Archive for the ‘Soundboard’ Category

Keychest bottom sanded

Sunday, October 16th, 2011

As mentioned last time, to get the head adjusted onto the body accurately in relation to the keychest, I needed to first sand the bottom of the keychest so it would match the curvature of the soundboard.

The keychest was run back and forth along its axis over two sheets of sandpaper on top of the soundboard.

KeychestBottom1

Sanding the bottom of the keychest to match the soundboard curvature

The four pieces of the keychest were not perfectly aligned on the bottom when I assembled them, and there were some small beads of dried glue coming out from the joints. So, all that is leveled as well as curved. The two end pieces required the most curving, due to their width and perpendicular orientation.

KeychestBottom2

Front of keychest after sanding bottom

It should be good enough now to finish adjusting the head. It definitely looks much better.

Head – neck notches 2

Wednesday, October 12th, 2011

Now that the tuning peg holes are drilled, I can go back to getting the head to fit in the notches I made in the neck of the body. The bottom edge of the head needed its final curve to be able to fine tune the notches. Plus, the angle on the two little feet needed changing to make them perpendicular to the angle of the keychest-mounting edge, which is mainly why I wanted to drill first, since the piece would have to sit on those for that operation, and might have dented them.

Neck07

Chiseling the curves to their rough outlines

[You can see in the above picture where the wood chipped out some on the right-most hole.] After chiseling came the sanding by hand. Leonard lent me a coarse-grained tube from an oscillating sander, and I used a wood dowel wrapped with fine sand paper to complete these curves.

Neck08

Final smoothing of curves and flattening of feet

The head-shaping that relates to the neck  is completed, but I’m still adjusting the neck to get a good fit. It’s almost there, but the head’s ‘yoke’ still doesn’t quite fit flush against the soundboard. Part of the problem is that the soundboard isn’t completely flat on the neck, so I will work on that.

Neck09

Upside down view of how the head fits into neck notches

Another thing I need to do before finalizing these head adjustments is sand the bottom of the keychest to match the curve of the soundboard. This will lower the keychest some in relation to the head, which will then require the head to sit lower, too.

I have been worrying throughout the design of this that the head won’t fit in the notches right so that it will not match the vertical end of  the keychest to make a good joint,  but this seems to be working out okay.

Neck10

Test fit of the body, head and keychest for proper alignment

After this will probably come the final shaping of the top curve of the head where the peg holes are, and narrowing the sides to the width of the keychest.

Lid design

Tuesday, July 26th, 2011

Well, the lid of a hurdy-gurdy is ideal for decorating, I think. Time for some more marquetry! I have thought of all sorts of things over the months: more folk dancers, a breton landscape, different gothic cathedral designs, various symbols, and so on. But those all seemed too complicated or I wasn’t completely sold on the idea. Many just didn’t fit well in a narrow rectangle.

The one I kept coming back to was a floor design on a landing of the Golden Staircase in the Doges’ Palace in Venice, Italy. The picture is from a Newsweek book from the series Wonders of Man that I’ve had since 1973. Glad I hung on to it four almost four decades to help solve this design need.

Lid-DogesPalaceGoldenStairs

Golden Staircase in the Doges’ Palace, Venice, Italy

Based upon the size, this is probably marble, not a parquetry wood floor, but it also would look great done in wood. I like the trompe l’oeil 3D effect. It is also a pattern that looks good extended horizontally in a narrow vertical space. And it looks equally good vertically, if the instrument is standing up.

I scanned the page and warped the perspective out of the floor until the edges were square again.

Lid-FloorDogesPalace

Floor section of picture all squared-up using Photoshop

Then I just had to repeat it to fit the lid and computerize it into a pattern. That was the hardest part, getting the angle right and the widths of the pieces to make it repeat correctly, ending at the proper place in the pattern at the sides.

Lid-Marquetry

Design created to the proportions needed for the lid using Corel DRAW

Lots of pieces, but at least they’re uniform strips. Yes, the ‘height’ of the 3D pattern is a little short. I may adjust that when cutting the veneer strips. On the ‘top’ pieces I decided to add a basketweave effect, which will require extra cutting. If the ‘bottom’ diamonds were a dark color, it would look like holes were were cut in the lid, but I think the contrast would be too glaring. I want it to be fairly subtle. To give it a little breton flair, I plan to inlay some black-white-black edging around it, as on the front of the keychest, and around the edge of the soundboard.

The next step is picking the veneers to use.

Trimming the keychest

Thursday, October 28th, 2010

I put in the wheel for the first time since gluing on the back. I needed to check the fore-aft keychest measurement, because I thought I had the side pieces slightly too long, so that they extended past where the sides of the body attached to the head block.

The instructions say the center of the 7th key has to be exactly 6 15/16″ from the bridge. And the bridge has to be about 7/16″ from the wheel. So, checking all that with the pieces in place, I found that the sides were in fact too long by 1/8″ to 3/16″.

KeychestFitCheck1

Chopstick serving as 7th key to measure proper spacing from the bridge

In the process, though, I discovered something else a little more bothersome — I had the whole keychest way too high. When putting a straightedge on the angle of the wheel, it rested right on the keyshafts! [At least it appeared I had cut the bottom of the sides at the right angle.] The best I could tell, the sides and end pieces needed to be cut down on the bottom by about 7/32″ to have the chanter strings the right distance above the keys. That’s almost a quarter of an inch. How’d I get so far off?

  1. When cutting the bottom edges of the keychest side pieces, I had overcompensated for the curvature of the soundboard. There is hardly any curvature at all to deal with 1 1/2″ either side of the centerline, even though I had doubled the curve amount from that specified. I knew I had to sand the keychest bottom to fit the soundboard curvature, but  I had about 1/8″ extra there — too much to sand.
  2. The wheel seems to sit lower in the body than on the plans. This is not a problem with the plans, but is related to some adjusting I did when making the braces in the body. I had added some 1/8″ thick wood to the tops of the large braces before rounding them. The reason I gave April 15th for this was…

You can see an 1/8″ thick strip of wood has been glued on top of the brace. The short brace is 4″ high, but the two larger braces were 1/8″ shorter. This modification to the larger ones makes all three 4″ high, which is the height of the body. This also makes the threaded hole for the bearing closer to the same height of the shaft hole in the end of the body. I could have sanded down more from the sides of the body and the top of the short brace, but decided to try this.

In hindsight, perhaps I should have made the small brace shorter and sanded down the entire top of the body more. Anyway, this obviously effects the wheel height, lowering it by whatever was left after rounding of that 1/8″ strip. You can see the strips I’m talking about here.

So, this accounts for why I was almost 1/4″ off on the first cutting of these pieces, despite all my attempts to accurately measure the plans. Jerry was good about letting me come over and re-do all these tedious cuts last night. Everything went well, thanks to his careful expertise and excellent tools.

Unfortunately, this necessary shortening messed up the nice double rabbet joint I had on the bottom of the keychest front. Now the base is thinner and weaker than the original piece. I will probably end up adding a second strip on top of the base to reinforce the joint.

KeychestFront12

The front piece after re-trimming, beside original piece

This front piece is now the same height as the original — what a coincidence! I was wondering why it was so much higher before. Hopefully, that’s a positive sign I’m more on the right track, now.

The good news is, if you’re making one of these kits and sticking to the playbook, you won’t have any of these self-inflicted problems. The keychest will be all put together, cut the right size, and everything!

Back glued on

Monday, September 27th, 2010

I’m getting behind here! The back was glued on a couple weeks ago. To try to catch up quickly…

First, the builder’s label had to be glued in position.

BackLabel

Builder's label in place with ermine border I designed

BackInside

Inside of back with label and center support strip

For nostalgia’s sake, I shot two last views of the inside showing the bracing and bottom of the soundboard, before the back was glued on.

Inside-LastView1

Inside-LastView2

And thanks to Leonard for the use of his clamps…

BackGlued

Back clamped in place, t-shirts protecting top and bottom

The big unwanted surprise during this process was how much the back slid around due to the glue before I could get two clamps tight enough to hold it in place. It was quite unsettling until I got that settled. Hopefully, enough glue got into the kerfing to make a good bond, and there wasn’t too much of it smeared on the label.

Soundhole inserts glued in

Monday, September 6th, 2010

We’re making all sorts of progress here lately! I also got the dark brown cocobolo inserts glued in under the “ermine”-shaped soundholes. I wanted the design to be as big as what is seen at first glance, but I didn’t want the actual triangular hole that big. Plus, I was worried about the light soundboard wood cracking along the grain where all the tufts come together at the top, or the two cross-grain tips breaking off at the wide bottom. The inserts glued in the bottom solve all these problems, hopefully — and make it look nicer, too!

If you missed what the “ermine” is all about, see this.

Soundholes5a

A two-tiered soundhole with its supporting cocobolo base

Another thing I did was round the edges of the soundboard holes. I used thin strips of sandpaper like a shoe shine rag, holding it top and bottom and rubbing it over the sides. I still need to file out the corners a little. 

EdgeInlayTiles5a

Same soundhole and edge before the weekend's work

Soundholes5b

The other soundhole with insert glued underneath

The inserts were glued in with carpenter’s glue, but little blobs of epoxy were added along the edge for good measure. I can’t afford to have one fall off once the bottom is glued on!

Soundholes6

Cocobolo inserts viewed from underneath

Outer diagonal inlay 5

Monday, September 6th, 2010

The edge inlay is done! Well, I might round the edge slightly, but the hard parts are done. This post is about the flattening of the edge tiles to soundboard level, another very worrisome task. They were all different thicknesses. Some whites were much thicker than the blacks and vice-versa. Many were rough on the top.

My first approach was encoring the sanding cradle, which had rounded the top to begin with. That got some of most uneven parts, but it was just taking too long. I changed to a sanding block which got them in the neighborhood, but was also grinding in ebony sawdust into my light-colored soundboard. I decided it was time to go with the cabinet scraper, which saved the day and gave fantastic results.

EdgeInlayTiles8

Final smoothing of the inlay top edge with a cabinet scraper

EdgeInlayTiles8a

Close-up 1

EdgeInlayTiles8b

Close-up 2

Outer diagonal inlay 4

Monday, September 6th, 2010

I labored over my hurdy-gurdy over Labor Day Weekend. I was very pleased –and relieved– to get the black and white diagonal edging flush with the edge and flush with the soundboard surface.

I was worried about using a router with a flush trim bit, because I was afraid it would split out bits of some of the tiles, since the grain of the pieces is parallel to the edge. So I did it by hand, first grinding it near the edge with a little drum sander on my Dremel tool. Then filing and sanding it smooth. This was not without its own perils, especially the hand-held Dremel part.

White Post-it tape was put around the body edge to help protect it from  the Dremel sanding bit.

EdgeInlayTiles5

Body clamped into work bench showing Dremel tool and bit used

EdgeInlayTiles5b

Close-up of uneven tiles before smoothing edges to match body

EdgeInlayTiles6b

Another close-up of rough-cut overhanging edges

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Close-up of final smoothed edge

Outer diagonal inlay 3

Wednesday, September 1st, 2010

On the home stretch! Here are tiles #43-48 prior to being glued in. The last slot is numbered so I will know how far I need to apply the epoxy. I also number the bottom of the tiles and put an arrow showing which side fits inward. This is important, because they aren’t interchangeable, and often end up getting knocked on the floor.

EdgeInlayTiles4

I'm almost done custom-fitting these tiles

This is the second side. The first side of 60 is done. The total will be 128.

Outer diagonal inlay 2

Wednesday, August 18th, 2010

I’m over halfway around the edge now! Glued the first six tiles of the other side on tonight, for a total of 68 so far. There were 60 pieces per side, not including what will be on the short neck. There is also a triangular “keystone” piece at the center of the crank end. I figure I have 60 pieces to go, including the neck. I’m putting one long piece along each side of the neck, because the head should cover up this area entirely. I’ll do 4-5 pieces on the neck top, though they probably won’t show either, except maybe their edges.

EdgeInlayTiles3

Sixty two custom fit tiles have been epoxied on in this view

Smoothing the edge and top is really going to be a job. The tiles are different thicknesses.