Space Bags

[bshaw147]

have an idea, not sure if it will pan out. to get a good seal i was thinking of putting my stator sandwich in a space bag, hook up a vaccuum and suck all the air out. ?
Bryan

[Calvin]

Hi,

no one can hear you cry in outer space.....aaahhhem vacuum

jauu
Calvin

[SY]

If you have a good vacuum pump, sure, it could work. You'll also need a breather cloth, sealant for the bag edges, and the other little bits and pieces used in making a layup.

[Calvin]

Hi


???? are you talking about encapsulating the completed panel in plastic film like Quad did it as a dust barrier?
Or do I have to think totally different?
In the first case a perfect vacuum will kill output completely.
In the second case please explain

jauu
Calvin

[SY]

I was under the impression that he was trying to do this for assembly purposes.

[bshaw147]

Hi Calvin and SY,
It's just for assembly purpose, it probably is not neccessary at all and we can just use our thumbs to force contact between the front and back. Thanks for your replies
B ryan

[SY]

I used two plywood boards and some cinderblocks.

[bshaw147]

right, i was just thinking of other ways, not that there is anything wrong with it. You are applying pressure over a larger surface area, so it will be squeezed more or less uniform and your D/S spacing will not be compromised. Take Care,
Bryan

[CharlieM]

I use vacuum bags at my workplace to compact and cure composite materials and I feel the need to caution you that vacuum bags can generate a HUGE force.

If you decide to use a vacuum bag you will need to regulate and limit the vacuum to prevent applying potentially damaging force to your stator sandwich.

I think you don't need much pressure (beyond contact force) to compress the glueline anyway-- nor would you want to apply pressure anywhere except over the glueline; whereas, a vacuum bag would apply potentially huge force (depending on applied vacuum) over the entire surface of the stator panel.

For example: If your stator panel is 4 square feet and you apply just 1/2 vacuum (15" Hg) to the bag, the total force would exceed 4,000 pounds (full vacuum would yeild twice that). That much force would easily deflect the stators into contact between the spacers; pinching the diaphragm and maybe even permanently bending/dishing the stators (between spacers).

Hope this helps :-)

Charlie

[Calvin]

Hi,

I agree with CharlieM. You only want pressure right at the glue joint. But You need it only for the one stator to which You glue the membrane. Its not neccessary to glue the second stator to the first. You can though, but with a sufficciently large contact area (glueline area ?) and the right glue a second glue joint is optional. ML for example used to fixed the second stator (front stator) just at the top and bottom of the panles. This makes dissassembling and servicing easier. Since this is probabely Your first major ESL project the chance (or wish) to dissassemble the panel is rather high.
Taping the two stator-halves together and constructing the speaker frame in a way that it puts slight pressure on the panel (self adjusting or -fixing) will spare You many curses later

jauu
Calvin