Ilikes2shred Posted March 4, 2009 Report Share Posted March 4, 2009 Hi again everyone. I remember seeing a guitar on here a while ago that you could tilt up and down to fade between two amps. This has really got my interest, but I can't seem to find the thread, despite my efforts searching. Does anyone know what guitar I'm talking about and possible the thread that it was in? Any help is very much appreciated. Quote Link to comment Share on other sites More sharing options...
Ilikes2shred Posted March 20, 2009 Author Report Share Posted March 20, 2009 Alright, well I still can't find it and it doesn't look like you guys are having any luck either, so..... Does anyone know of some type of switch or something that changes according to gravity (so I could accomplish what the guitar I was trying to find could do)? I have some ideas in my head of how I could do this, but I'd rather not build the part myself... Quote Link to comment Share on other sites More sharing options...
psw Posted March 20, 2009 Report Share Posted March 20, 2009 Mercury switches Quote Link to comment Share on other sites More sharing options...
orgmorg Posted March 21, 2009 Report Share Posted March 21, 2009 Hi, sorry I didn't see this sooner. Here's a pic of the guitar- I built this about 20 years ago, for a friend of mine. He's the one who did the electronics. All I know is that it is controlled by mercury switches like psw said. there's more to it than that, but I have no idea what. I think he managed to get a patent on it. Quote Link to comment Share on other sites More sharing options...
Ilikes2shred Posted March 21, 2009 Author Report Share Posted March 21, 2009 (edited) Thanks everyone! If I do end up making a similar control (assuming that won't infringe on any patent, although a quick search didn't turn one up), it looks like I will figure out the circuitry on my own. I'll be sure to post anything I may come up with. Btw Orgmorg: Beautiful work on that guitar. Edit: Never mind, design patents only last 14 years. Edited March 21, 2009 by Ilikes2shred Quote Link to comment Share on other sites More sharing options...
psw Posted March 21, 2009 Report Share Posted March 21, 2009 I'm not sure if there is a patent, but making something for your own use doesn't infringe patent. Mercury switches are something you need to explore...they are not difficult to understand. Basically...they are like a bubble level where a ball of mercury on a vial with contacts in it instead of the bubble...as the mercury rolls around, and because it is conductive...it can roll over the contacts and so switch things on and off. Multiple switches could therefore be used, but basically the angle of the switch would adjust for the switching on or off of whatever. I've not heard of a "fader" but I dare say a number of switches could make such a thing work relatively smooth as a fade...otherwise, just a pair could be arranged to switch pickups or outputs depending on the angle of the guitar... pete Quote Link to comment Share on other sites More sharing options...
orgmorg Posted March 21, 2009 Report Share Posted March 21, 2009 I mentioned the patent only because it made me think that there was considerably more than just a couple mercury switches. As I remember, he tinkered with it a great deal until he got it to pan smoothly from right to left. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted March 21, 2009 Report Share Posted March 21, 2009 Ho ho ho ho....perhaps taking it to an extreme, but how about Hall effect sensors to four outputs so you can pan your instrument around a 5.1 surround setup? Quote Link to comment Share on other sites More sharing options...
Ilikes2shred Posted March 21, 2009 Author Report Share Posted March 21, 2009 @ PSW: Yeah, I looked up the mercury switches and thought the same thing.... Not to mention that I would rather not have mercury in my guitar, even if it is safely contained. Right now I'm hoping I can base the fading off a simple pot with a weight attached to the shaft. That way the shaft will turn if the guitar is turned (Using both sides of the pot and the wiper). From there I will have to figure out a way to use the change in resistance to control the output levels for the left and right signals... which may take a while. The other option would be the tilt switches that use a metal ball to connect the contacts. Both these ideas are potentially problematic because shaking could cause odd things to happen. and on patents: The right conferred by the patent grant is, in the language of the statute and of the grant itself, “the right to exclude others from making, using, offering for sale, or selling” the invention in the United States or “importing” the invention into the United States. What is granted is not the right to make, use, offer for sale, sell or import, but the right to exclude others from making, using, offering for sale, selling or importing the invention. Once a patent is issued, the patentee must enforce the patent without aid of the USPTO. That's from the US patent website. It may be different in Australia, but in the US it sounds like the inventor can exclude others from even using the patented device if the want to. and @ Prostheta: That would be absolutely amazing, although incredibly difficult. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted March 21, 2009 Report Share Posted March 21, 2009 "Amazing" makes "incredibly difficult" more enjoyable and all the more worthwhile surmounting. For some strange reason, I have the image of Dave Gilmour in a gyroscope laughing maniacally whilst Herman Li waits in the wings with his awful accent waving his hands about saying "awight, yeah" a lot whilst being unable to actually play guitar very well at all. Quote Link to comment Share on other sites More sharing options...
Ilikes2shred Posted March 22, 2009 Author Report Share Posted March 22, 2009 I tested a basic circuit today that works off two volume controls (one for left, one for right) and it (purely the electronics) works fine. The problems would be with the mechanics... For it to work, I'd have to: a. find a usable pot that's full range is within about 30 degrees. b. get the pot loose enough that a small, light weight could turn it(using gravity). and c. make the weights small and contained (able to fit in a control cavity). I highly doubt I will be able to find something that will will work... How many tilt switches (mercury or other) do you guys think it would take to get it to pan smoothly? Quote Link to comment Share on other sites More sharing options...
orgmorg Posted March 23, 2009 Report Share Posted March 23, 2009 If I remember correctly, this one had 2 mercury switches, and relied on some funky circuitry to pan smoothly. My electronics comprehension is very limited, so I couldn't even guess what that circuitry was. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted March 23, 2009 Report Share Posted March 23, 2009 Hmmm....how about cheating and using the rotation of the rear strap button when manipulating the instrument as some kind of pot actuation thing? Difficult to maintain the load-bearing properties of the button whilst achieving this, perhaps. Or maybe even a modified b-bender? Quote Link to comment Share on other sites More sharing options...
Donovan Posted March 24, 2009 Report Share Posted March 24, 2009 I vote no mercury switches, the weight idea sounds intuitively best at creating a smooth effect. I'd find a way to use lead weight in a ball and socket joint for smooth operation if the axis of movement is not precisely aligned. Make it pendulum-like and the added length of the pendulum will provide leverage to magnify the power of the weight as well. Quote Link to comment Share on other sites More sharing options...
billm90 Posted March 24, 2009 Report Share Posted March 24, 2009 Just roughly thinking about this for 40 seconds. How about a slide volume pot, like in a mixing board. Maybe a 2 large metal balls on a track could push the slider side to side based on gravity? guess I would need to spend a little more time thinking about this. Quote Link to comment Share on other sites More sharing options...
Ilikes2shred Posted March 24, 2009 Author Report Share Posted March 24, 2009 I am very confident that the weight idea would work... It's just that I can't find any pots around 500K where the full range of motion is within about 30 degrees (the amount that would be practical to tilt a guitar). If anyone knows where to buy such a pot (or a usable alternative), please let me know. The slider idea actually sounds pretty good... assuming the sliding motion is smooth enough that a weight could push it. Right now I have a simple circuit that would lower the volume of each side in three steps (using mercury switches). I made a makeshift tilt switch, and will wire it up to test it. If it works, I will post the diagram. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted March 24, 2009 Report Share Posted March 24, 2009 (edited) Potentiometers and slide switches have inbuilt resistance to movement as they are designed to maintain the settings they are put in, so the force required to negate this opposing force would need to be considerable (most likely a bulky mechanism). Reducing the torque required to actuate the mechanism may cause problems in good contact between the track and wiper. Just throwing practicality around here, sorry. Devices like mercury switches etc. are either in a conductive or a non-conductive state (like a relay) so a degree of hysteresis would need to be electronically introduced to smooth the transition between both states for panning, as opposed to switching. This would introduce a degree of time from introducing the change between states (tripping the mercury switch) and achieving the "fully on" state. An RC charge/discharge circuit could allow the hysteresis to be controlled, or even adjusted to flavour with a pot. A Hall Effect sensor or two could feasibly be configured to have a free rotating magnet passing through the sensor's detection ranges, and have the supporting circuitry level and rout the signal to two sources accordingly. The axis on which the magnet would rotate depends on how you would manipulate the instrument to move between the two extremes. Orgmorg: Is the effect on the instrument instantaneous, or is/was hysteresis a part of the design solution? Edited March 24, 2009 by Prostheta Quote Link to comment Share on other sites More sharing options...
Mitch Posted March 24, 2009 Report Share Posted March 24, 2009 (edited) I think you could do this by pot modding. If you scraped away all but 30 degrees of the carbon track away and replaced the stuff you scraped away with wire or solder. Then scrape away a tiny (even along the length of the track) amount of the remaining carbon track to put the resistance up to the resistance you want from he pot. Then hang a pendulum from the shaft. That might work. I know the stew mac pots come apart easily and I'm sure that most others do also. Just an idea. Hope you understand what im talking about. EDIT: I can see problems with the tiny fine contacts in the potentiometer being forced against each end of the track by the weight of the pendulum. There are easy ways of getting round this Edited March 24, 2009 by Mitch Quote Link to comment Share on other sites More sharing options...
Mitch Posted March 24, 2009 Report Share Posted March 24, 2009 If you had a ball bearing running over a kind of railway track with one rail carbon and one rail steel or copper. One end of the carbon rail would be one output and the other end would be the other output and the steel rail would be the input. I can think of a few ways of doing this. Quote Link to comment Share on other sites More sharing options...
Ilikes2shred Posted March 24, 2009 Author Report Share Posted March 24, 2009 Prostheta: I was actually hoping to just be able to use a number of tilt switches which would close consecutively as the guitar is turned. As each switch would turn on, it would change the output level of either the left of right channel by a percentage of the original volume. This would produce a number of "steps" in the volume level, but hopefully they could be adjusted to limit how much they would be noticed. I am pretty sure that with three or four "steps", a quick pan (less than one second maybe) would seem perfectly smooth. I would use a circuit such as: This circuit would work off voltage-division, using the DC resistance of the pickup as the first resistor. As the mercury switches are activated, they open a new path to ground with a different resistance than the last, which would divide the voltage from the pickup in higher and higher ratios until a direct path to ground is established, at which point the volume would be zero (much like how a standard volume control works). However: If a degree of hysteresis would be needed, I would need to use a separate, DC (rather than AC) resistive-capacitor circuit to indirectly control the volume of the guitar, correct? (rather than using a resistive-capacitor circuit in the actual signal from the guitar... which would not produce the desired "analog" change in volume) Also, I like the idea of the Hall Effect sensor. All I would need to would be to feed the output of the sensor to control the degree of amplification (or de-amplification) of the the guitar signal. Quote Link to comment Share on other sites More sharing options...
Donovan Posted March 24, 2009 Report Share Posted March 24, 2009 Just roughly thinking about this for 40 seconds. How about a slide volume pot, like in a mixing board. Maybe a 2 large metal balls on a track could push the slider side to side based on gravity? guess I would need to spend a little more time thinking about this. To take this a tad further, slider pot, wiper modified to have a ball rolling across it, so the the ball, presumably on a bearing and attached electrically, IS the wiper. Some company must be doing some form of this "motion pot" or "tilt pot" idea already... oh wait, yep they are! http://www.frederickscom.com/sens_tilt_0717_4315.html. That would be smooth. Quote Link to comment Share on other sites More sharing options...
orgmorg Posted March 28, 2009 Report Share Posted March 28, 2009 Well I managed to get in touch with my friend, and he said that he was never able to get the mercury switch deal to work smoothly enough, and that the ultimate configuration involved a pendulum, like mentioned earlier, and some sort of optical device. That's about all he would divulge, which is just as well, since it's probably all I could comprehend, anyway. Quote Link to comment Share on other sites More sharing options...
Keegan Posted March 29, 2009 Report Share Posted March 29, 2009 (edited) What if it weren't a mercury switch, but a mercury pot of sorts? Like you have this semi-circular track made of something resistive, with one channel output on one end, and the other channel on the other. Then the other side of the track is just plain metal. I dunno how you'd go about building something like that, but it's just an idea, lol The only problem is that you get 50% volume in the middle, equally balanced between the two outputs. It'd still be a cool effect though... It'd be a lot easier to just build a foot-switch to do this, since you'd just need a basic wah pedal with a pot in it, or a blend pot to get 100% output in the center. If you want to use weights, you'll just need two equal weights(each enough to put torque on the pot, which could be something like half a kilo), something to drill a hole in the shaft of the pot(or some other way to attach the string to the pot), and some string. Kind of useless since it'll be so heavy, but if you hang the weights out of the bottom of the guitar it'll look cool =P Edited March 29, 2009 by Keegan Quote Link to comment Share on other sites More sharing options...
Donovan Posted March 29, 2009 Report Share Posted March 29, 2009 What if it weren't a mercury switch, but a mercury pot of sorts? Like you have this semi-circular track made of something resistive, with one channel output on one end, and the other channel on the other. Then the other side of the track is just plain metal. I dunno how you'd go about building something like that, but it's just an idea, lol The only problem is that you get 50% volume in the middle, equally balanced between the two outputs. It'd still be a cool effect though... It'd be a lot easier to just build a foot-switch to do this, since you'd just need a basic wah pedal with a pot in it, or a blend pot to get 100% output in the center. If you want to use weights, you'll just need two equal weights(each enough to put torque on the pot, which could be something like half a kilo), something to drill a hole in the shaft of the pot(or some other way to attach the string to the pot), and some string. Kind of useless since it'll be so heavy, but if you hang the weights out of the bottom of the guitar it'll look cool =P If you actually looked, the company I linked to about 3 posts above... this is exactly one of several models they use to do exactly what the original poster wanted. What you are describing is an electrolytic inclinometer, just one of several methods used to produce exactly the effect that is being looked for and more smoothly than any small number of mercury switches could ever do. It may not be as elementary as hoped, but still not rocket science and certainly not much more difficult than wiring up a bunch of mercury switches in succession. Think about it... this is a novel idea for a guitar, but not for other applications outside of ther guitar. Cars, boats, Wii controllers, tons of **** needs to provide its computer system with a measurement of tilt angle for various reasons. Quote Link to comment Share on other sites More sharing options...
Keegan Posted March 29, 2009 Report Share Posted March 29, 2009 Ah, sorry, I missed your link. How would you use that to change resistance to two outputs though? Isn't that more for feeding data to a computer system to interpret and decide what to do with? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.