some point.
Quote from: mjg on July 30, 2017, 08:06:04 PM
Lol... Our tap water was about 500k with the leads 1cm apart.
Man your tap water is better than the "6x filtered!" water I buy from the machine at the leasing office, thats just annoying. Yeah my local water has an absurdly high calcium content (desert ground water) and a stupidly high chlorine level because of a bad diatom problem we have in southern AZ. Tap water will go slimey and coat things in a lovely golden brown layer of goop in as little as a couple days, and when they tried lowering the chlorine dose everything started to smell like geosmin and methylisoborneol (ie: muddy and mildewy).
But, hey, at least we get cool things like being able to grow stalactites off our faucets, so that's something I guess.
Quote from: m-Kresol on July 30, 2017, 04:30:05 AM
this is all sorts of cool. Very creative!
^^^^
LOVE this!! The "science" video is priceless. And your kid is going to have chops!
Reviving this thread so I can have a humble brag about my kid.
The kid entered this in the science fair at his school and got first place. Then entered it in the Territory science competition, and got first place there too.
Then, it went to a national competition (Australia that is) and he found out today that it came in somewhere in the top 60 or so entries for the nation, and he was up against kids a few years older than him too.
So he's pretty happy with himself. He got to have cake tonight to celebrate. ;D
Time to start thinking what he can do for this year's project...
Quote from: mjg on February 19, 2018, 01:01:21 AM
Time to start thinking what he can do for this year's project...
There's always this fun bit of madness: https://www.zvex.com/about-the-candela-vibrophase/
(or in slightly less absurd style: https://makezine.com/projects/make-33/optical-tremolo-box/ )
Ahh yeah, the optical tremolo. We have already thought about doing one of those. I've got an old Walkman CD player that is just begging to have a new life.
How about an R.O.U.S. (Reverb of Unusual Size)?
Maybe you could make a reverb out of a loaf of bread. I kid but I'm blown away by the inventiveness of this project and this is my second look at an old thread. I think my styrofoam balls on coat hangers around a light bulb as the solar system was pretty cutting edge when I was a kid. Pretty caveman by today's standards.
dearmond tremolo control ... the rev willy g powers his with windex
That is so cool. Memories that will last. Good job Dad!
What's the song he's playing in the first clip? I know it, but I just can't place it...
Surfing with the alien, by Joe Satriani.
It's what he's been learning lately, so I hear it about 10 times a day. ;D
Winner! :D
Very nice!
I missed this first time around. Very, very cool.