Posts Tagged ‘volute’

More Scroll Progress

Please share with your friends!

More Scroll Progress

Final carving tasks

I had removed most of the rough wood, in the last post, and had smoothed the outside of the turns of the scroll.

Now it is time to undercut the turns of the scroll so that they have a more delicate look, and are physically a little lighter.

Carving the volutes.

Carving the volute and neck.

 

Completing the volute and pegbox.

Completing the volute and pegbox.

 

So, at this point the one scroll is essentially done, and the other will soon be done as well. I will complete the purfling on the two instruments before setting the necks, so that is next.

Thanks for looking.

If you found this post helpful, please share with your friends!

5 String Report #14: Final Varnish Preparation

Please share with your friends!

Final Varnish Preparation:

Advance warning:

An apology in advance: as I warned some time ago, I have a tendency to get out of “photography mode” and just pursue the tasks at hand, then suddenly realize that I was supposed to be doing “show and tell”. So, (sigh…) this time it will be more “tell” than “show.” But I do have some photographs of the tools involved.

Cutting the Purfling Channel

The first step in cutting the channel is to determine its boundaries. I usually use a compass to scribe a line 1.6 mm in from the raw edge of the plate, all the way around, including the corners and the ends, where the channel has to follow the purfling away from the edge. (This time I used a special tool, made by Jake Jelley, to do the same thing. I think it worked better.)

Tool for scribing the crest of the edge

Tool for scribing the crest of the edge. There is a collet-style pencil lead held in place, there.

That marks the outer edge of the channel, as well as locating the crest of the finished edge. I extend that line at the same distance from the purfling at the ends, so, at the ends I have two lines: one forms the crest of the edge, the other the edge of the channel. The dark Koa wood did not easily show the pencil mark, so I had to scribe firmly, and usually several strokes.

I then cut the channel with a sharp gouge, trying to keep it shallow, but following the scribed line all the way around. I used a larger gouge for the upper and lower bouts: a smaller one for the C-bouts.

Larger gouge for upper and lower bouts.

Larger gouge for upper and lower bout channels.

 

Smaller gouge for c-bout channel

Smaller gouge for c-bout channels

Scraping the channel and fairing the curves

Then I used scrapers to “fair in” the channel with the curve of the arching, and make sure there are no humps or hollows.

Large radius scraper

Large radius scraper (this scraper has four edges…each a different curve.)

 

Small radius scraper

Small radius scraper

 

Smaller Radius scraper

Smaller radius scraper

 

Smallest radius scraper.

Smallest radius scraper. This one has a long flat edge, a long curved edge, and both ends have a very small radius.

 

Flat scraper for final fairing-in of curves.

Flat scraper for final fairing-in of curves.

Outer edgework

Finally, I use a tiny plane and a file to shape the outer edge, curving smoothly from the scribed “crest” to the outer edge, where, hopefully, it will smoothly join the curve from the inner edge.

Planing the outer edge curve.

Planing the outer edge curve.

 

Filing the outer curves smooth.

Filing the outer curves smooth.

 

Final Neck and Scroll-Work

I also double-check the scroll and neck shape and contours. They must be scraped to perfection before I can move on. I use a template (copied from Henry Strobel’s books) to check the upper and lower shape and size of the “handle” portion of the neck, and then try for smooth transitions between the two.

Neck template

Neck template for upper and lower neck cross-sectional shapes.

 

Upper neck shape

Upper neck shape with template.

 

Lower neck shape with template

Lower neck shape with template

 

Scraping the Volute

The volute has to be scraped in both directions, otherwise the scraper will simply follow the grain and leave humps. (Ask me how I know…)

 

Scraping the transverse curve in the volute.

Scraping the transverse curve in the volute.

Final Varnish Preparation

At last I am ready for final varnish preparation. Everything has to be as perfect as I can get it, because every imperfection will definitely show up under the varnish. The tiniest blemish will show up like a neon sign once I begin the varnishing. Some people insist on only using scrapers, but at this point I feel fine about using very fine (400-grit) abrasive paper to remove the tiny blemishes.

ready to varnish

Pretty much ready to varnish. Looks pretty plain at this point, doesn’t it?

I removed the fingerboard for varnishing…it was only temporarily glued in place, originally, to aid in the neck setting procedure. While varnish is drying, I will shape the underside of the fingerboard, and lighten it, to enhance tone and projection.

After the varnishing is completed, I will glue the fingerboard permanently in place. I will also install the saddle, nut and pegs after varnishing. At that point, the violin will be essentially complete, and set-up is all that remains.

So: I’m sorry I missed the “in progress” photo opportunities, but, from here on out, it will be just progress reports in finishing. The mineral ground is next, and then the sealer.

Thanks for looking.

If you found this post helpful, please share with your friends!

How I carve a Scroll

Please share with your friends!

Cello Scroll Carving Made Simple 🙂

There is nothing special about the way I carve scrolls. As far as I know, this is how everyone else does it, too, more or less. I am only sharing how I do it.

Start by tracing and sawing out the profile of the whole neck.

I don’t have a photo of the scroll as a simple profile, but I begin with the billet (About 6″ x 3″ x 20″), and trace my template onto it, then use a bandsaw to cut the shape of the profile. I use a oscillating spindle sander to remove the saw marks, and perfect the profile right to the line. While the profiled block is still “square”–that is, while the sides are still parallel, I lay out the peg hole locations and use a drill press to make 1/8″ diameter pilot holes where each peg will be. I drill all the way through, so that the holes are clearly marked, and are perpendicular to the center plane of the neck.

Next cut out the pegbox and at least a few inches of the neck

I hollow out the pegbox before carving the scroll proper. Some people use a drill to get started. I have done it this way, but it seems a little risky, unless you put some sort of limiter on the drill, to avoid going too deep– and even then it is easy to go out of bounds. I use a narrow chisel to remove most of the rough wood, then a wider chisel to smooth the inside cheeks of the pegbox. I also saw off the excess wood on the outside of the pegbox, and plane those faces flat.

Then draw the shape of the scroll itself.

Usually we use a template for this, as well. Some people plot out each scroll with a straight-edge and compass. I have neither the time nor the inclination. In this case, my templates came from a poster of the 1712  “Davidov” Stradivarius cello, now being played by Yo Yo Ma. Some information was lacking, and I filled that in from Henry Strobel’s book on cello making.

And begin cutting:

Once the scroll is drawn out, I clamp the neck to my workbench and, using a Japanese-style pull-saw, I begin cutting slots nearly to the layout lines of the volute. I rotate my position a few degrees, and make another cut. I have to be careful to avoid cutting too deeply, but this method allows me to chip away the waste wood rapidly, and the scroll begins looking like a scroll rather quickly.

Beginning the scroll, proper.

Pegbox is complete, volute partially carved. The cut lines are visible on the portion of the volute that has already been carved. Now we will carve the scroll, proper.

Cutting more kerfs to remove wood.

Care must be taken to avoid drifting across the line into the turns of the volute.

Cutting a series of kerfs for wood removal in carving a scroll.

You can see the direction this is going…I will continue to slice down nearly to the line, rotating a little each time, until I have gone all the way around.

Using a gouge to outline the eye of the scroll.

Once the kerfs are all in place, and to the correct depths, I use a gouge to outline the eye of the scroll, so as not to damage it with the saw.

Kerfs in place, and eye of scroll deeply incised. Carving can begin.

All the kerfs are complete, and the eye is deeply incised with the gouge–I am ready to start carving.

Use a flat chisel to remove the waste wood, and the scroll begins to emerge.

I use a flat chisel to remove the waste wood, and the scroll begins to emerge.

Once the waste wood is completely gone the

Once the waste wood is completely gone the “undercut” carving can begin.

Bi-lateral symmetry

I try to make sure the two sides match symmetrically, before beginning undercut. I do the outside fluting last, to avoid damaging it while carving other parts of the scroll.

Bass side of cello scroll, nearly complete.

Here is the bass side of the scroll, nearly complete.

Treble side of cello scroll, nearly complete.

And, here is the treble side.

Cello neck and scroll, nearly complete.

The neck and scroll are nearly complete. I will continue to fine-tune and scrape the scroll, perfecting it as best I can, right up to the day I begin varnishing.

Fingerboard installed on Cello neck, with hide glue and clamps.

I have prepared the fingerboard, and now I have installed it, using hot hide glue and clamps.

So– that was entirely enough for today. Tomorrow I will continue to refine the scroll and neck, and try to get the neck set. If I succeed, then I can remove the mold and install the back plate.

If you found this post helpful, please share with your friends!