More Plowden Progress

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More Plowden Progress

Graduation

Graduating hard maple can be a tough, laborious job. Besides, there is always the possibility of carving too deeply and ruining the plate. So, I try to cut the risks by creating a “map” by marking the thickness every few centimeters, and then carving the “dots” until each “dot” is about the thickness I want. Finally, I connect the “dots”, using planes and scrapers, checking for thickness as I progress.

Creating the dots. The circled numbers are already the correct thicknesses.

Grafted Scroll and Neck-Set

Once the graduations are complete, and the inside of the back plate has been scraped completely smooth, I install the label and I am almost ready to close the corpus. In this case, however, I also had decided to use the scroll I had carved, but graft a new neck to the scroll, as the original neck was too thin: so there was a good deal more work involved. Here is the grafted neck, partially shaped, with the completed back plate:

Completed back plate with neck-grafted scroll. The heel was still not shaped.

I had been anxious to complete the back plate, and had not yet set the neck. So I completed the neck and installed the fingerboard.

Next I set the neck, so that the angles were all correct.

Neck-set, front view. The mold is still in place.

Neck-set, side view. Notice that the neck heel has not been trimmed flush, yet.

Closing the Corpus

Then I removed the mold, and installed the inside linings on the back edge of the ribs, shaped the linings and the blocks, flattened the back of the garland, and installed the back plate. I use spool clamps and a single large spring-clamp to close the corpus. My wife thinks the spool-clamps look like old-fashioned hair-curlers.

Closed corpus with spool clamps and a spring-clamp.

Trimming the Button and Neck Heel

Once the glue was dry, I removed all the clamps, cleaned off any glue that had squeezed out of the joint, and trimmed the button and heel. The dimension from the juncture of the top edge of the front plate and the side of the neck heel (from each side) to the very center of the curve of the heel, should be right at 26 mm. You can see the two marks I laid out with a compass, testing that distance: it was still a little too high in the center of the curve, so the neck needed to be trimmed a little more.

Purfling the Back Plate

Once the neck-heel and button were trimmed, I still had to perfect the outline of the back plate, making certain that the overhang was even all around, as much as possible. Then I laid out the purfling slot, using a purfling marker, and began incising the outlines of the slot.

Incised purfling slot. It will be corrected, and fine-tuned as I work, and look good with the purfling.

Next I cut the slot out, using a small knife and a purfling pick, then dry-fit the purfling, after bending it on the bending iron. Finally I glue it in place, using hot hide-glue.

Edge-Work

I marked a crest-line, about 1.6 mm in from the outer edge, then used a gouge and scrapers to carve the channel, and fair it into the plate surface. The edges were all still quite rough,and crude, so I began shaping them, using a small plane, and a half-round file, then sandpaper to get a smooth edge all around. I don’t use sandpaper much, but this is one place where it is appropriate.

Trimmed purfling, smoothed channel, and edges taking shape.

The front edges have to be finalized as well.

Finishing Process Begun

Once all the varnish preparation is complete, I brush a coat of coffee all over the instrument, to tan the wood a little, and raise the grain. When that is dry, I sand off most of the raised grain, using 400-grit sandpaper. This ensures that the grain will not raise too much during application of the spirit varnish, later. Afterward, I rub in a coat of gypsum in a coffee suspension, to fill the pores of the wood with particles of the mineral. This keeps the varnish from saturating the wood, and possibly dampening the sound.

Mineral ground drying. See how it obscures the wood? that goes away when the sealer is applied.

Back with sealer. — The sealer renders the mineral ground transparent, and it will never be visible again.

I expect that, by tomorrow, the sealer will dry sufficiently that I can begin varnishing. I am getting anxious, as the show is a week from tomorrow, and I am far from completing this instrument.

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January 2, 2019January 2, 2019

Purfling and Neck-set

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Purfling and Neck-set

Purfling the Front plate

It is a lot easier to purfle the front plate before the neck is installed. But I have found that I can get better results purfling after installing the plates, than before, though I was taught to purfle the plates very early, before even completing the arching. But what consistently resulted was that I could not reliably produce even-looking edge-overhangs when I purfled before plate installation.

So…beginning purfling, here:

I have scribed the lines, and am beginning to incise them. — I have scribed in the lines, using a purfling-marker, and am beginning to incise them.

Removing the waste wood fromn the slot. — Removing the waste wood from the slot, using a “purfling pick.”

Slot beginning to develop. — The slot is beginning to develop. I use the piece of purfling to check the fit of the slot.

Purfling slot is complete: ready for purfling. — The purfling slot is complete: ready for purfling. A knife, two purfling picks and the purfling marker are in view.

Purfling installed, but not trimmed: channel is next. — The purfling is installed, but not trimmed: the channel is next. I used the roller to press the purfling deep into the slot.

Neck Setting

I did not take as many photos as would have been ideal. I was concentrating on the work, and not thinking about pictures. Sorry.

The heel-end of the neck had to be as close to exactly the final shape as possible before I laid out the neck mortise. As it turned out, I had set the taper incorrectly, forgetting that I had deliberately left the heel long, so I had to re-shape the neck-heel. Fortunately, I caught it early, and was able to make the correction.

When setting the neck, I make no further changes to the neck-heel, but rather, I carefully shape the mortise to receive the neck-heel.

Five factors have to come together for a good neck-set:

The angle of the fingerboard to the front,
The height of the fingerboard above the front plate edge,
The transverse angle of the neck,
The transverse “roll angle”, and
The distance from the upper end of the fingerboard to the upper edge of the front plate. (130 mm)

All five really must be perfect. Sometimes I can get it quite quickly. This was NOT one of those times. (sigh…)

But the end result was quite satisfactory: all five were correct, and the fit was tight. I slathered in the hot hide-glue, and rammed the neck home one last time: no clamps were needed.

Next, I will check the back-plate fit, complete the back-plate graduations, install the label, remove the mold, clean up the interior, and install the back plate. This is the “Titian” Stradivari model. I decided to include a scroll-graft and an ebony “button crown” on the “Plowden” Guarneri del Gesu model. So there will definitely be some additional steps to completion, there. I will try to remember to take more pictures.

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February 10, 2018February 10, 2018

Scroll, pegbox and Neck-set

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Scroll and Pegbox completion: and Neck-set

Scroll and Pegbox Completion:

When I last posted, I had just temporarily attached the fingerboard to the neck, but had not carved the pegbox, nor the fluting on the back and top of the scroll. In the past I have completed those before attaching the fingerboard, but this time I was anxious to get going, and it seemed a good idea at the time….

So…I first shaved the fingerboard sides to fairly closely match the handle portion of the neck, and then began carving the pegbox.

Carving complete: scraping and filing to follow.

Then I could complete the outside of the pegbox, finish tapering and scraping the handle portion of the neck, and carve the fluting on the scroll. I still had the centerline I had scribed when I first cut out the scroll, so I worked from there, and tried to “color inside the lines.”

Nearing completion. — Neck is nearing completion, outside and inside of Pegbox are pretty much complete. No fluting yet.

Fluting nearing completion...back view. — Fluting nearing completion…back view.

Fluting nearing completion: front view. Lots of scraping left to do.

Neck Mortise

Before I can set the neck, I have to lay out the exact footprint of the neck heel on the centerline of the corpus, where I will cut the mortise through the ribs and into the neck-block. I have deliberately left the heel long, so that I can set it through the neck-block, and not have to worry about fitting against the back button, because I haven’t installed the back plate yet. I will trim the heel afterward, and, when I level the back of the corpus, just before installing the back plate, I will level the heel right along with the linings and blocks.

So here is how the neck mortise went:

Mortise layout — The mortise is laid out off the centerline, which you can barely see in this photo, because one top rib nearly obscured it.

mortise beginning — First, I removed the rib ends, and double-checked my layout lines.

Front plate cut out. — Then I removed the waste wood from the edge of the front plate.

Mortise carving — Then I began chiseling away the block wood, to open the mortise.

Neck-set

The mortise has to fit the neck in every respect: It has to be the right width and shape, so that the neck goes to the correct depth. (I wanted a 6mm overstand at the edge of the front plate.) It has to be the right depth so that the distance from the front edge of the nut, to the top of the front plate will be exactly 130mm. The sole of the mortise has to be flat, so as to fit tightly against the end of the neck, but at the correct angles, both laterally and fore-and-aft, so that the neck is not twisted in relation to the corpus, the centerline of the neck is in line with the centerline of the corpus, and the projection angle is either exactly right or just a shade high. I have had instruments change fairly rapidly after they have been strung at tension for a while, due to the top bulging a little as it is compressed by the string pressure, so, I deliberately set the projection angle just a tiny bit high, anticipating that it will change a bit under string tension.

Dry-fit check of overstand mark and neck length mark. Both are correct.

When I am finally satisfied that all is correct, I remove the neck one last time, slather the hot hide glue into the mortise, and shove the neck home for good. I quickly check all measurements, to make sure I got it in correctly. I only have a few seconds before that glue sets up permanently. Fortunately, all was still good, and I applied a single clamp to hold it until the glue dries.

What’s Next?

You can see that I have about 10mm of extra heel hanging out behind the back of the neck block. I will saw that off, nearly flush, plane it as close to flush as I dare, then, after removing the mold, installing the back linings, and trimming the linings and blocks, I will level the entire back of the corpus, including the heel, on a “sanding board.” When all is perfectly flat, I will install the back plate, and the violin will begin to take on a life of its own.

For some reason, after I close the corpus, or thereabouts, I cease to see the instruments I make as a “project I am building”, and simply see them as an instrument I am working on. I am working on a violin, at that point, not just something that will become a violin. It is a strange feeling, but it has happened on every instrument. A student, who built his first instrument under my guidance, put it another way: as the instrument came together, he suddenly said, “This is getting real!” I knew exactly what he meant.

Next time I will remove the mold, install the back linings, shape the blocks, and maybe get this thing closed up!

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February 5, 2018

Violin Progress

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Violin Progress

The Front Plate is Complete, except for the Bass Bar

This morning I got back to work on the scraping, and completed the outside of the front plate. The interior is also essentially complete, but still lacks the bass bar, so there is still that to do. I spent some time cleaning up the f-holes, and I am somewhat satisfied with them, but undoubtedly will do some tinkering later, just because I always do, and am never quite satisfied with them.

Front plate

Back Plate Graduations have Begun

I knew I probably needed to get going on the neck, but I really wanted to begin the back plate graduations, so I started in. This is about as far as I got. I will probably complete it tomorrow, but my hands were getting tired, and I needed to do something easier for a bit.

Back Plate Progress

Neck Beginning

You may recall that the neck block had been delivered to me in a trapezoidal cross-section. This is quite common, but it poses a problem for me, because, once I have the side profile of the scroll and pegbox laid out, I prefer to drill a pilot hole for each peg, using my small drill-press, so that the holes are all perpendicular to the centerline of the scroll. That is hard to do, with a sharp angled shape. So, I set my bandsaw for 1/4″, and sawed off a triangular slab from each side of the big end of the trapezoid, reversed them, and glued those slabs back onto the sides, near the thinner end of the trapezoid. I checked with my little square, to make sure I had them at an appropriate location, then clamped them home. Once the glue dries, I will square up the block, lay out the neck, drill the holes, and get going on carving the neck. Those wedges will be completely removed, long before the neck is done.

Slabs removed and rotated up, making it possible to square up the neck billet.

Slabs glued and clamped. When the glue is dry, I can square the billet, and proceed with neck layout.

A Break-time Treat

Ann and I decided to take a break and go for a walk, as Spring seems to have arrived early. As we neared home again, a pair of Bald Eagles passed by, flying low over our place, and landing in the trees at the front of the property, on the far corner. I had never before heard eagles “chatting” with one another. It was interesting hearing their clear, high-pitched chirps, and whistles, as they “talked” back and forth.

One of them almost immediately re-located to a thicker stand of trees across the road, but the other obligingly remained in sight, preening herself, until a passing hawk began diving at her, and she, too, moved into the thicker cover. I only had my cell-phone, but I did manage to get one photo.

Eagle in the distance.

Back to Work:

Squaring the Neck Billet

Once the glue was dry, I could square the billet, by sanding or planing off excess wood. Removing those slabs had left me with a few milimeters extra on the thickness, and much more on the depth, from front to back. So, since I had tried to plane it, but it tore out badly (as curly maple frequently does) I straightened the sides using the oscillating spindle-sander, and then laid out the neck details. I have made a new neck template, but it is just thin plastic. I will eventually make a light aluminum template which will be more durable. I first laid out one side, including the locations for the peg holes. Then I drilled the 1/8″ pilot holes for the pegs and cut the profile out on my small band-saw. After that, I was able to lay out the other side, and all the rest of the details; including the width of the heel, the width of the button, the width of the neck at the nut, and the taper of the pegbox into the actual scroll.

I forgot to take photos during that step (sorry) so all I can show you is the sawing procedure I used to remove the excess wood from the scroll:

I cut tangents to the curves, down to the scroll outlines from both sides.

Once I have cut sections all the way around, I can easily remove those sections and begin carving.

I will try to complete the back plate, the bass-bar, and the neck/scroll tomorrow. If I get that far, I will feel as though I am “on the home stretch,”, as the neck-set will then be the only difficult step left to do. We’ll see, though. There may be other priorities to pursue.

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March 4, 2017March 17, 2017

3/4-Size Violin Completion

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Completed the 3/4-Size Violin!

I had a number of other projects going, so I neglected to maintain the website presence…the only post lately has been of another violin resurrection. But…I hope to change that.

The last post was of the neck-set on the 3/4 violin. It looked like this– but the back plate was not made, yet. Most makers complete the entire corpus, then set the neck. I complete the rib garland and the front plate, then set the neck while the inside mold is still in place. This allows me to get the neck-set perfect, and to level the back of the garland, including the back of the neck-heel, before making the plate. When I install the plate, it fits perfectly, only requiring the final trimming of the heel and button together, to establish the optimum height in the center of the curve of the heel.

Completing the Back Plate

So, the next thing was to trace the back plate, and complete it:

Beginning to carve the back archings. There is a long way to go!

Once the arching is complete, I cut the purfling slot

Then I install the purfling, dry, to make sure everything fits correctly. That strip of aluminum is my bending strap.

Edge Crest marked — Then I mark the edge of the crest, so I know where to carve the channel.

channel complete — Then I carve the channel, using a gouge, and use planes and scrapers to fair-in the curves of the channel and the archings.

Arching and purfling complete — Here, the arching and purfling are complete…but the graduations (inside arching) are not begun.

Graduation

I begin by measuring the thicknesses all over the plate, so as not to run into any surprises and make the plate too thin. Then I use gouges and planes to bring all the thickness close to what I want. But, to make sure I don’t go too far, I measure and carve out small spots all over, to the exact thickness I want in each little “polka-dot”. That makes a “graduation map” that allows me to follow my plan to completion, by removing all the excess wood between the dots, thus “connecting the dots.”

There are other ways to do this. One involves a special tool, commonly called a “Strad-Spike”, because one was found among the tools of Antonio Stradivari. I have seen them and and have actually used them, but have never gotten around to building one. So…

graduation map laid out — Graduation map laid out.

By the way, I think it is interesting to hold the plates up to a lamp and see how much light comes through:

translucent spruce — That is a lot of light coming through that spruce plate…it is about the thinnest plate I have made.

translucent maple — Even the maple lets a little light through.

Closing the Corpus

Finally, to install the label and close the corpus. (I always forget to take a picture of the label…sorry.) Most makers put their label in after everything is fully completed. I used to do that, but I found it so frustrating to get a glue-coated label through the f-hole, line it up correctly and get it smoothed out on the back plate…all working through the f-hole…that I decided my labels will go in when I close the corpus; always. That means the label predates the completion by a few weeks at most, as a rule. I think one time there was a long wait, but that was the lone exception.

Fully glued and clamped, using hot hide glue and spool-clamps.

Closed corpus from the front. Dainty little thing, isn’t it? This is my first 3/4-size violin, and it feels pretty tiny.

Finishing

I removed the fingerboard so as to be able to easily access the entire exterior, for final scraping and finishing.

After that, I had a lot of “scraping and looking” to do. (Scrape and look, using a low-angle, dim light, then scrape and look some more.) When everything was as smooth as I could make it, and exactly the shape I wanted, I stained the entire violin with coffee, to get rid of the stark-white bare, new-wood look. It takes at least three coats, usually, to get the color dark enough that it will not shine through the varnish. The collateral effect is that the grain raises because of the water. So, I sand it lightly, to smooth the grain “just enough.” I want the grain to be visible in the final state, but not too visible.

Then, I rubbed in a coat of the mineral ground. I brush it on liberally, rub it in hard, with my fingers, then wipe it off as hard as I can, using a rag. When it dries, the instrument will be whiter than ever– chalk-white, all over. The first time I did this I was pretty alarmed at the look, but I had just watched Roger Hargrave do the same thing, and knew that the white mineral would completely disappear with the first coat of sealer or varnish. And it did!

Here is the violin with the sealer applied:

sealer front view — With three coats of coffee, and the dark sealer, the wood looks pretty dark. But it will look good under the varnish.

After that it was a case of applying several coats of golden varnish, then a few coats of red-brown varnish, and a final two coats of the golden stuff.

There is the front with the final coat of varnish.

Set-up

Standard set-up, and the violin will be done! That includes the saddle and endpin, as well as re-installing the fingerboard, fitting and installing pegs, a bridge, the nut, the soundpost, tailpiece, and strings. A chinrest completes the instrument.

Bottom of the violin before the endpin and saddle were installed.

Heres the plan: a rounded saddle to prevent “saddle cracks”. They work because there is no sharp corner to act s a stress riser.

There’s the footprint of the saddle: no further shaping is done until I cut out the mortise in the front plate.

Traced saddle mortise — I traced the footprint onto the front plate, and began cutting out the mortise.

cut out saddle mortise — Then I cut out the mortise using sharp gouges and a small knife. Any nicks in the varnish will be retouched later.

The varying thicknesses of the top plate can then be traced onto the saddle itself, and final shaping can begin.

Saddle and endpin complete — Saddle and endpin are nearly complete. The saddle will be filed a little more, and the varnish retouch will happen later on.

fingerboard and pegs installed. — I reinstalled the fingerboard, and while the glue is drying, I fit and installed the tuning pegs.

Fingerboard and pegs complete. Notice the nut is also intalled.

Completion

Finally the little violin is complete!

finished scroll — Close-up of the scroll

Thanks for looking. Please keep in mind that the Marylhurst Musical Instrument Show will be April 29th and 3oth. If you can make it, I hope to see you there. This little violin will be there for you to test drive, along with others.

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January 9, 2017January 10, 2017

3/4-Size Violin Neck-Set

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3/4-Size Violin in Progress. Purfling and Neck-Set

Purfling first, then Neck-set

When I last posted, the fiddle looked like this:

Purfling Slot Incised — Purfling Slot incised, but not completed.

Installing Purfling

This next step was to go back over the incisions, cutting them to the correct depth. Then I used a purfling pick (there are many different types) to shave out the waste wood from between the incisions. The last thing I do, before installing the purfling, is to go all the way around the slot, checking the width and depth with a scrap of dry purfling. I want the fit to be snug but not tight, and deep enough that the purfling will be flush with the surface of the plate. Here is the completed slot:

I used a bending iron to shape the sections of purfling, installing the Center bout sections first, and mitering the corners to form the desired “bee-stings.” As I cut the ends of the upper and lower bout sections, I have to check and be sure that the two mating miters will form a single sharp point, shaped exactly the way I want. This takes a good deal of practice. As one of my teachers told me, “Sure, this is tough! If it was easy, everyone would be good at it!” (Funny, that seems to be true in most walks of life…) Once the purfling is all in place, dry, I can begin gluing. Here is the dry fit:

Next I pry up the center of each of the center-bout strips, and, using a thin palette knife, I slip hot hide glue in under the lifted purfling, then, working quickly, I push the purfling back into the slot, and drive it home using a special tool. I start at the center ans work toward both ends, so that the glue being forced from under the purfling is driven along toward the ends of the center bout purfling strips, into the mitered corners, so that it glues the ends of the upper and lower purfling strips in place, as well.

Here is the freshly glued purfling, driven as deeply as I could manage, into the slot:

The next step is to sketch in a line 40% of the distance in from the outer edge, toward the purfling. It is a faint pencil line, but it serves as a guide to show me the limits to the channel…the broad trough around the edge of the violin:

Edge Crest boundaries inscribed…it’s a blurry photo, but you can see the penciled lines.

Then I begin cutting the channel: a trough whose outer edge is the line I just inscribed, but which cuts only as deep as is necessary.

Beginning of the channel. The Edge crest is still visible. I have just begun to cut the channel.

Neck-Set

I laid out the neck mortise, using pencil and straightedge. Then I cut the edges of the mortise, using a razor-saw, and carved the wood away to form the mortise. It is somewhat tricky (like all the jobs in lutherie), but I got it done. Once everything was perfect, I glued the neck heel into the mortise, using hot hide glue:

That was all I did that day. 🙂

The next step will be to remove the mold and install the back linings to the ribs.

Thanks for looking.

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September 7, 2015September 9, 2015

5-String Progress #8; Neck-set (and more)

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Five string Fiddle Progress: Neck-set and more

Completing the Scroll

Last week, I had left the scroll nearly finished, but still lacking the outer fluting under the neck, and still pretty rough. (Honestly, I continue “fine-tuning” scrolls right up ’til I begin varnishing.) So, the first thing was to get the scroll and neck completed well enough that I could set the neck.

I am never fully satisfied with my work, but I have to decide at an appropriate point that it is OK to move to the next step. However, scroll and neck carving is much more difficult after the neck is set, so I want to have them pretty close to how I want the finished product to look, before I begin setting the neck.

Setting the Neck

Setting the neck begins with careful layout of the heel “footprint” on the neck block of the violin body (often called “corpus”). I already had the centerline of each laid out, so it was a matter of transferring lines accurately, and then cutting along those lines so that when the wood was carved from between the saw-cuts, the heel of the violin neck should fit, snug and straight, into the prepared neck-mortise. I always leave a little extra, so that the mortise is too small to begin with: it is much easier to take off a little more, than to replace wood.

I did not take pictures of this procedure– simply wasn’t thinking about photographs, and I forgot. It went very smoothly, this time, though, and I think I had it ready to fit in around 30 minutes, or a little more. (Usually it takes me longer.)

Here’s the neck mortise, ready to receive the neck:

And here is the neck, dry-fitted into the mortise:

Once I knew that everything fit the way it ought, and that it was going to be straight, tight, and at all the correct angles, I was ready to glue. The things I have to check are five points of measurement:

The distance from the upper end of the fingerboard (where the nut will be) to the upper edge of the top plate (both sides) has to be 130 mm.
The neck has to be measurably straight, so that the centerline of the neck and scroll are a continuation of the centerline of the corpus.
The neck can’t be twisted (rolled side to side)…it should be level with the plane of the ribs, side to side.
The height of the upper edge of the heel of the neck (underside of the fingerboard) should be 6 mm above the top plate.
The height of the end of the fingerboard above the top plate should be between 19 mm and 23 mm, with 21 mm being optimum.

I realize that there are different ways of approaching virtually everything in lutherie, and there are sure to be experts reading this, who are shaking their heads, but: this is the way I was taught, and it has worked well for me.

I prepared the hot hide glue, and brushed it into the mortise, and onto the bottom of the neck-heel, and along the edges of the heel. Then I quickly rammed the neck heel home in the mortise, and checked to make sure all my measurements had held (primarily the height of the fingerboard above the plate.) All was in order, so I set it aside to dry. Here is the completed neck joint, with the glue squeezing out around the joint:

Back view. When the glue is dry, I will remove the mold and trim the blocks.

After the glue dried, I planed the neck heel flat, then removed the mold by breaking the glue-joint at each block (six places) and simply lifting out the mold. Then I trimmed the blocks and was ready for the back linings.

Exterior view: Looks good, doesn’t it? But it still has a long way to go.

Installing the Back Linings

The first thing I do to prepare for installing linings is to cut mortises in both sides of each block, into which to insert the linings. I use a thin knife and a very small chisel to cut the mortises.

I make the linings by first sawing the chosen wood to about 2 mm thick, in 2-3″-wide “planks”, about 18 inches long, and then using a wheel-style marking gauge to cut off strips 7 mm wide. I wet each strip and bend them around a hot bending iron, until I can fit them into the corpus. I want them to fit tightly. The center bout linings are bent in such a way that without clamps they would tend to buckle away from the ribs, so I use small spring clamps to dry-fit them. The upper and lower bouts will stay put on their own.

Then, one by one, I remove each lining and brush hot hide glue along the portion of the rib that will receive it, as well as on the lining itself, making sure the ends are liberally coated, as well as the full length and width of the gluing surface. I quickly re-insert the rib, and clamp it in place with as many small spring clamps as I can fit along its length.

That is it for today. I’m tired, and 3:45 AM will come all too early (back to work tomorrow).

The next step will be to level the back surface of the ribs and neck heel, and then trace the back plate from that pattern, so that it will fit perfectly. (The neck heel is still not in the correct finished shape, but the back plate button and the neck heel will be shaped as one piece, after the back plate is glued in place.)

Next time we’ll start carving the back.

Thanks for looking.

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April 10, 2013July 13, 2013

Cello Neck-set

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Here’s how I set the neck of a Cello

I’m quite sure it is virtually identical to how other makers do it, with one possible exception: I set the neck while the corpus is still on the mold, with only the front plate installed.

Cello corpus on the mold; front plate installed;

Lay out the mortise outline.

I lay out the center of the neck block, and perform the remaining layout from that centerline. The heel is to be 30mm wide, and the front of the neck where it joins the corpus is 42mm wide. So I mark 15mm to each side of the centerline at the heel, and 21mm to each side at the front plate. Double-check everything. It is a real pain trying to put wood back.

I check my measurements, and mark the location on each side of the neck where the front plat should sit when all is complete– 280mm from the top of the fingerboard, and 20mm down from the top of the neck at the front.

Then begin cutting.

I have five measurements in mind, which I check constantly:

I want the neck centered, obviously, but in terms of simple location, I accomplished that by careful layout– I want it centered, in that the fingerboard will be centered on the corpus, and the centerline of the scroll will be in line with the centerline of the front plate, as well.
I want the neck straight, in the sense that it is not rolled to one side or the other. I can check this by sighting across the “ears” of the scroll at the edge of the front plate. If they seem parallel, I am satisfied.
I want the neck the proper length. That 280mm mark I put on each side of the neck will let me know when I am getting close.
I want the front of the neck the right height off the front plate. That was the 20mm mark I put on each side of the neck.
Finally, I want the neck angle to be such that the bridge will be an appropriate height. I aimed for 65mm at the end of the bridge, so as to arrive at an 82mm projection at the bridge– the bridge, then would be roughly 90mm tall at center. There is some flexibility on this one, but not a great deal. In reality, all five of these measurements simply have to be within tolerance, or the instrument will not work right.

So, with all of that in mind, I measure from the 280mm mark to the end of the neck, to see aproximately how deep the neck mortise must be at the front, then use a Japanese pull-saw to slice along my layout lines to nearly that depth. I stay inside all my layout lines, as I want to leave a little room for adjustment.

Cello neck-set 1 of 6 — I begin by removing the section of front plate affected by the neck mortise, then use a chisel to remove the waste wood from the mortise itself.

The blue lines you can see in the above photo remain from my initial layout when I bent the ribs. I wanted to make sure they were long enough. (It was close!)

Cello neck-set 2 of 6 — I try to get the mortise nearly right on the first try, but deliberately leave some room for adjustment.

Cello neck-set 3 of 6 — You can tell from the location of my layout marks that I still am far from done– but the neck fits fairly well, and I will be removing paper-thin shavings from here on, and checking every step of the way.

Cello neck-set 4 of 6 — Now you can see that the layout lines are very close to what I wanted. In fact, I had deliberately marked my height at 21 mm, to give room for adjustment… and it is at 20 mm now, which is fine. The 280 mm mark is dead on target.

Notice that the heel is overhanging the back of the block by nearly 5 mm. That is fine– I will remove that excess wood when I flatten the back of the garland, and the back plate will be the last major component installed.

Cello neck-set 5 of 6 — Here is a closer look– the length from the top of the fingerboard to the edge of the front plate is pretty critical. a good player will notice any variation. the overstand (height above the front plate) is less critical.

Cello neck-set 6 of 6 — I checked and double- and triple-checked until everything was perfect, then slathered the hot hide-glue into the mortise and onto the neck, then rammed the neck home and clamped it tightly. I checked once more with the clamps in place, to see that the measurements were still OK. (Thankfully, they were!) Cleaned up with hot water and a brush. Now it just has to dry.

That clamping block in the photo above was just a scrap of wood– I cut it to the correct angle, then hollowed out a curved opening to fit the cello neck-heel. I glued a pad of 1/8″ cork into the cup, and it works very well.

And that is pretty much all I got done today. Cooked a roast… fed the cat, brought in the newspaper…that’s about it. Pretty tired.

Later tonight, if I still feel like it, I will remove the mold, and begin the final cleanup of the interior of the corpus. On the home stretch, now… well, almost! 🙂

(Edit: I did go back and remove the mold, but that was all for that night. 🙂 )

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