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Ken_N

Inside First

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Well the mold worked, but if I were to make another model guitar, it would have on outside mold.  It is far simpler.

The sides will need some coaxing to get where they're supposed to be.  This photo shows the high arch on the back. 

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I don't know if it is normal, but the cutaway made a crease in the arching that adds a lot of stiffness.

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It is 350 grams now.  I started doing the recurve at 500 grams.  The tap tone did not drop, it only became more flexible, and there are more tones all over.  It is at 370.  It seems really high doesn't it?  Maybe that's not M5.  Whatever; it's been there the whole time.

I made a little plane to smooth out the groove for the truss rod.  I wasn't going to use one, but "everyone" insisted.  I drilled 3/16 holes along the length first.  It worked great.  Now I'm fitting the joint for the head.  The birdseye for the neck wasn't long enough to cut out the head with the neck, so since it is supposed to be a late 18th century guitar from Guadagnini, I used the typical v joint.  It isn't too hard, but far more trouble than a scarf joint!

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19 hours ago, Ken_N said:

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It is 350 grams now.  I started doing the recurve at 500 grams.  The tap tone did not drop, it only became more flexible, and there are more tones all over.  It is at 370.  It seems really high doesn't it?  Maybe that's not M5.  Whatever; it's been there the whole time.

Your total side depth/height should be around 3" total.  Total means the outer thickness of your plate edges and rib heights combined.  So if 76mm is the total height suggested by me and you have two plates with 4.8mm edge heights each that should equate to let's see............ 66mm or so ribs heights needed only - don't go much higher.

As for m5 tap tone and hz.  These plates very well may be hovering around the 95 hz to 150 hz area when graduated correctly - I'm not really sure.  I'm just trying to compare a smaller plate of a violin to a 4/4 violin plate hz wise.  The smaller plate rings higher tone than a 4/4 plate hence my speculation of a bigger archtop plate ringing lower than a 4/4 violin plate.  I'm not really sure but my point is I'd like to see you get this all right the first time around tonewise and playability.

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The numbers were when I started.  Now it is 4 around the edge.  3-3.5 in the recurve and across the bouts.  The center is from 4-6 mm.   The thickness flow gradually downwards from the middle.  They don't rise at all until maybe 20 mm in.  I want a 10 mm fancy edge, like would normally go around a sound hole.  I'll finish tuning it when it is glued on the sides, and the edgework is in. 

I tapped it just now listening to an online tone generator.  The lower three are balancing on the center, and tapping the edge.  The other five are holding around the edge, and tapping around the plate.  There are notes all over the place.

65 C2

82 E2

109 A2

165 E3

235 Bb3

330 E4

350 F4

370 F#4

Maybe you could just call it E.  

It's no where near flimsy.

The belly is still thick, I want to put the f holes in before I thin it.  It is 350 grams too, and is basically 6-7mm thick, and 5 around the edges.  It is very resonant.  It will end up lower than the back.  It sounds way higher, but it is just so lively.  A quick check gave:

82 E2

165 E3

195 G3

388 G4

It has some flex already.  Not quite as much as the back, but more than the back had when it was 30% heavier.  

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I've done some things on the guitar.  The neck and back are glued on.  The belly is down to 248 grams, and is about ready for the diagonal braces.  I won't make them as tall and wide as suggested in the book.  I want to use nylon strings, and will have a lot less pressure on the belly.  Nylons go from 90 - 110 pounds, while steel has a much larger range: lights at 135 or so, and heavy gauge at maybe 180.    

I figure it at two thirds.  

Once I get the belly glued on, I can cut the edges down, and tune it.  Fingerboard extension, fingerboard, frets, and all the setup and finish stuff.

 

 

 

 

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The guitar is getting sealer on it now, and trying to darken it in the lights, and outside.  The back isn't doing anything.  Maybe it is changing, and I don't notice.  So I decided to finish up one that I am fixing.  I'm sure you guys don't wreck stuff when it's almost done.  I did a whammy on this one.  Wrecked the purfling grooves on the belly, and then figured that the back would be easier.  

One of my low points of not knowing when to stop.

So I pulled off the belly and made a new one.  It was still sitting there and I wondered why I didn't put a bass bar in it, and glue it on. I figured I'd do that, and then remake the back, since I saw the stock sitting on the shelf.  I checked the overhang thinking that maybe I messed that up.  Overhang and purfling grooves get me even before varnish has a chance to get me.  That's when I made up a little invention:  a specialty washer.  It fits my antique (well I've had it since I was at Lawrence Tech back in '74) pencil lead holder and works perfectly.  8 mm diameter plastic, and a 2 mm hole.  It was smooth before the saw started walking down it.  Maybe the surface roughness helps?

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The outline was fine.  I checked the inside arch, and it seemed good, but it needed the recurve put in. Then I checked the thickness.  It's too thin.  NICE!  Hadn't done that one before.  So I decided to make a new belly.  I sawed the billet in halve with my big Ryobi saw.  The BIG one.  Planed the saw cut flat.  Joined the edge, and glued it.  3 hours.  Not bad.  

So this morning I decide to rough it out.  First, I marked out the inside.  

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An hour later it was roughed out good enough.  It's real close. 

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Then I flipped it over and started roughing the outside.  I like to get a lot of it roughed before I saw it out, and it is harder to hold.  I mark the edge and the middle.  I was going for 6 mm with the marking pin machine.  The outside is always WAY thicker because it has SO MUCH stock.  The machine only really works when it is closer.

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Two and a half  hours later, and I had it sawn out, and about 6 mm plus thick.   It does create a LOT of chips:

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Forgot the pictures of the roughed out belly.  About a days worth of work.  I'm retired now, and 6 1/2 hours is a very full day.  I do lots of other things too.

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The other two were 105 and 110 grams.  This is at 200 grams now.  It is a 5 string viola with a violin string length.  It should look VERY COOL when it is done.  

I'm not botching this one up.

 

 

 

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We were out a while today. but I got 3 hours on the belly.  First I spent an hour, and got the pin holes and the cutout for the neck in.  Then I could get the outline cut right.  Then I marked out the f holes, cut them out, and started turning the rough shape into a shape that fits.  The plan is to blend everything in so that it looks right.  It should end up light, strong, and flexible.

9 1/2 hours so far.  This part should be the most fun, but it might take more time than I think.  We'll see.

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20190806_134937.thumb.jpeg.d34c21e4ef807f16b987e5d834089645.jpegMonday I only worked on it a couple of hours, and then I started doing some math to see where the inflection points would be.  I place points 35 mm apart, found the arch height, measured the width of the arch, and figured out where a curate cycloid would change from concave to convex.  It turned out, with this VERY FLAT arch to be 75 to 88 degrees. This is it Tuesday morning.  Well, I guess it's at the top! 

Yesterday, I worked on it for about 3 hours, just scraping it inside, and outside, bringing the whole thing, except the edges to about 3mm.  I'll leave it at that, fit a bass bar to it, and glue it on the sides.  It's 100 grams now, and pretty flexible.  I thought the Sitka was heavy, but I measured a piece of the scrap yesterday, and it is only about .4 sg.  Not bad for Sitka bear claw. 

It's based on a Maggini cello.  I drew one up from a photo, 1/2 size, and it had a 325 scale length.  I thought 5 string.  So that's what it is.

The arch is only a little over 15. I thought it was more, but I'm getting curling.  That would be a violin barely 14, or a cello at 30. I plan on making the back with a higher arch.  Many cellos are like that; maybe about 20 mm. That would be about 18 on a violin, and 40 on a cello.  Cello arches are quite flat aren't they?

So about 2 full days, 15 1/2 hours, to get a belly ready for a bass bar.  Violins are very labor intensive.

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So I have the belly glued on now.  The bass bar was fast and easy.  1 1/2 hours to cut and fit it. 1 1/2 hours to trim it down.  Add in glue time, and a little extra, and it is 20 hours to make a belly and glue it on. And it still needs purfling and tuning.

The tap tone before the bar was 90, 180, 280.  After the bar it is 197/294.

  Very labor intensive.

How long will it take to do a back?

 

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I had a piece for the back rough sawn out.  I started on the inside, and found that going crossgrain, and using the flea market gouge I bought couple years ago, and could never get comfortable with, it roughed the inside quickly.  It needed a hammer, but the worked.  I smoothed the other end with the Lie Nielson and flipped it around to get at the bottom end.  I.5 hours.  

The outside needed a lot of planing.  It was 27 mm thick,  I'm going for 21-22 for roughing to finish at 20.  I planed it down fairly flat, and then roughed a 900 mm radius on the long arch.  Blended it down to about 7 mm at the edge, and it is ready to put the pin holes in, and cut the outline just about to size.  I mark the line about 3.5 mm out, and saw on it, or at its edge, and file them even when the plates are both glued on.  

2.5 hours with my big wooden convex hogging plane.  It makes a ton of chips, and tires you out.  At least it tires me out.

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Thomas, 

I've never heard of that before.  I'll give it a try.  I have 4 thumbnail chisels that I use for scroll carving and scrapers.  I thought about making a longer handle as well.  It has a copper? band at the top to work with a hammer, but if it cut freely, and had more leverage, it should give more control.

I just looked on your thread, and saw your viol.  It seems like the jigsaw sudokus that come up in my daily puzzle set.  A 12 string guitar is one thing, but at least those strings don't go both over and under.

Well done.

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I have the back ready to glue on now.  It took about 18 hours total for it.  A lot of time smoothing out scratches, and grain. That will leave less to do later.  The edge is not done, but it shouldn't have a lot of stock on it; that tends to make purfling disappear.  I've done that before.

It is a little under 140 grams, and has a whole bunch of tones depending on where you hold, and tap it.  

85, 130, 170, 200,218 

 

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I glued the back on this morning.  I cut it out on the line of using the little plastic bushing I made that fits on my mechanical pencil.  It worked great on the belly.  I know there were a couple spots that were close, because I roughed it too close, but there are several spots that are even closer than those were. 

Oh well.  That's the way they will stay.

Tapping the body it sounds like my bigger 425 viola than the 406 viola.  The sound blowing on the f holes is the same as the 425 one too. It's at 207 Hz. and it really vibrates.  I guess they call that the A0?  I'm not that hip.  Looking at that plate tuning site, I guess it is about a fourth or so lower than a violin.  That should work.  Cool.  

How did it get so low?  Maybe the small skinny f holes?  The ribs aren't deep: 35-33 mm.  It's only 385 long.  

Hopefully it will sound like a viola with a E string that works.

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Well, I made it through the purfling.  That's what wrecked it the last time. Double purfling, so I cut the inside groove first, and glued the inlay in.  Then I did the outside groove. 

The belly is ready to finish up:

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The back needs more work.  These Brescian guys had crazy knife skills, were nearsighted, and had a lot of time on their hands.  I have the time.  We'll see how the fancy stuff turns out.

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A few days ago I commented on Jim Bress's Gallery about not liking finish work, or something like that.  It isn't that I don't like finish work; I just wish I was better at it.  I sometimes get impatient with it too.  Rough work, and getting things close is SOOO much easier, and faster.

I got copies of the inlay for the 5 string viola, marked the ends with my curved knife that does a lot of work, and then took the paper off the bottom one, and used a bent tool with a pointy v on it to widen the top of the knife cut.  Then I tried a new trick I found on a guitar forum.  A guy uses a Dremel to cut slots for abalone inlays.  I'm not that brave, but I tried it on some scrap maple, and it worked with the vee slot; if you're really careful.  It doesn't get it right to size, but the slot is easier to cut to size with a knife when the stock is gone from the middle.  A small file works to bring them to size.

It was a bad idea.  I didn't know it until I started to cut the slots with the knife.  

It made it flimsy.  It's only about 2.5 mm there.  I've done this before, but not so far up the body.  I did one line at a time, and got it done, but it has a different profile now!  The entire end rises up from the flat bottom with the long arch.  It doesn't look terrible, and the thickness is still there.  

I haven't filled anything yet, but I'm going to work on that sort of thing.  I always think of it as a lot of bother for people with good eyes; but I guess it's expected!

Well, I saved that one, and I"m only going to Dremel one line at a time.  You've been warned.

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While doing one of those one day at a time; so 6 days; I worked on the finish of the last two violins I made.  I used some 800 wet dry on them, and smoothed them more, taking some of the color off, and getting more of the look that I was going for:  leaves in the fall with sun shine behind them.  Something bold, but natural.  I don't have photos of them,  I'll wait until they're done.

Then I still had more time, so I started the pegs and tailpiece for the Gofriller violin.  It has a cream colored Royal Ebony fingerboard with heavy curl.  It looks cool.  I cut out some cream stock for pegs thinking it was the piece of Ebony.  It was the cream part of a Katalox board that I have cut for another Gofriller (I have three of them started).  It isn't as hard as the black, so I checked to see what it is, I didn't remember.  .81 sg.  That's good enough for pegs and a tailpiece.

I split one peg on the 3rd op. beating on it with a hammer with the center in the end, and made a replacement today.   An hour on the lathe and bandsaw,  (I have to change jaws twice) and about 45 minutes with a chisel and knife cutting the head.  They aren't the greatest, but they'll do.  They do add a little to the look I think.

Nice clear photo, isn't it?

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I'll do the tailpiece to use a modern adjustable tailgut, but I was thinking about eliminating the little stop on the bridge end.  A baroque tailpiece doesn't need them, I can't see what it accomplishes on a modern one.  Is it TRULY needed? Really, I'm asking.

 

 

 

 

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Looks nice Ken. The 80/20 rule seems to be in force with violin making...80% of the work takes 20% of the time, and the last 20% takes 80% of the time. I’m still not happy with my purfling skills. It will be a while before I punish myself with these Brescian patterns. Then there’s the actual finishing (varnish). I really like this part, which I think is a life long learning curve. I need to add more color (cooked resin) to my varnish before the weather turns. 

-Jim 

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I finished up the tailpiece, but looking at the photos at 50 Xs closer than even with my mag light, it could use more refining for the discriminating eye.  Luckily I don't have one, but we'll see what we can do.  

I make them so they balance in the middle.  Does it matter?  I don't know, but it's easy enough to do.  But I try to get them about 16 grams because that's what a couple store bought ones ran, and it is fairly hard to get it balanced for much less than that if you use very heavy wood.  One store bought (IV, because it's so easy) is only about 10 grams!  One of those weird ones with the crease in the top, and flats, not curves.  What's up with that?

I also made it without the thin stop.  Seems superfluous to me.  I made the slots wide enough for one of those tiny fine tuners on the E, and for a set of gut strings, but with a wound G. If anyone wants a straight gut G, a file can make it fit.  A wound D, gut or synthetic,  will just have a little extra room.

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