Sonus Faber Clone: Bending Sheet Ply Wood

Hi,
I was just reading a post about Wood Cabinets . In there, there was a link to pictures of the Sonus Faber factory. I have now been inspired to make a set of Sonus Faber look alikes, but using the two woofers and two tweeters I have available to me...

Apart from the shape, they won't be similar at all, and I can't bend solid wood SO...

How can I bend 19mm Ply or should I use thinner ply and layer it?

Is anyone interested in co-developing a similar system?

Gaz
 
I would HIGHLY recommend using a thinner ply, you'll find 19mm (3/4" for us americans) to be VERY difficult to bend over a short length and radius. I would suggest you look for the thinnest stuff you can get, in the 6-7mm range (about 1/4" to me) You'll find it easier to bend and work with. Of course this means you'll have to build yourself some jigs to hold the pieces together while the glue sets up.

Depending on what tools you have available to you, it might be just as easy to re-saw some wood to thinner layers and use that . (Or, if you can find it, use thin wood)

Good luck, and feel free to ask more questions!
 
It takes time and patience. Make a TEMPLATE of the horizontal xsection. Put that on your MDF and cut as many pc as to get the hight. if H=40 and mdf=2 then you need 20pc . You can add the baffle in two ways , with the template or seperatly. I hope this will stimulate your imagination.
 
If I would be doing this, I would use 3/4" maple boards used for hardwood flooring (tongue and groove for your advantage). I would soak them in water and then bend on a jig and let them dry. You would have perfect clone of Sonus Faber.;)
 

Attachments

  • pic2.jpg
    pic2.jpg
    36.8 KB · Views: 2,957
It was actually that tour that gave me the insperation. I was going to do a Tapered Pipe up until then.

* Is maple flooring expensive?
* How difficult is it to bend?
* How long do you soak it?
* When it dries in the jig, will it just stay like that? Will it never try and return to its normal shape?

For the back bit, I was thinking of lathing a piece half the height of the speaker and then cutting it in half. (My lathe doesn't reach 1.2m)

What would people think about having this as a closed box with an 8" sub firing from the bottom plate to the floor and a 6.5" mid and tweeter in the usually places? They are the drivers I have available...

Gaz
 

SpeakerBob

Member
2002-08-15 6:21 pm
UK
peterpan said:
It takes time and patience. Make a TEMPLATE of the horizontal xsection. Put that on your MDF and cut as many pc as to get the hight. if H=40 and mdf=2 then you need 20pc . You can add the baffle in two ways , with the template or seperatly. I hope this will stimulate your imagination.

Beware though! - this will eat through a lot of mdf - I've just bought 4 x 8'x4' sheets to do this! add a veneer and mine came to £210 inc vat (that was trade too:bigeyes: )

see :
http://www.diyaudio.com/forums/showthread.php?s=&threadid=5868&perpage=15&pagenumber=2

for more details
Cheers
Rob
 

MRehorst

Member
2002-05-17 8:48 pm
A lot of the antique radios I have worked on have fancy "bent plywood" cabinets. I believe that they were built up one layer at a time by bending a thin veneer over a form, then gluing additional sheets to it until the desired thickness was achieved.

Bent wood furniture is usually made by mechanically forcing the wood/plywood to the desired shape inside a steam pressurized container/press.

I think that with a lot of thought and some effort, a small system of this sort could be built for pretty low cost. Probably not worth the trouble, unless you're going to make a lot of speakers...

MR
 
Rarkov said:

* Is maple flooring expensive?
* How difficult is it to bend?
* How long do you soak it?
* When it dries in the jig, will it just stay like that? Will it never try and return to its normal shape?


In Canada it's about CAD 3-4 per Sq Foot.

Depending on width. But 2" width is easier to bend than 3". 2.5" is probably good in between size.

I woud imagine , maybe 12 hours (I never did it;) )

I think that it stays like this when dried.
 
I saw a DIY carpentry show on televish recently that detailed making curved skateboard decks.
The process entailed two sheets of thin plywood, application of glue between the two sheets and then placing them in a press until the glue set, with the result of permanent curves.
The glue that they used foamed out of the edges of the sheets.
Ask at a local joinery shop for more details.

Eric.
 
I've bent wood a few times and steam works a lot better than soaking. You can make a throw away steam box out of what ever wood is around. Many people use wallpaper steamers, but I just put my steam box with a hole on the stove on a pot of boiling water. I think I have heard the figure 45 minutes of steaming per inch of wood thickness.

I bent 3/4" birch. It was only 4" wide and was pretty tough. It did work, though. Make sure you make a very strong jig to hold the wood to shape while it cools.
 
OK, as I said above...This was only going to be a simple Tapered Pipe project...so last night, I decided what I was going to do...Cheat!

I am going to bend plywood by means of layering it and leaving it to dry in a jig. Before glueing my outside most piece, I will route lines into it at about 120mm distances (make it look as though the speaker is made up of ten parts. If I route far enough in (just past the first layer) then the dark stuff underneath will look very authentic (I hope)

I have attached an image to try and illustrate my point!

Gaz
 

Attachments

  • route.jpg
    route.jpg
    3.1 KB · Views: 1,789
I've just posted a reply in the "wood cabinets" thread about how to make bending plywood a bit easier. I probably should have put it in this thread (whoops)....but too late now.

My suggestion (in a nutshell): on the inner surface of the plywood rout some parallel vertical lines to make the plywood easier to bend. Once everything is all nice, fixed against the internal bracing and curvy, the routed grooves can be filled in.

Joseph
 
Here's my take on things. First, steam bending is easier than soaking and bending. Secondly, no, the wood will not retain the exact shape of the mold when released. It will deflect away from the mold slightly when released, but will then retain that shape. (So, over bend it slightly so you end up with the shape you want when you let it out) There is another technique I've seen mentioned, but never seen demonstrated and is significantly more dangerous, but faster. That involves using a blowtorch heating a piece of black (iron) pipe and bending the wood over the heated pipe (while still heating it with the torch) Again, I haven't actually seen it done, but have heard it works really well and is quicker than the steam bending or soaking methods. (it does tend to scorch the inside of the bend, so don't try this on something where the inner radius is visible)

As to the RobWells method, its not as difficult to get perfect matches as you think. This is assuming you have a router and a flush cutting bit. You simply make a template our of a 1/4" thick piece of hard board or plywood or whatever, cut the pieces close to the desired shape, attach the template and run along the edge with the flush trim bit. Viola! duplicate pieces without a lot of tedious matching! (Remember to wear a dust mask if doing this with MDF)

Man, I've posted more woodworking tips on this board than I do on the woodworking board I read!!!