Wednesday, May 18, 2016

Building a Lacôte 7 String

I finished my model of a 7 string Lacôte. Its construction follows the same principles as the six string Lacôte I discussed in four previous posts, the last on March 10, 2013. Navigate through "Older Posts" at the bottom of this page to view these.

I have measurements and photos of several Lacôte 7s and I examined another in detail several years ago. But I wanted to build a guitar that would appeal to guitarists outside the circle of period instrument enthusiasts so I decided to combine features from several guitars. I chose the body of one of Lacôte's décacorde guitars that is in Musée de la musique Paris, E.986.5.1.
E.986.5.1 Musée de la musique

The body is 443mm long, 248mm wide at the upper bout, 180mm at the waist and 310mm at the lower bout. The side rib depth measures 76.5mm at the front and 81mm at the rear. The front of the bridge is 126.5mm from the rear of the body. The rose diameter is 73.5mm and its lower edge is 335mm from the bottom edge of the body.
These were the measurements I made on my visit in 2012 and the ones I used building my model.

 Grant MacNeil, owner of The Twelfth Fret guitar store here in Toronto, has a passion  for romantic era guitars and there are always several in his store. I was fortunate that he offered me the opportunity to examine this rare 7 string string Lacôte before it was sold. The model has a short string length (580mm) and is now in a private collection so I didn't use it for my model. But the peghead is typical of Lacôte's work so it served as a fine example for my replica.

This closeup shows the similarity to Lacôte's  standard 6 string peghead design. He simply expanded it to include a side bracket to house the 7th string.

The original Lacôte tuners are mounted on plated metal strips that have corroded over time. Grant showed me photos of the detached peghead taken during the shop's restoration. The neck stock to peghead joint is a sort of concealed tongue and mortise. This appears only as an horizontal line across the narrowest part of the neck.

Rob Rodgers makes an elegant set of single Lacôte style tuners that were a must for this guitar.

The gears sit in recesses cut into the back of the head stock. The string rollers span the string slots and rest in blind recesses in the center spine. Installing each tuner takes time and accuracy. If I ran a production shop I would make templates and machine mill them. But I make one instrument at a time so I do it all by hand. I carefully laid out the design and used a scroll saw (Excalibur 16) to rough cut the string slots and recesses for each gear.

The sawed slots were clean but I erred on the side of caution and made them all a little too small. They needed to be enlarged and squared. I don't have a bench mounted vise so for jobs like this I improvise. The peghead is clamped to a squared block that is in turn clamped to the table. A second matching block is clamped some distance away. A long sanding stick with sandpaper attached on one face and both edges spans the gap. As long as I move the sanding stick perpendicular to the face of the peghead the finished work will be clean, accurate and square.
The string roller passages are blind, they do not go through the thickness of the peghead like the gear recesses and must be cut with a chisel. They require a lot of attention. The rollers on standard tuners fit snuggly in carefully drilled holes and yet smooth operation can be elusive. Tuner manufacturers even offer rollers with bearings mounted on the ends that fit tightly in the peghead holes but allow the rollers to rotate freely.
Since string tension pulls the rollers up toward the face of the peghead and back towards the nut the rollers have to rest precisely against the top and rear surfaces of their respective passages. Achieving this took some fiddling.  Initially, the passages for the rollers on each side of the string slots had to be cut undersize, slowly enlarged, testing the fit until they all worked smoothly.

Finally, I glued an ebony plate of the face and then opened up the string slots and cut the string ramps.

A matching maple plate conceals the roller ends in the center spine.

The two parts of the V-joint were  cut with the Excalibur scroll saw. Then I spent hours perfecting the fit.

I used Lacôte's iconic multi-piece design for both the rosette and edge purfling. But I added a later era style fingerboard and brought it to the edge of the soundhole increasing the number of frets to 19. Note in the previous photos of the historical guitars that both have short fingerboards with additional frets inlaid in the soundboard.

Twelfth Fret Guitar Shop

 Lacôte's choice of bridge design for his multi-string guitars is interesting. The bridge of the guitar from the Twelfth Fret is truncated. It is a simple rectangular block but otherwise contoured with a raised saddle area with the rear sloping to a thin edge like other Lacôte bridges.

The above is the bridge from Lacôte's décacorde conserved in St. Cecilia's Hall, University of Edinburgh. The tips are broken and the 'eyes' are missing but glue shadows pinpoint the location of the lost features.

I used the décacorde design and re-sized it for my 7 string bridge. Note that I angled the saddle to improve the intonation.

St. Cecilia's Hall University of Edinburgh

I have examined three of Lacôte's décacorde guitars and each time I have been impressed with the practicality and aesthetics of the contours of their necks. All were constructed in mahogany with a smooth transition onto the heel.

The advantage to this design is that the short smooth transition from the neck to heel allows the player easier access to the upper frets.

The entire guitar was finished with French polish, allowed to harden and rubbed out with various compounds.

All photos by the author.


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