How do our experts support a violin for alignment and accurate measurement?


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In recent years I have had to deal with the resetting of  two messed up necks (following M. Darnton's very well written explanations on the subject) and other various alignment issues. After struggling a bit (I am still very much an amateur at violin restoration) I have gradually evolved a method of being able to hold the body and neck in the position(s) that I require. A sort of "alignment cradle" if you will.

While I have seen all kinds of helpful pictures and explanations on every subject under the sun here, I wondered why I have never seen much on the subject of how to hold a violin for initial alignment checks, accurate measurements, subsequent neck setting operations, or countless other "alignment sensitive" tasks. Or am I just obsessive/compulsive/insecure about how I do such things? Or just less skilled than most of you at this kinda thing, such that I need a fixture like this  (ok, that is obviously true in any case )?

How do the experts (or amateurs) on this forum hold the body of a violin securely when they have to repeatedly keep rechecking alignment and other such things, say when trimming the base of a neck? Does one eventually just get comfortable and good enough without such a "crutch", or are you guys holding out on me?:(

A few pictures are attached of the method I now use to deal with my "dimensional insecurities". I have found it most useful in discovering where the outer edges of the bouts are relative to the endpin, base of the neck, scroll end of the neck, etc., etc. 

Basically this is just a good quality (dead flat of course) plywood board with some T-nuts installed in the back that allow me to adjust the maple supports that hold the body in exact position relative to the centerline marked on the board. On the board itself I pencil in all kinds of alignment info. I place the violin body in a position on the supports that seems to be the best centerline/string position relative to the centerline marked on the board. I note where the endpin is and where the base of the neck attaches to the body and try to figure out how to best align everything, be that moving the endpin, adjusting the neck (if really necessary), or whatever. By simply placing a small machinist's square or two in the right place I can find the position of the edges of any part of the violin relative to the assumed centerline/string path of the body.

Still to be finished is a way to make an adjustable support under the scroll position and some other details. I sprayed it with cheap shellac to preserve the pencil notations.

For me, the one disturbing thing about using a fixture like this is it becomes glaringly obvious how out-of-alignment many old fiddles were originally built. Apparently the common fiddle, as we know it today, is an admirable example of "fault tolerant" design.

Am I the only "dimensionally insecure/obsessed" person here?:wacko:

 

 

 

 

 

 

 

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Edited by Kev N
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32 minutes ago, Kev N said:

...How do the experts (or amatuers [sic]) on this forum hold the body of a violin securely when they have to repeatedly keep rechecking alignment and other such things, say when trimming the base of a neck?...

For the things you describe, in 30 years of working on violins professionally I have never needed anything more sophisticated than laying the instrument on a cradle on my bench, or holding it in my hands, or in my lap, or clamped between my thighs.  I have devised a few methods and fixtures for clamping a violin body for some gluing operations.

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6 minutes ago, Kev N said:

 

 

No need to hold onto the violin in this way for measuring alignment of the neck. What I do find useful is holding the instrument side ways on a surface plate and measuring distance from the surface to the sides of the nut and or finger board. When both sides measure the same the neck is in exact alignment with the outline of the instrument. The measurement can be very quickly and accurately done with either a machinists surface gauge or a graduated wedge slid under the neck.

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I've only set ~10 necks, but all of them have been correct, and I've always done it the seat-of-the-pants way.  If you're anywhere close to a good fit, it'll hold itself firmly in place.  I just push in the neck until it tightens up, and then I can take the measurements freely in my lap.  Pop the neck out, take off a few curls of wood, and repeat.  

If you've had good results with your jig, stick with it!  No sense messing up something that works for you.  

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1 hour ago, chiaroscuro_violins said:

I've only set ~10 necks, but all of them have been correct, and I've always done it the seat-of-the-pants way.  If you're anywhere close to a good fit, it'll hold itself firmly in place.  I just push in the neck until it tightens up, and then I can take the measurements freely in my lap.  Pop the neck out, take off a few curls of wood, and repeat.  

If you've had good results with your jig, stick with it!  No sense messing up something that works for you.  

What measurements are you taking that tells you the neck is correct?

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3 hours ago, nathan slobodkin said:

No need to hold onto the violin in this way for measuring alignment of the neck. What I do find useful is holding the instrument side ways on a surface plate and measuring distance from the surface to the sides of the nut and or finger board. When both sides measure the same the neck is in exact alignment with the outline of the instrument. The measurement can be very quickly and accurately done with either a machinists surface gauge or a graduated wedge slid under the neck.

Very elegant solution. Love it!

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1 hour ago, nathan slobodkin said:

What measurements are you taking that tells you the neck is correct?

  • Centered at the mortise
  • String length (usually 6mm mortise depth)
  • Tilted over towards treble by 1mm (cellos go the opposite way, but I haven't done a cello neck)
  • Aligned with the centerline of the instrument
  • 6-7mm overstand at neck heel
  • End of fingerboard 21mm above belly
  • 29mm projection at bridge, resulting in 33mm high bridge (EDIT: the projection should be 27mm or 28mm, on the off chance someone should use this for reference.  The error is explained later in this thread)

Do I miss anything?  This is how I was taught to do it by my master.  I can't think of any measurements that couldn't be taken with the fiddle in the lap.  

Edited by chiaroscuro_violins
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Thanks for your thoughts guys.

Nathan, maybe the story on why I first made it will help a little to answer the question, I hope....

I guess I didn't really mention it, but the way the jig came about had more to do with a few complicated rebuild/alignment situations than simply mounting a neck on a "normal" or new violin. It happened several years back when I ran into an old lower-end German instrument (roughly turn of the century) where the bouts were not at all symmetrical, the end pin was off, and the neck was also badly off in 3 axis (height, angle laterally and vertically due to a previous "repair") as well as the pegbox being badly twisted making it hard for her to tune or so she felt. Her leader (who she says played a Strad, but I wonder) apparently called it a "planter" . Well, every great violin has a name, right...^_^.

Anyhow, she was under no delusions as to it's value, but wondered if I would be able to do anything at all with it since it was worthless as it was. All this despite the fact that I had never even touched a violin before (although I should admit that I have spent decades doing all kinds of fairly precise woodworking and engineering work, etc.).  So, there I found myself trying to figure out exactly how to make a silk purse out of a sow's ear, so to speak, and get the strings to somehow "split the difference" with all these problems and at least feel more functional. That was where all the setup advice offered here was truly invaluable. Thanks.....

I realized that the best way for a noobie like me to visualize the string path and all my options with neck adjustments, end pin changes, etc was to be able to both hold everything in the desired new location, use a long straight line to take measurements and check alignment between the F holes, end pin, all along the fingerboard, etc, and try to at least balance those with the asymmetry of the bouts. That was where I realized how much a fixture of some sort could help an inexperienced amateur like me in such a difficult situation. Thus the fixture.

I won't say that in the end the job I did could put any real luthier's job at risk, but at least she was amazed at how much better it sounded (do I have to mention that the bar was pretty low by that point?:lol:). It was a blast though, but I have always enjoyed being in over my head a little. And it led to an addiction, fixing the occasional violin......

 

 

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4 minutes ago, chiaroscuro_violins said:
  • Centered at the mortise
  • String length (usually 6mm mortise depth)
  • Tilted over towards treble by 1mm (cellos go the opposite way, but I haven't done a cello neck)
  • Aligned with the centerline of the instrument
  • 6-7mm overstand at neck heel
  • End of fingerboard 21mm above belly
  • 29mm projection at bridge, resulting in 33mm high bridge

Do I miss anything?  This is how I was taught to do it by my master.  I can't think of any measurements that couldn't be taken with the fiddle in the lap.  

 

5 minutes ago, chiaroscuro_violins said:
  •  
  •  
  • 29mm projection at bridge, resulting in 33mm high bridge

Do I miss anything?  This is how I was taught to do it by my master.  I can't think of any measurements that couldn't be taken with the fiddle in the lap.  

29mm seems quite a bit high. I would consider that a failed neck set.

Who is this "master" that you reference over and over?

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18 minutes ago, arglebargle said:

 

29mm seems quite a bit high. I would consider that a failed neck set.

Who is this "master" that you reference over and over?

Message me.  I'm not going to post identifying information publicly.  

Also, I will point out that the OP was asking for opinions from:

5 hours ago, Kev N said:

experts (or amatuers)

I'm not claiming to be an expert.  However, does it matter terribly for this discussion exactly what measurements I use?  The question is not what the numbers are, but how you hold the fiddle when you're measuring them.  I assure you I can make it exactly 25mm if you like using the same method I've been using.  

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If the neck mortise is tight enough it comes down to a matter of checking that it is aligned with the centreline of the body. Using plate edges seems an unreliable way of doing this to me.

 

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19 minutes ago, chiaroscuro_violins said:

 However, does it matter terribly for this discussion exactly what measurements I use?  The question is not what the numbers are, but how you hold the fiddle when you're measuring them.  I assure you I can make it exactly 25mm if you like using the same method I've been using.  

Yes it does, if you are advising someone to set their neck at 29mm.  Why not use 35mm? Or 50000000mm? If the measurements don't matter, then f**k it. You yourself said 29mm projection. Did you mean that? Again, setting a neck at 29mm is a failed neck set in my book. So what were you saying?

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1 minute ago, arglebargle said:

Yes it does, if you are advising someone to set their neck at 29mm.  Why not use 35mm? Or 50000000mm? If the measurements don't matter, then f**k it. You yourself said 29mm projection. Did you mean that? Again, setting a neck at 29mm is a failed neck set in my book. So what were you saying?

No, I'm not "advising" anyone to do anything.  OP asked about methods to take the measurements.  I answered that.  @nathan slobodkin pried me about my measurements, which I provided *off the top of my head*.  This was never intended as advice to anyone.  

On closer examination of my notes, the number I use is actually 28mm.  As a relative novice violin maker, I haven't committed all the numbers to memory, and 33mm bridge - 4mm action = 29mm fingerboard projection.  Thankfully I don't set necks without consulting the notes!  

I've seen the number 27mm from other trusted sources.  I simply do not use that measurement.  The only explanation I have is that I was taught to use 28mm.  

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1 minute ago, chiaroscuro_violins said:

No, I'm not "advising" anyone to do anything.  OP asked about methods to take the measurements.  I answered that.  @nathan slobodkin pried me about my measurements, which I provided *off the top of my head*.  This was never intended as advice to anyone.  

On closer examination of my notes, the number I use is actually 28mm.  As a relative novice violin maker, I haven't committed all the numbers to memory, and 33mm bridge - 4mm action = 29mm fingerboard projection.  Thankfully I don't set necks without consulting the notes!  

I've seen the number 27mm from other trusted sources.  I simply do not use that measurement.  The only explanation I have is that I was taught to use 28mm.  

Fair enough.

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Let me add, before this goes off the rails, I really like the jig that Kev N (OP) made. It's a little overkill for the task at hand, but very well executed and very well thought out. Cheers to you! One of the best parts of this is always having the opportunity to think and problem solve and create. And you have done all three. Keep it up!

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Chiarascuro .and Dennis J,

I have many times set 6-10 necks in a day on new instruments and while the OP's jig seems needlessly complicated I can understand how it works. I am curious how one accurately measures the relationship of the neck to a center line without referencing the outline. Centering the mortise on the center line can be easily measured but of course one can pivot the neck in either direction leaving that measurement intact. Are you simply sighting the edges of the neck on a target bridge to get your second measurement?

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Since I don't do repairs where I need to reset necks, I get a lot of the primary alignments by being very careful about assembling the body to a precise centerline.  Then the remaining major alignment is getting the neck on.

For a fixture, the backbone is a 4x4 post, with some edge restraints bolted to it.  The violin is held vertically so I can easily illuminate and work on the opening, and sight along the fingerboard for alignment to the bridge.  The bridge is held on the body with a spring clip, with markings to indicate projection.  Strapping is a failsafe, in case the body pops out of the restraint... which hasn't happened yet.  I put light pencil marks on the side of the neck for overstand and neck length settings.  There are some alignment markings on the neck block to show where the centerline is.  The edge restraints aren't the best; I mean to rework it some day.

My guiding principles in this design:  1) Being able to see well and work easily on the mortise, with two hands free.  2) Minimize or eliminate handling of the body.  

 

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6 minutes ago, nathan slobodkin said:

Chiarascuro .and Dennis J,

I have many times set 6-10 necks in a day on new instruments and while the OP's jig seems needlessly complicated I can understand how it works. I am curious how one accurately measures the relationship of the neck to a center line without referencing the outline. Centering the mortise on the center line can be easily measured but of course one can pivot the neck in either direction leaving that measurement intact. Are you simply sighting the edges of the neck on a target bridge to get your second measurement?

This time I'll be up front about it: take me with a grain of salt!!  This is just how I do it, in response to being asked how I do it.  

When I'm making a new violin, I make sure the f holes and the saddle are perfectly aligned with the geometric center line.  I align the neck first by eye, and when it looks good, then I get out the rulers.  I put the rulers along the edge of the neck/fingerboard and see how they align with the f holes (which I know are centered).  This way I can measure the alignment very accurately.  

With a repair, it is a bit different.  I still use the f holes and saddle as the main reference points, but I have to make sure they're in the right place.  If they're not, I make a note of how far off they are and correct the alignment accordingly.  Extra care must be exercised if using the rulers, because a finished neck is not guaranteed to be perfectly straight on both sides.  I also have used your method of aligning the neck with the plate outline, if it's not too wobbly.  

Hope this all makes sense!  I'm always open to advice.  

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2 hours ago, nathan slobodkin said:

Chiarascuro .and Dennis J,

I have many times set 6-10 necks in a day on new instruments and while the OP's jig seems needlessly complicated I can understand how it works. I am curious how one accurately measures the relationship of the neck to a center line without referencing the outline. Centering the mortise on the center line can be easily measured but of course one can pivot the neck in either direction leaving that measurement intact. Are you simply sighting the edges of the neck on a target bridge to get your second measurement?

What I'm saying applies to new instruments, or at least test fitting a neck minus the fingerboard. That is to line up a centre line on the neck gluing surface with the centre join of the top plate.

That can easily be done with a straight piece of aluminium shaped to do the job.

 

 

 

 

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15 hours ago, Kev N said:

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if it works for you then use it.  

  when it is neck alignment time for me about the last thing i do is run a length of yellow stren fishing line taped into the pegbox so that the line divides the center of the nut, center of the fingerboard end, hopefully the bridge centerline without the bridge and finally over the saddle with some weight tied to the end - hopefully the line runs right down the middle of the end peg centering.

  After eyeballing using the line for alignment i walk away and come back later to see what there really is to work with.

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