[alljoe]

I just came back from my holiday, and picked up my tenor with slow springs and high action, leaving the Ferrari (best MKVI ever, perfect setup) in the case: all the issues disappeared!

As long as you do not have an immediate comparison, everything is fine.
Pads need to be replaced when they leak excessively.

i wonder if you were playing as well though. no immediate comparison doesnt seem like a good test. if you played that horn for a while and then compared to the other that would seem to account for "thats just what im accustomed to"factor

 

[ptung]

The height of action is a factor in how fast a keyboard feels, but a good feel is a combination of spring tension and key touch orientation *in concert* with key height. Key height should be determined by venting/voicing, but of course if a player requests a different venting you'd be unreasonable not to work around that. Often, though, when players feel like it's venting heights that are slowing them down it's actually something else, e.g. a key touch is out of position for that player or a spring isn't tensioned in a way that'd feel better for that player. Common (i.e. recurring) causes for action feeling slow to players are, for e.g., B2 and/or RH F spring tension being too light, Bis and/or C#2 tension being heavier than necessary, G tension having to be too heavy due to octave key sluggishness, low C/Eb touches being either too close or too far away from the pinky, RH thumbrest position being wrong for that player, even things like the strap ring's orientation causing hand positions to be awkward for that player mechanically. Usually it's not as invasive a question from a repair point of view as moving a strap ring, but the main point is that when it comes to improving feel/action it's easy to overemphasize key heights when actually a tweak (or a few minor tweaks) to spring tension and keytouch position can radically change a player's perception of comfort/speed.

 

[Dr G]

Palo,

How great is the influence of lubrication and sliding surfaces? Do you use Teflon sheet and low viscosity synth lubes?

 

[martinm5862]

The formula is not hard (physics), but finding the correct numbers to insert into the formula is not easy (laboratory work).

The formula for the top repeat rate is that it is proportional to the square root of <the spring stiffness> divided by <the angular momentum of the key>. The angular momentum depends mostly on the pad size and the distance from the pivot.

Usually, the best spring stiffness is found by trial and error (engineering).

Thanks. This problem has been keeping me up nights.

 

[Dr G]

Thanks. This problem has been keeping me up nights.

Don't forget to consider hand position, finger length, and the volume fraction of fast twitch muscle fibers.

And beyond all that... practice.

 

[davevillajr]

what about the length of the levers? the distance from the hinge to the finger touch in relationship with the hinge to the pad cup? all those angles and lever/pivot distances?

 

[patrik roseen]

So, let's say someone was creating a sax for the 21st century and it was important to really be able to open/close pads quickly.

Would you think that we would then have electromagnetic 'pads'. Our fingers would simply close/open a circuit controlling these electric pads.
There would not be any springs involved at all just floating or spinning pads in electromagnetic fields.

The control could be much more ergonomic when there was no mechanical connection between controls and pads.

 

[Dr G]

Ever play a WX7 or similar wind synth? I find the lack of feedback and the instantaneous response of the keys to be a detriment.

I'll stick with the old-fashioned sax.

"I'm happy with things just the way they are..." my mantra from grad school.

 

[patrik roseen]

So what you are saying is - there is a limit to how fast the pads should really close or atleast react to our imperfections.

When playing different electric guitars there are clear differences as to how fast one can play.
Some are very fast and respond quickly, one just has to put the finger on the string and the tone is there. Others requires that the string is pressed down to such depth that the response is noticably slower. When having played a fast one and picking up a slower one often means lots of slipped tones.
But going from a slow neck to a fast one is usually not a problem. One quickly gets used to the ability of playing fast.

(Sorry if I intruded in the analog discussion - did not mean to hijack this thread)

 

[SveinJo]

what about the length of the levers? the distance from the hinge to the finger touch in relationship with the hinge to the pad cup? all those angles and lever/pivot distances?

All these distances and masses are part of the calculation of the angular momentum.

A visual demonstration of angular momentum: Have you ever seen an ice skater making a slow pirouette with the arms stretched out? And suddenly spinning much faster when they pull their arms close to the body? What they are doing is reducing the angular momentum and since the rotational energy is the same, they rotate faster.

 

[ptung]

The height of action is a factor in how fast a keyboard feels, but a good feel is a combination of spring tension and key touch orientation *in concert* with key height. Key height should be determined by venting/voicing, but of course if a player requests a different venting you'd be unreasonable not to work around that. Often, though, when players feel like it's venting heights that are slowing them down it's actually something else, e.g. a key touch is out of position for that player or a spring isn't tensioned in a way that'd feel better for that player. Common (i.e. recurring) causes for action feeling slow to players are, for e.g., B2 and/or RH F spring tension being too light, Bis and/or C#2 tension being heavier than necessary, G tension having to be too heavy due to octave key sluggishness, low C/Eb touches being either too close or too far away from the pinky, RH thumbrest position being wrong for that player, even things like the strap ring's orientation causing hand positions to be awkward for that player mechanically. Usually it's not as invasive a question from a repair point of view as moving a strap ring, but the main point is that when it comes to improving feel/action it's easy to overemphasize key heights when actually a tweak (or a few minor tweaks) to spring tension and keytouch position can radically change a player's perception of comfort/speed.

Yes, I use teflon sheet, and a combination of different lubes that mix together well. What lube depends on what part of the horn, in part, and whether for a pivot screw or rod screw.

They make a difference, but less than properly fitting tubes and properly fitted keywork overall. I've also seen goofy uses of teflon that actually create friction rather than reducing it. Any contact creates friction, obviously, so if you're using a special material to minimize it you wouldn't want to use it in a nonsensical way.

Teflon compared to traditional cork, used the same exact way, seems to reduce friction by about 50% -- this is just a casual observation.

Teflon's handy for a bunch of different little idiosyncratic things that can affect player perception and "feel." One example's when, on a modern tenor, the G feels "squeaky," like it has a click, and it's due to the cork touch sort of squeaking against the cup below it. Sometimes players feel this and it feels to them like the pearl is loose. A good player will definitely notice it, like the proverbial pea in the proverbial princess's bed. A little teflon landing pad between the cork foot and the cup and the pea is gone. Something as inconsequential as that can actually be a big distraction, or the removal of one, for some players.

 

[alljoe]

no trouble. it relates. the point is to find something interesting to talk about

(Sorry if I intruded in the analog discussion - did not mean to hijack this thread)