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Bill Merkel

machine made violins also CNC "Betts"

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Can anybody describe some of the machines that have been used in the past to make what are termed "machine made" violins?   

 

Also, I was reading about what must be a more sophisticated machine approach using CNC and data derived from scanning the "Betts" Strad.  How did that turn out?

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The basic tool is the CNC router, which comes in a variety of sizes and capabilities.

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All of them run on computer instructions for cutting the shape; the Betts claim to fame is that the geometry from a scan of the original was used directly (with the appropriate translation into cutter language) to program the CNC router.

 

As Christopher posted, the machined plates are never quite like a smooth scraped finish, so that has to be done by hand, and some extra thickness must be allowed for it.

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I've seen a few plates milled out to a nigh-finished surface, and they stress me out. Can't kick your training, I guess. The consensus on the CNCed scrolls I've been around folks with far more experience than me working on is that closer is not better. When copying, the care needed to clean the artifacts of the router up takes more time than producing a new scroll with confidence in one's abilities...

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Well, if you are confident in your ability to clean up a cnc carved scroll then things go very fast. The last time that I did this it took me ~1hour to cnc the scroll and about an hour to carve it down to a look that I liked with small gouges. Then gave it ~30 minutes for a quick cleanup prior to varnishing.

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Here is a link to a webpage about the Betts:

 

http://www.steverossow.com/index.php

 

Rossow Stringed Instruments provides lutherie and custom CNC services for violins and other stringed instruments. It is owned and operated by Steve Rossow and is located in St. Paul, Minnesota.

In addition to designing and building original stringed instruments, Steve Rossow has invented a process that takes CT-derived data of famous stringed instruments and interprets the data, using a CNC machine he designed, to carve out and ultimately re-create historically-accurate replicas. See "Re-creating the Betts."

Please contact us to learn more.

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I think that CNC made instruments, if they can match the tone quality of handmade, might be the evolution in violin making. I would imagine that it is a very polarizing subject.

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I think that CNC made instruments, if they can match the tone quality of handmade, might be the evolution in violin making. I would imagine that it is a very polarizing subject.

 

If one ascribes to the notion that exact taptones, a certain flex under the fingers, or some other interactive experience in making a violin contributes significantly to tonal quality, then CNC would not be a very efficient tool.

If, on the other hand, you believe that dimensional control is the major contributor to tone, then CNC should be able to do just as well as handmade, IF the CNC programmer knows what he's doing.

 

I'm inbetween on this one.  Since I think wood properties are critical (and dictate what should be done carving-wise), a good maker would naturally take that into account as he goes along.  A good CNC operator would have to know ahead of time what to do to adjust the program for various wood properties, if he want to avoid an iterative process with the machine work.  If you can get a person (or team) with the skills and knowledge of a top maker and combine that with a CNC expert, I don't see any reason why you couldn't use CNC to equal that of handmade.  That's kindof a tall order to get all those skills together and agree on what to do, and if they expect to get a decent return for their efforts, it doesn't look cheap, either.

 

Of course, I'm assuming here you mean GOOD handmade.  CNC today can easily match the handmade VSO's that are cranked out by factories or inexperienced beginners.

 

And that's not even getting into the issue of what is good tone, and how you could establish if something is equal in tonal quality or not.

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If one ascribes to the notion that exact taptones, a certain flex under the fingers, or some other interactive experience in making a violin contributes significantly to tonal quality, then CNC would not be a very efficient tool.

 

If it hasn't been done, it would be interesting experiment to compare frequency characteristics of several plates made to within a close tolerance of each other by CNC.  They would be more dimensionally similar to each other than a maker could do by hand and might have the same frequency similarities to each other than a maker works hard to get by hand.

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I think that CNC made instruments, if they can match the tone quality of handmade, might be the evolution in violin making. I would imagine that it is a very polarizing subject.

Using my  CNC for instrument making.

My opinion

While many traditionalist believe the only way to build instruments is the "OLD "  way, the way the masters did.

Frankly, I have trouble with that philosophy.

It's not the tools that makth the instrument, but rather the timber, and shape.

Whether that  shape was  achieved  with  a piece of sharp rock, chisel, or CNC,  is really irrelevant.

Many  imagine their instrument makers toiling away all hours in the dark, with their chisels, spoke plane, then selling  at Aldi prices.

The reality is,  very little time, is spent  using those tools.

And who would want too.

When maybe 95% of your time is taken up reducing  timber into shavings  Who would not want a machine, working unattended, giving  those  precise measurements, in an hour or so. Thus, allowing the instrument maker to put the time into final slivers, and assembly,  and finish.

That  is where the instrument is really made. This is where you need to spend your time.

Not wasting your time turning wood, into shavings.

 

Cheers

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I believe the Chinese violin making competition specifies, no machine made work in their competition.  I just wonder how long it will be, if ever, before all competitions specify the same thing.  By this I mean all work must be hand done ( except pegs, tail pieces, and other accessories ) no copy machines. I know we have very valued members here who use CNC machines, heck I even have a duplicating router table.  Although I presently don't use it, I certainly could.  I find at present I enjoy the hand process, and it is almost as fast if you are doing one at a time. I know this is a slippery slope and I certainly don't want to get into an argument about which is best.  Just thinking out loud here.

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What was the name of the factory that had a movie made of their various operations ??   I mean,  they even glued bassbars without clamps.  No visible CNC here,  It seems the workers roughed and finished plates with hand tools only.  

 

I AM using a CNC,  but I do not have a scanned plate stored as data.   I wanted the machine for establishing arches involving straight and modified curtate cycloids.  I have just finished one top,   and I like the shape.

 

What I DON'T like is what has been pointed up by otheres.....  one has to leave perhaps half a mm to scrape off the tool marks.  I am currently looking into possible other final-pass tools.  What I have used this time is a round-nose grinder with coarse carbide grit.  This does not leave scratches,  the bad thing is that it compresses the wood slightly and you can see the stripes.   (I cut in a raster pattern of lines every 1/10 inch and 100 points transversly.

 

The 100 transverse points are plenty to give a smooth shape.  The 1/10" longitudinally is about as fine as the cutters can use to advantage.

 

As I said before,  this is not to save labor or eliminate "skill" but is to make identical arches to formulas.  The recent one is a relatively small arch,  I can change a single parameter to make a higher arch,  and I will do that in similar wood to see what sorts of differences there may be.

 

As to "no machine" making,  once you clean up the tool marks,  the finish surface is all "hand-done."   That takes skill too,  and I don't see how one could complain that the violin was not "handmade."   (Because,  at least,  my CNC is more a measuring device...  a drill press on steroids.

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I thought the OP was asking what machines have been used in the past- as opposed to those that are now used, ie. CNC.  Some early powered "copy-carvers" were in use in the late 1800's. There was one developed in England, and I wouldn't be surprised if the Germans also made one.  I am aware of at least one luthier using a copy carver, ca. 1900 or earlier, to rough-out scrolls, and at least experimenting with it for roughing-out plates.

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Ron1, I have seen a photograph of a factory in Germany with women running a duplicating machine that carves several plates at once. I believe the cutting mechanism was some type of a circular saw blade on the inside of this machine. I don't believe it was a router type of cutter.

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I think this is one reason why some of those old German trade fiddles sound good. They may not have corner blocks and sometimes the inside of the tops are just hacked with carved bass bars. They usually have nice arching.

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Here is a link to a webpage about the Betts:

 

http://www.steverossow.com/index.php

 

Rossow Stringed Instruments provides lutherie and custom CNC services for violins and other stringed instruments. It is owned and operated by Steve Rossow and is located in St. Paul, Minnesota.

In addition to designing and building original stringed instruments, Steve Rossow has invented a process that takes CT-derived data of famous stringed instruments and interprets the data, using a CNC machine he designed, to carve out and ultimately re-create historically-accurate replicas. See "Re-creating the Betts."

Please contact us to learn more.

Steve Rossow is no longer doing CNC for hire. Nice and knowledgable guy. Spoke with him a few weeks ago.

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Basic woodwork for a skilled luthier only takes a few minutes..... same speed as CNC....It is the final touches that take the time....

Absolutely!

A guy here fits patches with laser scan and cnc, a very fine machine that does a good finish. It would probably take it a week to carve a front...

Not even mentioning the time one needs for maintenance!

it's worth it for things you can't do by hand, ie patches that follow woodworm galleries, but I don't see the point for making. Yet.

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Only a fool would  be critical of anyone’s  hand skills.

 

But, I firmly believe the masters were innovative, using the latest tools and ideas of the day.

If other mechanical means were available, I think they would have been using them.

 

While, CNC’s are  definitely are not for everyone, or for every task. I  feel, the biggest problem associated with  Cnc,   is not the CNC machine.

Like computers, CNC are hi-speed morons,  Garbage In Garbage Out

 

CNC results are only as good as the  image, with out quality Imaging, code results will be poor.

Nobody is giving away  good  quality Dxf, STL Violin drawings , rare, if you are lucky enough to get one,  it’s  still somebody else's  design.

 

Few, are able to produce a 3D image of our own  particular design.  It’s time consuming, difficult   manipulating, fine tuning.

But,  when done, you have your own personal design. your own  individual template.

Full control of  what, how much,  is roughed out, what tolerance you want left, what degree of  finished.  

Hell, why not cut your blocks out at the same time? 

 

Any way, that's what I think. 

Cheers

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Maybe I'm just slow... but working spruce at my fastest, sloppiest pace still takes at least a couple of hours to hog out, and maple takes a lot longer than that.  If the CNC can also do the precise outline and purfling grooves (except for the very tips of the points), that's another bunch of time.

 

IF the CNC can run unattended, then there is no point to comparing how much time the maker and CNC take to cut the wood.  The important efficiency comparison is the man-hours (or person-hours) it takes to do the job.  Others with experience can chime in here, but it doesn't seem to me that you can just throw a slab of wood into the CNC, push a button, and leave the room to do other things.  Setup, indexing, and monitoring likely take time, and that's not even considering the huge up-front project of getting the whole system up and running properly, and getting the 3-D modelling and tool paths established and debugged.

 

Probably even more important of a consideration is the nature of the violinmaking job.  Do you want to sculpt wood with your hands, or do you want to service the technical demands of the CNC?  For some, there might not really be much of an option... a tech-deficient artist, or a klutzy computer whiz, for example.

 

I'm sure I could get CNC going if I wanted to.  But I don't want to.  I like carving wood, generally, except for removing large quantities of hard maple.  At times I could imagine having a CNC and knocking out forms and tooling very accurately and with minimal effort, another one in the plus column for CNC.  And perhaps in the future I won't physically be able to carve wood, making CNC closer to a necessity if I want to continue making violins.  But for now, I prefer the more traditional method.

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I think one looses some vital information in the making process by using CNC. But it is the last part of the work that gives the most important information.. So maybe he finishing scraping and works is good enough? I do not know. 

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