Vibration Monitor (Hyde, Wanttaja?)

Without giving too much away............ (yuk yuk yuk)

One can always post your questions at:
http://www.vibinst.org/default.htm

and usually somebody will be happy to answer.

Phase indicators can be a variety of schemes or devices. Proximity
probes, and notch. Strobe light. Magnetic interrupter. Photocell.
Even the old proverbial pencil and masking tape!

Kent Felkins
Tulsa

Strangely enough, that is what I *DID* for a living when Spectral Dynamics
was the industry leader in machinery diagnostics. Unfortunately, my job was
the circuit design, not the diagnostics itself, so all I concerned myself
with was the black box that took a defined input and produced a defined
output. There are times I wish that I had transferred to the applications
department. They were the ones that seemed to have the most fun (and the
most three martini Friday lunches).


Jim


"

Stangely enough, this is what I do for a living. No kidding.
I am an engineer at Bently Nevada, Corp, the industry leader in machinery
diagnostics.

"RST Engineering" wrote in message
...
Strangely enough, that is what I *DID* for a living when Spectral Dynamics
was the industry leader in machinery diagnostics. Unfortunately, my job
was the circuit design, not the diagnostics itself, so all I concerned
myself with was the black box that took a defined input and produced a
defined output. There are times I wish that I had transferred to the
applications department. They were the ones that seemed to have the most
fun (and the most three martini Friday lunches).


Jim



LOL.
I've been an engineer designing in the dark many times.
Fortunately at Bently, there is a large effort to train engineers in
diagnostics.
Then we can use personal experience in addition to requirements documents
when designing a new product.
Or, at least, we can determine if requirements make sense!

Adam

Understood. What I started out to do (and still plan on doing) is to have a
device that will stay permanently mounted to the engine that can be
calibrated (adjusted, signed, pick a verb) when the engine is known to be
good and light a "your engine is about to come apart" lamp at the
appropriate time.

What this group seems to be leaning toward is a lab quality device that will
allow for sophisticated diagnostics. That ain't the thrust of my Kitplanes
columns. KISS and BURP.

Jim

"RST Engineering" wrote in message
...
Understood. What I started out to do (and still plan on doing) is to have
a device that will stay permanently mounted to the engine that can be
calibrated (adjusted, signed, pick a verb) when the engine is known to be
good and light a "your engine is about to come apart" lamp at the
appropriate time.

What this group seems to be leaning toward is a lab quality device that
will allow for sophisticated diagnostics. That ain't the thrust of my
Kitplanes columns. KISS and BURP.

Jim


As is tradition, we tend to get off topic ;-)
I think you can accomplish this using the methods discussed.
Mount 2 proximity probes 90 degrees apart.
Calibrate the readings for normal low vibrations (be sure to account for any
nonlinearities in the probe).
Design the circuit to trip the buzzer/lamp when the vibration exceeds the
normal level.
You may need some analog circuitry to help (gain, etc).
But you don't need to get much fancier than that.

Adam

Proximity probes? Or accelerometers?

I understand about the analog circuitry and actually plan on making a five
or six channel filter at each of the possible resonance points relative to
the fundamental ... and then strobing the filters to light a "normal",
"low", "high" lamp for each channel.

Jim




As is tradition, we tend to get off topic ;-)
I think you can accomplish this using the methods discussed.
Mount 2 proximity probes 90 degrees apart.
Calibrate the readings for normal low vibrations (be sure to account for
any nonlinearities in the probe).
Design the circuit to trip the buzzer/lamp when the vibration exceeds the
normal level.
You may need some analog circuitry to help (gain, etc).
But you don't need to get much fancier than that.

Adam

"RST Engineering" wrote in message
...
Understood. What I started out to do (and still plan on doing) is to have
a device that will stay permanently mounted to the engine that can be
calibrated (adjusted, signed, pick a verb) when the engine is known to be
good and light a "your engine is about to come apart" lamp at the
appropriate time.


Excuse my ignorance, but couldn't you just feel the vibrations?

If you wait that long, you're probably more concerned if the chain that's
holding the motor to the firewall is going to break after the motor cuts
loose from the mounts. All too often, the vibrations start to pick up
seconds or miliseconds before a catastrophic failure.

To do such a health-monitoring function properly, you really want some
seeded fault data to characterize what a "bad" engine spectrum looks like.
How many engines do you want to sacrifice to get the data? You can approach
it from the "anything different from a healthy engine signature" standpoint,
but that will likely result in a ton of false positive fault indications.

"LCT Paintball" wrote in message
news:_Lq0e.14520$fn3.9681@attbi_s01...
"RST Engineering" wrote in message
...
Understood. What I started out to do (and still plan on doing) is to
have
a device that will stay permanently mounted to the engine that can be
calibrated (adjusted, signed, pick a verb) when the engine is known to
be
good and light a "your engine is about to come apart" lamp at the
appropriate time.


Excuse my ignorance, but couldn't you just feel the vibrations?