New Electric Action Systems

[MusingMuso]

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You forgot the "gripper-rod" pedals which would be such an aid to accuracy.

 

 

MM

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Which reminds me of the true story of a local organist, who stared blankly at his feet after playing the Reubke, and said, "I knew there was something wrong. I forgot to take my golfing shoes off."

 

(The pedal-board looked like it had been shot at with a 12-bore!)

 

 

 

MM

[David Coram]

So that's where I've been going wrong!

I wish someone had told me this before.

 

Do tell us, what's your teacher's name?

 

P.

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I only asked a civil question... I would not dare to criticise your technique, Paul.

[david_forde]

Wow – I didn’t think this would pick up as much as it did!

 

The whole joy of mechanical action is that it encourages a level of precision that I for one can only aspire to (prompting the comment that I should be content with slow pneumatics, but enough of that). Even with limited technique (and a limit to the amount of time allowed to improve it), there is something very special about the experience of total control over the key action – yes a good action is exacting (at times embarrassingly so), but that is no bad thing…a bit like cabbage, not always appetising but very good for you!

 

A point to note is that every mechanical action will feel different and as much depends on the design of the soundboard, pallets and keyboard as it does on the action train. The response will be different across the compass as the pallet size varies, to say nothing of the pallet-spring settings. Registration comes into the equation too – if one is playing on a soundboard with 10 stops and needs say 10mm of pallet movement to sound the full ensemble, it might be possible to fully sound a single 8’ flute within the first couple of mm of movement. If any sort of attack control is to be achieved, the ‘pluck’ element is of greatest importance which calls into doubt anything that obscures pluck in an action (whether through the engineering of the action or the use of assistance systems). This is why proportional electric systems seem a bit of a non-starter for me – as another correspondent noted, if there is no connection between the feel of the key and aural cue, there is little point in any control other than on and off. Perhaps proportional electric control has a more useful application in coupling, though to be honest electrical coupling on a mechanical organ makes the “mechanical” element a bit of a conceptual non-starter as far as I am concerned – better to be up-front and have electric action throughout. The idea of non-mechanical secondary pallets on the same groove is a dangerous one, calculated to ruin repetition – far better to have separate grooves, though even then the notes with on-off control will stick out like a sore thumb.

 

On the subject of pallet-bounce, in my experience this has less to do with the pallets and more to do with the keyboard and action train – actions without traditional thumper-rails suffer as the momentum of the action is not arrested, a problem not associated with key tensioned actions. I encountered one organ with suspended action where compass springs were added to the keyboard to eliminate the problems of key-bounce – making the effort of suspending the keys utterly pointless…incidentally in suspended actions the keys hang from the pallets and not the rollers.

 

Mechanical action is a real engineering design challenge for the organ builder – establishing how to balance control, repetition and weight could become a career odyssey!

D

[David Coram]

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Surely a suspended action can hang from rollers, which hang from pallets? You'd have some peculiar soundboard layouts without.

[david_forde]

Surely a suspended action can hang from rollers, which hang from pallets?  You'd have some peculiar soundboard layouts without.

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True - perhaps I am being a bit pedantic, but in practically all actions the train is hung from the pallet, against the force of the pallet spring and the wind pressure. The roller forms part of an action train and is used to move the action sideways as required by the layout.

 

It is possible to have a key action hung from an independently sprung lever between the pallet pull-down wire and the roller-board – sometimes used for dual key-action systems, where one hopes to avoid moving the tracker action train when using the electric system. The problem with that sort of system is that one plays against the retaining spring not the pallet…

[MusingMuso]

True - perhaps I am being a bit pedantic, but in practically all actions the train is hung from the pallet, against the force of the pallet spring and the wind pressure.  The roller forms part of an action train and is used to move the action sideways as required by the layout.

 

It is possible to have a key action hung from an independently sprung lever between the pallet pull-down wire and the roller-board – sometimes used for dual key-action systems, where one hopes to avoid moving the tracker action train when using the electric system.  The problem with that sort of system is that one plays against the retaining spring not the pallet…

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I'm probably going to wade into water here..............

 

People thought I was mad before, when I suggested on another discussion-board that the perfect compromise between mechanical linkages and EP actions might be hydraulic organ-actions.

 

Of course, I'm immediately aware of the implications of inertia in fluid-runs, and it would have its limitations, even with some sort of servo assistance. However, fluid is as solid as a mechanical-linkage, and that's the bit that interests me.

 

Fluids running through small-bore tubing have the advantage that they could totally eliminate stickers, trackers, roller-boards and all the other niceties of mechanical action, whilst retaining direct contact. The only problem is that of coupler actions.

 

It's just that in this day and age of small, precision components and plastics, it could probably be achieved quite easily. I've dabbled around with brake pistons and tubing, more out of curiosity than anything else, and the smoothness and lack of resistance is impressive, whilst long-term reliablity shouldn't be a problem at all.

 

I'll just crawl back under a stone...............

 

MM

[david_forde]

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I'm probably going to wade into water here..............

 

People thought I was mad before, when I suggested on another discussion-board that the perfect compromise between mechanical linkages and EP actions might be hydraulic organ-actions.

 

I'll just crawl back under a stone...............

 

MM

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Possibly not that mad at all, though I doubt the current organ market would stand the cost of developing such a system...otherwise it would have been done by now!

[Phil T]

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People thought I was mad before, when I suggested on another discussion-board that the perfect compromise between mechanical linkages and EP actions might be hydraulic organ-actions.

 

Of course, I'm immediately aware of the implications of inertia in fluid-runs, and it would have its limitations, even with some sort of servo assistance. However, fluid is as solid as a mechanical-linkage, and that's the bit that interests me.

 

Fluids running through small-bore tubing have the advantage that they could totally eliminate stickers, trackers, roller-boards and all the other niceties of mechanical action, whilst retaining direct contact. The only problem is that of coupler actions.

 

It's just that in this day and age of small, precision components and plastics, it could probably be achieved quite easily. I've dabbled around with brake pistons and tubing, more out of curiosity than anything else, and the smoothness and lack of resistance is impressive, whilst long-term reliablity shouldn't be a problem at all.

just crawl back under a stone...............

 

MM

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Hydraulic system, as in piston under the pallet and piston under the key connected together with small bore pipe full of hydraulic fluid?

 

Sounds interesting, and on the surface, very plausible.

[Pierre Lauwers]

So here is the organ action of the future:

 

http://www.secomeca.fr/maintenance-industr...hydraulique.jpg

 

Quite sensitive!

Pierre

[David Coram]

Actually, I think it sounds like an extremely good idea, very worthy of pursuing.

 

It could be partially electric too, with electric motors shifting fluid rather than pneumatics. It would probably be a lot easier to work on than pneumatics.

[MusingMuso]

Actually, I think it sounds like an extremely good idea, very worthy of pursuing.

 

It could be partially electric too, with electric motors shifting fluid rather than pneumatics.  It would probably be a lot easier to work on than pneumatics.

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No,no,no!!

 

Pneumatic compression or depression will do the job wonderfully. All you need is a servo chamber and a membrane on each activation piston rod; like a miniscule version of a brake-servo, using small, flexible discs. After all, we're only talking about a few grammes, not drilling to the earth's core!

 

Even that may not be necessary; dependent upon the fluid inertia within the tubing and the length of run involved.

 

To me, the main advantage would be a flexible layout, the possibility of detached consoles and STILL direct hydro-mechanical contact between key and pallet, and without the inherent mush of pneumatics. It is virtually impossible to compress liquids. The other advantage would be more or less standarised components for all situations.

 

An immediate application could be slider or ventil control; possibly Swell shutter control, because fluids can work in both directions: responding equally to compression or depression forces.

 

Interestingly, actual physical movement could be adjusted by the use of different bores in pistons, rather than having to work out specific fulcrum points on levers and pallets.

 

It should also be noted that should any servo-system fail, the system would still work; albeit a little heavier than before.

 

I reckon it would actually be cheaper than EP, because pistons are quite easy to make and extremely reliable.

 

MM

[Pierre Lauwers]

Just for the sake of it -hydraulic systems are veeeeeery sloooooooow.

They can handle huge torques (hence the pic above), but for ornamentings

in Couperin, you might encounter some slight problems!

It would be like shoting on a fly with a bazooka, and a heavy one

-how do you target a moving fly with this thing ?

Stick to the pneumatic.

 

Pierre

[Phil T]

Just for the sake of it -hydraulic systems are veeeeeery sloooooooow.

They can handle huge torques (hence the pic above), but for ornamentings

in Couperin, you might encounter some slight problems!

It would be like shoting on a fly with a bazooka, and a heavy one

-how do you target a moving fly with this thing ?

Stick to the pneumatic.

 

Pierre

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I’m sorry to disagree with you Pierre, and I can only speak from my experience, but I’ve seen hydraulic valves (actuators) operate in less than half a second. This is (I admit) in a system operating at 4000 psi and so is totally different to the system that MM is thinking about. The system that MM is on about is more akin to a cars braking system: The repetition of the ABS facility is still pretty rapid.

 

[Pierre Lauwers]

I’m sorry to disagree with you Pierre, and I can only speak from my experience, but I’ve seen hydraulic valves (actuators) operate in less than half a second.  This is (I admit) in a system operating at 4000 psi and so is totally different to the system that MM is thinking about.  The system that MM is on about is more akin to a cars braking system:  The repetition of the ABS facility is still pretty rapid.

 

 

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The problem are the 4000 PSI.

Let us imagine we have a simple kind of hydraulic action, without assistance

power of any kind.

Should you depress a key very slowly, it could work. But if you accelerate

the movement, the system will react as a shock absorber; the more quick

the depressing, the more the resistance will increase.

Should you try to overcome this by using bigger diameters for the fluid conducts

(at all levels), you will soon build an huge inertia, because you will have to move

a sheer volume of hydraulic fluid -heavier than wind!- with your finger.

Now we could use a power system, in which your finger only opens or closes

a valve, power actuating the action itself; but then you would need maybe not 4000 PSI but still far too much energy for an organ action. Better to go for TP or EP then...

 

"The repetition of the ABS facility is still pretty rapid."

(Quote)

Yes, but within a high pressure system (not the control from the pedal, but AFTER the servo) and on a very little course (about 0,1mm on the brake pads).

Pierre

[MusingMuso]

The problem are the 4000 PSI.

Let us imagine we have a simple kind of hydraulic action, without assistance

power of any kind.

Should you depress a key very slowly, it could work. But if you accelerate

the movement, the system will react as a shock absorber; the more quick

the depressing, the more the resistance will increase.

Should you try to overcome this by using bigger diameters for the fluid conducts

(at all levels), you will soon build an huge inertia, because you will have to move

a sheer volume of hydraulic fluid -heavier than wind!- with your finger.

Now we could use a power system, in which your finger only opens or closes

a valve, power actuating the action itself; but then you would need maybe not 4000 PSI but still far too much energy for an organ action. Better to go for TP or EP then...

 

"The repetition of the ABS facility is still pretty rapid."

(Quote)

Yes, but within a high pressure system (not the control from the pedal, but AFTER the servo) and on a very little course (about 0,1mm on the brake pads).

Pierre

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As a physical characteristic, the only thing which should be of concern, is whether the small amount of mechanical/fluid-friction and the weight of fluid within a hydraulic circuit, exceeds that of direct mechanical linkage, with all the bushes, squares, rollers etc.

 

Obviously, if one tries to use micro-bore tubing like a syringe, then it is going to be slow, but for those who wish to try this at home (NOT THE 4000psi VERSION!!!!), you simply get two brake cylinders, connect them with plastic tubing at the union, fill them with fluid and then bleed out any remaining air. The action is instantaneous, but I have yet to measure the amount of finger pressure required.

 

Please, please, please! Let us not think of this as a civil-engineering project deep beneath the Alps!

 

I'm really not sure whether or not this would have any possibly application as a key action, but I could certainly cut the costs of stop and swell-shutter actions, using double-acting pistons working on a looped hydraulic circuit, and incorporating a servo operating off the organ wind system. It may also work as a pedal action, where key weight is less critical.

 

Of course, one would have to pay particular attention to watertight seals (not the living variety....though that would be a great idea for the choristers!).

 

We wouldn't want this sort of disaster on our hands, would we?

 

http://soundtransit.nl/search/artistinfo.php?id=160 (Click on the sound clip of the organ in St.Vitus Cathedral, Prague)

 

 

MM

[MusingMuso]

Just in case you think organs are loud, try the Santa Pod Rocket Car on the link supplied in the previous post!

 

and it's gone!

 

 

MM

[Pierre Lauwers]

This astounishing MP3 reminds me of the lady journalist

at a meeting with G.W.B. who forgot to put her micro off

while going to the lavatories...

 

Pierre

[pwhodges]

This astounishing MP3 reminds me of the lady journalist

at a meeting with G.W.B. who forgot to put her micro off

while going to the lavatories...    

 

Pierre

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Not as embarrassing as forgetting to take off the PA mike at the end of a lecture before doing the same.

 

Paul

[Pierre Lauwers]

Not as embarrassing as forgetting to take off the PA mike at the end of a lecture before doing the same.

 

Paul

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Has it happened?

 

Pierre

[David Coram]

Has it happened?

 

Pierre

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It has once happened at the end of a service, yes - sound of tinkling water and vicar singing last hymn loudly and tunelessly to himself. Not at Romsey, before anyone wonders... our vicar sings with a tune at all times.

[pwhodges]

Has it happened?

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Of course! To a colleague of my wife. With a room-full of medical students waiting for the next lecture while the next lecturer looked for the mic.

 

Paul

[Frank Fowler]

Of course!  To a colleague of my wife.  With a room-full of medical students waiting for the next lecture while the next lecturer looked for the mic.

 

Paul

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The classic examples are priests forgetting to switch off the mike when taking confessions.

 

FF

[David Coram]

The classic examples are priests forgetting to switch off the mike when taking confessions.

 

FF           

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You used to be able to play a very good game at Clifton Cathedral; watch in the mirror as someone goes into the box, then get louder and louder and louder, count to three, and... stop. "YOU DID WHAT???"

[revdnsm]

On similar lines... and totally true.

 

A husband and wife Vicar and Deacon were just about to take a service. Husband comes back into the vestry throws his radio mic saying 'It isn't working'.

He turns to his wife and puts his hand inside her cassock alb to take her microphone. In fun she said' 'Vicar take your hands off your Deacon's boobs'.

At that piojnt the organ struck up and off they had to go to take the service.

 

They wwre met by a wide eyed congregation. That microphone was working!!

 

David W

[MusingMuso]

On similar lines... and totally true.

 

A husband and wife Vicar and Deacon were just about to take a service. Husband comes back into the vestry throws his radio mic saying 'It isn't working'.

He turns to his wife and puts his hand inside her cassock alb to take her microphone. In fun she said' 'Vicar take your hands off your Deacon's boobs'.

At that piojnt the organ struck up and off they had to go to take the service.

 

They wwre met by a wide eyed congregation. That microphone was working!!

 

David W

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As usual.....I know a story.....

 

This should amuse Nick Bennett, because it actually happened and involved the Worth Valley Railway in West Yorkshire. It also involved radio microphones.

 

At Ingrow Station, the children were enjoying a "Thomas the tank-engine day", and at the Parish Church, just across the road, they were enjoying Sunday morning communion.

 

The children squealed with glee at the station, and the faithful sang a hymn as the vicar went to the pulpit....nothing unusual about that. However, as the vicar switched on his radio microphone, the very instant that the "Fat Controller" began to take Thomas the Tank-Engine to task, the two systems started to interfere; both working on identical frequencies.

 

Just as the vicar was about to say, "In the name of the father etc," the PA system burst into life with "Well now Thomas, you've been a naughty boy.....a very naughty boy indeed."

 

Thomas, for his part, was getting a blessing and a lengthy sermon.

 

MM