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After getting inspired by Michael Colbert's nylon crossover build I'm starting one of my own. Mine will be based on a Ramirez using the LMI plans. Body will be the Ramirez shape with a 650mm (25.59") scale. Neck will be 13 fret with 1 13/16" nut and a dovetail. That should put the saddle within 0.2" of the location on the plans which were originally drawn for a 663mm scale.

My first question is how to handle saddle compensation. Based on Liutaio Mottola's calculator a straight line compensation would add 0.064" to the hi E and 0.055" at the low E with the G string getting some extra out to about 0.101". Do these numbers sound ok?

I need to finalize the compensation numbers so I can finish the layout.

I've never built a classical so I would very much appreciate your comments. Thanks!

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Steve Smith
"Music is what feelings sound like"

Classicals normally have a 12 fret to body neck. Shortening the scale length would move the saddle closer to the soundhole, and making it 13 frets to the body would move it even closer to the soundhole.
Ramirez did do some unusual designs - did he have one with a 14 fret to body model?

These values are in the range. I am not quite sure how the straight saddle is calculated. I just look at the individual string compensation. I place a straight perpendicular 3 mm saddle with 1 mm of compensation. ( about .040 to .120" range of compensation). If I have nut compensation I place it with less compensation as the high E can be right on the leading edge.

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http://www.Harvestmoonguitars.com

Clay, the plan I have is a 12 fret 663mm. I calculated the saddle position for for 12 &13 fret joins on the 650mm scale and the 13 fret put the saddle closer to the original position in the plans. I used steel string compensation numbers though so I will have to go back and redo it for sure so I get it as close as possible.

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Steve Smith
"Music is what feelings sound like"

John, I have no idea how Mr Motolla calculates the compensation but it seems to line up well with what you are doing. I will copy that if you don’t mind, it seem nice and straightforward.

On steel strings I leave the saddle flat and then use a piece of string on top to find the best intonation point for each individual string. Do you do something similar for the classical?

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Steve Smith
"Music is what feelings sound like"

Yes I use a bit of a high E steel string to find the intonation point.

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http://www.Harvestmoonguitars.com

Perfect, thanks!

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Steve Smith
"Music is what feelings sound like"

Hi Steve,
What I am coming up with is that changing the scale length from 663mm to 650mm moves the saddle position about 6.5mm closer to the soundhole, and going from a 12 fret neck to a 13 fret neck moves it about 18.24mm (the distance between the 12th and 13th fret) closer again to the soundhole, changing the saddle position to about an inch closer to the soundhole than the original plan.
I didn't calculate the compensation, but that is usually a fairly small amount for nylon strings.

I could be wrong, and will be happy to have explained the error of my ways.

Hey Clay, thanks for looking at that. My first calculations where just quick scribbles so I very well may have got it wrong. Now that I have good compensation numbers I’ll do through it carefully today and report back.

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Steve Smith
"Music is what feelings sound like"

Clay is correct that moving from a 12 fret to a 13 fret moves the bridge toward the sound hole. The shorter scale does as well. When I made 14 fret body join instruments I increased the scale length to mitigate the movement of the bridge somewhat.

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http://www.Harvestmoonguitars.com

I have completed 2 Nylon crossovers and used Greg Byers writings and symposium articles as reference. He has a drawing in this http://byersguitars.com/intonation/ that is real close to where I ended up. Did not need to work the nut other than removing length from the nut to 1st fret. I spent a lot of time searching the web and on the 1st used a 3/16" saddle but on second only 1/8" and on both the contact points of each string were well within the width of the saddle.

Fred

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

When Martin went to a 14 fret neck they "pushed" the upper bout down. No reason you couldn't do that on a nylon string crossover.
When Gibson went to a 14 or 13 fret neck on some models they just moved the bridge - that works too.

Soundholes and bridges have been moved around by the Major players without too much "Disturbance of the Force", so I don't fret about them too much.

What exactly is a nylon crossover?

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Hutch

Get the heck off the couch and go build a guitar!!!!

Thanks Clay, John. I had just done a different design and messed up these numbers. Interestingly, scaling off the plans (I know ) shows the Ramirez with about 0.040" compensation to the front of the saddle with a slight increase on the bass side.

The result of a scale change from 663mm (26.125") to 650mm (25.59") and maintaining a 12 fret body join will move the saddle 0.27" closer to the sound hole, not a big deal. As you stated a 13 fret join increases that to 0.98".

Thanks Clay, good catch and 12 fret join it is.

In the past I would just put some numbers on paper and go but I've been bitten more than once (last time resulted in making a new neck) so about 5 years ago I started doing a quick drawing just to be sure I've got the dimensions correct. I did one for this one this morning, I'll use it for a few other things like number of frets and overall fretboard length - important because I order fretboards from Andy Birko (I like his faux bound boards a lot!).

Here's a shot of the drawing I made.

_________________
Steve Smith
"Music is what feelings sound like"

Fred, thanks for the info and the link, it was worth reading.

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Steve Smith
"Music is what feelings sound like"

I have not noticed any benefit to angling the saddle on any of the nylon string guitars I have made. I started using an angled saddle at some point, noticed no benefit, and now just use a regular straight one again.

I like to move the nut forward a very fine bit and compensate the saddle by moving it back about 2mm. I don't think that being a crossover guitar has anything different than a regular classical guitar.

It is a classical guitar that 'crosses over' to a steel string guitar. IOW a nylon string guitar that has string spacing more like a steal string guitar, arched fretboard and saddle like a steel string but braced like a Spanish guitar.

It's basically a nylon string guitar for people more comfortable playing a steel string set up guitar. I made one once and frankly found it to be rather useless. I don't mean to sound disparaging, it was useless to me, but many people like them.

One thing I did do was make a reverse crossover and I found that to be more useful. So that is a steel string guitar with classical guitar string spacing's. Sounds great with a capo playing 17th century lute music

You're welcome Steve,
I build a lot of unusual instruments, and they become even more unusual when I mess up the numbers!

Ha ha - for sure. I still have that neck I messed up in the shop, maybe someday I can use it but it was cut too short for a size 5 so would probably have to be a uke.

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Steve Smith
"Music is what feelings sound like"

I agree with the description but would add emphasis on "more" "has string spacing more like a steal string guitar." I play both steel string and nylon string guitars everyday. I thought a nylon string with steel string spacing at the nut would be no problem. I find it very tight at 48 mm and my own choice would be 50 mm. My flamenco and classical default is 52 mm. I have no idea why 48 mm at the nut for nylon feels that way given that I am comfortable with 1 3/4" on a steel string. I picked 48 mm as it is basically 1 7/8" nut.

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http://www.Harvestmoonguitars.com

Hi John,
You might try stringing the 48mm with gut strings instead of nylon. Gut seems a little less "whippy" than nylon to me. Gut is more expensive and wears out quicker, but it does work better on some older style instruments.

Looks like we're getting a consensus on the compensation.

JF, What do you consider a 'very fine bit' for the nut compensation? At one point I used to cut about 0.050" off of mysteel string fretboards to compensate the nut.

Interesting that you found the crossover to be a bit useless, I hope that's not the case for me but if it is I'll just sell it. My issue is I need play nylon string parts occasionally, I have no trouble learning the parts and hitting notes on my steel string but I find a classical guitar fretboard just feels really awkward. My hope is that I can just play the parts on this one with no issues.

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Steve Smith
"Music is what feelings sound like"

You guys got me thinking about the nut width. I usually play a 1 3/4" and I do a lot of thumb over for some bass notes as well as chords like F2. I had been thinking to use a 1 13/16" (46mm) spacing at the nut but based on the comments above perhaps I should consider 1 7/8" (47.6mm)? I would have trouble going much larger. I also see that several of the manufactured cross-overs use a 1 7/8" nut.

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Steve Smith
"Music is what feelings sound like"

I would be interested as well to hear what others have experienced, especially those who almost exclusively play steel string. My experience surprised me, but I play both steel string and nylon everyday. It could be when my fingers feel the nylon strings they default to my nylon string programing.

Sorry about me switching back and forth Imperial/metric. All my nylon string knowledge is in metric all my steel string is imperial fraction and to make matters worse when I work on my milling machine I work imperial decimal.

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http://www.Harvestmoonguitars.com

Nylon strings carry lower tension than steel. They need to be higher off the fingerboard to allow for greater amplitude to produce a strong sound. Also, being slacker and having a lower Young's modulus than steel, nylon strings are easier to move sideways. All of this means that you have to allow more space between the strings for fingers. Every time I've made a 'crossover' nylon string with a nut much narrower than 1-7/8" they've come back shortly after getting it to ask if there was some way to make it wider. There is, but you don't want to go there. If the neck is wide at the nut you can cut a new one with the strings closer together and pushed toward the treble side. When you figure out what works based on some experience you can then carve the neckdown fairly easily.

Steel is pretty much steel, and most of the differences in saddle compensation between sets of steel strings are related to the action height (higher = more), string length (shorter = more), and variations in the construction of the basses, so far as I can tell. 'Nylon', like 'wood' is a name we use for a class of similar materials, which can vary from one to another as much as different species of wood can. Different brands of nylon strings can require far different compensation. Ideally you'd want compensate both ends of the string; the nut and the saddle. The guitar itself can also alter the needed compensation, depending on how the resonances of the air and the top line up with played pitches, and that's true of both steel and nylon string guitars, but it much more true of nylons, since they're more lightly built.