Under Saw Table Magnets?

benush26 · Post by **benush26** » Sat May 10, 2014 3:58 pm

I also wondered if larger magnets might have a negative effect on the PowerPro motor?? Or is that of no concern? I've found some 1" by 1" that have over 100 pounds of lifting force

Just curious

dusty · Post by **dusty** » Sat May 10, 2014 4:00 pm

benush26 wrote:I also wondered if larger magnets might have a negative effect on the PowerPro motor?? Or is that of no concern? I've found some 1" by 1" that have over 100 pounds of lifting force

Just curious

I would think that the physical separation between the table and the motor would prevent any interference. Magnetic field strength dissipates rather rapidly with distance.

beeg · Post by **beeg** » Sat May 10, 2014 4:06 pm

benush26 wrote: but that got me thinking about Gene's needs and wondered if a row of approximately 10 1" or larger magnets glued front to back would give enough of a field to hold the Magswitch.
Be well,
Ben

That sounds like it wood work BETTER than some kind of metal on the underside. BUT you wood have to be sure that you have to be SURE you glued the CORRECT pole facing the table top.

rpd · Post by **rpd** » Sat May 10, 2014 4:50 pm

Lee Valley sells rare earth magnets. There is a good article on their website that explains the magnets properties and how they are best used.
About Rare-Earth Magnets
I agree with Red (JPG), that the magnetic sheet would not be suitable. The "poles" on those sheets are laid out in narrow,alternating strips.

_________________________________________
|NNNNNNNNNNNNNNNNNNNNNNNNNNNN|
|SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS|
|NNNNNNNNNNNNNNNNNNNNNNNNNNNN|
|SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS|
|NNNNNNNNNNNNNNNNNNNNNNNNNNNN|
|SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS|

beeg · Post by **beeg** » Sat May 10, 2014 5:11 pm

Try this link instead.

http://www.leevalley.com/us/wood/page.a ... at=1,42363

fitzhugh · Post by **fitzhugh** » Sun May 11, 2014 10:22 am

Those fridge magnet type sheets don't have well defined north and south in the large scale sense, rather they have linear rows of alternating n & s. They also, get this, are one sided. Not totally but significantly so. They're formed by rolling a magnet over the iron filing filled plastic so the filings line up a certain way. Cool concept, Google "halbach array".

They might not work great with other large magnets; I picture the closely spaced alternating rows canceling each other out when used with a normal larger magnet. I haven't checked though.

A good potential source of quite strong magnets is old hard drives. They each have two very strong magnets:
[ATTACH]24991[/ATTACH]
They are the arc shaped parts, glued to the larger backing. About half seem to break when pried off.
Hope this is more helpful than off topic.

Gene Howe · Post by **Gene Howe** » Sun May 11, 2014 12:25 pm

I placed a stack of 2ea. 1/4" Rare-Earth magnets on the table and hung a 35mm Forstner by the end of the shaft under the table. I think this proves the concept. Next step is to obtain some steel shot and some cup magnets to further the experiment.