# Wind Instruments Parts



## Enthalpy

Where *woodwind joints fit* in an other, cork makes them airtight usually, or formerly a wound and impregnated thread. I try *heatshrink sleeve* at my bassoon's bocal presently.

The tighter fitting immobilizes the bocal as I wanted, but tighter cork would do it too. The result is stiff and can minimize the dead volume, which should ease the altissimo, but up to C# (just below the Sacre) where the comfort zone of the musician and the reed end presently, I notice no difference; maybe things change at higher notes.

These are the bassoon bocal without its cork, pieces of heatshrink sleeve, the bocal with the sleeves, and a zoom.






























The Chinese made the material affordable. It comes in many diameters and colours, length is commonly up to 1m. The diameter shrinks strongly and irreversibly at heat, from a hairdryer, a soldering iron, or with care from a lighter. No skills needed.

Two plies happened to fit at my bocal, first with grease, later without. At first try, the shrunk sleeve moved around the bocal, so I held it with instant glue, which could be applied because the bocal is conical.

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What can improve?

Each ply is too thick and stiff for an adjustment, I had luck. Also, the conical bocal holds in an inverted cone at the bassoon. Maybe double-sided adhesive tape below the sleeve can adjust the diameter and slope if it resists the heat. Or a thread wound below the sleeve, which would give some elasticity.

Heatshrink tape exists too, which enables big diameters, but I expect leaks where the tape ends. Below a sleeve maybe. Would it be thinner?

Inner layers could stop before the outer sleeve to provide a smooth, airtight and sturdy taper.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Here's my home-made *bassoon balancer*. It works for a French bassoon too.

Part of the idea is: hold at the boot for safety, pass through a ring added at the tenor branch for equilibrium.









The ring is added rather high on the tenor branch and this relieves the left arm. It consists of two turns of adhesive tape around the branch plus the length for a gamma eye. It crosses the concave part of the tenor branch, where it separated over time, which doesn't hurt. A professional embodiment must improve that.

The ring passing between fingers 2L and 3L was only a tiny bit too high, so a longer gamma may enable it.

Sewing thread tightens the gamma. This stabilizes the side position of the gamma to achieve perfect roll equilibrium. Other advantage, the ring doesn't pull sidewise nor away the adhesive tapes at the pictures' left that hold it upwards.

Marc Schaefer, aka Enthalpy


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## Enthalpy

*Bassoon balancer v3*. The string coming from the boot joint is redirected by a loop that now has its ends parallel to the body, while the ring perpendicular to the body passes straight over the loop. This v3 is much easier to build and to adjust.

















Still adhesive tape, about 3 plies. At the loop, two foldings give 90° each, and an added short tape part neutralizes the sticking side.

V3 too provides perfect roll balance and leaves some weight on the left hand, since an attempt with perfect pitch balance was unplayable.

The adhesive tape always separates from the concave portion of the tenor joint, so instead of sticking it there, this time I gave it roughly the loose length left by the spacing to the bass joint.









Marc Schaefer, aka Enthalpy


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## Enthalpy

*4c definitive version of my bassoon balancer*. Easiest to build and adjust. Time will tell if it's the most durable.
















4 plies of adhesive tape parallel to the tenor joint hold a ring. I superimposed the 4 plies first, holding the first ply between a desk's edge and my fingers. The tape needs some length to hold on itself near the ring. Several turns of a second tape around the joint holds the first tape against the joint as previously.

Duct tape (Gewebeband, toile adhésive) crept and began to tear at the edges. Surgical tape (Pflaster, sparadrap) crept, and the European tan looks silly on African wood too. Plain office adhesive tape is best up to now.

Duct tape and surgical tape crept at a D-shaped ring until holding at a corner, so a round ring is less bad.

Do use the shoelace that holds at the boot! It saved my instrument a dozen times.

Marc Schaefer, aka Enthalpy


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## david johnson

Interesting reading and pix. Can heatshrink sleeves be sanded?


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## Enthalpy

I have used a dozen times *isopropanol to clean one bassoon reed* and to disinfect it from bacteriae and virus.

This reed is very old and it becomes dull and unresponsive when a biofilm develops inside. Isopropanol eases much the mechanical removal of this biofilm (some bassoonists use a pipe scraper), often no mechanical action is needed. I give some drops in the reed at the bocal end over my usual plastic soaking box, then I soak and shake the reed for about 1min in the flown isopropanol.

The cleaned reed becomes responsive again. Could the biofilm be the cause of reed ageing?

Isopropanol, or isopropyl alcohol, is what gives hospitals their odour. It must be concentrated >70% but not pure. Its deadly dose is half that of usual alcohol, so rinse the reed. Concentrated usual alcohol (ethanol, ethyl alcohol) should work identically; I'd stay away from methylated spirits, whose denatonium tastes so badly. I haven't tried vodka &co, normally it's 40% ethanol so its antiseptic action isn't guaranteed.

My bassoon reeds are covered with wax to be airtight. Perhaps the more usual varnish dissolves in isopropanol and ethanol. I haven't tried with oboe reeds nor single reeds.

Marc Schaefer, aka Enthalpy


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## Heck148

Enthalpy said:


> I have used a dozen times *isopropanol to clean one bassoon reed* and to disinfect it from bacteriae and virus.
> This reed is very old and it becomes dull and unresponsive when a biofilm develops inside.


reeds certainly do deteriorate with time and usage....the "biofilm" can be cleaned out, and should be done periodically....I'd not use alcohol, tho.....tried it once - the aftertaste, even after thorough rinsing was really unpleasant....I use hydrogen peroxide H2O2 - let the reed soak a few minutes - the oxidizing action seems to soften and loosen the deposits....then clean with a pipe cleaner, run carefully thru the Reed, from butt end toward the tip....rinse....
this process may work once, maybe twice....but the cane itself breaks down with usage....I find that eventually, the reed will lose its fundamental and lower overtones...the sound shrill, thin, lacking in lower partials.....time for that reed to RIP.....
To form and seal the reed at formation, I use Duco cement....works great....the reed never comes undone...holds it very firmly...you must ream the reed however, because Duco shrinks, contracts on drying....use full reamer, and I always use a throat reamer as well....this really opens up the sound...with throat reamer never go to or past the first wire!!


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## Enthalpy

Heck148 said:


> [...] I'd not use alcohol, tho... tried it once - the aftertaste, even after thorough rinsing was really unpleasant... I use hydrogen peroxide H[SUB]2[/SUB]O[SUB]2[/SUB] [...]


This was methylated spirits I guess. Both isopropanol and ethanol, not tainted with denatonium, have a reasonable taste that washes away immediately.

I didn't try peroxide as my intuition told me it hurts the cane, but only experiment can tell. At least, it's less poisonous than hypochlorite.

Duco Cement: I should give it a try. Sturdier than wax is a definite advantage.

At least two bassoonists use a tiny brush to clean the reed's interior. Sounds interesting.


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## mbhaub

I quit trying to resuscitate reeds long ago. That biofilm is what gives reeds stability, I think. And peroxide ruined some reeds. I just loathe the time and trouble reeds can present - so I took an alternative route. I buy my reeds from a guy in Bulgaria. His construction is meticulous and detailed. And dirt cheap. Each blank comes out to about $2.50 - You can't buy GSP for that anymore. My only task then is the fine tuning and finishing which is no problem. Saves me my least favorite task of making the reed. 

I cheat even more for my contra reeds. A pro player in Germany plays the same model contra I do, we have similar ideas on what a contra should sound like. I buy four from him each year - although two would probably get me through. His reeds I don't even need to adjust or trim in any way. 

So when reeds start to go south - I toss them and move on and not worry about it.


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## Heck148

I've always enjoyed Reed-making, and became quite good at it...good teachers, I guess...high rate of consistency, good rate of successful outcome.
they do wear out, play out, the fibers break down and they are not redeemable....that's part of the game....I always found that using them in rotation prolonged reed life....you should always have 4-6 good general use reeds available...they can split or die during a performance....you also need some special ones - high register, low register response, ultra-soft for super-pianissimo stuff...
you need a variety - I wouldn't use the same reed for a Haydn symphony that I would for a Shostakovich symphony...- the demands are quite different.


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## Enthalpy

The *4d version of my bassoon balancer* has arrived! The triangular ring shall spare the adhesive tape. The tape hasn't crept to the side after 90min practice. I found only thick big rings.

The adhesive tape showed no wear nor tear after two weeks at the round ring, but I wanted to move the ring sidewise anyway.
















(click to magnify)

Marc Schaefer, aka Enthalpy


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## arpeggio

I hated reed making.

Because I am an amateur, I found making reeds interfered with the limited time time I had to devote to practicing.

I started using synthetics and for the past few years I have been using Legere.

When I attended a recital of the Breaking Winds I observed that they all used Legere. From them I learned that one needed to own several reeds and to rotate them. Even though they are expensive I eventually acquired five reeds which I rotate.

I also use Legere bass clarinet reeds and I rotate them as well.


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## Heck148

arpeggio said:


> I started using synthetics and for the past few years I have been using Legere.


are Legere reeds adjustable?? to any appreciable degree??


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## Enthalpy

To scrape a *bassoon reed*, a plaque inserted in the thin cane supports it and makes it convex. My *plaque is made of bone*.









The material offers the proper hardness to be filed or sanded at decent pace and resist accidents when scraping the reed. This seems better than the usual plastic or metal.

Sand paper doesn't let bone dust stink like machine tools do.

My raw material was already a commercial part, so I can't tell what bone of what animal it was. Ask the butcher.

Marc Schaefer, aka Enthalpy


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## mbhaub

Heck148 said:


> are Legere reeds adjustable?? to any appreciable degree??


Supposedly you can - but what a risk! And players I know who use Legere's say they only do very light tip work and maybe the rails. The thought of cracking a $150 reed is horrifying.

I do keep a Legere with me - just in case something happens and I have used it from time to time. For outdoor gigs it's fine - where subtle playing isn't a requirement. I do find that I can't play on it long; it wears the embouchure out. And I've seen streamed concerts from the Berlin Philharmonic where the principle uses one every now and then.

Sometime I'm going to make my own plastic reed from old cups. Have you seen this?


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## Enthalpy

Bassoon players, and oboe players supposedly too, use a reed reamer to fit the bore on the end of the conical bocal.

My bocal's end diverges by 1:50 or 1.15°. Reamers sold for that purpose (with a handle on the photo) diverge much more strongly, to fit varied bocal diameters I guess. Consequently, the reed fits only the bocal's tip and is wobbly.

I bought for 22€ a used conical *reamer for mechanical workshops. 1:50 is a standard, but 1.5°* did the job: the difference is 50µm over 8mm fitting length, which the cane absorbs. The reed doesn't wobble any more. A handle isn't mandatory, but mind your fingers with a new reamer.









My bocals are D=5.20, 5.30 and 5.50mm wide at the tip. The reamer starts with D=5.50mm, its nominal diameter, not 0.2 or 0.3mm narrower as sources claim. The narrower bocals perceptibly hit the bore's end and roll more easily in the reed, so I may try a D=5.00mm reamer. At 1:50 diameter slope, a 0.3mm narrower reamer plunges 15mm deeper in the reed's throat, which must change the sound a lot.

One could also have one reamer per bocal, possibly grinded to the desired diameter, but one reed wouldn't fit all bocals. Or better, all bocals could bear extra thickness at the end, machined to a cone with bigger standard slope and diameter. I have one such bocal, so the solution is long known.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Enthalpy said:


> The *4d version of my bassoon balancer* has arrived!


Broken after 51 days, that is 76h practice. Redone in 5mn, but durable would be better.


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## arpeggio

Heck148 said:


> are Legere reeds adjustable?? to any appreciable degree??


Sorry I took so long to respond.

Yes they can be, but they are very sensitive. Only one or two scrapes with a reed knife. Very rarely do I have to adjust them.


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## Enthalpy

My *bassoon balancer v5* adds adhesive tape in two directions to hold the triangular ring closer to the body. This limits the stressing angle where the two previous tapes cross and hopefully spares the tapes.

The method to superimpose tape plies applies further.









A professional embodiment would use durable materials like polymer film (Mylar etc) or fibres, good glue (like epoxy), something lighter than the thick steel triangle.

It would also prevent carrying the instrument only at the tenor joint. The shape of the part could be open, or completely different, with one other part on a strap originating at the boot fitting at the part at the tenor joint.

Marc Schaefer, aka Enthalpy


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## Enthalpy

david johnson said:


> Interesting reading and pix. Can heatshrink sleeves be sanded?


I've put *heatshrink sleeve on a second bassoon bocal*, similarly to Jul 18, 2020 08:13 PM here. 3 thinner plies instead of 2, and this time I needed sandpaper.

240 grit gives a reasonable pace at start. I didn't dare the vice, but sanding in the axial direction and the bocal on a table sufficed. The inner sleeve layer is shortest and the outer longest, so the ends show smooth transitions, better to sand and to introduce in the bassoon body.

I had to glue the inner layer on the bocal with cyanoacrylate, otherwise the sleeves rotate around the bocal. I did it after shrinking partially the first sleeve. This doesn't work every time.

I still ignore if the very stiff sleeves act differently from cork. But I enjoy the strong friction in the bassoon's metal fitting: *the bocal doesn't turn any more*, one plague less for bassoonists. I wouldn't dare that narrow fit in a wooden body end.

Marc Schaefer, aka Enthalpy


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## Enthalpy

During interventions on a wind instrument, screwdrivers may slip away from the screw and scratch the instrument. Normally it doesn't happen to trained specialists, but operations are slower.

The usual answer, for instance at computers, are *cruciform screw drives*
https://en.wikipedia.org/wiki/List_of_screw_drives​and many more, like the inner Torx.

Maybe instruments could adopt such screw drives to gain some safety and time? I understand many screws are taylor-made, and the slot head is then easiest, but just a cross head isn't so difficult. Or could the screws be processed from industrial ones? Keep the head, adjust the length and optionally the pointy end.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Long keys can get play on woodwinds. On a bassoon, a bass clarinet, on contrabasses... they can exceed 1/3m or 1/2m, but 0.2mm play, perhaps 0.1mm, hamper the operation of the pads at the covers. Compressed shafts don't work properly neither. Both do happen when a wooden body gets less or more damp, perhaps warm too.

One good solution splits the function in several assemblies, where the shaft that carries the cover is short. But this isn't always possible or desired.









At least one patent integrates some spring that pushes the shaft at the end opposite to the cover. The musician may push the shaft to the sides too, rather strongly if gliding from a lever to an other, so the spring must be strong. This creates strong stress where the posts hold in the wood, not desired over 1/2 or 1 century. And in the patent's drawings, little room is available for the spring.

==========

I propose instead to *pull the shaft at the end near the cover*. This creates no stress in the wood. The spring can reside outside the shaft to have room. I could be the same spring the brings the key to its rest position, especially if this avoids friction or noise.

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Alternately, *the shaft could get stops in both directions at the end near the cover*, and the opposite end move freely in the axial direction. In mechanical engineering, this is standard design with bearings. In the sketched design example, the screw in black holds in the shaft and presses against its end while the boule's length is adjusted to let the smooth part of the screw and the shaft glide with minimum play.

Usually, the boule is screwed in the body and later planed, bored, threaded. The orientation may then lack accuracy for my second proposal. But other boules exist, in two parts or more, that are already machined and get assembled with the proper orientation after a part is screwed in the body. This would let mass-production machines define the length of the boule and the screw.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Found with gratitude a glossary
shwoodwind.co.uk​so in my previous posts:
Shaft -> Barrel
Cover -> sometimes Cup
Lever -> sometimes Touchpiece
Post -> Pillar
Boule -> Pillar's ball, sometimes Pillar


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## Enthalpy

The pillars are screwed in a hole in the wooden body presently, so their orientation is unpredictable. The balls are then bored in the good direction, with manual skill as usual, and can get flat faces, a thread, a recess. If present, the conical screw tip accepts some misalignment.

Some designs let align the pillar after it's screwed in the body, at least in patents. My proposal instead:









Without a conical screw tip, the ball could belong to a subpart distinct from the pole and be *assembled with proper orientation by brazing*. An auxiliary metal sheet can protect the wood from the flame. Maybe auxiliary metal like massive pliers, or water in a sponge, can absorb the heat conducted by the pole. Quenching after brazing helps, faster heating means too if available at workshops.

15µm diameter play on 3mm length leave +-1.5mm tolerance at the opposite end of a 300mm shaft. The luthier could wobble that end by +-1.5mm around the other ball in both directions while the brazing filler solidifies, so the play is symmetrical.

At and near the ball displayed left, only chip machining defines the play. The materials should resist wear and survive brazing temperature. The screws could be commercial parts, possibly modified, maybe with a Torx, hex socket or cruciform screw drive.

The barrel end parts could be brazed, but since the nearby cups and touchpieces are brazed too, welding seems better. Friction welding is seducing, where the parts are pushed and rotated against an other. Maybe a boring machine achieves the speed for the small diameters.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Here the *pillar comprises a threaded post, of axial symmetry hence indifferent orientation, and a cap* oriented when assembling so its opening accommodates the barrel's head. A ball at the barrel's head accepts misalignments.









The post and the cap press directly against an other, leaving the barrel's head a well controlled play. If a drill bit with spherical tip, or any tool that makes the hollow for the barrel's head ball, also makes the surfaces of the post and the cap that press against an other, the play is more accurate.

A sheet spring could press the cap on the post, provided it's difficult to remove. At the sheet springs I saw, all bends and folds are parallel to an other, hence the bump in the cap to hold the holed spring. If a spring can have 3 or 4 legs instead of 2, the bump and the hole are superfluous.

The head could be welded at the barrel, possibly by friction as already suggested.

These parts can be mass-produced by automatic machines, possibly at a subcontractor, and their assembly saves most manual labour.

The ball of the barrel's head can be of steel of ceramic for accurate shape and to resist wear. A screw through a hole can then hold it at the barrel's head, maybe at the barrel directly. If the post and the cap wear out, they are just replaced.

Marc Schaefer, aka Enthalpy


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## Enthalpy

A similar construction can *save most assembling labour at the opposite end too*.









That barrel's end slides in its bored ball. This ball doesn't need to rotate and can be slightly larger so the post and the cap press it, or better, the post and cap have a slightly smaller hollow and distinct shapes. Or could the ball be part of the cap? Provided that the spring doesn't twist the barrel's end.

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Some *coatings resist wear* and brazing heat. Nickel doesn't gall but its unlubricated friction is strong. Chromium glides easily, but few alloys don't gall against it: bronze, aluminium bronze - no information about nickel silver. Nickel and chromium can be ground. Countless coatings exist. Nickel doesn't gall against itself because pairing is irrelevant.

Marc Schaefer, aka Enthalpy


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## Enthalpy

I've tried *Stroh Rum 80 and again isopropanol on bassoon reeds* since my Jan 18 message here.

80% ethanol Stroh Rum is a drink of repute as a cheaper antiseptic too. It smells strongly, colors the reed and destroyed one. It also corrugates the mouth's skin. Maybe dilution to 70% would save the reed and the mouth, but I didn't try again.

Isopropanol (1L for 5.90€ on eBay) regenerated one more reed that became responsive and clear-voiced again but not tinny, without any mechanical action. Cleaning mechanically the reed inside hadn't brought this. Maybe isopropanol removes the damping biofilm better while sparing the cane and its strength. This reed is varnished at the shaft, and I dipped only its tip.

70% ethanol (without tannin) would smell better but is expensive, so I haven't tried yet.


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## Enthalpy

Instruments with *sideholes could have inserts* there. Or is it already done?


Smoothening the hole's inner end, where it meets the air column, is easy at an insert before it is mounted but difficult at the wall alone.
scienceforums​
The hole dimensions adjust the intonation at least at oboes. Replacing the insert chosen in a set is reversible.
Some oboes have chambers, I claim their resonances make a mellower sound
scienceforums​A set of inserts lets adjust the intonation and can keep the resonance unchanged.
A protruding ring makes the airtight contact with pads. It wastes scarce wood, needs difficult machining, and wood can split there or lose its flatness. An insert is easier and can use durable polymer (Vectra...) or metal.









The inserts are cheaply turned to complex shape.

==========

Looks feasible with or without inserts: *smoothening the hole's outer end*, where it meets the pad, could improve an instrument further, like undercutting does at a clarinet.
scienceforums too​Flutes do it. Pads covered with gut or fish skin and adjusted with paper may help.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Here's a *variant of my playless keys* of May 15, 2021 at
03:11 PM - 06:26 PM​








All fine tolerances are at cylinders, that's easier to manufacture than precise balls.

The displayed sheet springs press the balls firmly on the pillars. This needs further thinking. Wire springs may be better, or a screw if it doesn't rotate the ball.

The screw that retains the key must be well tightened, or key movements will loosen it. I'd have a hexagon or equivalent at the part where the screw holds.

The barrel ends can be brazed, or rather welded by friction. Turning them after welding improves the alignment if needed but takes time.

Marc Schaefer, aka Enthalpy


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## Enthalpy

I've been using *70% isopropanol on my bassoon reeds* for almost a year now, time maybe to share observations.

I received finished reeds from Neuranter in a transparent tube with bottom and stopper. Such a container, but bigger than a reed, contains now the isopropanol. Since the alcohol is antiseptic, most times I only refill a bit. The 5,90€ litre from eBay is still almost complete. Isopropanol diffuses through the container and deforms it.

After playing, I soak the reed several times deep in isopropanol. After the last dips, I blow through the reed, except the very last time. Isopropanol then evaporates in the air from the "disinfected" reed, without rinsing water.

A reed serves me several months for 80min a day. I make no mechanical cleaning at all and notice no deposit - a deposit did grow previously, without any cleaning. The varnish on the reed is unscathed, wax too.

I ignore how isopropanol compares over time with mechanical cleaning. But it works.

70% isopropanol should be an excellent method to disinfect reeds, for instance made by a professor for a pupil. I got used to the smell, like nurses do. 70% isopropanol is only twice as toxic as 70% ethanol, it's cheap, it doesn't destroy the reed like Stroh Rum did immediately, and isn't disgusting like methylated spirits.


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## Enthalpy

I carry my instrument daily with this home-made *bassoon harness*. This harness is also better for my alto saxophone than the neck strap. I even used it shortly for the bass tuba.

(Click expands)








All straps are 30mm wide, wider may improve for heavier instruments. I sewed with fisher's polyamide line, doubtful idea.

Usual harnesses cross two straps in the musician's back, which compresses my neck and armpits. Workarounds improve that. At my harness, the straps keep a comfortable spacing because a third strap, horizontal in the musician's back, joins them.

Something like safety pins could immobilize the horizontal strap, or the straps could be sewn together and have four length adjustments then. Some people may benefit from additional length. Extra hardware can immobilize the floating ends. The horizontal strap could be adjustable.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Condensation water is unwanted at the side holes of woodwinds: it hardens the pads, produces noises, wets the fingers. I suggest to install in the bore, before the side holes, alternating *strips of hydrophilic and hydrophobic materials to divert the water* before it reaches the holes.









Metals, many ceramics, polar polymers tend to be hydrophilic. Polyolefins and hydrocarbons, fluoropolymers, silicones tend to be hydrophobic, which a lotus effect strengthens. Some wall materials are already hydrophilic (alloys) and others hydrophobic (polypopylene), saving one kind of strips. Nickel layers can embed Ptfe, I didn't try if they're hydrophobic. Good behaviour at brazing heat is wanted at metal bodies.

Coating the holes is easier than the bore, and coating the hole inserts I suggested here on Aug 29, 2021 is even easier.

How efficient are these strips? Not obvious, because at the bassoon and other low instruments with narrow side holes, the air has a strong oscillating speed and movement, which may push the drops anyway.

Marc Schaefer, aka Enthalpy


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## mbhaub

That's crazy. On a bassoon the dimensions of those tone holes is crucial and oh so temperamental. Adding anything, no matter how tiny can screw up intonation and response. Even the yuck that builds up from use if not cleaned regularly, and even then you have to be very careful not to scratch the rubber or metal liner, which can also mess things up. I know a player of an otherwise fine bassoon with a really obnoxious C vent hole. She fits a thin, short piece of plastic straw which helps to stabilize that one note, but it sure makes the C# goofy. (If she would just get a Leitzinger bocal!)


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## Enthalpy

Fully agreed! Any added layer, except for a few µm, would call for a groove to bury it.


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## Enthalpy

At my beginner's bass tuba, the rotary valve actions are noisy. Maybe the following applies to better instruments too.

The stops that limit the valve's rotation let the action rebound. Maybe they're of polyurethane, very durable. *Other elastomers rebound far less*, the champion of my trials being a perfluorosilicone, for instance Viton. But damping elastomers creep. Cork is also very silent. Trials shall tell.

The present design lets metal and elastomer parts bump at once over their full height, option displayed at left. *Spreading the contact a bit over time would make it more silent*. The biconical contact displayed at the centre can have more cones spread over the height. The curly brace section displayed at right squeezes high frequency noise better; erf(x) is an inspiration, complete theories exist from signal processing, I expect little from them here.

[Click for full size]








Other noise source: the cheap action has play, and the musician's finger pushes the rod but the spring pulls it, so the parts bump loudly against an other at each use. Putting the spring at the end of the transmission chain, at the valve, would leave the *rod always pushed or always pulled*.

The transmission could even use a string, depending on where the valves reside. This removes also a nonlinearity in the action, as is known from some chromatic horns.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Narrow curves in the air column allegedly hamper the emission and muffle the sound. Widening them is difficult between two bores in a same piece of wood, say at the boot of a bassoon, or at my rackett design for a contrabass clarinet, as this would make heavier instruments and lengthen the curve, which may not fit between two side holes then.

I first propose to *widen the inner radius of a curve* and keep the outer radius. The curve remains short.

Nederveen computed on page 60 of _Acoustical Aspects of Woodwind Instruments_ that at same cross area and mean fibre length, a curve reduces the inductance but leaves the capacitance untouched. So the wave impedance drops at a curved bore of given section.

At the curve, I reduce the cross area to keep the wave impedance, computations on the sketch. I do it mainly near the inner radius to increase it. As the modification changes alpha, the computation needs a few iterations.

[Click for full size]








The illustrations use pixels (px) as a unit; at left, 2px/mm would resemble my old French bassoon, just rounder.

At the centre, I make the cross section elliptical. The curve keeps wall stiff. The ellipse has the same inductance, capacitance, acoustical length and wave impedance as a round section of same minor axis, just scaled by the ratio of major to minor axes, and Nederveen's formula still gives alpha. The reduced minor axis lets increase the curve's inner radius from 6 to 9.2px, a good relative improvement. The transition from the round section must be smooth.

At the left, I fill the innermost part of the curve, maybe with microballooons and epoxy, which two electroforming steps can coat. I suppose Nederveen's alpha can be computed algebraically but I didn't make the effort. Instead, I took the cross area computed for the ellipse, and filled the round accordingly. The inner radius climbs from 6 to 11.5px.

==========

I also propose *sections not round* that let increase the curve's inner radius at identical cross area. The designed walls retain curvature in both directions to be stiff and avoid losses.









At centre left, the ellipse reduces the minor axis, so at identical mean radius, the curve's inner radius increases from 6 to 10px on the example. But matching smoothly the round 44px bore to 54 and 36px axes adds distance: at 10px curvature radius, twice 8.7px.

At the centre, the same ellipse keeps the outer 50px radius for 14px inner radius. The smooth transitions take twice 12.7px and the bigger curve 6.3px.

A racket construction and others leave no room for an ellipse, example:
talkclassical​A more angular section fits better. To keep some curvature, I use the ellipse's polar equation and double the angle, which keeps the area and more maths. Then the gained area lets shrink one dimension, here by 38/44.

At centre right, the mean radius stays at R=28px, the inner radius increases to 9px, while the R=9px transitions from the round bore take twice 6.7px.

At right, the outer radius is kept to increase the inner radius to 12px. The transitions take twice 10.4px and the bigger curve 4.7px.

==========

With bigger inner radius too, a section can be reduced for uniform wave impedance. The advantages aren't as big.

The transitions might combine with the curve, possibly with adaptive radius, to save length. I didn't investigate.

Some instruments had a metal curve that spread before turning on a bigger radius. This wastes much more length than my proposals.

A retrofit must be possible, especially on bassoons. An increased inner radius allegedly eases the low notes. Evening out the wave impedance would ruin an existing design but is worth a try at an evolution.

Marc Schaefer, aka Enthalpy


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## Enthalpy

R[sup]2[/sup] and m[sup]2[/sup] in the formulas, corrected here. The shapes were correct.


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## Enthalpy

Ahum. I wanted a squarish section that stays a bit round everywhere for stiffness, but the sketched e[sup]2[/sup]=0.174 achieves only 44px*40px as on left side of the _even more correct_ illustration. 44px*38px on the right side needs a maximally flat section from e[sup]2[/sup]=1/4. Thin electroformed Ni or NiCo isn't stiff enough, it takes thicker walls then.

[Click for full size]








Here are, for an example 36mm bore contrabass clarinet, thicknesses that attain 4500Hz elliptic resonance in a straight tube. The instrument plays fundamentals >500Hz so >3kHz overtones are desired, but the wall can usefully dampen the strident >4500Hz components.



Code:


            E GPa    r kg/m3    e mm     m g
--------------------------------------------
Ni+Co        100?      8000      2.5!!   165
Zn alloy      84       6600      2.5     136
Ti !         103       4512      1.9      71
TiAl ??      165       3900      1.4      45
Al alloy      71       2660      1.7      37
--------------------------------------------
                                     D38 L69

Electroforming 2.5mm nickel takes too long, so the *curve shall be cast*. The best casting alloys, ZnAl3 and AlSi12, need a protective layer against corrosion, maybe Cr. Cast Ti must be expensive, TiAl worse. My choice is AlMg5 AA5083 despite casting takes longer: this one might resist corrosion in a wind instrument, thick anodisation helps it much, and it can be colored.

The masses in the right column are for one curve. At a rackett shape, 3* 100g make Al perceivably lighter than Zn.

Marc Schaefer, aka Enthalpy


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## Enthalpy

My *bassoon balancer* of Mar 28, 2021 failed after 10 months. Repaired in 10 minutes. This time the adhesive tape didn't break, but it crept over months where it should stick. So the design that spreads well the forces is sound, and with good materials like epoxy, the parts should last forever.

===========

Some cheap hardware for reed adjustment.

The *reed knife* isn't a box cutter as it serves for my reeds only. I trust the tall trapezoid blade, it's slightly wider than a bassoon reed, and sharp enough to cut the tip by mere pressure and scrape the reeds. Even retractable, like the 200€ reed knives have. Only drawback: the handle goes lower than the blade edge. 2.99+1.79€ over eBay with three blades.

[Click to enlarge]








The *reed reamer* isn't a wood reamer for the same reason. Nothing as sharp as I know for metal, so I must insist even in _Arundo donax_, but at least I can hold it with the fingers directly. dD/dx=0.1 like the expensive special reamers, and the tip narrower than the initial reed bore leaves less burrs - I ignore hypothetic drawbacks. My reeds hold firmly on the 1:50 bocal. The reamer cost me 7.49€ from China over eBay.









Marc Schaefer, aka Enthalpy


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## Enthalpy

Before bending, metal tubes are filled with water ice to prevent buckling. I've just seen in videos that lead too serves occasionally. Alas, the vapour of molten lead is toxic, a serious concern.

Lead melts at 327°C and cost 2€/kg in 2018. Maybe *bismuth* (271°C, 7€/kg) or *tin* (232°C, 16€/kg) can replace it. This depends on their behaviour upon bending, and needs further assessment of their toxicity.


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## Heck148

Enthalpy said:


> The *reed knife* isn't a box cutter as it serves for my reeds only. I trust the tall trapezoid blade, it's slightly wider than a bassoon reed, and sharp enough to cut the tip by mere pressure and scrape the reeds


I've always used jeweler's end cutters to clip the tip of the reed....I got one from Bill Polisi way back in c '66, and still use it today...very accurate, easy to use, you NEVER split or damage the tip - cutting pressure is straight up/down....I use a bigger version of the same tool for the first, rough cut of the blank, after it is assembled...



> The *reed reamer* isn't a wood reamer for the same reason. Nothing as sharp as I know for metal, so I must insist even in _Arundo donax_, but at least I can hold it with the fingers directly. dD/dx=0.1 like the expensive special reamers, and the tip narrower than the initial reed bore leaves less burrs - I ignore hypothetic drawbacks. My reeds hold firmly on the 1:50 bocal. The reamer cost me 7.49€ from China over eBay.
> 
> View attachment 163733


I, of course, use a reamer to create the proper tube opening, and to assure tight fit on the bocal....I also use a throat reamer, which I've found to be very effective....it opens the throat, produces a bigger tone...also I use Duco cement to seal the reed [no thread] - Duco contracts as it dries. so you must always have the reed on mandrel tips while drying....then ream the throat, in case it has shrunk...this opens it right up...frees up sound and response.


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## Enthalpy

Some oboes have chambers in their tone holes. I described how the chambers can absorb strident sound components, there
scienceforums​Here I propose to *add chambers to other wind instruments, hoping to obtain a mellower sound*.









This example is for a trumpet. The chambers sit on a special tuning slide that the musician chooses when he wants the mellower sound. It can be done for other instruments, for instance at the bocal of a saxophone or a tuning slide of a French horn. As the chambers target more specifically the undesired sound components, I hope the instruments can bring a colorful but mellow sound, what thin walls and resonating materials don't achieve. Then the rest of the instrument would logically be built for bright sound, with damping materials like silver and stiffeners.

Péter Rucz described a flute stopper with a sort of wideband chamber. Maybe several tuned chambers improve the effect. I didn't even put figures.

An oboe has resonances at the strident 4.5-10kHz, but a trumpet doesn't, so the chambers must short the tube's wave impedance, less easy. The drawing isn't accurate to the pixel! The holes must be very narrow, like 0.7mm or less; more holes enable longer ones. 20µm felt in the capacitor, possibly as a sintered sparse coil, may be better than a narrow inductor, if it stays dry because it's hydrophobic. First figures suggest more than a chamber per semitone; they can sit on several rows. Drying the chambers need a quick access: maybe a metal spring band combined with an elastomer or cork, some clever design is still needed.

The chambers add volume to the air column. A locally narrower bore acts both on the capacitance and the inductance to keep the wave impedance. The wave becomes slower, so this portion must be shorter.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Heck148 said:


> I've always used jeweler's end cutters to clip the tip of the reed. [...]


Like this?
etsy​


Heck148 said:


> [...] I also use a throat reamer [...]


I plan to find or buy a tiny round file for that. Already noticed how important it would be.


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## Heck148

Enthalpy said:


> Like this?
> etsy​


 Yes, that's the right tool...you just need to get the right size...obviously, the blades need to be longer than the tip of the reed width.



> I plan to find or buy a tiny round file for that. Already noticed how important it would be.


I got the throat reamer years ago, I think from Forrest's.....long time ago...shouldn't be too hard to find...

With the throat reamer, you must be certain not to insert, to push it past the first wire....if you push into the blade you may well cut thru the thinner cane making a hole right by the collar...then the reed is trash...


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## Enthalpy

I suggested on Feb 26, 2022 to fill tubes with tin instead of toxic lead to bend them. *Tin alloys* could be advantageous:

Eutectics with Cu or Zn don't dissolve these elements from the tube.
Alloys are harder. It that better?
Alloys melt at a lower temperature. Advantage?
Some eutectics with Sn, and their melting points:



Code:


°C   Cu%   Ag%   Zn%
====================
227  0.7
221        3.5
217  0.9   3.5
199              9.0
====================
°C   Cu%   Ag%   Zn%

Sn-Ag-Cu serves for electronics.

Bismuth alloys and eutectics are known too.


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## Enthalpy

Some musicians put *cigarette paper on the teeth* to protect the lip when playing a reed instrument.

The brand Kingsgard disappointed me in this use, as it breaks up easily. I tried OCB and Marie: these are stronger. They also seem to adhere better on the teeth.

It's not a matter of thickness: OCB 25µm, the others 35µm.


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## Enthalpy

Rotary valve rotors are too heavy at a tuba to my taste, so here are thoughts about *aluminium rotors for rotary valves*, hoping that acoustics doesn't demand heavy rotors.

Corrosion-proof alloys are very soft and they gall, and an alumina layer is abrasive, so the aluminium alloy needs a protective layer.

Then, AA7075 can make the shaft and the wide part at once. Or a wide part holds on a shaft of harder alloy (CuNi15Sn8), say by being fit when hot. But if the thermal expansion shall match the casing of copper alloy, or if harder aluminium is wanted, rapid solidification can provide that, it cost 30€/kg two decades ago
rsp technology​Alternately, 20-25%vol ceramic powder in aluminium alloy matrix adjust the ppm/K of Metal-matrix ceramic. Cutting tool wearout is a worry, graphite choppers might be better.

An electrolytic or electroless nickel or nickel-cobalt layer protects against corrosion and doesn't gall. The deposition parameters adjust the hardness. Tin-nickel would be very hard.

Marc Schaefer, aka Enthalpy


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## Enthalpy

Some woodwinds have *curves in the air column*. My bassoon built in 1915 has a sharp edge between the two bores and a cork to tap the common chamber, pictured left. Most recent instruments have a curved metal tube to widen the inner radius, pictured right, but if a tone hole must sit there, the luthier needs this additional technology and the fabrication takes time.










As pictured second left, CNC machines can now easily mill a round inner curve. This leaves room for toneholes in the wood (or polymer), even long holes if wanted. My cork has a thin cover (of bone?), it could be hard and thick as on the flute if needed.

Convex inner edges hamper the flow, concave outer corners don't. A nearly flat cork defines locations of broader and narrower sections that can cancel out for waves long enough. Only at unimportant 3kHz on a bassoon would the imperfection be strong.

In the alternative pictured second right, the shell too leaves room in the wood for tone holes, it can be stiff, and is easier to remove from a mould or a matrix than a complete tube.

Possibly known, but useful.
Marc Schaefer, aka Enthalpy


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## Enthalpy

In the option depicted second right in last message, the *curve's shell could be of light metal*, and then thickness makes it stiff. I hope AA5083 (Al-Mg5-Etc), optionally anodized, resists corrosion there. A few retailers offer it work-hardened to H34, advantage over casting
alu-stock.es - alumisan.com​
CNC milling, possibly by a subcontractor, makes the shape quickly. Or stamping, for which a good home-made press suffices.

Pulling the cork removes it from my bassoon's boot, very convenient to dry the bore. I want to open all turns as quickly: some kind of spring and lock?

A seat of flat cork can seal the curve. Or maybe an O-ring.

Marc Schaefer, aka Enthalpy


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## Enthalpy

I suggested designs for *curves in a wooden body*
 talkclassical - talkclassical
I enjoy swift disassembling to dry my French bassoon, but the designer should choose a shape that leaves no grease in the bore.

==========

I put *cigarette paper on my teeth* to play reed instruments
 talkclassical
Two more brands adhere well and are strong: Muskote (35µm) and Gizeh (35µm).

==========

To *lock and unlock the springs at my woodwinds*' keys, I use "Haekelnadel" (they serve for clothes usually)








I got for 8.50€ a set of 12 sizes beginning at 0.5mm, of which 0.75mm fits my bassoon well. The bamboo shaft is better than plastic.
ebay.de/itm/403141468590 (replace "de" as you like)

Their steel bends under limited force, not a drawback in this use. My mini propane burner is too weak, so I ignore if this steels hardens by quenching.


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