Measuring the tip?

[Subtone Sam]

What tools do I need to take accurate measurement of the tip opening and how its done? Thanks!

[Paul Coats]

Sam, first, you cannot measure the tip opening with feeler gauges. Any feeler that will insert under the tip will be way smaller than the tip.

Some place a glass gauge (a piece of glass, about 3/16" thick, with lines marked on it, to be used with feelers for measuring the facing curve) on the table, and try to measure from the glass to the tip with calipers. That does not yield good results, either. To catch the caliper tips in there, you must measure too far in, and again, you are not getting a true TIP opening.

There are several ways that do work. The old standby is the "tapered wand guage". This is basically a rod that has a flat machined on one side, at a very slight angle to the rod. So, it is thinner on the end, and gets thicker farther down the rod. There are markings for tip opening. You place the glass gauge on the table, lining up the edge of the end of the glass with the tip of the mouthpiece. The tapered wand is inserted gently, with the rounded side touching the mouthpiece tip rail, and the flat side touching the glass. It is gently inserted until it just stops. The tip opening is read off the markings machined on the wand. This is the old standby method, used at the Runyon factory, and by many mouthpiece techs.

John Winslow, the ligature guy, makes a kit from his Madison Enterprises. It has a machined aluminum fixture that is placed on the table of the mouthpiece. This fixture holds a dial indicator. The probe of the dial indicator is positioned as close to the tip's edge as possible, and a reading taken from the dial. This is the tool and method I use.

And another way... this was shown to me by mouthpiece maker Ron Coelho. His glass gauge has a hole drilled in the butt end. He uses a dial caliper with this. He positions the glass gauge with the hole over the edge of the tip. He inserts the depth probe of the dial caliper into the hole, and butts the end of the caliper square against the glass. He runs the inidicator down until it touchs the tip. He reads off the dial, and subtracts the thickness of the glass.

If you measure the same mouthpiece with different tools and methods, you may very well get slightly different measurements. BUT, you need to be consistent, and be able to measure the same mouthpiece 10 times, and get the same reading each time. This is more important with mouthpiece work, than the actual measurement.

[MojoBari]

Some place a glass gauge (a piece of glass, about 3/16" thick, with lines marked on it, to be used with feelers for measuring the facing curve) on the table, and try to measure from the glass to the tip with calipers. That does not yield good results, either. To catch the caliper tips in there, you must measure too far in, and again, you are not getting a true TIP opening.


That's the method I use. I read to the inside of the tip rail and I also use the calipers to measure the width of the tip rail. The wand type gages measure to the inside of the tip rail. The Winslow gage is a great if you own one. I would still measure to the inside of the tip rail. Measuring inside the rail is very sensitive to your centering, but is not sensitive to distance from the tip. The very tip is sensitive to centering and finding the very tip. Plus, the portion of the reed that is on the tip rail does not contribute to sound. So I think measuring insid the tip rail makes more sense. But a few makers seem to go for the very tip.

The difference between the tip opening inside the tip and at the very tip is not huge. Something like .003-.004". I'm pretty sure the chart we all use have a mixture of inside and outside measurements.

[Subtone Sam]

Paul C.&Mojo,thanks for very informative answers!

[Paul Coats]

Where Mojo measures on the tip rail is different from where I measure, so he and I would get slightly different measurements, but we both get consistent measurements, which are what is most important for our purposes.