Posts Tagged ‘bassbar’

3/4-Size Violin Progress

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3/4-Size Violin Still in Progress

Last time… if you remember… it looked like this:

Progress as of January 2nd.

Progress as of January 2nd.

F-holes and Bassbar

So, I went ahead and cut out those f-holes, using an f-hole “drill” my children bought for me, and an X-acto knife.

F-holes

F-holes cut out and ready for the bassbar…outside view. They still will require a good deal of refinement.

 

Then I chalk-fit a bassbar blank, and glued it in place, using special clamps made by Jake Jelley, the friend who encouraged me to continue building instruments.

Bassbar blank with clamps.

Bassbar blank with clamps. You can see the f-holes cut out…they still need more trimming.

 

Shaping the Bassbar

I carved and planed and scraped the bassbar into what I judged to be an appropriate shape for this instrument. Both it and the f-holes will receive a bit more scraping and shaping before they are varnished. The whole instrument, actually, is fair game for tweaking, refining, and perfecting, until the varnishing begins.

F-holes, bassbar and graduations

F-holes, bassbar and graduations nearly complete. Outer edges have been rounded to approximate their final shape.

Installing the Front Plate

I aligned the front plate as closely as I could with the rib garland, and applied six spool clamps–one for each inner block. Then I loosened one clamp at a time, and, using a thin palette knife, I slipped hot hide glue between the plate and the blocks and linings. I rinsed the edge, overhang and rib quickly with hot water, and wiped it with a rag, then re-tightened the clamp, and added more clamps between that clamp and the next, repeating the procedure untill all the edges and especially all the blocks were securely glued and clamped, and relatively clean.

Front plate installed, using spool clamps.

Front plate installed, using spool clamps. Ann thinks these look like hair-curlers. 🙂

 

Back view of mold with front plate installed, and spool clamps.

Back view of mold with front plate installed, and spool clamps. The mold will be removed after the neck is set.

 

Purfling Comes Next

Not everyone does things in the same order. I have had trouble, in the past, getting my edge overhangs even all the way around. If I install the purfling first, then I am locked in, so to speak, and if the overhang is uneven, there is nothing much I can do. But if I purfle after installing the plate, I can take time first to adjust that overhang, using files and scrapers, until I am satisfied that it is the way I want it, and then purfle, following my adjusted edge shape.

Installed front plate, from the mold side, showing the overhang.

Installed front plate, from the mold side, showing the overhang. Notice that there are no back linings, yet.

 

Purfling laid out and lightly incised.

Purfling laid out and lightly incised. (The shadow is my head– I was too close to the plate.)

 

The idea at this point is to just deepen the lines a bit, not to try to cut the full depth of the purfling slot. You can see that, in some places, the waste wood begins to pop out on its own. Most will have to be removed using a purfling pick. Here is a closer photo of the incised purfling lines:

Close-up of the incised purfling lines.

Close-up of the incised purfling lines. That corner will still undergo significant shaping and refining.

 

So…next time, I will show the completed purfling, and the neck-set– I hope. 🙂

 

Thanks for looking

 

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Five-String Fiddle Progress post #3

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5-string progress #3

Arching and F-holes

Last time, I had traced and cut out the top plate, and actually, I began the work on it, thinning the plate to the desired arching height– but that is when I discovererd that there was a bark inclusion that extended right through the upper bouts. So, for those “sharp-eyed” among you, who notice that the grain has changed; Yep. It surely has! Too bad…I liked the grain of the spruce in the plate I first chose, but it turns out it was just a little too interesting.

So, on this plate, all I have done is the outer arching and the layout and incision of the f-holes. After completing the arching, but before final scraping, I laid out the distance from the upper edge of the plate to the “stop” line (where the bridge will stand) at 195 mm, then laid out the distance between the upper eyes at 42 mm. I used a plastic template that I made years ago (cut out of an old flexible face-shield– the kind welders use when they are grinding steel) to lay out the shape of the holes, then incised them deeply with a thin knife. They would have been virtually invisible in the photos, so I traced them again with a sharp pencil after incising them, so that you could see them in these photos.

Arching and f-holes

Arching complete, f-holes laid out and incised.

Arching: Final Check

Next I checked the arching by sighting edge-ways at the plate, to see whether the main stem of each f-hole is fairly parallel to the rib-plane. Usually I find that I have left the arching a little too “puffy” around the lower stem and lower eye area of the f-holes and need to plane away a few more strokes to get the stems lined up. I don’t think the looks of the f-holes are the main issue, here– the shape of the arching is fairly critical to the sound, as best I can understand, and this is just a “marker” for me to check.

Side view of f-holes.

Checking to see that f-holes are aligned with rib-plane.

Obviously, this alignment is something I have to do before I try to complete the inside carving, or there might not be sufficient thickness left to do the final adjustment. I try to estimate and get this area as close to correct as possible before laying out the f-holes, but I have had to adjust them at least a little, every time, so far.

After I am satisfied with the overall shape of the arching, I use scrapers to reduce all the lines and ridges left by the finger planes into a smooth continuum.

Graduation: Beginning the Interior

Once I have the outside arching the way I want it, I can start on the inside, and the final graduation of the plate. I hold a pencil in my fingers so that about 9 mm protrudes onto the plate, and then run my fingers around the edges…nothing precise about it: it is just a guideline for carving. I want to leave this area untouched until the last bit when I am scraping the inside, before installing the bassbar. I use the same template that I use for the final shape of the end blocks to scribe the shape of the area to be glued to the blocks. I scribe in the corner blocks  with a curved scraper that just happens to fit the shape I want. All this outer perimeter area will be left flat until the last step before installing the bassbar, and/or installing the plate on the ribs. I want just the gluing surface flat when I am ready to install the plate.

Inside front plate, before carving

Inside carving plan.

Preparing for Graduation: Measure First!

It pays to use a caliper and check the thickness all over before beginning to carve. I do have a mental image of the desired shape of the interior, but I do not have a mental map of the thickness of the plate, so I measure at least the areas that already feel pretty thin to my fingers, and decide how much should come off in each area. As it turns out, this time, no areas are really borderline, but some are within 1.5 mm or so, so I will be careful around those places. I am aiming for about 3.5 mm down the middle, fairing down to 2.5 in the upper and lower flanks. and a few places 2 mm, very likely. I will try to leave some areas a little thick, where there is a likelihood of cracking, but in general, I expect this will be a pretty thin plate…the spruce is a little dense (which I have had good results with in the past), so it can stand to be a little thinner than usual.

After the inside is carved and scraped to my satisfaction, I will complete the cutting out and shaping of the f-holes, then chalk-fit and install the bassbar. I will post photos of all that.

Thanks for looking.

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Bass Bar installed and trimmed–F-holes refined. Edge-work begun.

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The Bass Bar is in place and trimmed. The F-holes have been refined, somewhat, and the edge-work is begun.

Bass-bar was #1 on the list!

I installed the bass-bar first thing this morning (chalk-fit to the inside of the plate in the exact location it was to be glued, then glued with hot hide glue).

Then, while the glue was drying, I went and did other things. Swept up the shop, changed the tires on my car (snow tires have to be off this weekend), and designed some display stands for the upcoming show at Marylhurst University. I had intended to begin the graduations on the one-piece cello back plate today, but after I did the tires, I was pretty worn-out, and hurting, so I decided it was time for a break, and, since the glue was dry, time to trim the bar.

Bass Bar in the rough

Here’s what the bass-bar looked like in the rough, when I took the clamps off:

Cello Bass-bar in the rough, viewed from the top.

Bass-bar in the rough, viewed from the top

Cello Bass-bar in the rough, viewed from the side.

Cello Bass-bar in the rough, viewed from the side.

Bass Bar Trimmed and finished:

And here is what it looked like after planing it to the shape I wanted it to be:

Finished cello bass-bar from front

Finished cello bass-bar from front

Finished Cello Bass-bar from side

Finished Cello Bass-bar from side

Edge-work and final prep for finishing

Although you probably really can’t tell in the photos, I have also scraped the entire plate, inside and out, under low-angle light, to get every dip and hump as smooth as can be.

Also, I began the edge-work; I first planed a small (3mm) bevel all the way around the inside edge, then rounded it with a file, to establish the inside curve of the edge. The outside will be treated the same way, after the plate is installed on the garland. It is much easier to manipulate the plate by itself, instead of the whole cello, so I want to do as much as I can before it is assembled.

I also spent time refining the f-holes; smoothing the inner edges, matching bass to treble shape, etc. That, too, is much easier before the plate is assembled with the garland.

Tomorrow I will try to graduate the back plate.

Gotta do taxes, too, though.  (Hooray for Turbotax!)

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