aftertouch.. who needs it

[maxd]

who needs aftertouch?

why do piano techs put in a mm or so of aftertouch, even if it's not needed?

do you guys know what aftertouch is?

[gruffalo]

not sure what you mean. could you explain it to me in detail?

[pianistimo]

nobdy needs it.  it's the bane of any good piano's existence.

[maxd]

after the first escapement is tripped and the hammer is released just a mm or two before striking the strings the key does not need to go down any further.

if the mechanism is working properly you need to stop the key from going down any further.

once the key is released at this point the second escapement should raise the hammer towards the strings even if the key is slightly released.

if there is a mm or two of aftertouch the hammer will not release right away and slow the action.

there is also lost motion..

some techs just don't have a clue, or are afraid to have a key dip inferior to 10mm.

correct me if I'm wrong.

[pianistimo]

seems that you see this most on used pianos. 

steinway always seemed to have their action under control with the new pianos.  i'm sure there are many others.  i like to have just a fraction (not even a mm) of that little space - but 'whew'  you don't need a 1/2 inch.

sit at the piano.  touch a key.  put pressure down until you feel resistance.  stop.  that is the aftertouch, right?!  it's the part that is left to blow in the wind.

[ramseytheii]

after the first escapement is tripped and the hammer is released just a mm or two before striking the strings the key does not need to go down any further.

if the mechanism is working properly you need to stop the key from going down any further.

once the key is released at this point the second escapement should raise the hammer towards the strings even if the key is slightly released.

if there is a mm or two of aftertouch the hammer will not release right away and slow the action.

there is also lost motion..

some techs just don't have a clue, or are afraid to have a key dip inferior to 10mm.

correct me if I'm wrong.

I don't understand anything about this post.... so aftertouch is the double escapement?  But I thought that was one of the greatest advances in piano technology ever.  Are you sure that people should not be pressing the keys all the way down, or am I misunderstanding you?  It seems that for a proper technique for repeated notes, you actually have to not allow the key the raise above that initial point of resistance, not keep it above. 

Walter Ramsey

[will]

Not sure I know exactly what you mean but.....are you talking about the point after which nothing you do to the key can affect the way the hammer moves towards the strings?
How about: this area of free play allows the pianist to decelerate the keys after sound has been created and before the keys reach the keybed. This means there is less impact on the player and sound by not needing to crash all the way down into the keybed.

[timland]

Aftertouch is the distance a piano key moves with diminished resistance after the escapement of the jack is complete. If you didn't have any aftertouch the keyboard wouldn't feel right and would be more difficult to control. It's usually .030" - .060". About the thickness of a penny.

[pianistimo]

i don't notice it when coming off of the keys - but greatly notice it before playing them.  you have this silent 1/4'' on some pianos - that you have to 'dive' through before you affect the action in any way.  this is what bothers me.

if the escapement is correctly adjusted - it is tight.  the hammers are free to do quickly what they need to do and there is nothing that the piano tuner actually does to improve the action excepting taking it out and putting in a whole new action, imo.  you want all of the notes to sound even and have the SAME action.  (i'm not discounting tuners - i'm just saying - buy a good piano.  you get what you pay for sometimes.  kawaii seems to have a nice action, to me, and it is medium priced).

on pianos that are too tampered with - different keys have slightly different 'tightness' levels (or are completely loose).  i tend to like a stiff fast acting action that begins to affect the action immediately slightly after the 'penny' level surface area.  then, isn't there more time for the action to do what it needs to do - and you can play repeated notes a zillion times in the double escapement area?!

[timothy42b]

Now you've thoroughly confused me.

Above, it looks like some are talking about after touch being the distance the key travels after the hammer strikes, and some talking about after touch being lost motion before the hammer starts to move.  ??

I have a third kind of after touch.  My digital piano is programmable to add special effects by pushing harder after the key is down.  I don't use it much but it can be useful. 

[pianowolfi]

https://www.musiciansnews.com/piano/encyclopedia/92/aftertouch.shtml

[pianistimo]

pianowolfi - you shouldn't do this   confusion reigns.

as i see it - aftertouch is similar to beforetouch.  ok.  you push until resistance.  then finally the old piano sounds.  after you literally stick your head inside the piano and pull the hammer away from the string.  then you sit back down and pull the key up, but some piano keys just get stuck at that halfway point for some reason.

[ramseytheii]

https://www.musiciansnews.com/piano/encyclopedia/92/aftertouch.shtml

Oh, I see why I didn't get it, it's for electronic keyboards!

Walter Ramsey

[quantum]

Now I'm confused. 

More explanations please.  Maybe some simple definitions of the action parts and what they do, so we can understand the concept of after touch.

[maxd]

you press the key which raises the hammer towards the strings.. to prevent the hammer from pushing on the strings the first escapement is triggered which detaches the lever tied to the key from the hammer.. the hammer therefore strikes the key and falls downwards onto the catch..once the first ecapement is triggered there is no need for the key to go any lower, other than for mechanical reasons due to tolerances in the action (no mechanism behaves perfectly so you need a mm or so more)..

so now you have the finger on the key, the hammer is caught in the catch...

you now release the key slightly, therefore freeing the hammer from the catch..

the butterfly spring inside the mechanism (double escapement!) raises the hammer close the string... the lever which connects the key to the hammer slips under the hammer again and the hammer is ready to 'fire' even without raising the key all the way up to the rest position...

this is the double-escapment principle..

some pianos have additional movement  downwards after the first escapement but this extra key-depth only slows the action down.

[marco_from_brazil]

According to Reblitz, after touch is necessary in order for a vertical piano backchecks ( The felt cushions that hold the hammer some halfway to the strings when you play and hold a loud note ) to work properly. What happens is that some actions, when regulated to the standard dimensions of 10mm key dip and 44.5mm hammer stroke ( or distance to the strings ) won't work right that way, something about the jack not tripping far enough from where it pushes on the hammer butt.

So a little aftertouch, like 11mm key dip instead of 10mm, won't make the action feel weird and will fix these problems, although more than that does feel strange.

Now, again, that is for an UPRIGHT. Properly regulated grands aren't supposed to have ANY after touch, I believe.

[gfiore]

All grand actions have aftertouch. Aftertouch is the distance the key travels after the jack escapes from the knuckle. Each manufacturer has there own idea spec of how much there should be, which is usually between .025 minimum, to -.060 maximum.
 Insufficient aftertouch may cause the hammer to double strike on the string, while excessive aftertouch may cause the jack to jam into the rep lever window cushion and possibly break off the jack tender. Aftertouch is basically a safety measure to insure correct function of the action,  but it also influences how the action feels to the pianist.