drawing up a lute plan - neck width

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geoff-bristol
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drawing up a lute plan - neck width

Post by geoff-bristol » Thu Nov 23, 2017 3:19 am

I am trying to draw up a lute plan - with a view to making one sometime. I am working on a 580 scale - 305mm body width - 6 course - 2 single 4 paired. So a few questions as I got a little stumped with it.

Does 65mm neck width at the body joint seem too wide. I'm working on string spacing at nut of 44 - single to middle paired bass. But what at the bridge ?

What is an acceptable neck thickness at the body joint ? ( Total ) This determines the upper body curve at the joint.

I was going to have the joint at the 9th fret - is this a good idea - or is 8th fine.

My other issue is the radius of the main curve of the body. Its going to be 11 piece - but is that curve a genuine 180 deg half circle across the instrument - or is it just a compond curve to suit ones build ? Is the curve at the neck joint made to suit the neck proflie ?
All this governs the shape of the mould - both crosswise and lengthwise ?

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Michael.N.
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Re: drawing up a lute plan - neck width

Post by Michael.N. » Thu Nov 23, 2017 8:43 am

I think I can answer most of your questions but not at the moment - workshop is going through a major revamp, so all the relevant info isn't immediately to hand.
As for the half circle. You can build to a half circle but I don't think any historical lutes were done that way. Most were a flattened half circle. I think either the Heiber or the Venere comes closest - around 5% flatter than a true half circle.
I think your string spacing at the nut seems to be correct or at least very close. I seem to recall making my vihuela's around 50 - 52 mm nut width so your 65 mm figure will be close too. Don't forget these numbers will vary on historical instruments so there's no one definitive answer, just a range.
I should have the information in under a week.
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Re: drawing up a lute plan - neck width

Post by OldPotter » Thu Nov 23, 2017 9:13 am

PM sent.
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geoff-bristol
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Re: drawing up a lute plan - neck width

Post by geoff-bristol » Thu Nov 23, 2017 8:05 pm

Michael.N. wrote:
Thu Nov 23, 2017 8:43 am
I think I can answer most of your questions but not at the moment - workshop is going through a major revamp, so all the relevant info isn't immediately to hand.
As for the half circle. You can build to a half circle but I don't think any historical lutes were done that way. Most were a flattened half circle. I think either the Heiber or the Venere comes closest - around 5% flatter than a true half circle.
I think your string spacing at the nut seems to be correct or at least very close. I seem to recall making my vihuela's around 50 - 52 mm nut width so your 65 mm figure will be close too. Don't forget these numbers will vary on historical instruments so there's no one definitive answer, just a range.
I should have the information in under a week.
Thanks - it all helps - no rush.
I am also confused over seeing some info on lute fingerboards being radiused ? So how does that work at the top junction ? I have presumed the top to be flat - and even if it was domed it would be very slight - no way similar to a radiused board ?

I have drawn up the neck joint and that seems ok - the angle of the joint helps there.
I have felt the semi circle is a bit tubby - and may appeal to those who want some sort of geometry - but in reality it does not hang together too well like that. Its way easier to make the mould shape to suit what I need - then fit ribs to suit.

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Re: drawing up a lute plan - neck width

Post by Michael.N. » Thu Nov 23, 2017 9:15 pm

Baroque lutes have a radiused fingerboard, renaissance lutes are flat or very minimally radiused - I believe. It's a mighty long time since I did any lute making so I'll have to check that.
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Re: drawing up a lute plan - neck width

Post by simonm » Thu Nov 23, 2017 9:50 pm

Michael.N. wrote:
Thu Nov 23, 2017 9:15 pm
Baroque lutes have a radiused fingerboard, renaissance lutes are flat or very minimally radiused - I believe. It's a mighty long time since I did any lute making so I'll have to check that.
That is what I have always heard. I have only done one lute. A 10 course renaissance type about 30 years ago. Flat fretboard. I considered a Baroque lute with a curved fretboard as being way too advanced for my (lack of ) skill. Various music instrument museums have/had plans available for historical instruments if I recall correctly. And there are some online catalogues with the basic dimensions. I think a few of the UK lute makers might also have some details on line too but I don't have any links bookmarked.

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Re: drawing up a lute plan - neck width

Post by geoff-bristol » Fri Nov 24, 2017 12:20 am

Yes - thats my confusion - Renaissance and Baroque ( big subject if you ever studied the arts ! )

As I gather it after more trawling through cyberspace - flat boards are better 'slightly' domed to make gut frets sit tight. ie flat but not really ! - and the edges need to be well rounded.

I have drawn up a peg box - based on a nut 10mm deep - rebated in to the neck about 5mm. That gives a good turning radius around the corner. Pegboxbox cheeks 18mm deep, 5mm thick. These should just clear the outer strings similar to violin - so pegbox cheeks should be in line to nut/board edge. Peg holes at 12.5 spacing( alternate )
That gives the back of pegbox at just 8mm forward of nut face - which seems ok gap to first fret (that is an awkward area )
Its a pretty skinny box for 11 pegs - but the pull is all in line. Angle is about 95 deg to neck line.

I got good info from the lute Society pages on ' troubleshooting' your lute. Ie - bridge pair gaps, nut pair gaps, action at 8th etc.

For the rosette I have plans for a stronger pair of reading glasses form Lidl :shock:

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Re: drawing up a lute plan - neck width

Post by Ricardo Barros » Fri Nov 24, 2017 8:32 am

Hi Geoff

I very strongly recommend mr David van Edwards course. It comes with very detailed plans and instructions, full of practical tips. I’ve been building a baroque lute sucessfully in the last months with it alone, it is fantastic. This is my first lute, so I am afraid I don’t have much knowledge to share myself.
Sergio Abreu 2012 (sp/ir)
Ricardo Barros 2013 (cd/ir)

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Re: drawing up a lute plan - neck width

Post by Michael.N. » Fri Nov 24, 2017 11:01 am

Yes you need to round the edge and you can give the board the slightest of cambers, otherwise the tied on frets can lift in the centre. Don't use a soft wood for the neck either, cedrela is too soft unless you are going to veneer it. Perhaps something like rock maple or a hard/dense sapele, it will resist the fret gut better although it will still mark a little.
Rosette and bowl making are the difficult parts, at least in achieving very clean looking and confident work. The more you make the easier and faster it becomes. If it's a one off you just have to take your time and do the best that you can. Even if it doesn't turn out stellar it will very likely work as a lute and may even sound extremely good. Whatever we think clean precise work doesn't necessarily mean great sound, nor does work that is a little rough around the edges mean poor sound.
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Re: drawing up a lute plan - neck width

Post by simonm » Fri Nov 24, 2017 3:50 pm

Michael.N. wrote:
Fri Nov 24, 2017 11:01 am
… Don't use a soft wood for the neck either, cedrela is too soft unless you are going to veneer it. Perhaps something like rock maple or a hard/dense sapele, ….
Mine was actually very soft. Poplar. But it is veneered with Anegre which is quite resistant and of course an ebony fretboard. I was told at the time that poplar was a common wood for this purpose historically at least in the German speaking world. It also has a nice big 6" nail in the neck to body joint. Apparently the reason is to prevent the neck destroying the top in the even that the neck joint breaks under string pressure. Apparently also done in things like cello or so I heard.

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Re: drawing up a lute plan - neck width

Post by geoff-bristol » Fri Nov 24, 2017 10:16 pm

Good point on neck and tied frets. I'm planning on figured maple.
I am drawing up a bowl form based on a flattened semicircle. Its lowered by 15mm at the peak height - lessening off toward to both ends on the long arch. The crossection then becomes more of an arch form.
I'll make a rough bowl in hardboard formers on a board - and play about with some stiff card. I can see then where there are any issues.
With a compound curve I may have to use narrower ribs - rather than 11.

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Re: drawing up a lute plan - neck width

Post by Michael.N. » Sat Nov 25, 2017 3:11 pm

It's not so much the number of ribs but the angle of the rib joints. That will change from rib to rib, which it does on rather flattened lute bowls. Lute bowls based on a semi circle don't vary or vary much less from rib to rib, at least that is the theory. In practice you will almost certainly have to continually adjust to obtain good rib joints. It's one of those things that you have to do to get a feel for it.
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Re: drawing up a lute plan - neck width

Post by geoff-bristol » Thu Nov 30, 2017 1:36 am

Michael.N. wrote:
Sat Nov 25, 2017 3:11 pm
It's not so much the number of ribs but the angle of the rib joints. That will change from rib to rib, which it does on rather flattened lute bowls. Lute bowls based on a semi circle don't vary or vary much less from rib to rib, at least that is the theory. In practice you will almost certainly have to continually adjust to obtain good rib joints. It's one of those things that you have to do to get a feel for it.
I have made the mould - and have lined it out to 13 ribs spacings and they seem to align ok. I'll now dress the segments flat.
The long arch is quite flattened ( by 15mm off the half circle full semi ) This radius is not constant - its proportonal to the width of the cross-section.
Also - the model is has the max width quite low down - as I like that shape.

What I cannot really sort out is how to insert the fillets. If I use cypress I would like ebony strings - anything dark its maple.

I have read they should be about 2.5mm x 0.8 - but to bend ebony that shape sideways is a bit iffy. - and little chance I would have thought to bend it on an iron ? How is that going around the end curve of the bowl ?
2.5 x 2 seems a bit fat ? I can make up 2.5mm x 2mm - then bend it - then plane it to 1mm after its bent. Then maybe it could be tacked to the last rib fitted edge - with pins on the frame ? On an open mould and titebond any fillet glued in as the joint is made between two ribs is likely to slip !


The long arch template - and the half profile stood up beside. Divide dinto equal 13 segments by divider. Lines seem fair - and can be tweaked when I flatten the segments. The base board is part of the mould ( I have to modify the front block arrangement) I sanded it fair in the end with a 'strap' of 80 grit !


lute-1-rough.jpg
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Re: drawing up a lute plan - neck width

Post by simonm » Thu Nov 30, 2017 8:42 am

Do you recall this documentary? Worth a look. I don't recall everything that is in it but it is certainly worth looking at.
Michael.N. wrote:
Sun Jan 29, 2017 8:41 pm
That would be this:

https://vimeo.com/50766784

I didn't have that planing jig when I made my renaissance lute bowls. I just used my largest plane mounted in the vice. I can understand how that jig would make things a little easier though.

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Re: drawing up a lute plan - neck width

Post by Michael.N. » Thu Nov 30, 2017 8:47 am

Firstly I ain't no expert on lute making! and what little lute making that I've done has to reflect back almost 20 years.
Of course your spacer has to be taken into account on the width of the rib -0.8 mm doesn't seem much but after 3 ribs you are 2.5 mm too wide. Rib structures can quickly get out of hand if you aren't careful. I only used a black spacer on my second bowl but I'm not sure if it was ebony. I think I may have dyed some pearwood but to be honest I really can't remember for sure. 0.8 mm sounds about right. The technique that is used to bend the spacer is to cut a slot in a solid bending iron, kind of a rounded/convex bottom to that slot. I used a hacksaw which gave me just enough clearance for the spacer. It's this slot that supports the spacer and helps to prevent it from twisting.
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