Bridge fitting problem on Shar Amadeus Viola

[Mike D]

First of all please forgive the leaps of assumptions I will make in this write up.  I purchased a blem Shar Amadeus viola as wrech around for travel etc.   It actually has a pretty nice sound but being an engineer I can't leave well enough alone.  So I did the normal setup stuff soundpost and bridge.  The problem that I'm having is because eventhough the bridge fits perfectly without the strings.  Under string tension the bass side seens to change shape making the end of the bridge pull away from the viola surface.   Is this normal for violas to do this?  I've set up only 2 violas before this and none of them had this problem.   

 

OK so heres where the assumptions start.  In puting in the sound post I noticed little squares of wood down the center line on both the top and the bottom plates.  To make sense of this my theory is that the plates are CNC machined and the wood blocks are just the reminants of this process.  Inspecting the base bar I see no evidence thats its glued in.  Makeing me believe that its also CNC machined.  If this is the case would this viola benefit from a real base bar thats glued in?  Since I'm doing it myself I'm not concerned about cost.  Its more of a fun project.

 

I was also going to experiment with tap tuning just as a learning experience.

The sound of it right now is very nice on the C and G strings actually its perfect.  But its kind of echoy on the D and A strings.  It actually kind of rings when playing on those 2 strings.

 

Any thoughts in regard to changing the base bar?

[Barry J. Griffiths]

I'd be totally surprised if the bassbar and the centerline cleats were 'left' in the viola rather than glued on. What makes you think the bassbar is not glued in place? Also, which part of the bridge foot is not fitting (towards the fingerboard, towards the tailpiece, to the inside, to the outside)? Photos would help a lot. You might also contact Shar and ask how the viola was made.

 

     Barry

[Mike D]

Well I've thoroughly inspected the bass bar as much as I can without removing the top plate.  I cannot see any evidence of glue anywhere along the length of the bar.  When I look at my Eastman and Gliga I do in fact see glue on the edges where the bar meets the top plate.   On the Amadeus the bar looks completely homogenous with the rest of the wood and it seems to actually rise out of the plate itself.

I'm not sure why anyone would glue little squares of wood on the top and bottom plates what would be the purpose of that.  Its not seen on any of my other instruments.

 

The part of the bridge that is being a problem is the side that sits over the bass bar.  

[JSully]

Could it simply be that the shar viola had excess glue wiped off, and is fitted better?

[JoeDeF]

In puting in the sound post I noticed little squares of wood down the center line on both the top and the bottom plates.  To make sense of this my theory is that the plates are CNC machined and the wood blocks are just the reminants of this process.  Inspecting the base bar I see no evidence thats its glued in.  Makeing me believe that its also CNC machined.  If this is the case would this viola benefit from a real base bar thats glued in? 

 

The little squares of wood down the center are probably cleats, which are fairly commonly found in lower-grade instruments.  Cleats are glued in as a sort of insurance against failure of the center joint (though they are not necessary if the center is well joined).  Probably the factory wanted as much insurance against returned product as possible, and added them "to be safe."  They are probably not remanants of CNC machining.

 

Integral bass bars (carved into the spruce top) were common in some earlier eras of factory/piecemeal production, but I have no information about if they are in use today in factories or not.  If the bass bar is integral, the individual grain lines might give you visual confirmation that it is truly one piece.

[Mike D]

Well let me say I have no complaints with Shar instruments.  I think their Concert line is extremely well made.  I was very impressed with the one I rented.    I was just trying to figure out whats wrong with the Amadeus that I have.    And even if I do nothing I'll be happy with it as a camping/travel viola.  Its just that it hasn't seemed to respond to a setup like the others have and I'm trying to make sense out of it.   

 

I can't imagine that  1/8 inch by 1/8 inch blocks of wood would make any difference to structurual integrity of an instrument. 

 

Guess I'll go ahead and pop the top plate off.  It'll be a good learning experience.  Nothing to loose.

[David Hart]

I would need to see a picture of the bridge to know what you're going on about. 

 

Usually I would be looking for evidence the bass bar was carved rather than a lack of evidence it was glued. The CNC machined instruments in China are usually more expensive, as the cost of buying the machinery far outweighs the cost of employing people to make violins by hand. To see if the bass bar is carved in, you would need to see the grain lines matching the top perfectly, and down at the edge where the bass bar meets the top I would expect to see a little rounding where whatever tool used didn't quite reach. In old fiddles you would expect to see bad carving marks both in the top and bar where they'd cut the bar down to thickness.

[JoeDeF]

Well let me say I have no complaints with Shar instruments.  I think their Concert line is extremely well made.  I was very impressed with the one I rented. 

 

If I came across as denigrating the Shar instruments by using the term "lower grade," that was not my intent;  sorry.  I meant factory-made student instruments, a category which ranges from surprisingly good considering the price, to very poorly made, and everything in between.  I would guess that Shar is probably towards the better end of that continuum, though I haven't played or set up any of the Concert line.  Certainly Shar would agree that their student-quality factory instruments are of a lower grade than their luthier-made instruments;  that's what I meant.

 

 

I can't imagine that  1/8 inch by 1/8 inch blocks of wood would make any difference to structurual integrity of an instrument. 

 

1/8 inch by 1/8 inch does sound too small to be likely to be a cleat.  Maybe post some photos - they would help with understanding the bridge/bassbar issues as well.

 

This does sound like a good learning opportunity for you, and a fun project.

[Michael Richwine]

Has anybody ever actually seen a Chinese violin with evidence of CNC machining?  Our people spend a LOT of time in the Beijing area, and work with some pretty big producers, and haven't seen any cnc machinery yet. Chinese government is trying to keep as many people employed as possible, and up till recently, labor has been cheaper than machinery as well.  Some of these workers are incredibly efficient.

 

I would think that carved-in bass bars would be harder to do and take more time than fitted bass bars, and there's no way that the cleats are remnants of any CNC process.

 

Even on cheap violins, glue squeezeout is cleaned up pretty well. I see it on amateur repairs, but seldom on new instruments.

[L.D.L.]

I have been in many violin factories from Guangzhou to Shanghai, and I have never seen a CNC machine used on any violins.

 

My wife is Chinese and been to more violin factories than I have and she has never seen them used on violins.

 

Also, I have never seen them carving in the basebars .

 

 

 

Factory made violins from China are hand made by many different people doing one small part.  They get very fast at it because they are paid by the peace most of the time. (  not just by the hour) . Just for example, one person mint cut out "F" holes all day every day.  Well , if that is all you have to learn, one can get very fast and good at it.

[UG Fiddlesmith]

I hope you avail yourself to considerable reading up on what you propose in popping off the top as it is pretty easy to create a real mess if you don't know what you are doing.  If you pull a lot of splinters the time to repair will be considerable and the value of the instrument will surely decline.  It would certainly be worthwhile to get assistance opening this instrument and don't forget that you have top put the top back on when you are done looking.

[emvln]

I have seen one or two, probably prototypes, but they were definetly cnc'd. The mill marks stood out. Their labor costs are rising quickly. They must at least be experimenting.

[Michael Richwine]

I spent the majority of my life involved in machining wood. CNC machinery has a lot of advantages for many kinds of production, but with violins, there are no parts that can be used directly from the machine. You have essentially the same problems you do with a copy router or a copy lathe. Rotary cutters such as ball-end mills, compress the wood significantly making marks that are very unsightly unless they are planed or scraped off.  They don't come out with hot water or any other technique except for planing or scraping.  You have to take the last half millimeter to a millimeter off to get an acceptable surface.  Scrolls would be even worse, because you'd really need a five axis machine to get any kind of detail, and even then you've got a lot of handwork to do to get anything that looks right. So they would be fine for roughing, but there's still a lot of hand work that has to be done to make an acceptable prouct. The way the Chinese factories work, I'd guess you might save a two to four man-hours per instrument, and at Chinese labor rates, and as productive as they are, it would take a lot of instruments to pay for a $150,000 five-axis machine. Add into that the government's desire for full employment, it might push back the use of CNC machinery farther than one would expect.  I don't know.

 

Just for an example of productivity, in the shop where we buy our rental instruments, the guy who fits the pegs does 200 instruments a day, and the quality is not just acceptable but pretty decent for a student instrument. The peg shafts aren't polished, but they're well shaped and uniform, and they work.

[emvln]

I agree with Mike on the wood compression issue. If you can rough out within 1to 1-1/2 mm at a ratio of 4 cnc plates to 1 hand plate. there would be a profit. A $25,000 3 axis bridgeport would spit them out like crazy, with the person having a minimum amount of skill. The chinsese are good businessmen. They will do what they have to do to make a bigger profit. Just because you have never seen a giant squid doesn't mean they don't exist. One of my many side jobs was a designer/cnc programmer.