Monday, 10 August 2020

Building a 13 Course Lute, Start to Finish, 21: Fitting and Shaping the Bass Rider; Gluing in the Peg Box

Hello friends--welcome back to the ongoing tale of a 13 course lute. In our last episode, I fitted the pegbox, and glued and carved-in the chanterelle tuner. Today, I shall finish the pegbox installation by making, fitting and carving the bass rider, and then gluing the completed peg box into the neck.

I make the bass rider of quarter-sawn pear, the same material that I've used for the peg box and the chanterelle tuner. The piece I've selected is a couple of millimetres thicker than the finished dimension. There's enough material in this piece for two bass riders, so I'll trace them out back-to-back and rough in both at the same time.

My template has locations for peg holes and for some larger radii within the pattern that I will drill out with forstner bits.

I've screwed my blank down to a backing plate for a couple of reasons. First, I have to be able to drill through the material and into something beneath, so that the drill won't splinter out the backside of the piece. Second, I want to be able to clamp and hold the piece securely so it doesn't become a nasty out-of-control helicopter when I start drilling (I've seen it happen.)

The backing board is clamped securely to the drill press table.

The pear is pretty tough material, and there's a lot of thickness to get through. To ease the stress on both the drill press and the bit, I take small cuts and lift the bit up frequently, and rub wax on the sides of the bit.

With all the peg holes and radii drilled, I use a coping saw to remove material from the teardrop cutout.

Then I can cut out one of the blanks on the band saw, and get to work shaping it in the swivel vise. I use a chisel to shape most of the outer profile, cutting in from both sides across the width of the piece. For the cutout, I use knives and a small gouge. 

The overall shape looks pretty good for now. I've used my template to mark the approximate depth of the inside of the pegbox, and the approximate contours of the sides and foot.

Now it's time to fit up the peg box temporarily, and see how the bass rider should align on it. This is my basic gluing rig for peg boxes (you'll see it in action when I glue the peg box at the end of this post.)
I have a fairly good idea of how the bass rider fits on the peg box of the original Schelle lute in Paris, since I'm working with some very nice photographs of that instrument taken by Grant Tomlinson (as you'll see below.) However, I still need to clamp it to the peg box and stretch a string from the bridge to check its alignment, in both the horizontal and vertical axes, and adjust the position as needed.
One of the great advantages of the Schelle peg box-bass rider combination is that, unlike other peg box-bass rider pairs of the era, this one does not slope to the side. Instead, because the peg box is made over-wide and extends out the bass side about 10mm, the bass rider sits in direct alignment with the bass side peg box cheek, and there is virtually no torque being applied by the 12th and 13th course strings. In my experience it's a much more stable arrangement than some other examples I can name--one being the 13c Burkholtzer in the Vienna KHM. I've never personally examined the Burkholtzer lute, but from the photos below I get the impression that the bass rider may have drifted outward somewhat over the years.

Photo by Robert Lundberg, JLSA XXXII, 1999, p.42

Photo by Stephen Gottlieb, courtesy Grant Tomlinson
Perhaps I'm wrong and it hasn't moved a hair since it was built, but in any case it seems to me that such an arrangement is very vulnerable, an accident waiting to happen. Such an accident did, in fact, happen to an instrument based on the Burkholtzer belonging to a friend of mine, and he sent it to me to fix. My repair involved figuring out a way of removing the bass rider's tilt and straightening it out to improve its strength, somewhat like the Schelle bass rider. You can read about my solution to the problem here:  A Bass Rider Fix, For Nelson. 

Back to the task at hand. With the bass rider clamped to the peg box and aligned carefully, I am able to mark out locations both on the peg box cheek and the bottom of the bass rider. Then I can lay out the basic contours of the cheeks, and start carving out the recess.

I set up the rider in a portable vise in the drill press, and drill a number of holes to a certain depth.

I remove most of the material with gouges.

Eventually I can work with small flat chisels to square up the sides and bottom.

I also cut and file a small channel, into which the nut will eventually be fit.

Then I remove as much excess material as possible, with flat chisels, gouges and knives. (It's much easier to do in the vise than after it's glued onto the peg box!)  
The small violinmaker's knife with a curved blade allows for very good control when removing material. (Notice the little piece of dowel, which makes the bass rider a lot easier to hold in the vise.)

There's my working shape--I've still got a ways to go, but I think it's good for gluing in.

Fitting the bass rider into the peg box is a lot like fitting the chanterelle tuner, which I described in last week's episode: the slot is about 2.5mm deep, with the front edge square to the cheek, and the back edge angled slightly. I have chiseled out this area by hand, but will run over it with my dremel router and then clean it up with files and a chisel. (The block of wood inside the peg box provides a flat surface for the router to ride on.)

With the channel cut and the rider fitted into it, I can check the alignment one more time before gluing up.

Here's my nylon fishing line stretched from the position of the 12th course octave on the bridge. I know how far away I want that string to be from the 11th course bass string, and I know how high I want it to be in relation to the nut slot on the rider. This alignment looks good to me--I'm going to heat up my glue, and get this bass rider glued into the peg box.

Here are all the pieces. Along with three c-clamps, I've got a small piece of spruce to protect the front of the foot, and a small shaped caul that fits in the back end of the rider. There's also a thick piece of spruce on the back of the peg box, to protect it during clamping.

The length of the foot means that unlike the chanterelle tuner, the bass rider needs to be clamped in place.

When the glue has dried and I've cleared the excess away next morning, I can carve the piece in. I hold it on a piece of leather in my lap and work mainly with the small, curved-blade violinmaker's knife across the grain. 

I like the textured surface I get with that knife--it allows me to see the developing shape pretty clearly, and I can get a good overall form before moving on to finishing tools.
The tools I use for that part of the process are a set of Japanese finger rasps from Lee Valley Tools; fine files; and small curved scrapers.
I like the finger rasps--they cut well but aren't too aggressive, and leave a nice surface that can be finished with scrapers.

Here's my result: I think it's an elegant shape. The front leg needs to balance lightness with strength, as do the cheeks, and the width of the rider must gracefully taper to width of the peg box cheek into which it's glued. In addition, that teardrop cutaway wants elegant curves and well-chamfered edges (and I quite like the way it mimics, a little, the shape of the chanterelle tuner on the far side of the peg box.)
It's a lot of fun to sit down and carve something like this, and actually figure out the shape of the thing by doing it. It's a process of continual discovery, a period of intense looking and observing--turning the thing in your hands, adjusting the light source, seeing how the curves and recurves work and evolve, trying to get a sense of the overall visual and physical balance. It's a very satisfying experience, one of the most satisfying of my whole lute making practice.

Of course, I'm greatly assisted in this work by the set of photographs I have of the Paris Schelle, some of which you see in the photo above. These were taken by Grant Tomlinson on one of his European research trips in the 1970s and 1980s. It's been my privilege throughout my professional career as a lute maker to have had ready access to Grant's entire collection of his photographs of historical lutes. I've also benefitted immensely by having access to the notes Grant wrote on those trips for all the lutes that he examined. He looked at instruments in museum collections in England, France, Italy, Germany, Belgium; dozens and dozens of instruments altogether, a real treasure trove of information. Many of the dimensions of the lute I'm telling you about building were adapted from measurements that Grant took in his travels. And, of course, the photos are extremely helpful in puzzling out shapes and details. I owe Grant a ton; I owe Grant a house.

Let me ask you a question. After reading that last paragraph, are you not the least bit jealous of me, and the access I've had to all this wonderful information about historical lutes?

Well, you needn't be. At least, you'll only have to be jealous of me for a little while longer. A few years ago, Grant approached the Lute Society of America and offered to give it his archive: hundreds of photos, and hundreds of pages of hand-written notes, on dozens and dozens of historical lutes. The LSA accepted, and for a few years now, Grant and Phil Rukavina, the LSA's web master, have been toiling away at scanning the pages of Grant's notebook, digitizing photo negatives (many of which had never been printed before), and getting the results up online. I know that it's been a great deal of work, for both of them, and I know that not quite all the work is done yet. However... a little bird has told me that the work is finally nearing completion, and in a little while, the whole world of lute makers will have access to this invaluable resource. I don't yet have a date, but when the launch happens, I will let you know. So please stay tuned.

But enough talk! Back to lute making. What's left to do is get this peg box, with all its encrustations, onto the neck of the lute.

I've sized a number of times, with hot glue size, the base of the peg box, and the rebate for the peg box in the neck of the lute. When that size has dried--next morning--I re-flatten the peg box and re-fit it in the rebate. 
My final fit. I'll warm up my glue, and get set up.

Here's my peg box gluing jig: just a piece of ply with cork lining the underside, and an angled block screwed on. I use the jig for pretty much all my peg box gluing jobs--depending on the lute, I'll swap out the block for one with a different angle. I also need to adjust the distance of the block from the end of the neck, again, depending on the lute.

This is pretty much the whole set-up. Four cam clamps on the back end of the jig, one up near the peg box rebate. That should be enough clamping pressure to keep the thing from pulling forward when I glue in the peg box and put clamps on it.

One feature I might draw your attention to here is the pair of wedges I've placed between the edges of the jig and the edges of the neck. I need them because of the fingerboard's rather extreme curvature. (If I use this jig on a renaissance lute, the flatter fingerboard means I don't need the wedges.) 

This is the basic posture of the instrument when I glue on the peg box--belly-down on the bench pad, propped up on the stems of the cam clamps. By the time I get the peg box on and a couple of ratchet clamps in place, the lute will be a little end-heavy. I've found that the best way to keep it from tipping over--and at the same time protect the lute from any mishap--is just to lay on pieces of fabric. I have a green velvet piece on the back, topped with a folded sheet of heavy green fabric (which I once used for a photo backdrop.) I'll probably put some towels on top of that too, just to be on the safe side.

To locate the peg box for gluing, I hold it accurately in place and press a piece of 1/2" masking tape over the front of the joint, from the bottom block of the peg box down onto the end of the neck. I will then take a small, sharp knife and cut that piece of masking tape in two, exactly at the joint. When I glue up, I will be able to align the peg box by aligning the edges of the bisected piece of tape.

This is one of the dry runs I do to work out details before gluing up. In a minute, I'll take of the clamps, then check my glue. If it's hot and the right consistency, I'll heat both the peg box base and the rebate with the hair dryer, then brush hot glue on both. Quickly but calmly I'll place the peg box in the rebate, and rub it side to side ever so slightly, bringing the locator tapes into exact alignment. Then I'll place one cam clamp, and snug it, then the other, and then snug both. And that will be that. 

I look for good glue squeeze-out all around the joint. I will also paint some hot glue around all the edges of the joint, so that the glue, as it cools and contracts, will help to pull the two sides of the joint together. (I've used this technique many times during construction; see, for instance, gluing on the neck, in episode 4.)

I think the fitting and gluing went very well, and I'm looking forward to coming in tomorrow morning, cleaning up the excess glue, and seeing how things look. There are a few more little jobs to do before finishing out the peg box and neck, and I will tell you all about them next time. 

Monday, 3 August 2020

Building a 13 Course Lute, Start to Finish, 20: Fitting the Peg Box, Making the Treble Rider

Hello friends, and welcome back to the 13 course chronicle. In today's installment, I want to describe a couple of operations: measuring out and cutting the rebate for the peg box, and fitting the peg box into it; and making the chanterelle tuner, and fitting, gluing, and carving it in place. I had imagined that I would also talk about fitting and gluing the bass rider, and then gluing the peg box onto the lute, but I think that's a little much to bite off for one blog post. I'll save those tasty bits for next time.

Just to catch you up, I've made the basic peg box and veneered it with ebony, front and back. I have also, by now, completed the varnishing of the lute back. It took four coats of varnish, and it looks great. (You'll get a glimpse or two of it in this post, but I'll show you some nice pics of it a little later on.) So now it's time to put lute and peg box together, and start bringing this instrument down the home stretch.

The first order of business is to confirm the string length of the lute, and mark the neck cut-off. From the very beginning of work on this lute--as far back as my original working drawing--I have allowed for an extra 5mm of length on the neck. This was meant as a bit of insurance against mishap, and against neck length lost in fitting and re-fitting to the body. Now I can remove all the excess length that remains.

I mark out the string length, and the width of the nut, with a long ruler.

I also measure and mark an accurate centreline on the neck, and from this draw perpendicular lines at those points. Because the neck surface is distinctly curved, it's difficult to use a flat square to mark them out. Instead, I use this piece of mylar with a centreline and squared end.

Now I can make the cutoff, which I do free-hand. My weapon of choice for this operation is a 'gent's saw' from Veritas, with a lot of wax rubbed on the blade. 

One useful consequence of having to make this cutoff is that I get an accurate record of the thickness and curves of the neck and fingerboard of this lute. I'll file this one away in a box with all the others, and use it for future reference. (All necks and fingerboards work out a little differently in practice, no matter what you plan. I think this particular neck/ fingerboard is going to be quite comfortable, and I will refer to it for future instruments.)
I trim up the end of the neck with a low-angle block plane (taking very fine cuts, and stroking inward from each side), and files. Then I can start laying out the peg box rebate.

All the measurements for the rebate are taken from my working drawing. I first mark the neck thickness that I want, shown by the line drawn across the neck. I extend this line up the sides of the neck with the marking gauge.

I then 'tilt' those lines up the side slightly by eye, and mark them with a straight edge. For the back line, I mark the width of the rebate at three points--the centre of the neck, and at each side of the rebate. I then connect the three points by drawing a line with a flexible curve.
By the way, I don't treat these lines as gospel, but as guides. No matter how beautiful my working drawing is, the actual lute neck and peg box will vary slightly from it. I leave a fair amount of room for adjustment, then when fitting work toward the lines using the peg box itself as my ultimate guide.

With layout complete, I can clamp the lute neck securely to the bench edge. I use a spacer to raise the neck slightly off the bench, so that the belly doesn't rest on the bench (the green pad beneath it is there as a precaution.) There's a piece of leather between the fingerboard and the spacer piece, which prevents slippage, and protects the neck against marring during the fitting-up process. 

I use the gent's saw again, and make the cut at the back of the rebate first.

I then make a series of cuts to facilitate the removal of material in the rebate.

A 1" chisel, held close to the tip for good control, works well for removing the excess.
The same chisel works well for flattening the bottom of the rebate.

The peg box itself is the ultimate reference in fitting this joint, so I need to prepare it carefully. I first must flatten the back surface so that it's completely flat--especially in the bottom 10 mm or so, which will fit into the rebate.

I must also flatten the bottom of the peg box, having first made the angled cut-off with the band saw. (The angle is taken from the working drawing.) I use files and sanding blocks to get the surface I want, and I check the flatness with an engineer's square.
[Edit August 6:]

I feel I must pause here, and open up a small can of worms. If you have been following this blog series closely, you will recall that in an earlier episode--episode 8, to be specific-- I described the process of planing a small slope or 'twist' in the upper neck surface. This operation was one of the jobs I did immediately before fitting the belly into the body, and the effect was to lower the action of the treble side of the string band in relation to the bass side. As I mentioned then, this technique is one of the keys to making an instrument with a very low and comfortable action; it's also something that I needed to take account of and plan carefully for, all the way back to the beginning of designing and making a working drawing of the instrument.

Well, here is another place in the building process where I need to take account of this 'twist.' Since the treble side of the neck, at the nut end, is now about 1mm lower than the bass side in relation to the body, if I fit up my peg box perpendicular to the neck (viewed from the nut end of the lute), it's not going line up with the middle rib of the lute. Instead, it will lean a little askew, to the bass side. Maybe that doesn't seem like a big deal, but with a long peg box like this one, the effect could be a little jarring. I compensate for it by tilting the cut-off of the bottom of the peg box slightly, making the bass side of the box about 1mm longer than the treble side. That straightens the peg box up in relation to the body. It's not hard to do, and it doesn't make fitting the peg box in the rebate any more difficult, so I just do it--not only for 13 course lutes, but for every lute I make (because I use the fingerboard 'twist,' to a greater or lesser degree, on every model of lute in my repertoire.)

Is that clear?

[End of edit.]
During the process, the back corner edge of the peg box becomes very sharp. Since I know that my rebate can never be made that sharply, I want to relieve this edge slightly, which I do with a stroke or two of a very fine file.

With the peg box accurately shaped, with very flat surfaces on the back and bottom, I can get to work finalizing the rebate. These are the main tools of the trade: bevel-edged plexiglass sanding blocks. 
I generally work on the bottom of the rebate first, coming down close to the lines I've drawn. I can check the flatness of the bottom surface with the engineer's square, but the best check is to hold the peg box in place, and look for gaps at edges and corners. I can also press the peg box down, especially at the outer edges, to see if I can feel any rocking. It should go without saying that by the time I've finished fitting the joint, there should be no rocking at all, and the peg box should be completely solid.

With the bottom of the joint very close, I can pay more attention to the back side of the rebate. I check for flatness by pressing the peg box into the joint at the corners--if I see any side-to-side rocking at all, I know I've got work to do to flatten the back of the rebate.

One spot where the peg box can be held out is along the very back corner of the rebate. I clear this corner with sharp chisel and knife.

While I'm fitting the joint, I also want to keep an eye on the peg box angle. It doesn't particularly matter if the peg box angle matches exactly the angle that I've made on my working drawing. However, a few months back I made a case drawing from that working drawing, and it would be best if the lute conformed to that drawing as much as possible. I would hate to make a lute that didn't fit in its case! 

There's my fit, and it is as tight as I can make it. I have a few operations to do before I glue the peg box on, and I will eventually size the joint (both the peg box and rebate surfaces) and re-fit it, but for now this looks very good. I can finalize the dimensions of the peg box, and start fitting my chanterelle rider and bass rider. 
By the way, don't be alarmed that the peg box looks a lot wider than the neck rebate--that extra width is on purpose. The treble side of the peg box fits flush in the rebate, while there is about 10mm or so of overhang on the bass side. You will see the reason for this in my next installment.

My working drawing tells me what the final width of the peg box should be, and I can now plane the peg box cheeks down close to those final dimensions. However, as with the other parts of this fitting operation, those dimensions are ideal, and must be set aside in favour of the dimensions as I find them on the lute. So, I plane the bass and treble peg box cheeks alternately, keeping their dimensions as close to identical as possible, but I keep my eye on the developing fit of the treble side of the peg box in its rebate.

I use my planing box and low-angle block plane to trim the sides.

Here's the fit that I'm looking at. I want the angle of the peg box cheek that I'm planing to fit the edge of the rebate as closely as possible. I (and I hope you) can see just the smallest bit of the bottom of the rebate in this photo. It's a pretty close fit, though I might just take one plane stroke on the outer edge of the peg box cheek (the left side of the cheek, as we view it) to bring it a touch closer to flush. Then I will check it one more time, and then (I hope) call it a final fit.
With the peg box now at its final dimensions, I can start fitting up some attachments and doing some final shaping inside the peg box. First attachment is the chanterelle tuner.

I cut blanks from a piece of quarter sawn pear.

After cutting out and shaping at the bench, I mark the cheeks and take the piece to the band saw.

The photo's a bit out of focus, but you get the idea: wedges tilt the piece so I can do the cutout at the correct angle.

Then I can finish shaping the piece with files in the swivel vise. As you see, I've relieved the inside corners with a small file. (I do it at this stage, because it will be much more difficult to do once the tuner is glued into the peg box.) The little dart at the back edge is a feature I use for pretty much all the chanterelle tuners I make. It's derived from the Schelle bass rider (which you'll see next episode), but I think it gives a nice finished shape to the chanterelle tuner too. 

These are my marks for the chanterelle tuner rebate. The front line is perpendicular to the peg box cheek, while the back line is at about a 10° angle.

With the chanterelle tuner's location marked, I can carve in the bottom block, using a pair of skew chisels. (A little water brushed on the block makes this carving a lot easier.)

I cut these lines for the rebate flared at a slight angle outwards. You can't see in this photo, but I've drawn a line with my marking gauge at a depth of 2.5mm, which will be the depth of the rebate.

I remove most of the material with my dremel router base.

However, I still need to finish the rebate with chisels and files.

I'm about to start fitting the chanterelle tuner into the rebate. What I'm doing here is marking the bottom of the tuner, for reference, with a series of lines at the same angle as the back edge of my rebate.

I then fit the tuner by trimming the back edge, with my low angle block plane set very close. I follow the reference lines, and tilt the plane slightly to get the correct compound angle at the back edge.

I proceed very carefully, checking the fit often. The front edge is at 90°, so I don't have to worry about that. The angled back edge is the only one I trim.

It's easy to see how the fit is developing, and which angles need adjusting.

Almost there.

There it is: the fit is nice and snug. The tuner overhangs about 1mm inside the peg box.

Now that that's fitted, I can do a last little bit of carving inside the peg box: a little bird's mouth in front of the chanterelle tuner.

And now that the peg box cheeks are at their final dimensions, I can fit an ebony veneer cap at the tip of the peg box.

A bit out of focus, but nice and flat.

I glue this piece on at the same time as I glue on the chanterelle tuner. The veneer is slightly larger than the peg box tip, and I've backed it with a piece of plexiglass.

I put hot hide glue on it, stick it in place, and hold it there for a few minutes to let the glue set.

Then I start putting pieces of tape on it, with light pressure at first, then longer pieces with a stronger pull.

That should be plenty of clamping pressure. 

And here is my gluing rig for the chanterelle tuner. Actually, this is the very first time I've ever used a shaped caul like this to glue in this piece. I'm not sure why--maybe it was because I knew I'd be blogging about this, and wanted to glue it 'properly.' But to tell the truth, I don't think it needs this. I usually just put glue on both surfaces, and slip the tuner in place. The compound angles at the ends of the rebate provide excellent clamping pressure, and the tuner will not move. (It will also never come out of its place on the finished instrument, unless there's a sledgehammer involved.)

Next day: trimming veneer. I do this with my low angle block plane, which works well even on end grain, which is what I have here. However, I must dock the corner (with a chisel) first, or the plane will tear away the side of the veneer.

That's my result with the block plane--all that's left is to make flush with files.

Like so.

And here's my chanterelle tuner, with excess glue removed, awaiting in-carving. I've sketched a few lines to guide my shaping.

It's not the easiest piece to hold--I brace it up against the bench edge with a piece of leather to guard against marring or denting corners or edges. I do most of my work with a small, curved knife blade, cutting across the grain.
I also use fine files, and a number of small scrapers that I've made from x-acto blades. The curved scrapers are most useful for this job.

Here are some views of my final shape on the chanterelle tuner.

It's a rather complex shape to make, and it's large enough that there's a danger of ungainliness if it's not done right. I try to get my lines smooth and a little stout, I would say; I don't want them to be weak. 

The final shape of the outside of the tuner is not based on an historical lute, but is of my own design. I shape it to recall the nazar, the 'evil eye' charm that one sees in many middle eastern and south asian countries, which I first encountered on a trip to Istanbul many years ago.

And that is all for today. Next time: the bass rider, and gluing the peg box in place.