Guys,
Not that I need to build anything right now, but how do you go about making a curved piece of woodwork? A curved cabinet for example.
I know the method of lots of slices all cut out and stacked but I'm thinking more along the lines of what was done here -
http://www.briangt.com/gallery/jason-towers
I saw those pics and it made me wonder. I saw the same board like that with all the strips when I went around a furniture makers. They were making a large reception table but I couldn't see how you 'set' the wood with all those strips to be stiff.
How is it done? Please share the secrete!
Not that I need to build anything right now, but how do you go about making a curved piece of woodwork? A curved cabinet for example.
I know the method of lots of slices all cut out and stacked but I'm thinking more along the lines of what was done here -
http://www.briangt.com/gallery/jason-towers
I saw those pics and it made me wonder. I saw the same board like that with all the strips when I went around a furniture makers. They were making a large reception table but I couldn't see how you 'set' the wood with all those strips to be stiff.
How is it done? Please share the secrete!
hes cut a series of bars of wood that travel vertically, used 3mm or so ply on the outside, gluded and stabled the outer material on.
The better way to do it would be with multiple layers of ply + bracing structure, but you cant see the inside of his speakers so it could be how he did it.
look up laminiating plywood curves in google, you should find something.
The better way to do it would be with multiple layers of ply + bracing structure, but you cant see the inside of his speakers so it could be how he did it.
look up laminiating plywood curves in google, you should find something.
uhhh...ahte to rain on your parade, but to me it looks liek he did the old cuts in an mdf board.
ive seen it done sucessfully before, its not usually perfectly smooth, might require some bondo work.
if you really DONT understand what i mean, you sjtu cut a series of striaght cuts with a table saw 3/4" to 1" apart and use the little slats as spaces to bend it (leave about 3 or 4mm of material, you dont cut all the way through the board)
ive seen it done sucessfully before, its not usually perfectly smooth, might require some bondo work.
if you really DONT understand what i mean, you sjtu cut a series of striaght cuts with a table saw 3/4" to 1" apart and use the little slats as spaces to bend it (leave about 3 or 4mm of material, you dont cut all the way through the board)
mmm that sounds like the stuff I saw the furniture manufactures using, only it looked ready made all slatted.
I had a quick google and it mentioned using two sheets like that face to face and then to glue them. Will doing this really get them to hold their shape? I'd somehow have thought they would both want to return to being flat?
I had a quick google and it mentioned using two sheets like that face to face and then to glue them. Will doing this really get them to hold their shape? I'd somehow have thought they would both want to return to being flat?
I've heard that steaming the wood works really well for some types of (ply)wood..(don't try it with MDF,or fiber/chipboard stuff!)
I've also heard of people steaming and bending numerous thin sheets,and bonding them together afterwards,basically building up a curved piece of plywood one layer at a time.. Be sure to let the wood dry and/or "set" before glueing it. and leave it in the mold as it dries,so it doesn't get warped out of shape.
I've also heard of people steaming and bending numerous thin sheets,and bonding them together afterwards,basically building up a curved piece of plywood one layer at a time.. Be sure to let the wood dry and/or "set" before glueing it. and leave it in the mold as it dries,so it doesn't get warped out of shape.
I agree. What you do is start with some somewhat thin plywood. You make curved formwork (kind of like you were making braces for the curved sheets). You clamp the plywood around them (gradually if necessary) and steam thoroughly and let dry. You would be advised to use the formwork as permanent bracing.
This is more difficult with thick pieces. If you are determined you may bend a second sheet and bond it to the first. You could also use other materials to build up the mass/thickness of the panel, or heavily brace and lead line it for example, if you wish.
This is more difficult with thick pieces. If you are determined you may bend a second sheet and bond it to the first. You could also use other materials to build up the mass/thickness of the panel, or heavily brace and lead line it for example, if you wish.
xstephanx said:
Yeah, I did some store fitting work for a while, im pretty familiar with the process.
On closer inspection it looks like deep grooves in particle board, bent, then with a layer of flexible ply stapled + glued onto the outside.
http://www.briangt.com/gallery/jason-towers/IMG_1726
Directly translated we would call it bend MDF. Over here you can buy it in ready made sheets (about 9 -12 mm) and it works really well. Next to that we have bent-triplex and Fuma (trade name not the wood).
I've tried them all and I'm sticking with fuma, which is 7 mm thick and consists of two 3 mm balsa layers with a 1 mm rubberlike layer inbetween. It's also the material of choice because of the light weight.
For the finish you can use 1 or 2 mm thick baltic birch (Finland), which is about the same price as 15-18 mm baltic birch but you can make really small bends and with a excentric sander you can make it as smouth as silk. Bend MDF and triplex are smooth enough themselve.
Some pics: http://groups.msn.com/luidsprekers/f18.msnw
If you glue two sheets together while in bended shape they will keep that form because the 2 forces are not working together and by this make the resulting force smaller. Which in turn is easily counteracted by normal wood(PVA) glue.
Only when in free standing form the ends might move hardly noticeable which shouldn't be a problem anymore if you use a third layer or as you probably use a mainframe anyway.
Wkr Johan
My uncle has made some guitars and he showed us oneday the wood that is used on the sides of the guitar. It bends easily. What you do to get it into position on the guitar is soak it in water and then he had a barrel made with water inside over a flame (gas bottle) then you use that to dry(?) the wood while shaping it. I think that when it dries it will stay in that shape, or close.
It was a while back so all the details aren't clear.
It was a while back so all the details aren't clear.
There is a company in the US that makes cylinders out of plywood. They can be had in big sizes like sonotube. You can get the right diameter to give you the radius of curvature that you require in the finished product and cut it out of the plywood cylinder. I lost my link but a Google ought to do the trick.
Rademakers said:
Okay, reviving an old thread. I now do want to build something curved! I want to make an open baffle with decent sized curves on each edge to reduce diffraction issues. I might even like to bend it in 2 dimensions (across and along the grain) so that there is a wider flat section for mounting the woofer, while there is a smaller flat front section with a larger curve for the mid.
I'm hesitant to use kerf cut wood as I want to be able to in-set the drivers from the back, with a rounded over edge on the front. If the wood is not solid right through this will look very odd. I also want something VERY strong because I plan to tension it to raise its resonance above the range of the woofers.
So I am thinking of building a frame to bend thin sheets over and layer them up.
So, the questions really are whether there is an ideal type of plywood for bending in this way (where to buy in he UK?)? And also will it really hold its shape when removed from the frame just by bending and gluing thin layers of ply together? Or will it bend some way back to its original shape? I was thinking of making an 18mm or 25mm thick baffle.
The curve radius would be about 60mm I guess.
This material is available commercially. It's around a $100 per 4x8. Find a serious local lumber-plywood supplier and give them a call. Different thicknesses have different minimum bending radius.
On the other hand, you could take regular plywood and make a few hundred cuts on the table saw to achieve same results.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=116653&highlight=
On the other hand, you could take regular plywood and make a few hundred cuts on the table saw to achieve same results.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=116653&highlight=
For a broad but brief showing of several different methods of achieving curved loudspeakers, download this zip file
http://members.optusnet.com.au/~gradds55/curved.zip
unzip then open the html file called
curved sided loudspeakers.htm
http://members.optusnet.com.au/~gradds55/curved.zip
unzip then open the html file called
curved sided loudspeakers.htm
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