Quadrex foam grills: how were they made?

[shinola]

Anyone know how the original quadrex grills were made? I was thinking they were sculped with a hot wire, but apparently that's a no no with polyurethane foam. I guess that leaves either some sort of knife or bandsaw type blade?

[Kay Pirinha]

Hi,

maybe the foam was expanded in a negative mould, just like egg crate pattern foam?

Best regards!

[DES-1]

Maybe member sonofagun might be of help to you as he manufactured reproductions: #1

[shinola]

Kay,

Eggcrate foam is actually made with a bandsaw. Its sawed while being squished by two convoluted rollers, see video below.

Foam poured in a mold has a non-porous skin on the outside, so I'm pretty sure it's cut, not molded.

DES-1,

I'm not sure sonofagun would like to share his "trade secrets" unless I buy his foam grill manufacturing business for $12,000! Also he indicated making the grills is labor intensive, so I imagine he is hand cutting the foam with some sort of jig.

As a guess, I would imagine JBL has the foam sawed with some sort of CNC wire bandsaw, but who knows.

[DES-1]

[QUOTE=shinola;423387]Kay,


DES-1,

I'm not sure sonofagun would like to share his "trade secrets" unless I buy his foam grill manufacturing business for $12,000! Also he indicated making the grills is labor intensive, so I imagine he is hand cutting the foam with some sort of jig.


LOL, trade secrets! I think you are right about the manufacture methods, no doubt the methods used back in the day are stone age compared to the present.

[Don C]

I think I saw the rig for sale once. Some metal plates cut to match the profile needed from the side, and a bow with a hot wire for cutting.

[shinola]

I think I saw the rig for sale once. Some metal plates cut to match the profile needed from the side, and a bow with a hot wire for cutting.

Thanks. I assume this was an aftermarket thing, not jbl factory equipment?

[Don C]

I would assume so as well.

[sonofagun]

[QUOTE=DES-1;423388]

Kay,


DES-1,

I'm not sure sonofagun would like to share his "trade secrets" unless I buy his foam grill manufacturing business for $12,000! Also he indicated making the grills is labor intensive, so I imagine he is hand cutting the foam with some sort of jig.


LOL, trade secrets! I think you are right about the manufacture methods, no doubt the methods used back in the day are stone age compared to the present.

Stone age? Actually, I have found that companies today I have approached have failed miserably at reproducing L100 Quadrex grilles even though they have cnc machines costing many thousands of $$!!!