Key contact restoration

[Gareth Magennis]

"Kaz Kylheku" wrote in message news:20160115082713.452@kylheku.com...

On 2016-01-15, Gareth Magennis <sound.service@btconnect.com> wrote:

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

---


Thanks, might give that a go.

Look, you quoted Jeff without using the correct > characters,
*including his signature*, and put your reply after the signature!

Without the > characters, it looks like your posting is a plagiarism
of Jeff.

When I went to reply to you, your entire reply disappeared, because
your reply looks like an extension of Jeff's signature, and a proper news
client removes everything after the "-- " signature mark when you reply. I
had
to copy and paste the above from the terminal.

Please use Usenet correctly or FOAD.






I would direct your juvenile rantings to Microsoft instead.
It is they who have made Live Mail do this, and they won't fix it.


Most of us seem able to cope with this though.

 

[John Robertson]

On 01/15/2016 11:30 AM, Dave Platt wrote:

In article <EI2my.44923$Wj7.3205@fx33.am4>,
Gareth Magennis <sound.service@btconnect.com> wrote:

Is there a tried and trusted way of adding a conductive contact pad?

For what it's worth: I've had pretty good luck restoring conductive
pads using a product called Neolube #2. It's a water/alcohol
suspension of extremely fine graphite, with a small amount of a
thermoplastic resin (possibly cellulose acetate?) as a binder. It can
be applied with a fine brush or Q-tip.

I recently purchased a bunch of surplus Kenwood UHF mobile radios.
About half of them had intermittent or non-working keys on the molded
keypads. The pad sheet had originally been made with some sort of
sprayed-on or molded-on conductive coating, and I could see where it
had been worn off the keys in question (the rubber was shiny and I
could actually see the shapes of the corresponding PC-board traces).

Cleaned with alcohol, painted on a couple of thin coats of Neolube,
and they work fine.

I can't swear as to how long it will hold, but Neolube seems to have a
respectable "grip" on the surfaces I've painted it onto. Its info
sheet is interesting... they talk about how its carbon is so pure than
neutron activation of contaminants isn't an issue, and so it's rated
for use in nuclear reactors.

I can't find a distributor in Canada for Neolube, however MG Chemicals
makes a product for renewing rubber contracts:

http://www.mgchemicals.com/products/prototyping-and-circuit-repair/circuit-repair/rubber-keypad-repair-kit-8339/

Available in Vancouver from Main Electronics and RP Electronics.

Not cheaper than the US stuff...

In the US you can get it from Micro-Mart:

http://www.micromark.com/neolube-2-fl-oz,8383.html

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

[Dave Platt]

In article <a4ednQUhGuOXxgTLnZ2dnUU7-eGdnZ2d@giganews.com>,
John Robertson <spam@flippers.com> wrote:

I can't find a distributor in Canada for Neolube, however MG Chemicals
makes a product for renewing rubber contracts:

The lawyers might have something to say about enforceability in that
case

In the US you can get it from Micro-Mart:

http://www.micromark.com/neolube-2-fl-oz,8383.html

That's where I got mine.

Warning: for a tools junkie, the Micro-Mark catalog is dangerous.

 

[Gareth Magennis]

"whit3rd" wrote in message
news:316ad299-e7a3-4c21-a2bb-29605ef4b3f4@googlegroups.com...

On Friday, January 15, 2016 at 2:47:08 AM UTC-8, mike wrote:

On 1/15/2016 1:22 AM, Gareth Magennis wrote:

The customer has ripped out all the contact buttons on the right side of
the keyboard, the left side set is still in place and working.

I can't imagine you can manufacture new keys at a repair price the
customer could tolerate.

There's a guy who shows up at local ham radio swapmeets and sells
radio attachment gizmos.
He has a 3D printer and claims to be willing and able to make custom
gizmos.

It ain't quick, but you could digitize the shape of an ideal key set, get a
3D print of
its upper and lower surfaces (actually, just the lower surface is critical,
the upper
can be done with hand tools), and mold your own key sheet.
If left-side and right-side match, you can (with care) dupe a left-side
sheet,
building molds by (if necessary) bronzing the model item.

It'd be easier to get an off-the-shelf product, but most manufacturers
(google on
"elastomer kepad" aren't big on stocked items.

<http://www.eecoswitch.com/wp-content/uploads/2011/08/ElastomerKeypads.pdf>

So, are there any similar keypads on any items that have spare-parts
departments?






Yes, that is exactly the question here.

I need to cannibalise a contemporary keypad assembly that has conductive
pads at least 5mm diameter.

Failing that, I need to make my own rubber knobs, and somehow incorporate
conductive rubber 5mm pads to operate the PCB switch pads.



I don't think this is actually possible in any kind of reasonable
time/effort scale.



Gareth.

 

[Look165]

First, clean the PCB with domestic alcool or the good old KF from
Siceront KF (Now F2).
Second, rip the keys contacts with fine abrasive so it is clean.
Third apply some (silver) conductive ink (Microworks for instance).

It's done (let dry 10mn).

I did it for a TV remote control and it works perfectly.

The more simple is often the best !

Contacts are around 0.1 ohm !

Gareth Magennis a écrit :

Hi,

I have a very old synthesiser where the top panel rubber contact
switches no longer work, because the owner has removed the contact strips.

This is the synth:
http://www.vintagesynth.com/sci/stk.php


The contact rubbers are pretty much 10cm x 10cm x 10cm cubes, but they
have a rather large contact footprint.
The corresponding PCB contact gap between the two lands that need to be
bridged is also rather large.
http://tinypic.com/r/14xdmo3/9



So, I am looking into the possibility of replacing the missing buttons
by cannibalising a somewhat more contemporary keypad that has extra
large contacts.

Here's a typical example I found at Farnell. It might be possible to
cut it up and glue it to the keyboard and make things work, if the
contacts are large enough.
http://uk.farnell.com/storm-interface/70160101/keypad-storm-700-16way-grey/dp/9810064




Anyone any such experience here?

I know it's a long shot.



Cheers,


Gareth.

 

[Kaz Kylheku]

On 2016-01-15, Gareth Magennis <sound.service@btconnect.com> wrote:

I would direct your juvenile rantings to Microsoft instead.
It is they who have made Live Mail do this, and they won't fix it.

Using Live Mail even though it sucks and you know it is *your* choice.
Why *should* they fix it when hordes of lemmings will use a free piece
of crap as-is? You're the reason they won't fix it.

The responsibility for conforming to Usenet guidelines is yours alone;
you can't deliberately use some program you know is broken and blame
it on the programmers.

*That* is juvenile; a seven-year-old can easily be found who has a more
sophisticated view of the world than this.

 

[N_Cook]

On 15/01/2016 08:24, N_Cook wrote:

On 14/01/2016 23:01, Gareth Magennis wrote:
Hi,

I have a very old synthesiser where the top panel rubber contact
switches no longer work, because the owner has removed the contact
strips.

This is the synth:
http://www.vintagesynth.com/sci/stk.php


The contact rubbers are pretty much 10cm x 10cm x 10cm cubes, but they
have a rather large contact footprint.
The corresponding PCB contact gap between the two lands that need to be
bridged is also rather large.
http://tinypic.com/r/14xdmo3/9



So, I am looking into the possibility of replacing the missing buttons
by cannibalising a somewhat more contemporary keypad that has extra
large contacts.

Here's a typical example I found at Farnell. It might be possible to
cut it up and glue it to the keyboard and make things work, if the
contacts are large enough.
http://uk.farnell.com/storm-interface/70160101/keypad-storm-700-16way-grey/dp/9810064





Anyone any such experience here?

I know it's a long shot.



Cheers,


Gareth.




What is the minimum resistance/mm of gap required?

Is it simple on/off contacts or is change of R monitored for key "action"

 

[Jeff Liebermann]

On Fri, 15 Jan 2016 11:15:52 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

I found a part I had made using Flexane 94, which shows 85, so that's
much to hard to flex. I don't have something handy that will work,
but I'll do some catalog searching this weekend. Offhand, I would
suspect that bathroom caulk, rain gutter seal, or other commonly
available silicone rubber compound might work but might also be too
soft (typically 25 to 30 durometers). Structural silicone might be
harder. Digging:
http://www.siliconeforbuilding.com/pdf/structuralglazing/Data_Sheet_SSG4000_UltraGlaze.pdf
Argh... only 39.

One of my customers, who customizes automobiles, recommended this
stuff:
<https://www.freemansupply.com/products/liquid-tooling-materials/mold-making-silicone-rubber/bluestar-addition-cure-silicone-rubber/v-340-mold-making-silicone-rubber-low-viscosity>
<http://www.miapoxy.com/p-124-bluestar-v-340-silicone-rubber.aspx>
Note the 400% elongation before tearing. Ideal would be 45 to 50
durometer, so methinks the 45A version might work best. He didn't
have a cured sample, so I dumped a blob on a piece of wood. We'll see
what it looks like on Tuesday.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[Jeff Liebermann]

On Sat, 16 Jan 2016 10:32:36 +0000, N_Cook <diverse@tcp.co.uk> wrote:

>Is it simple on/off contacts or is change of R monitored for key "action"

<http://oi65.tinypic.com/14xdmo3.jpg>
The piano keys on a synthesizer might require some form of velocity
sensing which most assuredly is NOT resistive. The buttons in the
above photo are for turning things on/off and are therefore simple
on/off connections.
<http://www.dummies.com/how-to/content/key-feel-and-response-of-keyboards.html>



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[N_Cook]

On 16/01/2016 18:44, Jeff Liebermann wrote:

On Sat, 16 Jan 2016 10:32:36 +0000, N_Cook <diverse@tcp.co.uk> wrote:

Is it simple on/off contacts or is change of R monitored for key "action"

http://oi65.tinypic.com/14xdmo3.jpg
The piano keys on a synthesizer might require some form of velocity
sensing which most assuredly is NOT resistive. The buttons in the
above photo are for turning things on/off and are therefore simple
on/off connections.
http://www.dummies.com/how-to/content/key-feel-and-response-of-keyboards.html

I don't know how many contacts are required.
I just tried taking a standard simple 10x10mm footprint click switch
apart , parts just clipped together. Cutting a disc of thin <1mm
silicone rubber, placing over the dome contact and reassembling , the
click noise and abrupt click action disappears, but still functions.
If they can be soldered to the pcb, ignoring the resistive pads, then
only a matter of fudging the right size and height of top protrusion to
glue over the stem of the switches,if necessary .
Well thats my halfpennyworth

 

[Gareth Magennis]

"N_Cook" wrote in message news:n7e66d$vm5$1@dont-email.me...

On 16/01/2016 18:44, Jeff Liebermann wrote:

On Sat, 16 Jan 2016 10:32:36 +0000, N_Cook <diverse@tcp.co.uk> wrote:

Is it simple on/off contacts or is change of R monitored for key "action"

http://oi65.tinypic.com/14xdmo3.jpg
The piano keys on a synthesizer might require some form of velocity
sensing which most assuredly is NOT resistive. The buttons in the
above photo are for turning things on/off and are therefore simple
on/off connections.
http://www.dummies.com/how-to/content/key-feel-and-response-of-keyboards.html

I don't know how many contacts are required.
I just tried taking a standard simple 10x10mm footprint click switch
apart , parts just clipped together. Cutting a disc of thin <1mm
silicone rubber, placing over the dome contact and reassembling , the
click noise and abrupt click action disappears, but still functions.
If they can be soldered to the pcb, ignoring the resistive pads, then
only a matter of fudging the right size and height of top protrusion to
glue over the stem of the switches,if necessary .
Well thats my halfpennyworth







Look at the photo, I need to replace the 0-9 data entry keypad on the far
right of the panel, and the four buttons to the left of it.
http://www.vintagesynth.com/sci/stk.php


The customer has said he wants the keyboard for his own use, so doesn't
require it to be restored to original condition, so I am now thinking I
might be able to find a 16 way keypad and wire it directly to the switching
matrix, and pretty much glue it to the top panel.
(He now realises ripping out the old pads because they didn't work properly
was not a good idea. I think he has been using a screwdriver to operate the
pads)

It will need some hacking because from memory, 0 - 7 have a common line, 8 &
9 use part of another, and the other switches I think are kind of random in
the matrix.



Gareth.

 

[Gareth Magennis]

"Kaz Kylheku" wrote in message news:20160115224710.851@kylheku.com...

On 2016-01-15, Gareth Magennis <sound.service@btconnect.com> wrote:

I would direct your juvenile rantings to Microsoft instead.
It is they who have made Live Mail do this, and they won't fix it.

Using Live Mail even though it sucks and you know it is *your* choice.
Why *should* they fix it when hordes of lemmings will use a free piece
of crap as-is? You're the reason they won't fix it.

The responsibility for conforming to Usenet guidelines is yours alone;
you can't deliberately use some program you know is broken and blame
it on the programmers.

*That* is juvenile; a seven-year-old can easily be found who has a more
sophisticated view of the world than this.





Yawn.

Get over it. Everyone else can adjust and read it just fine.

 

[Jeff Liebermann]

On Sat, 16 Jan 2016 20:32:28 -0000, "Gareth Magennis"
<sound.service@btconnect.com> wrote:

How to quote properly with Windoze Live Mail:
<http://www.dusko-lolic.from.hr/wlmquote/>
More:
<https://www.google.com/#q=windows+live+mail+usenet+quote>

The customer has said he wants the keyboard for his own use, so doesn't
require it to be restored to original condition, so I am now thinking I
might be able to find a 16 way keypad and wire it directly to the switching
matrix, and pretty much glue it to the top panel.
(He now realises ripping out the old pads because they didn't work properly
was not a good idea. I think he has been using a screwdriver to operate the
pads)

Well, if you're going to butcher the synth, then it might be possible
to just solder in some switches with a long shaft. Something like
these:
<http://www.ebay.com/itm/221708447229>
Yes, that's 100 pcs for $1.74. I bought 1,000 and no problems. The
extra long shaft is handy for attaching a push button. If it sticks
through the synth panel, you win.

It will need some hacking because from memory, 0 - 7 have a common line, 8 &
9 use part of another, and the other switches I think are kind of random in
the matrix.

No hacking required with the above suggestion.

Am I getting a commission on this deal?

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[whit3rd]

On Saturday, January 16, 2016 at 5:40:15 PM UTC-8, Gareth Magennis wrote:

...really only
interested in having some way to program it, now he has destroyed the input
capability.
He just wants some way of using it in his studio, aesthetics are not part of
the equation.

I'm thinking I could perhaps knock up a 16 way keypad and hardwire it in,
say, 5 hours? (not counting the hours of research I am currently
undertaking)

Oh, just buy a 4x4 keyypad, they[re not completely unavailable

<https://www.adafruit.com/products/1611>

Hand-wiring would be one way. If the buttons magically line up, just cut the membrane
part off and do a transplant.

 

[Gareth Magennis]

"Jeff Liebermann" wrote in message
news:klll9bpdnqcscame7l7rifntjm1gksdbfo@4ax.com...

On Sat, 16 Jan 2016 20:32:28 -0000, "Gareth Magennis"
<sound.service@btconnect.com> wrote:

How to quote properly with Windoze Live Mail:
<http://www.dusko-lolic.from.hr/wlmquote/>
More:
<https://www.google.com/#q=windows+live+mail+usenet+quote>

The customer has said he wants the keyboard for his own use, so doesn't
require it to be restored to original condition, so I am now thinking I
might be able to find a 16 way keypad and wire it directly to the switching
matrix, and pretty much glue it to the top panel.
(He now realises ripping out the old pads because they didn't work properly
was not a good idea. I think he has been using a screwdriver to operate
the
pads)

Well, if you're going to butcher the synth, then it might be possible
to just solder in some switches with a long shaft. Something like
these:
<http://www.ebay.com/itm/221708447229>
Yes, that's 100 pcs for $1.74. I bought 1,000 and no problems. The
extra long shaft is handy for attaching a push button. If it sticks
through the synth panel, you win.

It will need some hacking because from memory, 0 - 7 have a common line, 8
&
9 use part of another, and the other switches I think are kind of random in
the matrix.

No hacking required with the above suggestion.

Am I getting a commission on this deal?





Er, no, because it is not possible to solder these switches, or even mount
them, to the conductive pads on the PCB.


I am still in favour of a 16-way keypad glued to the synths top panel, with
flying leads/ribbon cable (hidden beneath such keypad) attached directly to
the keyscan ports.



Gareth.

 

[Jeff Liebermann]

On Sun, 17 Jan 2016 00:48:23 -0000, "Gareth Magennis"
<sound.service@btconnect.com> wrote:

Er, no, because it is not possible to solder these switches, or even mount
them, to the conductive pads on the PCB.

They don't need a low resistance connection. Just a connection. You
can probably glue them in place with some hot melt glue. Or, if you
want something better, solder tiny squares of sheet copper to the
switch legs, and glue that in place. If you like spending your
customers money, try some conductive graphite flake or silver "paint"
and bury that under a layer of hot melt glue.

I am still in favour of a 16-way keypad glued to the synths top panel, with
flying leads/ribbon cable (hidden beneath such keypad) attached directly to
the keyscan ports.

Common decency, aesthetics, and my moral obligation to clean living
prevent me from offering an opinion of that idea. Sure, it will work,
but will be seriously ugly and messy. It's ok to fix something but
when you're done, it has to look good. Perception is everything,
which begs the question of whether the customer is going to pay for a
hacked keypad fix.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[Gareth Magennis]

"Jeff Liebermann" wrote in message
news:sgpl9bhpp53216b7h0shbmqoq5b3iqlrhn@4ax.com...

On Sun, 17 Jan 2016 00:48:23 -0000, "Gareth Magennis"
<sound.service@btconnect.com> wrote:

Er, no, because it is not possible to solder these switches, or even mount
them, to the conductive pads on the PCB.

They don't need a low resistance connection. Just a connection. You
can probably glue them in place with some hot melt glue. Or, if you
want something better, solder tiny squares of sheet copper to the
switch legs, and glue that in place. If you like spending your
customers money, try some conductive graphite flake or silver "paint"
and bury that under a layer of hot melt glue.

I am still in favour of a 16-way keypad glued to the synths top panel, with
flying leads/ribbon cable (hidden beneath such keypad) attached directly to
the keyscan ports.

Common decency, aesthetics, and my moral obligation to clean living
prevent me from offering an opinion of that idea. Sure, it will work,
but will be seriously ugly and messy. It's ok to fix something but
when you're done, it has to look good. Perception is everything,
which begs the question of whether the customer is going to pay for a
hacked keypad fix.





Well, exactly. Though I'm privy to information you are not, being as I have
talked to the customer.

He knows he has really f888ed up this keyboard, but is really only
interested in having some way to program it, now he has destroyed the input
capability.
He just wants some way of using it in his studio, aesthetics are not part of
the equation.

I'm thinking I could perhaps knock up a 16 way keypad and hardwire it in,
say, 5 hours? (not counting the hours of research I am currently
undertaking)
Then I would be charging him something like 2 or 3 hours, and we would all
be happy.



Sometimes Work and hobby, and just trying to help someone out, merge into
something you actually might quite like to attempt!




Gareth.

 

[N_Cook]

On 16/01/2016 19:40, N_Cook wrote:

On 16/01/2016 18:44, Jeff Liebermann wrote:
On Sat, 16 Jan 2016 10:32:36 +0000, N_Cook <diverse@tcp.co.uk> wrote:

Is it simple on/off contacts or is change of R monitored for key
"action"

http://oi65.tinypic.com/14xdmo3.jpg
The piano keys on a synthesizer might require some form of velocity
sensing which most assuredly is NOT resistive. The buttons in the
above photo are for turning things on/off and are therefore simple
on/off connections.
http://www.dummies.com/how-to/content/key-feel-and-response-of-keyboards.html





I don't know how many contacts are required.
I just tried taking a standard simple 10x10mm footprint click switch
apart , parts just clipped together. Cutting a disc of thin <1mm
silicone rubber, placing over the dome contact and reassembling , the
click noise and abrupt click action disappears, but still functions.
If they can be soldered to the pcb, ignoring the resistive pads, then
only a matter of fudging the right size and height of top protrusion to
glue over the stem of the switches,if necessary .
Well thats my halfpennyworth

I read original ref as top manual for top pannel. The above idea was for
unobtainium contacts under piano keys, rather than just a controls
pannel where any old switches , in place of pcb pad contacts, would do