Tech/maintenance My new "DIY" pads...

Pete Thomas · Jan 14, 2022

DavidUK said:
the accessory market is huge in the guitar world.

It is in the saxophone world. Often a very much larger mark up than on saxophones (for which people tend to shop around more and expect discounts). Less shelf space and insurance costs, ofetn much quicker supply chain. retailers will tell you this.

Plus these days there are maybe ahigher percentage of less experienced players who have not yet realised that they needn't believe all the hype about sound enhancing gizmos etc. (speaking generally, that last bit obviously doesn't apply to your product*)

In your case if this is marketed as something for players to buy while out reed shopping then yes, retailers should love that. As regard techs, as you know what Stephen says is probably best taken on board.

However to stand any chance convincing anyone, then it will be a huge gamble "bringing it to market" as dragons would say.

*Come to think of it, I don't know. Soemoen is bound to say that the magnetic field bends the sound waves in such a way as to enhance the tone.

Stephen Howard · Jan 14, 2022

DavidUK said:
Surely tone holes need to be level for leather pads? You don't seem to overlook uneven ones when doing a review.

Mine could be even better at accommodating unevenness. Or are you imagining them to be hard rubber?
They're not like Jim Schmidt's, demanding level tone holes or they won't work.

Ideally, yes, they do - but if necessary it's possible to 'deform' a pad to seat over a warped hole. They won't magically deform all by themselves, and you have to provide a way of ensuring that they don't shrink back at a later date.
A pad of sufficient softness that it can deform in an instant to cover a warped tonehole, time and time again, is going to feel horrible beneath the fingers - and you can forget about any notion of accurate regulation.

Clivey · Jan 14, 2022

It was knocked into me when I studied business that rule 101 was a new start up has to while making the initial business plan prove by presenting results of survey that there is a real demand for the service or product . This is required to estimate cash flow etc.

I think the only situation David's idea would have sufficient demand is if he can persuade a manufacturer to install his system during the manufacturing process. David would require a contract to protect his IP, but there's nothing stopping manufacturers ripping the idea or undercutting David if he decided to become a supplier.
@DavidUK
More power to your elbow. Perfect your design and you may find a partner in the east that may help.

DavidUK · Jan 14, 2022

Some synthetics, as I have discovered, deform to a certain degree when compressed and hold this "compression set" as may be desirable to accommodate unevenness. Kind of a moulding process if you like.

Leather/felt pads can be manipulated manually to accomplish the same.

The synthetic compression set may be almost zero, so that they bounce back with no impression left by the tone hole, or they may deform permanently to 25%, 50%, of their thickness.
If I had a tone hole 0.5mm out of level and a 1mm thick synthetic sealing ring, it may be possible for the seal to form an exact impression/mould of the undulating rim and hold this sufficiently to also give a good feel to the pad.

My issue with this, for uneven tone holes, is that my pads may rotate and take the original pad "moulded in" seat away from where it started thus making the problem even worse. I either cater for level tone holes, find a low compression set seal which can rotate AND be leak free in a new position, or stop the pad from rotating. I've given all of these some thought over the past months and still need to hit that eureka moment. It'll come. A balancing act, as is everything related to finding the right sealing material.

Jim Schmidt insists on a level tone hole and nothing else. In due course I might advertise that I can provide alternative seals for uneven tone holes but this would be a nightmare to supply and get right. I'd be better sending them off to a tech to get them levelled - yet more work for techs!

Colin the Bear · Jan 14, 2022

Just a thought. What material does the jsax use for pads?

DavidUK · Jan 14, 2022

I don't know Colin. Has it sold well? This is my first thought.

LostCircuits · Jan 14, 2022

DavidUK said:
Ermmm... isn't this what I have made happen? You describe it precisely, other than a ball and socket. Mine is half a ball, half a socket.
They do not float around when lifted but stay in their levelled position. If accidentally moved, when next closed they regain the tone hole level and stay there.
That's why the strong magnet is so ideal.
No manual tightening or loosening needed. It's automatic.

mhhh. looks like you know how strong magnets work :clapping:

stitch · Jan 14, 2022

DavidUK said:
Also pad height setting and adjustment almost becomes fun when it's a mechanical operation with a screwdriver and spanner.

I think you're really talking about pad THICKNESS rather than height. Surely the height is set by regulation corks/screws?

DavidUK · Jan 14, 2022

Yep, you got it. Height adjustment = effective thickness of pad. As if you were adding or removing glue/shellac.

Clivey · Jan 14, 2022

@DavidUK
Re prevention of rotation of your pads . A spline and matching female socket would work .It would not have to have a tight match.

https://search.brave.com/images?q=spline

Hamfist · Jan 15, 2022

It sounds like a very promising idea indeed David. I'll be following your progress with interest. I love tinkering with instruments but feel rather intimidated by a lot of the workings of the saxophone. To make this aspect of the sax much more DIY friendly sounds great.

Well done.

DavidUK · Jan 15, 2022

Clivey said:
@DavidUK
Re prevention of rotation of your pads . A spline and matching female socket would work .It would not have to have a tight match.

https://search.brave.com/images?q=spline

I did think of this, but a ball headed Allen "spline" to fit in the socket head of the adjustment screw wouldn't work as the screw socket would need more side to side movement which the magnet's countersink wouldn't allow. It wouldn't self-level.

The ideal is to allow the pad to rotate, and as Jim Schmidt explained to me, this extends the life of his pads (once again fixed off-centre to the tone hole, in the centre of each key cup) as any slight wear is borne by multiple seats formed as the pad rotates. But... of course he insists on dead flat tone holes.

I've come across plenty of leather pads, on level and uneven tone holes, which "overflow" down the side of the tone hole forming a deep seat which then grips the sides. This is undesirable. But even a fine looking leather pad may, under a microscope, reveal a degree of side gripping as the "rough" leather spills over the sharp edge of the hole. Ideally all holes would be dressed to a smooth small radius, like a smaller version of a rolled tone hole. But if you're going to do this you may as well get your tone holes level first.

So I have to find a material which is both smooth so as not to grip, squidgy enough to seal and accommodate slight unevenness, low compression set so as not to form a deep seat, and hard enough not to feel spongey under the fingers without too much noise. Quite an ask.

But then, why would leather be the best? Did whoever invented the leather pad have the massive variety of specialist materials we have now? No, of course not. They maybe had a choice of animal?

The right solution is out there (and lots of it in my house) but finding it is like a needle in a haystack rather than a cow hide in a village 150 years ago.

LostCircuits · Jan 15, 2022

DavidUK said:
I did think of this, but a ball headed Allen "spline" to fit in the socket head of the adjustment screw wouldn't work as the screw socket would need more side to side movement which the magnet's countersink wouldn't allow. It wouldn't self-level.

The ideal is to allow the pad to rotate, and as Jim Schmidt explained to me, this extends the life of his pads (once again fixed off-centre to the tone hole, in the centre of each key cup) as any slight wear is borne by multiple seats formed as the pad rotates. But... of course he insists on dead flat tone holes.

I've come across plenty of leather pads, on level and uneven tone holes, which "overflow" down the side of the tone hole forming a deep seat which then grips the sides. This is undesirable. But even a fine looking leather pad may, under a microscope, reveal a degree of side gripping as the "rough" leather spills over the sharp edge of the hole. Ideally all holes would be dressed to a smooth small radius, like a smaller version of a rolled tone hole. But if you're going to do this you may as well get your tone holes level first.

So I have to find a material which is both smooth so as not to grip, squidgy enough to seal and accommodate slight unevenness, low compression set so as not to form a deep seat, and hard enough not to feel spongey under the fingers without too much noise. Quite an ask.

But then, why would leather be the best? Did whoever invented the leather pad have the massive variety of specialist materials we have now? No, of course not. They maybe had a choice of animal?

The right solution is out there (and lots of it in my house) but finding it is like a needle in a haystack rather than a cow hide in a village 150 years ago.

I think you are overthinking the issue. If you are using rare earth magnets, the magnetic force will be enough to create sufficient friction and prevent rotation.

You could circumvent the problem altogether if you would devise a system like the valves in a car engine. That is, you have a push rod that is centered over the tonehole via a "key guard" and which is spring loaded to be open unless an actuator pushes down on the mechanism. In that case, the movement would be 100% axial with no angular or lateral movement. The pad resonators have a female thread where the push rod engages. If you need to change pads, you unscrew the pad, slide it out and put in a new one. You could even make the entire system from plastic for super low weight and cost (injection molded rather than 3D printed). In this case you don't need magnets at all, just a few ball point pen springs. All components needed would tally up to probably less than $5.- in mass production. Plus the actual pads. But you could go with "arched" or beveled plugs that "descend" into the tone holes and keep the pads "hard" while you put an insulating O-ring on the chimney. I know it wouldn't look like a real saxophone anymore :confused:

And, you are 100% correct that there are new materials out there, just think of the "self-healing" cutting boards

mizmar · Jan 15, 2022

LostCircuits said:
while you put an insulating O-ring on the chimney. I know it wouldn't look like a real saxophone anymore

And, you are 100% correct that there are new materials out there, just think of the "self-healing" cutting boards

In the spirit of idle curiosity... Why not have the sealing on the chimney and leave the keycaps hard or empty? Some fancy material that can be cured / moulded in place to fit each key? They seem to be able to make silicon rubber and such to almost any specification these days. It'd make the keys lighter, so faster, no?
I've no doubt folks have been round that merry-go-round...

DavidUK · Jan 15, 2022

Car valves rotate in their guides/seats so I'm not sure that would assist. I'm not fully understanding the whole concept.

Moulding a seal onto the tone holes may assist levelling them but to do this the seals would need an integral stiff ring or we'd be back to trying to level them manually. I don't think there's enough tone hole sticking up to mould to. An insert in the hole would mess with tuning no doubt. Good thought though. I'll ponder it.

LostCircuits · Jan 15, 2022

mizmar said:
In the spirit of idle curiosity... Why not have the sealing on the chimney and leave the keycaps hard or empty? Some fancy material that can be cured / moulded in place to fit each key? They seem to be able to make silicon rubber and such to almost any specification these days. It'd make the keys lighter, so faster, no?
I've no doubt folks have been round that merry-go-round...

That's exactly what I was saying. The problem with this thread is that instead of trying to find a solution that is "engineered to work, it is looking for an evolutionary path to address one problem which may not even be a problem, i.e. leather. And, to be fair, there is nothing wrong with that, we are all striving to come up with a better mouse trap all the time.

Personally, though, I've spent decades of my professional life to throw out the old completely and think of the new approach in a "problem-oriented" way The entire mechanism of a saxophone, going back to clarinets and flutes is about 200 years old without any real changes. And embellishing it by different pad materials is perfectly fine but if you really think about what you want to accomplish, you might find an entirely different approach is more economic and powerful. Just look at the Koenigsegg TFG engine.

And @DavidUK, I am not trying to criticize you, rather provide some extra food for thought. Martin had the beveled tone holes but you might put the bevel on the inside to get a self-centering mechanism

I don't have my cad software but here is a crude drawing, in this case I'd use a hydraulic actuator

DavidUK · Jan 15, 2022

To get a car engine valve to seat exactly needs a long sturdy valve guide precisely aimed at the valve seat centre.

A valve sealing inside, rather than on top of a seat will leak if it moves off dead centre a few microns whilst trying to self-centre. It cannot work. One edge will tip up leaving a gap. It's pointless being self centering if it sits inside the seat.

The only way to self centre is a flat hole rim and flat "flap" (pad) on top per my design, and the current standard arrangement.

Concave pads, or conical ones won't work unless fixed to mate precisely with the tone hole. For any pivot point for these to be self-centering it would also have to be able to move sideways in all directions to accomodate this. Impossibly complicated.

Whereas a flat disc with flat tone hole can slide across the rim of the hole, something protruding into it cannot.

Colin the Bear · Jan 15, 2022

The very first tone hole pads were on the fingers.

mizmar · Jan 15, 2022

Blowing across the top of a hollow reed or bone was, probably, the first wind instrument innovation. Then; cutting them to length, then pocking holes, alternative sound generation... Then all hell broke loose with ... The Key... Should have stopped before that.