I got a few heavy duty control panel push buttons at the dump. They're
big (1" or so diam), with internal lights. I hooked them up as
START-STOP buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP
button is. But it doesn't seem natural. I instinctively reach for the
(dark) START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use
them that way.) Or opposite. I.e., the STOP button is lighted when the
lathe is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

Bob Engelhardt wrote:

I got a few heavy duty control panel push buttons at the dump. They're
big (1" or so diam), with internal lights. I hooked them up as
START-STOP buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP
button is. But it doesn't seem natural. I instinctively reach for the
(dark) START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use
them that way.) Or opposite. I.e., the STOP button is lighted when the
lathe is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

I think this is a case of how is your brain wired. I'd go for lighting up the red when
the machine is running but that is the way I think. I get irritated by the yes/no no/yes
buttons on credit/debit card check out terminals. I think Yes should be on the left, no on
the right. Sorta like the gas pedal needs on the same side no matter what make or model.

On cnc's, the feed hold button lights up when the machine is in feed hold so someone else
(many) thinks differently.

Now in the case of a cnc in a noisy plant, seeing the current condition makes sense
because you likely can't hear it running.

Of course three states are being shown. No lights off, Green running, red stopped.

I sympathize with you.

Wes

On Fri, 19 Jun 2009 19:24:17 -0400, Bob Engelhardt
wrote:

I got a few heavy duty control panel push buttons at the dump. They're
big (1" or so diam), with internal lights. I hooked them up as
START-STOP buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP
button is. But it doesn't seem natural. I instinctively reach for the
(dark) START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use
them that way.) Or opposite. I.e., the STOP button is lighted when the
lathe is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

NFPA 79/JIC Electrical Standard for Electrical Machinery reserves red
pilot lights for "Danger, Abnormal Condition, Fault Condition." Green
lights indicate "Safe Condition (Security)." Your setup would seem to
conform to those definitions.

I think a better indication of START/STOP functions is pushbutton
shape. A recessed PB for START and a big red mushroom head PB for
STOP, but those aren't always available at the dump.g

BTW, NFPA 79 is voluntary and by no means universal, but is a good
guide to normal industrial practice.

--
Ned Simmons

On 2009-06-20, Ned Simmons wrote:
NFPA 79/JIC Electrical Standard for Electrical Machinery reserves red
pilot lights for "Danger, Abnormal Condition, Fault Condition." Green
lights indicate "Safe Condition (Security)." Your setup would seem to
conform to those definitions.

I think a better indication of START/STOP functions is pushbutton
shape. A recessed PB for START and a big red mushroom head PB for
STOP, but those aren't always available at the dump.g

BTW, NFPA 79 is voluntary and by no means universal, but is a good
guide to normal industrial practice.


I would agree with Ned.

i

Yup. Drives me crazy, too.
You think you've got troubles:
I just bought a Chinese generator controller/metering box. It has
two pilot lights. The Green one is labelled "Show Off" and Red is "show
On".

Pete Stanaitis

PS This box has 3 ct's in it and other circuits and switches so I can
read phase voltages, currents and frequency as I fire up my 3 phase
induction motor turned single phase generator connected an old US made
12 hp Briggs getting fuel from the Chinese woodgas generator running on
wood chips.
--------------------------------------------------------


Bob Engelhardt wrote:
I got a few heavy duty control panel push buttons at the dump. They're
big (1" or so diam), with internal lights. I hooked them up as
START-STOP buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP
button is. But it doesn't seem natural. I instinctively reach for the
(dark) START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use
them that way.) Or opposite. I.e., the STOP button is lighted when the
lathe is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

On Fri, 19 Jun 2009 19:24:17 -0400, Bob Engelhardt
wrote:

I got a few heavy duty control panel push buttons at the dump. They're
big (1" or so diam), with internal lights. I hooked them up as
START-STOP buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP
button is. But it doesn't seem natural. I instinctively reach for the
(dark) START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use
them that way.) Or opposite. I.e., the STOP button is lighted when the
lathe is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

I don't know what's usual practice, but I'd want the button requiring
the next action from me to be illuminated. That would suggest that
stop would be illuminated when running, start would be illuminated
when stopped.

The logic of having the illuminated button annunciate the current
state of the machine, while flawed, is satisfied he if it's
running, the stop button is lit and so on.

The logic is flawed because start and stop are not states but external
stimulus events that cause a desired state to be the next state. Ya
can't (and don't need to) start a machine that's already running or
stop a machine that's already stopped.

On Fri, 19 Jun 2009 23:33:25 -0500, Don Foreman
wrote:

On Fri, 19 Jun 2009 19:24:17 -0400, Bob Engelhardt
wrote:

I got a few heavy duty control panel push buttons at the dump. They're
big (1" or so diam), with internal lights. I hooked them up as
START-STOP buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP
button is. But it doesn't seem natural. I instinctively reach for the
(dark) START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use
them that way.) Or opposite. I.e., the STOP button is lighted when the
lathe is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

I don't know what's usual practice, but I'd want the button requiring
the next action from me to be illuminated. That would suggest that
stop would be illuminated when running, start would be illuminated
when stopped.

The logic of having the illuminated button annunciate the current
state of the machine, while flawed, is satisfied he if it's
running, the stop button is lit and so on.

The logic is flawed because start and stop are not states but external
stimulus events that cause a desired state to be the next state. Ya
can't (and don't need to) start a machine that's already running or
stop a machine that's already stopped.

I agree with Don. the buttons should be lit or unlit to show what is
the next legitimate available option. a separate indicator should be
used for status.

the red/green logic is the worst colour coding known.
it is the most common form of colour blindness and there are two
opposed schools of thought. the older instrumentation logic where
anything red was dangerous to approach (usually because it was
running) or the modern traffic light logic of green go (running) and
red stop.
it is dangerous territory in industrial environments.

Stealth Pilot (retired control systems boffin)

"Bob Engelhardt" wrote in message
...
I got a few heavy duty control panel push buttons at the dump. They're big
(1" or so diam), with internal lights. I hooked them up as START-STOP
buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP button
is. But it doesn't seem natural. I instinctively reach for the (dark)
START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use them
that way.) Or opposite. I.e., the STOP button is lighted when the lathe
is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

Have the "START" light lit when the machine is running and don't light the
"STOP" button at all.

On Sat, 20 Jun 2009 23:45:52 -0700, jk wrote:

Ned Simmons wrote:



NFPA 79/JIC Electrical Standard for Electrical Machinery reserves red
pilot lights for "Danger, Abnormal Condition, Fault Condition." Green
lights indicate "Safe Condition (Security)." Your setup would seem to
conform to those definitions.

I would disagree, It does not conform. The machine running is NOT
an Abnormal or Fault condition.

It's a Danger condition; the spindle is in motion. The book gives
examples:

Voltage applied: cycle in
automatic: faults in air,
water, lubricating or
filtering systems: ground
detector systems.

But an amber lamp is a better fit:

Amber (Yellow)

Attention

Motors running; machine in
cycle; unit or head in
forward position.


OTOH I dislike that whole section of 79.

I'm not wild about it myself.

I think having the red STOP
button illuminated is a good idea, I just don't think it conforms to
79s requirements.

Personally, I don't like the illuminated red, thus my earlier comments
on button shape as a cue rather color.

--
Ned Simmons

Bob Engelhardt wrote:

This is gonna drive my crazy unless I get an answer,

Maybe you should just skip the lights. I just knew this one would have multiple
viewpoints.

Wes

"Bob Engelhardt" wrote in message
...
I got a few heavy duty control panel push buttons at the dump. They're big
(1" or so diam), with internal lights. I hooked them up as START-STOP
buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP button
is. But it doesn't seem natural. I instinctively reach for the (dark)
START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use them
that way.) Or opposite. I.e., the STOP button is lighted when the lathe
is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

Normally the red stop light indicates a not ready state such as E-stop
tripped, motor overload kicked out, etc, etc. The ready light indicates no
error condition, ready to start. The green light if for running. Red
mushroom head pushbuttons can be placed about the machine wherever they are
convenient.

If the machine is somewhat complicated, you can use multiple E-Stop relays,
maybe one for manual E-stop buttons and limit switches, another for drives
and overloads, etc. You can have an indicator for each E-Stop relay type
letting you know to look for a tripped button/switch or a motor overload.
Sometimes we just look in the electrical cabinet to see which E-Stop relay
is not pulled in, narrows it down somewhat.

RogerN

On Sat, 20 Jun 2009 19:05:11 -0400, Wes wrote:

Bob Engelhardt wrote:

This is gonna drive my crazy unless I get an answer,

Maybe you should just skip the lights. I just knew this one would have multiple
viewpoints.

Wes


I suggest that you give some thought to what the lights are going to
actually do for you.
Will having a lighted switch actually give you any additional, needed,
information? There is the machine, spindle going round and round; do
you need a light to tell you that something is going on?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

If the machine is somewhat complicated, you can use multiple E-Stop relays,
maybe one for manual E-stop buttons and limit switches, another for drives
and overloads, etc. You can have an indicator for each E-Stop relay type
letting you know to look for a tripped button/switch or a motor overload.
Sometimes we just look in the electrical cabinet to see which E-Stop relay
is not pulled in, narrows it down somewhat.


One of the fellows I work with is ADAMANT (Noisily so!) that an E-stop
means it is 'Fireman safe'. His definition is that a fireman can take
his ax to the cabinet and not worry about the usual smoke and sparks. He
does not like graceful shutdown E-stop (the computer/PLC shuts things
down in a particular order to minimize damage, engage a brake, etc. I'm
adamant about need for the E-stop button, not so sure on the no graceful
shut down stuff. OK, he got his start doing machines at Los Alamos so he
probably has reason for his thinking.

Bob Engelhardt wrote:
I got a few heavy duty control panel push buttons at the dump. They're
big (1" or so diam), with internal lights. I hooked them up as
START-STOP buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP
button is. But it doesn't seem natural. I instinctively reach for the
(dark) START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use
them that way.) Or opposite. I.e., the STOP button is lighted when the
lathe is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

Don't know if it's legal but I have 2 green lights. 1 for forward
motor rotation, 1 for reverse motor rotation. Neither light on =
stopped. From any distance - a light on = bad. Nice when you're leaving
the area and giving the once over. Seems logical to me.

"Bob Engelhardt" wrote in message
...
I got a few heavy duty control panel push buttons at the dump. They're big
(1" or so diam), with internal lights. I hooked them up as START-STOP
buttons for my lathe. I used green for START & red for STOP.

I wired them so the "ready" button is lit. I.e, when the machine is
stopped, the START button is lighted & when it's running, the STOP button
is. But it doesn't seem natural. I instinctively reach for the (dark)
START button to stop the lathe & vice versa, sometimes.

Is this the way buttons are usually lighted? (If so I'll learn to use them
that way.) Or opposite. I.e., the STOP button is lighted when the lathe
is stopped & START when it's running. Indicating status/state.

This is gonna drive my crazy unless I get an answer,
Bob

The way you have it is what I've always seen...

On Sat, 20 Jun 2009 21:39:38 -0500, RoyJ
wrote:


If the machine is somewhat complicated, you can use multiple E-Stop relays,
maybe one for manual E-stop buttons and limit switches, another for drives
and overloads, etc. You can have an indicator for each E-Stop relay type
letting you know to look for a tripped button/switch or a motor overload.
Sometimes we just look in the electrical cabinet to see which E-Stop relay
is not pulled in, narrows it down somewhat.


One of the fellows I work with is ADAMANT (Noisily so!) that an E-stop
means it is 'Fireman safe'. His definition is that a fireman can take
his ax to the cabinet and not worry about the usual smoke and sparks. He
does not like graceful shutdown E-stop (the computer/PLC shuts things
down in a particular order to minimize damage, engage a brake, etc. I'm
adamant about need for the E-stop button, not so sure on the no graceful
shut down stuff. OK, he got his start doing machines at Los Alamos so he
probably has reason for his thinking.

I did a lot of work for a division of XXXX about 15 years ago where,
in my opinion, they'd occasionally get carried away with safety
concerns. On a not awfully dangerous packaging machine I built they
insisted that if an operator opened a door or pressed the cycle stop
1) the motion controller interrupted the move in progress; 2) spring
applied brakes on all axes came on; 3) the servo amps were disabled;
4) and contactors removed power from the amps. Resuming the cycle
reversed the process.

They also required both an E-stop and a POWER OFF pushbutton, even if
they had exactly the same function, i.e., they were wired in series.

On the other hand, they were so strict about ISO 9000 that when a 3rd
shift operator (it's always 3rd shift's fault g) damaged the
mechanical interlocks on a very dangerous machine I built, it took
several weeks to get a label applied to the door that said, in effect,
"DON'T FORCE THE DOOR, YOU IDIOT" due to all the documentation
required.

Their excuse for the extreme caution was that one of their maintenance
mechanics was working with his upper body between the mold halves of
an injection molder without going thru the lockout procedure. You can
guess the rest.

--
Ned Simmons

Let the Record show that Bruce In Bangkok
on or about Sun, 21 Jun 2009 07:50:29 +0700 did write/type or cause to
appear in rec.crafts.metalworking the following:
On Sat, 20 Jun 2009 19:05:11 -0400, Wes wrote:
Bob Engelhardt wrote:

This is gonna drive my crazy unless I get an answer,

Maybe you should just skip the lights. I just knew this one would have multiple
viewpoints.

I suggest that you give some thought to what the lights are going to
actually do for you.
Will having a lighted switch actually give you any additional, needed,
information? There is the machine, spindle going round and round; do
you need a light to tell you that something is going on?

What I found useful were the panels which had various things lit
up: spindle [direction], coolant, chip belt, etc. Three lights on
the left side of the panel lit up "all is good". etc, etc.

What I don't like are little lights, or little buttons. I've
crashed more than once because I couldn't find the "cycle stop" button
- and the big crash came because I hadn't "learned" to hit the big red
button.

Bottom line - _IF_ you use the lights, use them always the same,
at least in your shop. Conforming them to an industrial practice will
lessen the problem of doing things differently 'here'.
-
pyotr filipivich
We will drink no whiskey before its nine.
It's eight fifty eight. Close enough!

Let the Record show that syoung on or about Sat,
20 Jun 2009 22:44:40 -0400 did write/type or cause to appear in
rec.crafts.metalworking the following:

Don't know if it's legal but I have 2 green lights. 1 for forward
motor rotation, 1 for reverse motor rotation. Neither light on =
stopped. From any distance - a light on = bad. Nice when you're leaving
the area and giving the once over. Seems logical to me.

In a noisy shop, you can't always hear if the machine is stopped,
or if the run is complete. So I like "big" lights I can see which
tell me "We're all done" Or "Something needs a human to make
decision." Even I can hear "something is going badly wrong!" most
of the time.
-
pyotr filipivich
We will drink no whiskey before its nine.
It's eight fifty eight. Close enough!

Ned Simmons wrote:



NFPA 79/JIC Electrical Standard for Electrical Machinery reserves red
pilot lights for "Danger, Abnormal Condition, Fault Condition." Green
lights indicate "Safe Condition (Security)." Your setup would seem to
conform to those definitions.

I would disagree, It does not conform. The machine running is NOT
an Abnormal or Fault condition.

OTOH I dislike that whole section of 79. I think having the red STOP
button illuminated is a good idea, I just don't think it conforms to
79s requirements.
jk

"RoyJ" wrote in message
m...

If the machine is somewhat complicated, you can use multiple E-Stop
relays, maybe one for manual E-stop buttons and limit switches, another
for drives and overloads, etc. You can have an indicator for each E-Stop
relay type letting you know to look for a tripped button/switch or a
motor overload. Sometimes we just look in the electrical cabinet to see
which E-Stop relay is not pulled in, narrows it down somewhat.


One of the fellows I work with is ADAMANT (Noisily so!) that an E-stop
means it is 'Fireman safe'. His definition is that a fireman can take his
ax to the cabinet and not worry about the usual smoke and sparks. He does
not like graceful shutdown E-stop (the computer/PLC shuts things down in a
particular order to minimize damage, engage a brake, etc. I'm adamant
about need for the E-stop button, not so sure on the no graceful shut down
stuff. OK, he got his start doing machines at Los Alamos so he probably
has reason for his thinking.

Most of the equipment I've worked on has the E-Stop kill the Output power,
solenoids, motors, hydraulics, anything that can cause movement, but the
inputs were often left on. I would think you would need some power present
to even be able to reset an E-Stop, unless it's a mechanical stop. To be
fireman safe you'd need to kill the power feeding the cabinet. On inverter
motor drives, sometimes there is a time delay to kill them. That is because
the drive can stop the motor faster in a controlled stop than it will stop
if the power is killed. On some of our most dangerous machines, we have
plugging switches that reverses the motor power until it's nearly stopped
and kicks out with zero speed sensing switches, to stop rollers before
someone can be killed by them.

I always thought it was funny how on the job you have to make everything so
safe but on the way to work there is nothing that prevents you from opening
your car door while going to fast (maybe on some cars, but not any I've ever
had). There are no safeties on most cars to prevent you from crossing the
line into a path of another vehicle, nothing to prevent you from running
people over, nothing to keep you from falling asleep while driving. But at
work it needs to be almost impossible to get hurt.

RogerN

"RogerN" wrote:

But at
work it needs to be almost impossible to get hurt.


Or work on it. (repair)


Wes

"Wes" wrote in message
...
"RogerN" wrote:

But at
work it needs to be almost impossible to get hurt.


Or work on it. (repair)


Wes

Maintenance at our plant has to break the safety rules to work on equipment,
such as reaching in a machine in automatic, running with covers off, or
being in an electrical cabinet while power is on. They realize maintenance
can't fix a machine and follow all those safety rules and we get by, but if
we get hurt, they use the excuse that we were breaking the safety rules. I
haven't found a way to lockout/tagout a machine and measure voltages to
locate a problem.

RogerN

On Sun, 21 Jun 2009 09:28:36 -0500, "RogerN"
wrote:


"Wes" wrote in message
...
"RogerN" wrote:

But at
work it needs to be almost impossible to get hurt.


Or work on it. (repair)


Wes

Maintenance at our plant has to break the safety rules to work on equipment,
such as reaching in a machine in automatic, running with covers off, or
being in an electrical cabinet while power is on. They realize maintenance
can't fix a machine and follow all those safety rules and we get by, but if
we get hurt, they use the excuse that we were breaking the safety rules. I
haven't found a way to lockout/tagout a machine and measure voltages to
locate a problem.

RogerN


At my former place of work (retired), electrical work was done under
specific training and procedures. Managers had to sign off on
specific individuals trained to perform specific tasks requiring work
near energized conductors. I had training and approval for
programming and troubleshooting VFDs in energized (460V) enclosures.
Safety equipment was specified in the procedures and appropriate to
the task.

I think your management would be found liable in an OSHA investigation
if anyone is ever hurt.

Pete Keillor

Wes wrote:
I think this is a case of how is your brain wired. ...

I do too, none of the comments have convinced one way or the other. I
also think that, within reason, any way can become familiar.

I sympathize with you.

Thank you.


Bob

Ned Simmons wrote:
... A recessed PB for START and a big red mushroom head PB for STOP,

Yeah, that'd be nicer.

but those aren't always available at the dump.g ...

I'm happy with what I can get. Beggars & choosers, you know.

Bob

Don Foreman wrote:
I don't know what's usual practice, but I'd want the button requiring
the next action from me to be illuminated. That would suggest that
stop would be illuminated when running, start would be illuminated
when stopped. ...

Better put, but that was my thinking, also.

Bob

Wes wrote:
Maybe you should just skip the lights. I just knew this one would
have multiple
viewpoints.

I could try it easily enough. My intuition is that having the STOP
button illuminated would be an advantage in an urgent situation.

Bob

Bruce In Bangkok wrote:
I suggest that you give some thought to what the lights are going to
actually do for you. ...

The thought was that the lighted-ness would be a cue as to what to do next.

Bob

On 2009-06-21, RogerN wrote:

"RoyJ" wrote in message
m...

If the machine is somewhat complicated, you can use multiple E-Stop
relays, maybe one for manual E-stop buttons and limit switches, another
for drives and overloads, etc. You can have an indicator for each E-Stop
relay type letting you know to look for a tripped button/switch or a
motor overload. Sometimes we just look in the electrical cabinet to see
which E-Stop relay is not pulled in, narrows it down somewhat.

[ ... ]

Most of the equipment I've worked on has the E-Stop kill the Output power,
solenoids, motors, hydraulics, anything that can cause movement, but the
inputs were often left on. I would think you would need some power present
to even be able to reset an E-Stop, unless it's a mechanical stop.

On my Emco Maier Compact-5/CNC lathe, the E-stop button drops
power from *everything* -- including the CPU, so the program which you
spent some time entering by hand is lost before you can save it. This
makes me very reluctant to use the E-stop button. Granted, a 5" swing
machine with stepper axes is not too much of a hazard anyway. :-) But to
me, this extreme of E-stop action seems to be overkill.

On some of our most dangerous machines, we have
plugging switches that reverses the motor power until it's nearly stopped
and kicks out with zero speed sensing switches, to stop rollers before
someone can be killed by them.

That sounds like a good ides.

I always thought it was funny how on the job you have to make everything so
safe but on the way to work there is nothing that prevents you from opening
your car door while going to fast (maybe on some cars, but not any I've ever
had).

Even worse -- I've seen some cars with the door hinges in the
back. Imagine what happens when you open the door at highway speeds.
:-)

There are no safeties on most cars to prevent you from crossing the
line into a path of another vehicle, nothing to prevent you from running
people over, nothing to keep you from falling asleep while driving. But at
work it needs to be almost impossible to get hurt.

Can you imagine how much would have to be added to a motor
vehicle to give that degree of safety? Can you imagine what it would
cost? Can you imagine how much the owners would complain?

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

pyotr filipivich wrote:
...
What I don't like are little lights, or little buttons. I've
crashed more than once because I couldn't find the "cycle stop" button
...

That's kinda' what got me to the big push buttons. Before them I just
had an ON-OFF toggle, but a couple of times in a panic it wasn't easy to
find. At least not fast enough.

Bob

Rick wrote:
The way you have it is what I've always seen.

Thanks. Not that I'm trying to conform, but that tells me that I'll
probably get used to it pretty quickly.

Bob

"Bob Engelhardt" wrote in message
...
Wes wrote:
Maybe you should just skip the lights. I just knew this one would have
multiple
viewpoints.

I could try it easily enough. My intuition is that having the STOP button
illuminated would be an advantage in an urgent situation.

Bob

I also like the idea that the red indicator means danger and would draw your
attention to the red button in an emergency. Just like you do not go into
an intersection on red, it makes sense not to reach into a machine with a
red light.

That's not the way it's done at the plant I work at but the "red = danger"
seems intuitive to me. I think we have red lights on some machines when
they are running, but the buttons are wired so that the red on the e-stop
lights up when there is an e-stop condition.

RogerN

"Bob Engelhardt" wrote in message
...
| Wes wrote:
| I think this is a case of how is your brain wired. ...
|
| I do too, none of the comments have convinced one way or the other. I
| also think that, within reason, any way can become familiar.
|
| I sympathize with you.
|
| Thank you.
|
|
| Bob

How about if you just leave things the way they are and add a lighted
indicator saying " Machine is Running" when the Start button is energized?

DoN. Nichols wrote:
On 2009-06-21, RogerN wrote:
"RoyJ" wrote in message
m...
If the machine is somewhat complicated, you can use multiple E-Stop
relays, maybe one for manual E-stop buttons and limit switches, another
for drives and overloads, etc. You can have an indicator for each E-Stop
relay type letting you know to look for a tripped button/switch or a
motor overload. Sometimes we just look in the electrical cabinet to see
which E-Stop relay is not pulled in, narrows it down somewhat.

[ ... ]

Most of the equipment I've worked on has the E-Stop kill the Output power,
solenoids, motors, hydraulics, anything that can cause movement, but the
inputs were often left on. I would think you would need some power present
to even be able to reset an E-Stop, unless it's a mechanical stop.

On my Emco Maier Compact-5/CNC lathe, the E-stop button drops
power from *everything* -- including the CPU, so the program which you
spent some time entering by hand is lost before you can save it. This
makes me very reluctant to use the E-stop button. Granted, a 5" swing
machine with stepper axes is not too much of a hazard anyway. :-) But to
me, this extreme of E-stop action seems to be overkill.

On some of our most dangerous machines, we have
plugging switches that reverses the motor power until it's nearly stopped
and kicks out with zero speed sensing switches, to stop rollers before
someone can be killed by them.

That sounds like a good ides.

I always thought it was funny how on the job you have to make everything so
safe but on the way to work there is nothing that prevents you from opening
your car door while going to fast (maybe on some cars, but not any I've ever
had).

Even worse -- I've seen some cars with the door hinges in the
back. Imagine what happens when you open the door at highway speeds.
:-)

That's why they're called suicide doors.

There are no safeties on most cars to prevent you from crossing the
line into a path of another vehicle, nothing to prevent you from running
people over, nothing to keep you from falling asleep while driving. But at
work it needs to be almost impossible to get hurt.

Can you imagine how much would have to be added to a motor
vehicle to give that degree of safety? Can you imagine what it would
cost? Can you imagine how much the owners would complain?

Enjoy,
DoN.