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FatsoForgotso
Bronze Member
80 Posts |
 Posted - 02/25/2008 : 16:43:23
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| I plan on building myself a pedalboard in the near future and I had heard that you can use magnets to hold in the pedals so you can switch up the pedals fast and not use any velcro strips. Does this affect the pedals insides? |
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ronster
Gold Member
Australia
645 Posts |
Posted - 02/26/2008 : 12:42:19
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Hmm magnets?!? That sounds like great idea!
I can't answer your question but I would love to see pics of your board when you are done! I use high density foam and cut it out. It's similar to the BCB-60.
Good luck  |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 02/26/2008 : 15:35:45
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Boss pedals are made from aluminum.
Aluminum is non-ferrous.
Non-ferrous materials are not attracted to magnets.
Transparent aluminum on the other hand...  |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 02/26/2008 : 15:48:25
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quote:
Originally posted by DeFrag
Boss pedals are made from aluminum.
Aluminum is non-ferrous.
Non-ferrous materials are not attracted to magnets.
Transparent aluminum on the other hand...
Hi DeFrag, FatsoForgotso & guys
You're right about the cast aluminum Boss cases,
but the base plates are made from bright or plated steel.
I just checked with one of my test magnets.
FatsoForgotso
Where did you hear about this - or see this?
It's an interesting idea.
Please tell us more about what you've heard.
Regards Dr. Bob
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DeFrag
Moderator
USA
3409 Posts |
Posted - 02/26/2008 : 16:25:20
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Good news Bob.. I should have known that. AlNiCo magnets might not affect much inside through the steel bottom-plate. However, rare-earth magnets are pretty damned strong.
Placing a steel plate between the magnet and the area where you don't want any stray magnetic field, can often make the stray magnetic field in the target area stronger. Magnetic metals like steel have a lower resistance to the passage of flux lines than does air. Therefore, all the flux lines on their way from the top of the magnet will prefer to move through steel rather than through air. This means that any flux line which intersects a steel object will proceed through the steel object until it needs to exit the steel object to return to the bottom of the magnet. Since the flux lines like to move through the steel more than through the air, all the flux lines possible tend to collect in the steel object for as long as possible. This will be true as long as the steel remains out of magnetic saturation. The thicker the steel the more flux lines can be captured before the steel object becomes saturated. The steel object acts like a "flux channel", where it grabs all the flux lines it can and channels them down to where they need to exit to get back to the magnet.
Another factor complicating this process is somewhat counter intuitive. A piece of steel is attracted to the area where the magnetic field has the strongest gradient (most inhomogeneous), not the strongest absolute field value. An interesting example (don't try this at home!) is to drop a nail into a super-conducting magnet. The nail will be strongly pulled into the top of the magnet and will fall freely through the homogeneous region of the magnet and stick near the bottom exit port of the magnet. If you take a wooden stick and push up on the nail it will move freely back through the homogeneous region of the magnet but will be very difficult to push out the top. This is because, even though the field in stronger in the center of the magnet, it has less magnetic gradient in the homogeneous center of the magnet than near the ends of the magnet where the flux lines spread out on their individual return path arcs.
So, in our example of placing a steel plate between the magnet and the area we desire to shield from the magnetic field, the ends of the steel plate will have all the flux lines possible trying to get into it, traveling down to where they must exit to get back to the magnet (the flux channel) and exiting in a big bunch. Remembering that the more flux lines, the stronger the field, what we have accomplished with our actions is to make the magnetic field near the ends of the steel plate stronger (collected flux lines) and more inhomogeneous (bent more). Both of these points make the stray magnetic field more of a problem near the ends of the steel plate. One way to overcome this problem is to make the steel plate much larger that the desired area to shield. As the dimensions of the steel plate get larger, the larger the area of the lowest magnetic field behind the steel plate.
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DeFrag
Moderator
USA
3409 Posts |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 02/26/2008 : 16:52:22
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Hmm... this is a VERY interesting and clever idea. Some initial thought leads me to the conclusion that the magnetic fields would have no ill effects.
"bad" magnetic fields are ones that are varying in intensity. You can't generate an emf(=noise/hum) with a non-varying magnetic field (Faraday's law: emf=d[Phi]/dt), so I don't think there would be a problem with noise injected into the pedal because permanent magnets create a non-varying field ([Phi]=constant).
It seems that the only question is whether the strong magnetic field would damage anythiung inside pedal, and again, I don't think so. Silicone doesn't care, and there aren't any electromechanical devices like relays (not sure how potentiometers or the on/off switch would react, but they are pretty robust).
VERY interesting... great topic
Laurie |
Edited by - Laurie on 02/26/2008 16:53:52 |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 02/26/2008 : 16:56:33
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| In short, I wouldn't think that even strong magnetic fields would actually damage anything inside a pedal. Rather, they may in fact adversely affect the tone by inducing anomalous behavior within the circuits as the components operate together while playing through them. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 02/26/2008 : 17:13:39
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Interesting DeFrag...
Thinking some more, at the sub-atomic level, an electron moving through a strong magnetic field will actually have it's path deflected (think cathode ray tube). I wonder if that effect would be enough to cause anything strange to happen in the wires/components of the pedal?
I don't think the pedal would be damaged by trying - it *maybe* would just sound wierd??
Hmmm.... and hmmm... again
Laurie |
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FatsoForgotso
Bronze Member
80 Posts |
Posted - 02/26/2008 : 19:30:14
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this is interesting. I'm hearing the exact opposite from people over at harmony central forums. I'll trust you guys over them anyday. Once I get the money for it, I'll get cracking on it and hopefully it will work  |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 02/27/2008 : 08:26:12
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Hi Guys
And to confuse the issue even more, there's MuMetal....
Who said Mu-What!? 
Hey FatsoForgotso
Can you direct us to the link where you read all this.
Regards Dr. Bob |
Edited by - Dr. Bob on 02/27/2008 09:12:23 |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 02/27/2008 : 08:48:13
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| Mu-metal is a nickel-iron alloy (75% nickel, 15% iron, plus copper and molybdenum) that has very high magnetic permeability. The high permeability makes mu-metal very effective at screening static or low-frequency magnetic fields, which cannot be attenuated by other methods. |
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FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 02/28/2008 : 05:24:22
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Go with the velcro.....all this talk of what a magnet will do to a pedal is headmelting..... it's like being back in science class............... |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 02/28/2008 : 05:30:54
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| Hmm.. I must agree with the Great Franzoni after all. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 02/28/2008 : 06:25:07
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Hey FatsoForgotso... if you ever to give it a try, I'd like to hear how it went!
Laurie. |
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FatsoForgotso
Bronze Member
80 Posts |
Posted - 02/28/2008 : 08:24:26
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| I'd like to hope I could use magnets, I don't wanna put velcro strips on my pedals. |
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Topic |
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Pedalboard Question
