X-77-Tonewheel Generator - BEARINGS - LUBRICATIONS - UPDATE-15FEB23 - switch problem?
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Thanks Chris ....now I can proceed with a little confidence ...but one simple question ....where are the actual contact points? I was able to take a few photos of what I believe is the contact area ..."from one side".? There are two conditions, the first is "make" and the other is "break" (B) I have looked at the switch assembly for closely. The "outer boards" appear to be only a "non-conductive mounting method" for the terminals (4) on the outside and perhaps the "springs" (1 ?) which you referred to.? ? The arrow marked "2" is the slider which has cavities milled into it.? The arrow "1" shows what's called a detent feature, but in this case it is the method of pushing and releasing this "spring" which is making and breaking contact ...which is truly hard to see. Hence the second photo (B) which the detents are released into the milled pockets (seen in the first photo) ....and supposedly, the actual contact point "3" is broken (?).? You can see a little bit of a "shadow line" as if there is now a "gap" in this condition. The third unmarked photo is just a crop of the photo above it, trying to get a closer "look" at this contact point area. I just need to know if I am correct, if this spot identified as "3" is in fact where the contact is (?)? If correct, then I know where to concentrate on on the opposite side which is going to be tricky to reach. I might consider some way of using a thin, cleaner-soaked cloth to get between the contact points and move back and forth very delicately. This being said, do you know if there is any actual "point" per se ...or is this merely flat metal-to-metal contact?? I note that it appears each contact may actually have TWO contact points. The "springs" appear to be "split" on the ends. I hope you can follow my "query". Sorry for the length. I just want to understand what's going on before I do anything. Thanks Wayne PS - is there a lube that should be used on these switches?? I notice that the "Main Only" switch feels and sounds different from this "Echo Only switch. I can't see any different between the two (no obvious evidence of extra lube)?
On Thursday, February 16, 2023 at 03:16:33?AM PST, Chris Clifton <clifton.christopher@...> wrote:
Those are the type of switch used in many Hammond models, E, L and M-100 series are the most common ones, and of course, your X-77. Switch cleaner is indeed the first course of action, and may well
be sufficient to cure the problem. Don't even think about
dismantling the switch assemblies, it shouldn't be necessary
anyway. I have found that when switch cleaner doesn't work on
these switches, it's usually because the moving leaf contact has
bent slightly, and no longer presses hard enough against the fixed
contact in the on position. I've found that by gently pressing the
contact spring with a small screwdriver near the fixed end it's
possible to bend the contact slightly and increase the contact
pressure. I stress "gently", only a small bend is necessary, and
it will be hard to undo if you over do it. On 15/02/2023 17:49, Wayne Tarling via
groups.io wrote:
Well, "guessing" the
instructions as to which screws, etc., the entire top assembly
comes right off very easily, exposing what needs to be exposed
and the top metal cover, ditto.
As it turns out, (as the
experts already knew/know), these tabs/switches are all
mechanical.? They were not meant to be disassembled (all
rivetted together), and looking at how the entire tab
assemblies have been manufactured, Hammond has considered the
possibility that things might fail, and figure out ways for
fixes to be done.
The only thing I cannot "see"
clearly is the slide contact which is sandwiched between the
boards.? I am very reluctant to split this assembly apart. It
may be far more logical to use a cleaner first and find out
what the results will be.? ? Any thoughts from anyone?
For the non-experts, here are
photos of these tab/switch assemblies.
and the suspected tab:
----- Forwarded Message ----- From: Wayne Tarling <tarlingw@...>
Sent: Tuesday, February 14, 2023 at 05:51:29?PM
PST
Subject: Fw: [hammondzone] X-77-Tonewheel
Generator - BEARINGS - LUBRICATIONS - UPDATE-14FEB23 -
switch problem?
Well everything went reasonably well.
TWG running very quiet.? Manuals functioning?
....pedals not.
I opened up the console base panel,
which had not been touched yet.
I disconnected the 77 Leslie previously
as it had too much power hum for the stage I was at.
(Didn't need to be listening to it)
a)? with the pedals not "responding", I
thought I would try the "Pedal Bus-Bar Shifter".? It
has a slot on the end of the shaft as if for a
screwdriver, but I thought I would try turning with
my fingers first.? To my surprise, the shaft moved
very easily CW about 90¡ã? and not so much CCW ....so
I left it re-positioned 90¡ã CW.? ? I tried the
pedals ....no change.? ?I went back to the speaker
selector, "Main Only" and "Echo Only", just moving
the switches, and immediately had the pedals working
with "Echo Only" depressed. (147)? I was quite
surprised with this as this selector had been down
previously with no response.? I went through all the
pedals and drawbars and everything was working.
b) I powered down to connect the 77
Leslie. Powering back up got the 8-10 seconds of
power hum, which subsided more significantly this
time and put the "Main Only" speaker selector down
and had full pedals (77) ....but I couldn't tell if
the 147 was still functioning.? Pushing the "Echo
Only" tab down and found the 147 was now NOT working
with the pedals. (It had been 20 seconds ago)?
Keyboards were fine (both).? I ended up flicking
this (Echo Only) switch up and down, getting mainly
electrical contact clicking with no connection for
the pedals.? (????)
Unfortunately, looking at the back of
the organ, the entire bank of these switches are
buried behind a metal box running full length.?
There are also a few screws on the top of this metal
box, which can only be accessed with the top of the
console removed.
With much "playing around", I am
getting to the summary that the "Echo Only"
tab/switch (147) is either not making a proper
contact for some reason ...perhaps just a cleaning
needed?? The "Main Only" switch, when down, (77) the
manuals and pedals function fine ...as they should.?
I also note, that the power hum from the 77 Leslie
is far less now. Pretty much quite acceptable ....as
compared to the 147 which has a very too noticeable
hum.? ?I see some notes on "HUM" on page 20 & 24
of the Hammond Manual.? I'll check that out later.
Does anyone have any knowledge of
accessibility to the "Echo Only" switch?? I cannot
see in behind.??
I am looking at page 20 and 21 that
reference "removing the top.? There is a section
about removing the top:
Is this the correct instruction?? I'll
have to look around for each of these details,
(where these screws are) assuming this is the
correct instruction.
Then of course, I am hoping this switch
can be tested for "make" condition ....and then can
the contacts be cleaned or fixed?
?.....or do I have this all wrong and
there is something else causing this problem?? ?So
far the problems have been principley mechanical in
nature.
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¿ªÔÆÌåÓýI've just got this switch assembly from an L-100 out of my loft.
If you very gently press where my screwdriver is, that pushes the
spring below the actuator inwards. That makes the part of the
spring above the actuator move outwards. The normal range of
movement is quite small, a millimetre or so. You only need to
change the position of the spring by a fraction of that to make a
difference. On 16/02/2023 17:57, Chris Clifton
wrote:
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Got it ..thanks.? Now I can see the very obvious "gap" at the contact point as well.
On Thursday, February 16, 2023 at 10:23:53?AM PST, Chris Clifton <clifton.christopher@...> wrote:
I've just got this switch assembly from an L-100 out of my loft.
If you very gently press where my screwdriver is, that pushes the
spring below the actuator inwards. That makes the part of the
spring above the actuator move outwards. The normal range of
movement is quite small, a millimetre or so. You only need to
change the position of the spring by a fraction of that to make a
difference. On 16/02/2023 17:57, Chris Clifton
wrote:
Yes, the clear plastic part is what actuates the contacts, the springs (1) in your photo. The contacts open when the dimple in the spring moves into the cavity in the actuator. When the actuator is moved so that the dimple in the spring is on the land between cavities, this pushes the spring outwards to make contact with the fixed contact (3) in your photo. What I have found from experience is that if a switch doesn't make good contact after treatment with switch cleaner, pressing the narrow part of the contact spring slightly inwards with the tip of a small screwdriver causes the end of the spring to move outwards, making a better contact when switched on. A very small movement is usually sufficient. The actual contact point can be seen in your first photo. On
the end of the spring (1) you can just see the ends of a pair of
(palladium?) contact wires just under the fixed contact (3).
These contacts are actually very similar to the key contacts in
the manuals of Hammond organs. Small pieces of semi-precious
metal wire spot welded onto the contacts. On 16/02/2023 16:47, Wayne Tarling
via groups.io wrote:
Thanks Chris ....now I can
proceed with a little confidence ...but one simple question
....where are the actual contact points?
I was able to take a few
photos of what I believe is the contact area ..."from one
side".? There are two conditions, the first is "make" and
the other is "break" (B)
I have looked at the switch
assembly for closely. The "outer boards" appear to be only a
"non-conductive mounting method" for the terminals (4) on
the outside and perhaps the "springs" (1 ?) which you
referred to.? ? The arrow marked "2" is the slider which has
cavities milled into it.? The arrow "1" shows what's called
a detent feature, but in this case it is the method of
pushing and releasing this "spring" which is making and
breaking contact ...which is truly hard to see. Hence the
second photo (B) which the detents are released into the
milled pockets (seen in the first photo) ....and supposedly,
the actual contact point "3" is broken (?).? You can see a
little bit of a "shadow line" as if there is now a "gap" in
this condition.
The third unmarked photo is just a crop of the photo
above it, trying to get a closer "look" at this contact
point area.
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