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neopolitan builder needs direction
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Author:  jim daniels [ Sat Feb 04, 2012 6:09 pm ]
Post subject:  neopolitan builder needs direction

I am lookng for a book or article on building a bowlback or 'neopolitan' mandolin. can anyone help?

Author:  cphanna [ Sun Feb 05, 2012 12:39 pm ]
Post subject:  Re: neopolitan builder needs direction

Hi, Jim. I stumbled into a beautifully documented thread over on anzlf some time ago. The builder is not making a mandolin. He's making an arch lute. But his process of making the form and assembling the bowl staves is so well documented you could almost figure it out by looking at his pictures. In addition, the builder seems quite knowledgable about lute family instruments overall. If you correspond with him, he might be able to point you towards the literature you need. Take a look:

www.anzlf.com/viewtopic.php?f=1&t=3611

If the link doesn't work, go to that forum website and click through to page three of the discussions. Scroll down and look for the thread titled "building arch lute." It is a very worthwhile thread.

Patrick

Author:  cphanna [ Sun Feb 05, 2012 1:45 pm ]
Post subject:  Re: neopolitan builder needs direction

Jim, in this thread at mandolin cafe, several resources are mentioned. Also, Graham McDonald demonstrates building a canted top. I am sure you can glean some info from the thread, and the forum members will most likely be able to steer you to any info you need.

http://www.mandolincafe.com/forum/showt ... k+building

Patrick

Author:  Graham McDonald [ Tue Feb 07, 2012 8:49 pm ]
Post subject:  Re: neopolitan builder needs direction

There is little published information building bowlback mandolins. Robert Lundberg wrote an article for American Lutherie in the 90s on canted soundboards on a couple of old neapolitan instruments which is well worth finding. As Patrick mentioned there is a chapter on canted soundboard construction in my mandolin book, but I didn't venture into bowlback body construction. Robert Lundberg's book on lute building has lots of info on staved bodies (on a slightly larger scale) and pulling apart a couple of old bowlback mandolins should give you some idea of how they went together. There are various threads on the Mandolin Cafe which have dealt with various aspects of repairing/restoring bowlbacks and a trawl through those will be of help.

Good luck with your project

graham

Author:  jim daniels [ Thu Feb 23, 2012 2:59 pm ]
Post subject:  Re: neopolitan builder needs direction

I am having trouble with my fret board, fret placement. Could someone explain to me or direct me to a site that explains the 'RULE OF 18' ? I know i can find a fret calculator on line but when i use it my spacing (when i tune at the 1/2 octive fret doesn't look right on my tuner). I really would like to know how to calculate my on fret spaces using the 18 rule. please help? thanks jd

Author:  Chris Oliver [ Thu Feb 23, 2012 3:42 pm ]
Post subject:  Re: neopolitan builder needs direction

Jim,

You can get really deep into the calculations, but, the rule of 18 is pretty simple at face value.

    1. You take the scale length and divide by 18. This gives you the distance from the nut to the first fret.

    2. Now, subtract that distance from the total scale length. Divide that length by 18. This new result is the distance from the first fret to the second fret

    3. Repeat as many times as necessary.

Now, when measuring from fret to fret, for more accuracy, you should measure from the nut to the fret. So... to find the distance of the second, add the two measurements up and measure from the nut.

The rule of 18 has been updated and method has been changed several times. I see that a factor of 17.817 is used as well as special intonations calculated by various engineers.

So as an example:

Scale Length: 25.54"

Code:
1st Fret distance (from nut or zero fret) = 25.54" / 17.817 = 1.4334"

2nd Fret = (25.54 - 1.4334) / 17.817 = (24.1211 / 17.817)  = 1.3538"

Or... 2nd Fret distance from Nut = 2.7872


I hope these are working out... I'm writing these blind here. None of this takes compensation for string thickness here either....

Is the 1/2 octave fret the 6th fret?

Author:  Shaw [ Sun Feb 26, 2012 3:30 am ]
Post subject:  Re: neopolitan builder needs direction

I was going to suggest that you get a set of the plans that Elderly sold for a Wurlitzer tater bug mandolin by H.E. Brown but it appears they don't sell it any more. I bought this a few years ago because I have a couple bowl backs laying around that I wanted to restore for myself but never really found the time. i wanted to see how these things were put together. It's not a bad set of plans. I have tried searching for other sources of this plan but found none. Maybe someone else knows of some plans....Mike

Author:  jim daniels [ Sun Feb 26, 2012 10:39 am ]
Post subject:  Re: neopolitan builder needs direction

Hey Mike Shaw!! I just paid $$ for a broken Bowlback on ebay, would you be interested in selling yours? thanks for the info on the scale. thanks jd.

Author:  cphanna [ Sun Feb 26, 2012 12:47 pm ]
Post subject:  Re: neopolitan builder needs direction

Jim, I thought of you again when I stumbled into this site today:

http://www.the-blueprints.com/blueprint ... struments/

There is a bowlback plan among several others, downloadable in PDF form, and free with a registration and log in. Looks somewhat basic, but perhaps useful to you.

Patrick

Author:  Shaw [ Mon Feb 27, 2012 1:25 am ]
Post subject:  Re: neopolitan builder needs direction

Hey I'm sorry I prefer not to sell them since they are hard to come by and I may need them again in the future....Mike

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