 The Clarinet BBoard
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Author: Dan Shusta
Date: 2010-01-05 06:57
I remember reading a response about the difference between "measured" facing length and "actual" facing length with the reed installed.
Now, I don't have any fancy, expensive measuring equipment. So, I had to improvise. I learned on the internet that "see through" "cleaning paper" used to dry pads is either 0.0005" or 0.0008" inches thick. The standard measuring tool for determining facing length, if I remember correctly, is 0.0015" inches thick. So, I reasoned, that the "cleaning paper" would give a more accurate reading of where the actual facing or curve away from the table begins. As for a measurement tool, while shopping at WalMart, I noticed a small metal ruler that gave measurements in inches as well as centimeters. (One inch equals approximately 2.54 cm, which equals 25.4mm which, when converted to 1/2mm steps equals 50.8 1/2mm steps per inch.)
So here is what I did:
1. I polished my mouthpiece table by rubbing it on a single sheet of newspaper which was laid on a flat plate glass. I wanted to make sure my mouthpiece table was flat.
2. I "reversed" my Fibracell reed and placed it on the mouthpiece about 1" above the lower edge of the window. I held it firmly in place with my left thumb.
3. I inserted the "cleaning paper" until it stopped. The stop was abrupt because any further pressure would instantly start the paper to fold or crumble.
4. I moved my left thumb over to where I estimated the bottom edge of the cleaning paper was.
5. I put the mpc close to the computer screen for increased background lighting, placed the bottom edge of the ruler on my thumb and, because the "cleaning paper" is almost transparent, I read the ruler and came out with 34. The reading was the same on both rails.
6. I next installed the reed in my normal fashion.
7. I, again, gently inserted the "cleaning paper" until it came to an abrupt stop. I must say, I was surprised and quite puzzled at the results. For what I came out with was 41/42.
I checked the reed. Perfectly flat. I determined this by placing my thumb on the butt end of the reed on a flat surface and I could not insert the "cleaning paper" under the reed end. I also noticed that the reed end made no upward movement. I did the reverse and came up with the same results.
So...I appear to have a perfectly flat reed and a perfectly flat mouthpiece table and yet, the facing measures much longer when the reed is installed. (My ligature is a Rovner SS-1R with all of the inner bands cut out basically turning it into a Rovner "light" ligature with the upper band placed directly next to the edge of the mpc window.)
I'm not sure if any of the above has any useful value. I would like to know why there is a difference. Also, I sense that the increased facing length affects the playing performance of the mouthpiece.
Any suggestions, comments, ideas or speculations are most certainly welcomed.
Dan Shusta
Madisonville, KY
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Author: kdk
Date: 2010-01-05 11:55
One problem may be that your initial measurement with your thumb has lots of room for inaccuracy. If you want to measure the actual start of the curve, even thin cigarette paper may be too thick, but also the placement of your thumb was an estimate and your thumb is too mushy to measure anything that fine.
It might work better to use a piece of plate glass with measurements marked down its length from a clean edge (like a standard mouthpiece gauge that comes with refacing kits). moisten the glass, put the mouthpiece on it lining its tip up with the starting edge of the measurement scale, and then looking through the glass to see where the mouthpiece loses contact with the moisture. Even this includes some error because of the thickness of the water film on the glass, which may or may not be thicker than the paper you're using.
Whether or not you'd still get different measurements with the reed off and on the mouthpiece, I don't know. There is often a deliberately placed curve in the table that is supposed to make the reed more springy when a ligature is tightened over it. Maybe your ligature is actually pressing the reed slightly into such a curve and forcing (as the curve is meant to do) the reed out a little away from the table. Or the difference may be caused by the difference in the way each measurement was taken.
Of course, beyond a certain point it may not really matter. The measurements that people talk about, including the one with the .0015" feeler, are meaningful only as one way of comparing mouthpiece facings to each other. As long as everyone involved in a conversation about facings is using the same reference points, mouthpieces can be compared. Hand re-facers who are interested in more precision need to use more feelers - more reference points along the curve. The manufacturer of the blank is probably the only one who has the ability to control the dimensions at the level you're trying to see.
I think a little caution is appropriate, though, about polishing the table of a mouthpiece before checking any of this. Cleaning it thoroughly is one thing, but if in polishing it (rubbing it against anything - even newsprint) you take anything off the surface of the table besides dirt, you could alter the mouthpiece's playing characteristics. Keep in mind that many mouthpieces are not designed to be flat - they are cut slightly concave (as I mentioned before) to increase (in theory) the spring of the reed and improve response. Flattening the surrounding areas above and below the curve could result in less curvature. The small amount you'd scrape off is probably negligible, but it might be enough to move that contact point with the reed a nanometer or two or close the tip opening an infinitesimal amount. I'd avoid that step just on principal.
Karl
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Author: BobD
Date: 2010-01-05 12:41
With all due respect,Dan, what is the point? First of all, even when one uses the standard tools and protocol one can get different measurements on successive trials. Second, it is, I believe, common knowledge that ligatures affect reed positioning. Perhaps you are actually attempting to illustrate that determining facing length is a nebulous exercise......or that the Earth is not really flat.
Bob Draznik
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Author: stevesklar
Date: 2010-01-05 12:49
Dan,
I'm not sure what your objectives are .. but
It's very hard to gage a mouthpiece without the proper equipment. The smallest gage that we use is 0.005 inches in thickness (some may have thinner). This gives us an approximate location of the starting point (after all, it's not "0" which is the actually starting point). We then use a variety of slightly thicker gages to measure the facing curve of each rail.
You could actually go to an automotive store and get a set of 20 flat sheet spark plug gages as a starting point.
I've always checked for the flatness of a table by using a razor blade with a strong light source behind the mouthpiece. Place it in various areas of the table from top to bottom and left to right and at angles to check the complete flatness. This is probably the easiest quickest method to learn.
The metal ruler is a good idea. In the Morgan mouthpiece gage sets it comes with a glass ruler which allows you to more easily see everything.
The primary issue you will find with using any ruler is getting used to not moving the ruler and (re)setting it at the tip properly if you accidentally move it .. as any movement will make the previous numbers useless if it is not put in the same place each time. Butt it up against something flat but you also have to make sure both are parallel to the object.
I hope that helps.
fyi, here some compiled info I have on some mpcs, much more not listed
http://www.clarinetperfection.com/clmpcdesign.htm
facing and tip info
http://www.clarinetperfection.com/clmpcTypes.htm
general info
http://www.clarinetperfection.com/clmpcNomenclature.htm
also keep in mind. when playing above the initial curve, especially way above many players actually bend the reed and their actual staring point is further up the facing curve. Putting the reed on a flat surface after playing helps correct this. I've seen some really bend reeds after it comes off the mpc.
somewhere I have a link to a recording of playing at various positions of the curve and you can hear the tonal variances from close to the tip and moving further down the curve to the point of where the reed separates from the mouthpiece.
the various facing lengths do affect the playing characteristics of the mpc. Also the tip opening affects things too. The facing and tip info page may have some info on what you are looking for
also, read this Vandoren mpc page on various examplse and Vandy's descriptions
http://www.clarinetperfection.com/clmpcVandoren.htm
Good luck .. hope the above helps a little
the earth isn't flat ??
geez .. next someone is going to tell me Santa Clasu doesn't exist. =-)
edited - made the links work
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Stephen Sklar
My YouTube Channel of Clarinet Information
Post Edited (2010-01-05 12:54)
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Author: Dan Shusta
Date: 2010-01-05 15:04
My point in all of this is to try and determine what caused the facing length to change. I'll try different ligatures today and see what happens.
IMO, if the facing length increased, the tip is probably more open and, if this is true, IMO, the mpc may be more resistant to play.
I simply want a 34 mpc to play like a 34 and not like a 41.
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Author: knotty
Date: 2010-01-05 15:38
I wonder if the change in facing length is because of the ligature's compressing pressure on the reed, distorting the reed a bit?
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Author: Dan Shusta
Date: 2010-01-05 15:54
That's pretty much my theory. I'm beginning to wonder if different ligatures affect facing length and tip opening by applying pressure to the reed at different points depending upon the type of ligature used.
I was beginning to wonder about the flatness of my mpc table, but gently placing the metal ruler on the table showed it to be perfectly flat.
I'll try some different ligatures later on...
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Author: Caroline Smale
Date: 2010-01-05 20:30
A technique I use for measuring closer to the "real" lay length is to cut a small piece of kitchen foil and burnish the straight edge flat on a sheet of glass. This produces a rigid feeler blade of 0.0005" or less with the grade of foil we typically get over here.
Used in conjunction with a glass guage you can read the length very accurately and also see the eveness of the start of the lay very clearly.
If you don't have a proper glass guage its quite easy to make up a usable alternative with a narrow piece of plate glass scribed with your preferred measurement symbols. Use the scribed side against the lay to prevent parallax (sorry if I'm teaching you to suck eggs!)
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Author: Dan Shusta
Date: 2010-01-05 21:31
Well, I did some testing. To sum it up in short, different reeds along with different ligatures produced different results. The worst readings I got was with a Rovner Dark ligature. No matter how hard I tightened the screw, I could slide the "cleaner paper" almost all the way down to the ligature!
As I stated earlier, perhaps all of this has little to no value. However, the more testing I do, the more valuable a tool it appears to be "for me".
IMO, one of the important aspects of any ligature is to "seal" the reed to the mpc. Any "leakage", IMHO, simply adds more resistance which makes tone production more difficult.
In my tests, the Fibracell "sealed" better than a newly flattened cane reed (I used 600 grit sandpaper) and the modified Rovner "Light" far surpassed the "Dark" ligature in clamping a majority of the reed body to the mpc.
FWIW
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Author: Arnoldstang
Date: 2010-01-05 22:20
One thing I have noticed in my refacing experiments is that if the table is not absolutely flat it is quite common to get different facing length measurements when you press with thumb in different locations. If it is flat then there is more consistency even if you move the thumb. I would assume the ligature would create inconsistencies with the same non flat table. What is amazing is that many things work! The significant measurement for facing length might even be the length when you apply your own unique embouchure pressure. This might even out the numbers. Let's face it the reed vibrates with your embouchure on it....it isn't a bagpipe chanter reed that acts independently of embouchure pressure.
Freelance woodwind performer
Post Edited (2010-01-05 22:29)
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Author: stevesklar
Date: 2010-01-06 08:39
Dan,
You've hit on the point of why one of the reasons a glass plate is used for measuring. A reed gets warped from playing, may change flatness from humidity, even when you push it at various locations on the mpc you may bend it slightly .....
The glass is much more stable and you can see through it.
The synthetics will (should) be more stable than any cane reed.
The reed should start going away from the curve at the curve area - of course ones embouchure may also warp the reed down. If there is space after this curve from the reed to the mouhtpiece you can get air leaks.
Some initial experiments from people trying to reface mpcs is that their curves are uneven and sometimes goes well into the table.
As you test more you will want to improve your technique and improve your equipment. This will give you more consistent tests and you should be able to duplicate measurements.
At one point I was also interested on how ligatures hold a reed. I took a variety of ligatures, tried to use a consistent pressure, and used a mocked up foam reed to see how the various lig forces acted on a reed. I documented my summary findings on my website.
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Stephen Sklar
My YouTube Channel of Clarinet Information
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Author: Dan Shusta
Date: 2010-01-06 14:01
Stephen:
Perhaps a misconception exists here. I wasn't refacing a mpc and trying to check to see how well I was doing. I was merely trying to develop a simple technique in which anyone could check to see if their actual, reed in place, facing length was equal to, near, or very far away from the measured, true facing length of their mpc.
Yes, I've used a glass gauge before. I don't have one now (wish I did!), but that really wasn't the point of what I was doing. I just wanted a simple way to check "real world" playing length of the facing and, IMHO, I think I've done just that.
Sliding the "cleaning paper" clear down to the ligature means that something is clearly wrong. Either the mpc table is not flat, the reed is warped or maybe a combination of the two.
(Do you or anyone else know where I can get another glass measuring gauge? I keep emailing JJ Babbit about it but get no response.)
My thanks to all of you for your comments.
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Author: Brad Behn
Date: 2010-01-06 17:53
Jim Green is the product manager at Babbitt, and he is the person you should contact. They do have glass gauges as well as tip gauges calibrated to thousandths of an inch. Also they offer the five standard feeler gauges: .0015, .010, .024, .034, .050, all at a reasonable price.
Babbitt's phone number is on their "History" page: http://www.jjbabbitt.com/company.htm
And you can call and ask for Jim, or contact him by email. The receptionist should be able to provide his email address, or you can contact me for it if you like.
One more thing, if you are concerned about the table's flatness, you shouldn't trust a metal ruler, as they are not made for our purpose. An inexpensive tool that will provide excellent results is a straightedge: http://www.wttool.com/product-exec/product_id/17540/nm/Straightedges_with_Double_Bevel_Blades_WT_Import_
Brad Behn
http://www.clarinetmouthpiece.com
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Author: Chris Hill
Date: 2010-01-06 19:49
Dan,
I may have an extra glass I can give you- let me check, and I'll get back to you.
Chris Hill
BTW- polishing a mouthpiece table can change the flatness. Most common is that it will add a "rocking horse," as Mr. Matson used to say.
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