I have this crazy idea to make speaker cabinets with bent plywood walls. It doesn't have to be crazy bent, just a little is fine.
What would happen if I tool a 4 ft long 24" wide 3/4" piece of plywood, sat it on 4' long, 4" posts and put a towel in the middle and poured boiling hot water on it for 3-4 hours, and then put a big heavy steel 4" pipe in the middle lengthwise while continuing to pour hot water.
Basically heat and water to soften it and then weight to bend it gently into where it will be comfortable.
And It will give me a 48" long, 24" wide bent piece of plywood where the middle is 4" lower than the edges. It wont be a proper circle or much of anything curve (well it will be a catenary wont it ??? )
Cool.
Srinath.
What would happen if I tool a 4 ft long 24" wide 3/4" piece of plywood, sat it on 4' long, 4" posts and put a towel in the middle and poured boiling hot water on it for 3-4 hours, and then put a big heavy steel 4" pipe in the middle lengthwise while continuing to pour hot water.
Basically heat and water to soften it and then weight to bend it gently into where it will be comfortable.
And It will give me a 48" long, 24" wide bent piece of plywood where the middle is 4" lower than the edges. It wont be a proper circle or much of anything curve (well it will be a catenary wont it ??? )
Cool.
Srinath.
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Laminate several sheets to form curved plywood...yes
Bend plywood...not very much
Or make saw cuts most of the way through on the inside of the part you want to curve and fill with glue when curved...there is a name for this technique...escapes me right now.
Here's how to make a thick piece of laminated wood in whatever shape you want - start with the laminations and glue, not with a premade piece of plywood:
https://www.youtube.com/watch?v=QRBzl9FbJP0&feature=youtu.be&t=53s
https://www.youtube.com/watch?v=QRBzl9FbJP0&feature=youtu.be&t=53s
I`ve done it in a project - used a gym bar to bend the plywood and warm water. Problems you`d encounter unless you use extra screw pressure as on the first pic:
- Glue will not disperse even inside the two bent planes leaving cavities
- No matter how you do it, if no restricting form is used, you will not have the panels match perfectly on the x-axis. I knew this would happen and made them larger than needed, then had them cut with a saw which also clears problem 3 ( next one )
- When you bend them, the edges of the speaker panel would be made of varying 90 degree forms ( toothed as the plane is warped ). To later attach the front and rear baffles, you`d need these cut.
The easiest way to accomplish this is to first build a bending press that would keep the material tight and would allow for greater pressure. Do not underestimate plywood - a 900mm/40mm/8mm sheet would support your own weight without bending that much ( fulcrums at the very corners ).
Second easiest way is to use thin sheets of mdf - I used 4mm on this one, and glue them together, then bend to the desired shape. Once polymerised, the glue would keep them from returning to their original, straight, shape.
- Glue will not disperse even inside the two bent planes leaving cavities
- No matter how you do it, if no restricting form is used, you will not have the panels match perfectly on the x-axis. I knew this would happen and made them larger than needed, then had them cut with a saw which also clears problem 3 ( next one )
- When you bend them, the edges of the speaker panel would be made of varying 90 degree forms ( toothed as the plane is warped ). To later attach the front and rear baffles, you`d need these cut.
The easiest way to accomplish this is to first build a bending press that would keep the material tight and would allow for greater pressure. Do not underestimate plywood - a 900mm/40mm/8mm sheet would support your own weight without bending that much ( fulcrums at the very corners ).
Second easiest way is to use thin sheets of mdf - I used 4mm on this one, and glue them together, then bend to the desired shape. Once polymerised, the glue would keep them from returning to their original, straight, shape.
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Yeah bendy ply is the thing to go for, comes in different thickmesses which will allow you a tighter radius with the thinner stuff. The exterior stuff doesn't bend quite as much but makes a far more rigid finished product. I make all my speakers with this stuff. Brilliant stuff. Shame you aren't in the UK I'm just setting up a custom speaker building company 
Hi
I'll be using bendy plywood as well . For flexibility there ( short grain ) or ( long grain ) direction . This is a link to an Australian company but has some info .
Austral Bendy
Here's a sample they sent me to try .
Cheers
I'll be using bendy plywood as well . For flexibility there ( short grain ) or ( long grain ) direction . This is a link to an Australian company but has some info .
Austral Bendy
Here's a sample they sent me to try .
Cheers
Attachments
wiggle wood in the center with a couple layers each side of 1/8" bending ply. Use rigid glue and the strength will amaze you.
My preferred glue: unibond 800
Vacuum Pressing Systems -- Veneer Glue
I believe a vacuum press is a must have for a good lamination.
Vacuum Pressing Systems -- Vacuum Veneering
Vacuum Press Kits and Systems
My preferred glue: unibond 800
Vacuum Pressing Systems -- Veneer Glue
I believe a vacuum press is a must have for a good lamination.
Vacuum Pressing Systems -- Vacuum Veneering
Vacuum Press Kits and Systems
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