Dumb mistakes again


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A few months ago I started a scroll for my Allard model. I used Manfio's method and glued a scan from the poster and its flip to my blank. Figured I'd maybe get one closer to being right. I finished the scroll up yesterday, except for the fluting, and was opening up the pegholes with the tapered reamer, and realized the holes were in the wrong place! I drilled them right dab in the center of my glued on pattern, but they were apparently just drawn in anywhere. The A peg is way out of reach. I haven't reamed the A yet, and the rest are still undersize, so I might be able to fix it. I guess the easy way isn't so easy.

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Well Mike, a few days ago, I applied glue to a corner block before I realized that I had bent the C-bout rib backwards, leaving the rough side out. (I plane the outside surface when the plane blade is sharpest)

Fortunately, I had enough rib material to bend a new piece.

Unlike mine, the result of your faux pas could be considered artistic. :)

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Unlike mine, the result of your faux pas could be considered artistic. :)

Yes, there are makers who deliberately reverse the slant of the flame in the middle bout ribs, resulting in the flames at the corners coming to a point at either the top or bottom corners. The effect is quite striking and attractive.

Here's an example from David Van Zandt's website, vanzandtviolins.com:

converging flame corners

Of course, if you do it to one C bout rib, you might want to do it to the one on the other side, too; or maybe not.

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A few months ago I started a scroll for my Allard model. I used Manfio's method and glued a scan from the poster and its flip to my blank. Figured I'd maybe get one closer to being right. I finished the scroll up yesterday, except for the fluting, and was opening up the pegholes with the tapered reamer, and realized the holes were in the wrong place! I drilled them right dab in the center of my glued on pattern, but they were apparently just drawn in anywhere. The A peg is way out of reach. I haven't reamed the A yet, and the rest are still undersize, so I might be able to fix it. I guess the easy way isn't so easy.

Well you can fix that one, and since you didn't screw-up the A peg, then that is good.

If you are not going to screw-up on one peg, then I would sat the A peg is the one to not screw-up!

So I guess you could say your glass is half full then ....of green beer!

And your belly is half full with the other half of that green beer!

Happy St. Paddy's Day!!!! Oh I miss that beer mug emoticon !!!!!!!!

Please note that April Fool's day is next inline!

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I applied glue to a corner block before I realized that I had bent the C-bout rib backwards, leaving the rough side out.

I just noticed I've done the same thing with two of my ribs (which were bent and glued months ago).

Well it's good to know the fiddle will be nice and smooth looking on the inside :)

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Hmmm... I'll see your disagreement, and raise the pot by another.

It is interesting that you should allude to the Coriolis effect. This phenomenon was arguably the most influential one I ever came across with respect to fact checking.

Many many years ago, I had stumbled upon the claim that the Earth’s rotation determined the direction of spin in a vortex, such as a draining body of water like a tub or sink. I even told others of this as a matter of trivia, only to later learn that while the effect exists, it is far too weak to manifest on its own accord and is swamped even by very small currents present in initial conditions. I felt duped, and vowed never to utter another fact of physics without having adequately corroborated the validity with good sources.

Clearly his mislabelling had something more to do with him being on the wrong side of the planet, and thus he is merely upside-down compared to the rest of us.

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I can remember as a young undergrad physics student learning of the Coriolis effect -- thru a great story about the gunners in British Navy firing their long-range guns near the Falkland Islands, and missing by a tremendous amount until factoring this in. At last I could put a name on those stories about southern toilets draining in reverse direction.

Then our professor, when faced with this, said that no, it wasn't true, citing initial effects etc., etc. He actually was a good professor, nice fellow, very smart. We all wrote it down.

Except one guy. Later, he watched the water drain in the sink we had in our student lounge. Watched which way it spun. Then filled it again, and before draining, set up a whirl in the counter direction. Pulled the plug. The water drained. The spirial motion he set up slowed, and then reversed itself into the direction it wanted to go.

So I to this day don't know what's correct about the Coriolis effect and toilets. I did learn, though, that just because someone smart said something is or isn't so doesn't make it that way.

Back on topic: many years ago, on a violin, I fit the e-peg in the hole closest to the nut. Proceeded to fit all the pegs in following that pattern. Looked at what I had done, and then learned how to make bushings.

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My conjecture is that something (or several things compounded) in the sink's geometry or construction favoured one direction, and this overwhelmed his effort to counter the effect. The fact that the favour would fall to the correct direction for the Coriolis effect was even odds, so this does not say too much. It might have even had root in the drain, and thus was not visible to inspection. My own experiments seemed to confirm the ability to induce a change in vortex direction, but since the effect is real, in an ideal container, there is clearly some realm of ideal initial conditions where the effect could manifest.

According to a Wikipedia article in 1962, an MIT professor named Shapiro proved the Coriolis effect does manifest with ideal conditions in a perfect sink.

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I've watched the bathtub drain on many occasions and noted often the water will swirl one direction for awhile, only to slow down and reverse direction, and then eventually revert back to the original direction sometimes. I haven't noticed any definite pattern. The biggest thing I've noticed is this factor hasn't helped me to build a better violin yet.

Don't outboard motors need a reverse pitch prop to move forward in the southern hemisphere? :)

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lol yeah... well it is MY conjecture that water spinning around has nothing to do with the topic (or the board, for that matter), and the continuation of such a conversation would lead to SPAMMING of this thread, ultimately resulting in a global disinterest and frustration at the inability to continue a constructive yet comical conversation. 

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Here is my latest dumb mistake. I often use blue painters tape to keep track of various pieces during a repair, a small splinter, etc., that I tape to the inside plate of the violin. On this particular fiddle, I had "saved" the sound post just in case it happened to fit after reassembly. I found it after fitting a new post and peeking inside to admire my post fit. :)

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That's at least funny, and easily fixable. I'm pretty sure I've posted all my dumb mistakes as I make my first violin, such as making the plates too big (requiring resizing of the garland) or gouging the scroll cheek with the bandsaw. Of course, I've always got the "newbie" excuse, but hopefully I won't repeat the same mistakes on my second fiddle...

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I fitted the bar on the wrong side some years ago....

Sorry that my first post to this forum fits this category, but I just fitted, glued and tapered my violin bass bar before thinning it to 5.5mm. I'm wondering if I should attempt to fix this - risking damaging the top plate - or leave it at the current 6.3mm?

TIA,

--Bruce

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