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Bending the Ribs for the 1581 Dias Guitar
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10117&t=21665
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Author:  William Bustard [ Thu Mar 26, 2009 7:23 pm ]
Post subject:  Bending the Ribs for the 1581 Dias Guitar

Hello all. I am new here and I wanted to post something interesting as my first post.
My real name is Bustard

Recently I had been fooling around with older style guitars and thought Id try to build one of those Belchoir Dias ones with the fluted back ribs.
I thought it would just be cool to build one, learn how to bend the beautiful ribs and then maybe adapt it into an modern style steel string design, with an idea to lighten up the body.

I would like to say that I am no Luthier but a sculptor, trained designer/artist who likes to dabble in creative solutions to gain knowledge and understanding of design and materials.
I was dismayed as I could find no info on the net for this process so thought Id better here.

I have used this process for other artistic wooden creations and have easily bent wood up to 2mm!

Thats an old pulley wheel from the scrap yard.

After a little research and development I have created the double-bent ribs and find that what seemed difficult is actually very simple and fast. Even faster than hand bending a regular guitar on a hot pipe.

My Dias instrument, the first is not very good but there is still lots more to do and the first one of course is the hardest.
If there is anyone interested I would try answer any questions in regard to such things.

Since I am no luthier per say but an artist , I thought sharing the details might interest some who may have been trying to acomplish this design. As you know in Art there is no true property, at least in my Philosophy.

Im sure there are those who may enjoy just seeing how I did it, taking the idea and running with it to create there own designs or copies of that fabulous instrument or the Chambre Viheula.

Some would misdirect others looking to creat by deception or keeping secrets.
A fine local luthier once told me there are no secrets, and I dont think there should be.

The method is extremmely fast and 100% effective with Two daily sessions on the pipe of about 10 minutes each created all the ribs shown in the photo.
I just bent them like you would a side by spraying them with a little water, finding the right temperature and rolled them.
I trimmed them with a knife and the rebent prior to placing them in the mold overnight incase were are not quite dry.

It would be nice to see some of you fine luthiers, professionals, incorporate the fluted back ribs into some American steel stringed style instruments.
I beleive something very beautiful sounding and looking could result.

The thickness of this wood is 1.2mm for the Dias to allow for slight sanding to the final 1mm. It is flamed western Maple. I chose this because its easy to bend.


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enjoy, Im finding out that bending the ribs is the easiest part of this construction.
Thanks for looking! Hope some like it and can use it for some cool stuff..

Author:  Jim Watts [ Thu Mar 26, 2009 9:29 pm ]
Post subject:  Re: Bending the Ribs for the 1581 Dias Guitar

Bustard, welcome to the forum.
That's pretty interesting and a good idea on bending the flutes into the ribs.

Author:  William Bustard [ Fri Mar 27, 2009 9:00 am ]
Post subject:  Re: Bending the Ribs for the 1581 Dias Guitar

Thanks very much Jim

The pipe was shaped to the radius of the Dias and a heating element from a cooking grill installed. I control the heat by turning it on and off.

Due to the lack of information on the subject when I was trying to develop the method I put myself in Dias's shoes.
I think Im pretty certain this was the method used by the originator.
I could be wrong but it seems to make sense given the local, the Kingwood wood used originally came from SA. Now thats a long time ago and sailing ships were pretty big in the world.
What we find on ships...blocks and tackles, with wheels just like that one but probably made of wood.
The Lathe was top technology in those days.
In my research I veiwed many pictures of woodshops and round objects appeared everywhere.
Pure luck would have me find a wheel with the right r.


I do not know what Luthier Stephan Barber, the modern originator does but I thank him for sparking the interest and greatly appreciate the Drawing he made in the 70's.
It is still available from the Royal Collage of Music in England for purchase.

The next step will be to try RW and perhaps Ebony.

Author:  Laurent Brondel [ Sun Mar 29, 2009 6:41 am ]
Post subject:  Re: Bending the Ribs for the 1581 Dias Guitar

Interesting solution Bustard, thanks for posting.
I once asked Daniel Larson how he bends the ribs on fluted back vihuelas, he very graciously sent me pics of the process: a steam box and wooden form where the ribs are fastened with rope and left to dry. I would be pretty sure the late Renaissance makers were using this method, perhaps inspired by boat builders.
For those interested in the vihuela there is a pretty complete book on the subject (with detailed pics and dimensions of the Chambure and Diaz instruments) published by the Musée de la musique de Paris (in French). One ought to visit Alexander Batov website:
http://vihuelademano.com/

Author:  William Bustard [ Sun Mar 29, 2009 9:32 am ]
Post subject:  Re: Bending the Ribs for the 1581 Dias Guitar

Yes I thought of the steam box too It is one thing that boatyards would have so it is related aswell but...


I also read a lot of stuff on the net with no clear description of a quick and easy fix and
most seemed to dance around the issue.
so I thought Id put one here to help other lazy and impatient Dias builders.


Looking at pictures of old vihuelas and lutes, violins etc,from days long past the
hot pipe was quite popular for bending. Oh those nasty scorch marks...

This method requires cutting the ribbon into shape after bending.
One advanatage is the quick drying time.

A bunch of blanks may be made very quickly and placed in stock for use as needed
or you can just place it in the mold, trim tyo size and leave it.

These ribbons dont care how big your box will be either...might be a usefull feature.

Heres a shot of the basic ribbon pulled from the mold.
Image

A cool advantage of using a pipe one can make 40-50 in an hour and put them in the cupboard.

Thats CDN 25 cent peice to show the raDIAS of the flute.

Author:  DGr33n [ Mon Apr 13, 2009 3:21 am ]
Post subject:  Re: Bending the Ribs for the 1581 Dias Guitar

Thank you very much for sharing, I look forward to learning here at OLF

Author:  William Bustard [ Mon Apr 13, 2009 3:06 pm ]
Post subject:  Re: Bending the Ribs for the 1581 Dias Guitar

Your welcome, Im new here too.

I would like to point out that the rib produced with this method must still be put in a mold to get the required shape. This simply overcomes the difficult part of getting the double bend easily without breakage(usually).
This is due to the fact that they are both done at the same time, under a steady constant even pressure.

The guitar show was built on the fly w/o the use of a mold. It is very imprecise as is seen by the "wonky" back staves.
This minimilist approach to the construction allows me to find out what is absolutley nessesscary to realize a successful rendition if the Dias 1581.

I will shelve it and use it as a model to further the technique of building another of this 420+ year old instrument.

I have built a mold and will try another maple body to check the design and working drawings which where adapted from Barbers 1976 study of the instrument.

Author:  Antonio [ Mon May 25, 2009 10:07 am ]
Post subject:  Re: Bending the Ribs for the 1581 Dias Guitar

Bustard,

Thank you for sharing,
I was quite surprised to see that there is a surviving Portuguese musical instrument from 1581.
If I understood well you heat the round pipe to what temperature?

Author:  William Bustard [ Mon May 25, 2009 8:40 pm ]
Post subject:  Re: Bending the Ribs for the 1581 Dias Guitar

Hi Antonio. Well I havent developed a controlled heat source so I basically heat it up and bend away until it begins to scorch. This is one disadvantage as the heat is on the side we be lookin at when its done.
But when it starts to scorch I turn it off and wait a minute then start bending until it doesnt work and turn it on again and so on. Its pretty hot Id say 400f the wood drys pretty instantly.
Ive been trying wenge and think I will have to use some super soft or something as it like to crack on the ends. Also I have found that the longer peices seem to work better and trim to length after.
This is a good way to get the basic shape it still must be put in a mold. So whjat I doo after its overbent slightly I spritz it again and run it through very quickly keeping it slightly moist before placing it in the mold.
The problem I had with cracking occured when doing the double bend separatley, with this method its all at the same time.
It is fun.

Author:  Michael.N. [ Mon Sep 21, 2009 1:00 pm ]
Post subject:  Re: Bending the Ribs for the 1581 Dias Guitar

An interesting method of achieving the double bent rib and it obviously works.. I remember this coming up on the Barber/Harris website. They didn't quite say how it was done (or at least how they did it) but they did give indications. I think they ruled out the steaming method and any idea of hot sand, Having previously veneered the back of a Lute neck using the cold bending technique I was curious to see if it would produce the double bent rib. I quickly made a wooden former and armed with nothing more than a bit of string and some water I managed to produce a rib with the correct curvature. It does help if the wood is slab sawn.

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