 The Clarinet BBoard
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Author: awildman
Date: 2018-07-16 01:46
I acquired a wreck of an old German boxwood clarinet circa 1880. It's not particularly relevant, but I believe it to be pitched in C, low pitch. Of course it is currently unplayable, so I decided to do a few measurements just for fun. That's when I ran into the puzzle.
This clarinet seems to reverse taper significantly in the top joint. I don't have proper set of measuring tools, but a set of digital calipers and some math gave me a good approximation. Top opening approximately 13.8mm, and the bottom opening 13.2mm. Measuring the depth of the accessible toneholes all the way to the bottom (far inside wall) and doing math leads me to believe that the taper is pretty consistent from top to bottom. FWIW, the instrument seems to have been well played at one time, and only minor warping of the wood. It's really quite straight for old boxwood.
The lower section, on the other hand seems to widen immediately. The only measurement I can get on the bore is at the very top and it seems to be 14.3+.
So the bore goes from 13.8 to 13.2 over 9 inches of the upper section, and then goes to 14.3 immediately beyond that. This is rather different from my modern clarinet. What sort of impact might this have on tone and resistance etc?
Further, does anybody have suggestions for bore measuring tools/methods? My poor calipers just aren't made for inside measurements like this.
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Author: Alseg
Date: 2018-07-16 18:57
Attachment: Internal caliper small jpg.jpg (14k)
Attachment: tosca variety aug 2014 2.jpg (199k)
here you can see two types of internal spring calipers. One is digital from Germany and very expensive, the other is available from Japan (Mititoyo and others), also costly, and others are Taiwanese, which are decent and lesss expensive. It allows you to ascertain whether the bore is distorted elliptically.
These measure from a set zero, so you need a standard, as seen in the second photo (the ring with a brass finish)
Former creator of CUSTOM CLARINET TUNING BARRELS by DR. ALLAN SEGAL
-Where the Sound Matters Most(tm)-
Post Edited (2018-07-16 19:04)
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Author: Caroline Smale
Date: 2018-07-17 00:39
Cheapest option is probably the simple bore guage that has two opposing arms, sprung loaded outwards and with a locking mechanism by turning the handle.
Having set and locked the measurement you then withdraw the guage and read the distance the arms are apart using a normal vernier guage.
Quite accurate (very accurate with practice) but a bit time consuming to use.
A proper bore guage with a long probe and dial guage is far better, but more expensive.
Don't go for too much precision - one of my guages measures to 0.0001" - but then you start measuring the grain pattern in the bore !!
0.001" is quite enough.
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Author: Tony Pay ★2017
Date: 2018-07-17 01:29
Make it playable. It’s not so hard.
(Blutak, clingfilm etc.)
Tony
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Author: clarnibass
Date: 2018-07-17 07:25
The regular spring bore gauges that Caroline suggested is what I'd suggest too.
>> Quite accurate (very accurate with practice) but a bit time consuming to use. <<
Yes, this is a standard method, usually measuring the bore gauge with a micrometer, which is extremely accurate. Machinists often use this for things that are far more critical than the bore of a clarinet.
>> Don't go for too much precision - one of my guages measures to 0.0001" - but then you start measuring the grain pattern in the bore <<
If I understand, inch vernier calipers are pretty accurate to 0.001"? Metric vernier calipers are usually only to 0.1mm (you can roughly estimate to closest 0.05mm sort of). So I prefer a digital or dial calipers. I have micrometers that measure accurately to 0.001mm (a micron) but I've never used that for clarinets and I'm wondering if it's even possible, if the material is not too soft for that.
Post Edited (2018-07-17 07:27)
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Author: awildman
Date: 2018-07-17 18:54
Found some cheap bore gauges. Not long enough to get all the way in. Enough to measure about halfway. The top end is actually a cylinder of 13.93mm and the taper starts somewhere beyond that. Bottom opening is actually 13.4, and goes to 13.86 at one inch in. I assume, then, that the taper blends in at around 3 inches from the bottom. A couple of toneholes in that area have undercutting etc, so I am guessing that the taper is present to compensate for intonation, and possibly for finger spacing.
I might try the saran wrap and blutack thing in the next couple weeks. Anybody have suggestions on what sort of reed to use with a German C clarinet from that era?
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Author: Tony Pay ★2017
Date: 2018-07-17 23:40
>> I might try the saran wrap and blutack thing in the next couple weeks.>>
Don't knock yourself out.
>> Anybody have suggestions on what sort of reed to use with a German C clarinet from that era? >>
What era? You say 1880, but why? Photo? Mouthpiece?
Answer: one that you can make work.
Tony
Post Edited (2018-07-17 23:42)
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Author: awildman
Date: 2018-07-18 01:43
The mouthpiece is wood, with grooves for string ligature. Maybe not original to the clarinet, but old.
The keys are attached to the posts via pins rather than screws. There are only two ring keys. The maker, C Kruspe died in 1885. Also, it is just old.
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Author: awildman
Date: 2018-07-18 07:04
Well, I am only 41 years old, but often feel as if I were born in the wrong century. ;-)
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