Ron(UK) wrote in message
...
N Cook wrote:

so sequence is 3 or 4 bits of shims around the outside surface of the
voice
coil cylinder and into the slot.

More than 3, most recone kits include 10 or 12 thin shims, but as many
as you can comfortably slide into the gap without forcing it. Better to
have lots of narrow ones than a few wide ones. And they go on the inside
of the coil former, that`s why you have to take the dust dome off.


Glue the cone to frame and when cured, remove the cards and glue back
the
skirt.

Don't remove the shims till the outer suspension is glued.

Assemble the voice coil and shims without adhesive, get a feel for how
the coil former will slide down into the gap with the shims in place,
you have to get it right first time.

Apply contact adhesive to the basket and rear suspension (spider)where
they mate, then slide the voice coil down into the gap with the shims in
place. the spider should adhere almost immediately.

Leave that to set, then - leaving the shims in place - glue around the
outer suspension, and stick it to the basket. let it cure then slide
out the shims, and if you did it right, there will be no scraping. Once
you resolder the pigtails you can run a low frequency sine wave through
it to check, but not too high power!

If all is well, drop the dust dome in and run a bead of bostik around it
- you can use evostik but it can get stringy, even PVA glue works.

I have a can of silicone spray for sewing machinists cutting out tables,
spray some of that onto the inside surface of the voice coil cylinder ?

Don't spray anything in the magnetic gap, it`s not necessary and could
lead to problems later, the voice coil should never come into contact
with the pole pieces.

Some horn drivers and tweeters have viscous liquid in the gap, either a
ferrofluid or some other gooey liquid, but if it wasn't there to start
with, don`t experiment...

The foam in the vent is just there to keep the dust out, and to help
prevent any chuffing at low frequencies, it`s not critical, but don't
use foam that is too dense, it relies on air passing in and out of that
vent to cool the coil.


Hth

Ron(UK)

The 0.08mm thick aluminium dome must have been press-formed (or that very
hands-on turning type process that I forget the name of) with a cylinder
extension to the dome and the cylinder section is glued to the inside of the
VC former. So had to cut around the dome to remove and have to hope the
final gluing-back holds up against the air pumping process.
I'm thinking of some golf tees in the rim mount holes to give sliding
alignment with the holes in the periphery of the cone on re-assembly.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/