Yamaha Piano pedal mechanism

[Engineer]

On Sep 11, 8:54 pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:

On Tue, 8 Sep 2009 01:56:48 +0100, "Arfa Daily"
arfa.da...@ntlworld.com> put finger to keyboard and composed:

"Engineer" <junk2...@rogers.com> wrote in message
I have three pedals on my General Music PRO-1 keyboard.  Two are are
KORG brand and the other is something else but the same design.  I
took one apart a few year ago to clean and, IIRC, it was a compression
design.  They work perfectly, don't fail and I only paid about $25
each.
Cheers,
Roger

You got me there. What's a 'compression' design ?

Arfa

Strain gauge??? Capacitive transducer???

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Yes, a strain gauge of some type for variable resistance... it's been
a while since I looked inside them! No potentiometers or linkages
except pedal fulcrum.
Cheers,
Roger

 

[Bob Larter]

Franc Zabkar wrote:

On Tue, 8 Sep 2009 01:56:48 +0100, "Arfa Daily"
arfa.daily@ntlworld.com> put finger to keyboard and composed:

"Engineer" <junk2007@rogers.com> wrote in message

I have three pedals on my General Music PRO-1 keyboard. Two are are
KORG brand and the other is something else but the same design. I
took one apart a few year ago to clean and, IIRC, it was a compression
design. They work perfectly, don't fail and I only paid about $25
each.
Cheers,
Roger

You got me there. What's a 'compression' design ?

Arfa

Strain gauge??? Capacitive transducer???

A column of resistive wotchamajiggits that get compressed when you push
the pedal, like sewing machines.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

 

[Sylvia Else]

Sylvia Else wrote:

The sustaining pedal on my Yamaha electronic piano is become rather
flaky. Sometimes it doesn't sustain when pressed.

So I disassembled the piano enough to get at the mechanism, (removed 12
screws, and 6 bolts), and was rather surprised to see that the business
end consists of a potentiometre.

I'm not really surprised that it's failing. In fact, the surprise is
that it's lasted so long. When a piano is played, the sustaining pedal
is in constant use. I can't help feeling potentiometres were never
designed with that kind of use in mind.

The design seems rather primitive.

Sylvia.

I just today received the new pot.

It's an odd device. Over most of its range the resistance doesn't vary.
All the change occurs within quite a small angle. This makes a kind of
sense, given that the pedal mechanism doesn't rotate it far. But it
seems to imply that the pots were specially made, which can't have
helped to keep the price down.

Sylvia.