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Bill Merkel

machine made violins also CNC "Betts"

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10 minutes ago, Delabo said:

You are not nit-picking. Your posts on this subject  have been astute and bang on the money. :)

Why thank you!  I'm very glad someone thinks so! ^_^

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I wonder if there's not an element of if I'm going to give somebody $10-20k for something, he's going to work hard for it.  Maybe even some this famous person is gonna sweat and be my slave. 

I wouldn't care what tools were used if the results are what I expected.  In fact I might think the maker was extra bright for not making it as hard as possible on himself.  But I don't see it romantically at all; no interest in violin making lore and imagery.

Usually when a craft is being taught well, you will first learn to use the old methods and tools from the say "golden age", for the sake of a good background.  Then in the next phase you forget that and use modern techniques to get you up to speed in the modern world.  It's up to the craftsman to decide what is lost or gained, from his perspective.

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19 minutes ago, Bill Merkel said:

But I don't see it romantically at all; no interest in violin making lore and imagery. 

Ah, that would explain a lot.

My computer sits here on a 17th century oak table, and next to me is an English walnut bureau with  a beautiful stepped interior circa 1720. Behind me is a handmade Arts and Crafts mahogany bookcase complete with makers label. My wife prefers modern stuff and does not understand my love of old hand made one off items. :)

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13 minutes ago, Delabo said:

Ah, that would explain a lot.

My computer sits here on a 17th century oak table, and next to me is an English walnut bureau with  a beautiful stepped interior circa 1720. Behind me is a handmade Arts and Crafts mahogany bookcase complete with makers label. My wife prefers modern stuff and does not understand my love of old hand made one off items. :)

You're lucky.  We seem to be stuck with our older antiques circa 1910... my computer is sitting on an ~1930s oak office desk, it will be an antique any year now!  :)

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I am sure many of you have sold a good violin to an excited 16 year old grade 7/8 player! They go through an agonising trial of the 6 - 8 violins that I put out for them (both modern and old) Come the moment of truth when 'the' violin is chosen, the ecstatic face, even a hugging gesture - this is 'my' violin and I'll call it ..."virginia' or anna or tony - whatever!

Then the equally excited parents who have just shelled out $1000s - 'so where was it made, by whom, how are violins made, why is it called a Strad copy? I have recounted the Schonbach/Saxon/Miracourt story so many times and each time they hang on  my words just thirsting for the mystique and lore which goes with that unique instrument we call a violin. Sometimes I will spend an hour just explaining the story of violin and always to appreciative ears.

The very thought of a computer controlled CNC would spoil it all!

 

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35 minutes ago, Bill Merkel said:

My computer mainly sits on my knee, circa 20th century.

20th century ?

That's one old and slow machine !

Is it valves or transistors !

You old romantic you :lol:

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I noticed in the VSA thread Christian Pedersen won an award and I was thinking maybe a less expensive way to get one of his fiddles might be to look for a Burak & Pedersen, from the '90s I think.  Then I realized for that purpose it would matter a lot less what tools he used than how involved he was.

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Most better chinese "factory" violins are actually completely handmade by pretty skilled workers and still no one is willing to pay more for these. Many pre-industrial revolution Markies or Mittenwald violins were made by skilled humans and they don't fetch the high prices. If high profile luthier decides to use CNC as one of his tools while maintaining his level of quality I cannot see how he can increase his output to much more than typical 10-12 or so a year.

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5 minutes ago, HoGo said:

Most better chinese "factory" violins are actually completely handmade by pretty skilled workers and still no one is willing to pay more for these. Many pre-industrial revolution Markies or Mittenwald violins were made by skilled humans and they don't fetch the high prices. If high profile luthier decides to use CNC as one of his tools while maintaining his level of quality I cannot see how he can increase his output to much more than typical 10-12 or so a year.

Thanks HoGo for all  your post on CNC and all the other's sharing there cnc expertise , now can you share the steps to go about getting to learn the CNC part of getting a violin profile Thanks

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12 hours ago, carl1961 said:

Thanks HoGo for all  your post on CNC and all the other's sharing there cnc expertise , now can you share the steps to go about getting to learn the CNC part of getting a violin profile Thanks 

I don't want to hijack this forum (or get banned for these sinful CNC ideas) so I will keep it simple, feel free to PM me if you want to ask more.

I'm no expert by far but learned a few things along the way and have few friends with experience who can help me out with new things. CAD work depends heavily upon the software package you use. Solidworks is very different from Rhino (that I use) or others and while some general rules hold in all, the details of the work order can vary. Also depends on what kind of model you want to create - if you want to get general parametric model (that will allow you to change parameters like arching or position of f holes or such easily without redoing the model) you need software that allows it (like SolidWorks) and also decide which parameters you will use already before you start - that is somtething for the next generation of luthiers as it takes time to learn the tricks (todays youngsters grew with computers in their hands so for them it would be natural) I never used parametric myself so I would be more effective using simple models and re-do parts of model manually if needed.

You can start with cloud of points (3D scanning existing part or cloud generated from CT scan by specialized software like in the Betts project) or with drawings. First has it's advantage in copying old deformed, damaged instruments with all the weird surfaces (to the precision that the scanner or CT allows) the latter will be best for designing general violin model for one's own work either basen on old violins or new personal model. You can use this kind of model for copying but would have to allow more room for finishing by hand to add any of the weird shapes.

I will show you my CAD model of mandolin based very closely upon famed "Loar" Gibson F-5 mandolin... This was my first larger project in Rhino I ever created (and I never took Rhino lessons other than reading through help files or doing my own stupid mistakes) adn it came out pretty nicely. Here is simplified version how I created the outside plate surface:  I started with lots of measurements and even got a CT scan of original (thanks to my friend who had a nice one in shop for maintenance and took it to local hospital and they did scan it just for asking - they were so surprised and got curious how it will go...) DIsclaimer - I'm math and IT guy so computers and geometry are natural for me (this is perhaps my advantage over many others) but I believe anyone with good eye and logic thinking can do at least simpler models without lengthy learning. I started by getting good drawings into computer  - I already spent my time drawing them before . I got good scans/ photos (made specifically to avoid distortion) and adjusted them in photoshop to real size (not only size but also any distortion or skew etc, so they fitted the measurements in several directions) I traced all the important outlines and crossectional views in Photoshop and then created full vector drawings in Illustrator. These were exported into Rhino. They were just bunch of lines in one plane so you need to place all the lines into their spatial positions and this created the base from which the smooth surfaces are generated. I used not only few crossections (in my case 5 across and 1 along arch) but also topographical map of arching I generated from some 50 or so crossections from CT scan. This way I got enough data to keep some of the asymmetry of arch (unintentional by Gibson). I checked them all and corrected any misfits (caused by some distortion of arch due to string tension) and adjusted the curves so they all crosed in space like the construction of ribs of ship hull. From there the work is quite simple application of CAD tools to generate smooth surfaces over the curves - there are several methods for this and depends on your data how to do it with best result, but basicly you are ew clicks away from final model of the surface. Inside surfaces are much simpler if you know thicknesses at given points you can generate grid of points shifted inside from the surface of arch by given mounts and then create smooth surface over the points connected to the edge flat (created simply from the original planar outlines).

On violin the hardest would be scroll but there are tools in CAD that allow simple creation of spatial curves from two views (frontal and side), and from there getting the surfaces connecting the curves would be easy. All you need is good presise drawings to start.

My guess would be that good trained (automotive) CAD designer could create full violin model in few hours provided he gets good vector curves (computer drawings) to start with.  Then starts the hard part of fixturing parts, selecting best router bits and cutting speeds for given CNC and how close to the model to cut and creating code(s) for the machine etc.

Here are some views of my model (each part of the model is separate item as in reality):

 

 

CAD_F-5-01.jpg

CAD_F-5-02.jpg

CAD_F-5-03.jpg

CAD_F-5-04.jpg

CAD_F-5-05.jpg

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Just to add to HoGo's post, CAD/CAM can be used for so many other purposes that are extremely relevant to violin making. For example below is visualization tool showing the difference between a pretty serious soundpost distortion as measured and a corrected symmetrical version based on the cinque sections.  These tools allow for a more circumspect view of how these instruments age over centuries and some of the original intent behind their geometries.

 

 

SymonAsym.jpg

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On 11/15/2018 at 5:31 AM, Johnmasters said:

You are assuming that the buyer knows how it was made,  aren't you?  Don't tell them.

Yeah, and if they insist to know,... well Jacob would know how to deal with them.

 

On 11/15/2018 at 5:31 AM, Johnmasters said:

(And I laugh at those who want to cut outlines with a bow-saw and not buy a cheap bandsaw.)

You are right, it`s hilarious. Old Stan, Charlie, Jacques... would be ashamed.

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On 11/14/2018 at 8:46 PM, JacksonMaberry said:

John, out of curiosity, how long does it take for the CNC to rough the exterior arch? 

A pass takes about 40minutes.  My machine is accurate, but primitive compared to store-bought ones.

Also,  I don't hog the wood,  so I probably make three or four passes.  But I can go to another window and read the news or go on the internet.

It is not for mass-production.  If I DID try to set up a factory,  I would use the CNC to make patterns (of hard wood) and use these in a pantograph.

 

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On 11/15/2018 at 1:32 AM, Delabo said:

The term "brain made" describes a huge range of mass produced items which required brain power to build and program a machine to make stuff.

Once your machine is up and running you could leave anyone suitably trained to attend to it. Even if you died it could still  produce violins. Violins made this way are reproducible many times over without either hand or mind being used.

But the term "Mind and Hand" does actually describe how a violin made by hand is produced. And as old age approaches the mind may no longer  function as well, and quality drops off, until the maker succumbs and dies. From that point on violin making ceases by that person. His or hers total lifetime output can now be counted and we can marvel at the skill and beauty that the human mind and hand can produce.

I am not saying that what you are doing is not very clever, it is, but call a spade a spade, its machine made.

It is NOT machine-made,  and this is a stupid prejudice.   The machine roughs out parts, that is all.  there is a LOT of hand-work at the edges and the CNC-cut surface. 

I can see that you have not used a CNC for anything.  Besides,  one cannot tell how things are roughed out.  And if "machine-made" is a valid notion,  what is wrong with it.

I wrote my own programs to do the work,  and I think it is as clever as other practices I read about on this forum.  Everyone seems to imagine their own work going into the future and becoming valuable antiques.

HAHAHAHAHAHAHAHA

 

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22 hours ago, Delabo said:

20th century ?

That's one old and slow machine !

Is it valves or transistors !

You old romantic you :lol:

Delabo-  I think Mr. Merkel was referring to the age of his knee, rather than his computer.

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On 11/15/2018 at 1:01 AM, carl1961 said:

for rhino3d users they have this curtate cycloid plugin, I could not figure it out LOL (yet) you have to know how to enter the info manually

 

http://www.rhino3d.e-cnc.com/curtatecycloid/curtatecycloid.htm

The formulas are simple.  you can subtract a term that represents the radius of the rolling circle and also change variables so that the middle of a cycle is at the middle of the plate.   Simple algebra.

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On 11/15/2018 at 3:34 AM, carl1961 said:

well I've always enjoyed all your help here and am amazed at what you can do. every one in my family at your age, could not even know how to turn a PC on! Thanks for your postings

I am 74,  and my limitiing factor is the boredom after 50 years of doing the same thing.  I still make my own pattern viola,  but I knock off work when it becomes tedious.  I do not have arthritis or any other physical detriments.  Also, even though I am loosing my skill at mental arithmetic,  all tool usage seems to be as though I were younger.

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On 11/15/2018 at 8:06 AM, Matthew Hannafin said:

 

Surely a bunch of brainiacs in Massachusetts know more about violin making than bow-saw users!

That is a cheap shot.  I majored in physics, but that has little to do with what I do in the shop.  I make violas now because they all turn out well.   There are too many violins now anyway.  

I can change arching height with a single change of one parameter.  Also,  finishing the rough arch does require a little bit of an eye.

"Brainiacs"  are just people who have a strong interest in something.  For example math and physics.  Physics may inform a little bit,  but most people miss the boat because of all the problems of damping in each normal mode.  I have commented in the past about things which I would probably take back.   The physics people are nowhere any closer than the traditional makers who use tap-tones or other resonance measurments.

 

 

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1 hour ago, Johnmasters said:

It is NOT machine-made,  and this is a stupid prejudice

I do not wish to derail this thread, and perhaps this could be discussed in a new thread. But meanwhile I only need point you to the comment you made in your previous post...........

  "But I can go to another window and read the news or go on the internet".

You seem to contradict yourself by your own admission that the machine makes the plates while you do something else.

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2 hours ago, Delabo said:

I do not wish to derail this thread, and perhaps this could be discussed in a new thread. But meanwhile I only need point you to the comment you made in your previous post...........

  "But I can go to another window and read the news or go on the internet".

You seem to contradict yourself by your own admission that the machine makes the plates while you do something else.

The machine follows instructions I have given it.   Giving the instructions is not easy.  I spent a LOT of time inventing the programs I use.   You obviously have not tried a CNC approach.  (It is not easy;  it would be impossible for someone with poor math aptitude.)  You must be rather young to still be enthralled with the romance of "hand-made" violins which in any case cannot be defined.

The code has a little more than 13000 lines,  but this is generated by an algorithm I invented.

Your last line pertains to the "last step" in the entire process.  "Makes the plates" .... ridiculous.   You do not know how it works.   How old are you anyway,  and what is your educational background?  A trade-school for violin makers ??

 

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