Structure of airgap/airbucker pickups?

[jmcorey]

Hi all,

Has anyone taken one of these pickups apart and looked at the arrangement of the magnet and pole pieces? I am curious about how they keep the magnet away from the pole pieces. Do they use something to fill the gap other than air, or just glue the magnet down carefully so it does not contact the pieces/screws? Is the magnet a bit thinner than the usual magnets? Is there anything between the magnet and the base plate?

Thanks for your assistance.

Joe

[LucidInterval]

I belive I recall that they use a thin plastic spacer. I think someone here cut up a milk bottle and used that.

[jmcorey]

Is that all? I thought for certain the magnets would be a bit narrower!

Joe

[WARRENLEELYNCH]

Originally posted by jmcorey
Is that all? I thought for certain the magnets would be a bit narrower!

Joe

Joe, I have taken the air spacers out here is what dimarzio does for this design,
are you familar with a keeper bar?
it is the metal bar the screws go into on ALL pickups.
dimarzio uses plastic keeper bars on both sides of the polepieces.
the slug side is cool how they did it, it has a regular size slug pole down to where it goes into the keeper bar(also plastic)
at this point it is much narrower,to fit into the hole. they use regular size magnets BTW.
this is how they reduce magnetic pull and in turn get the "aged 5" effect with a full strength alnico 5. it brings down the output some(about 50-60 millivots) and makes the pup more dynamic.
dimarzio does not nor ever did use a alnico II magnet in ANY model of thiers
if you want to make a air bucker out of any other brand,you have to remove the metal keeper bar on the screw side,and install a thin(1mm) strip of plastic between the magnet,poles on both sides of both coils(slug and screw it is a tight fit). it is effective and cheap

[WARRENLEELYNCH]

BTW,it is crucial to get the plastic strip the EXACT size of the side of the magnet

[jmcorey]

Originally posted by WARRENLEELYNCH
BTW,it is crucial to get the plastic strip the EXACT size of the side of the magnet

Where can you find a 1 mm thinck piece of plastic? And why is it crucial to get the fit to be so exact??

Thanks for your especially informative posts.

Joe

[WARRENLEELYNCH]

Originally posted by jmcorey
Where can you find a 1 mm thinck piece of plastic? And why is it crucial to get the fit to be so exact??

Thanks for your especially informative posts.

Joe

it just happens that the plastic used on milk bottles is 1MM thick.
what i did was used a EXATO knife and cut the plastic into spacers and inserted them into a C5(alnico 5 pup)
why is it crucial to get the strip exact?
well if it is not the magnetic field will not be 100% blocked if the strip is smaller, and if it is too large the bobbins dont fit right,they crush the strip,making it uneven
you know dimarzio is something else,some think you can just take thier spacers out and use them in a duncan,gibson,etc? guess what? you CANT!
dimarzio's keeper bars holes are not aligned with duncan and gibson pole spacing LOL!!!
duncan has a 50mm and dimarzio is just slightly less,just enough to NOT be able to use them
so that is when i did the plastic milk strips thing! GOT MILK? LOL!!!

[jmcorey]

Then the screws just go through the bottom plate?

That is a pretty thin strip to make sure it is lined up exactly.

Thanks again, I think it is worth trying!

Joe