Vibration Monitor (Hyde, Wanttaja?)

"Ernest Christley" wrote in message
om...
How about stress monitors built into the prop (I have no idea if anyone
makes such a thing). Would help you to carve a perfect prop.

How much would someone pay for the software to analyze this data? Also,
you'd probably need structurally integrated sensors, which would have to be
strong enough to support the loads. This would be a pretty tough engineering
problem in itself.

Miniature temp probes and air pressure sensors that you can stick all
over the place.

More software. Sure it could be done, but cheaply enough for the average
home builder?

Vibration sensors stuck inside control surfaces and different parts of
the skin. Early warning system for flutter.

Might be really expensive to get the signals characterized well enough for a
warning system.

Nothing is stopping anyone from doing any of this with wired sensors.
It would just be cleaner and easier if the wire can be left on the spool.

There's a ton of stuff stopping people from doing this right now. It's
money. None of the stuff you've mentioned is even remotely innexpensive. I
know people who've researched this stuff with the wired sensors for several
years, and haven't gotten much of it out of the lab. Yeah, with steady
improvements in computational fluids, finite element, mems tech, sensing
tech, etc., this stuff will be eventually packaged into something us
home-builder types can afford to use. However, most of it is still too
damned expensive, manpower intensive, and technically immature for even the
military to employ on huge aircraft development programs like JSF. By the
time this stuff really becomes generally available, I'm sure there will be
something better than blue tooth around.

Pete Schaefer wrote:
"Frank van der Hulst" wrote in message
...

First thing would be Bluetooth headsets... no more cords tangling round
the cockpit.


That would be pretty nice. But now you need batteries in your headset to
power the audio amp.

Yeah. I wonder whether head movement would produce enough power... like
the 'self-winding' watches of the 1970s.

Next would be various engine instruments... EGT, CHT, etc.

I guess you'd need some devices (i.e. wires) for routing the signal through
the firewall or around it. How much lighter would this be than, say, a
twisted pair for CAN?

Not necessarily... I guess you're talking about a metal firewall
shielding the signals, right? But, assuming a fibreglass cowl, mount a
self-powered repeater someplace where the engine instruments can see it,
and where the instrument panel can see it (e.g. a bump on top of the
cowl, on a wingtip, on the leading edge, on the landing gear perhaps).
An extra benefit is that you no longer need (as many) penetrations
through the firewall.

Maybe move the entire radio receiver out to a wingtip or somewhere well
away from the engine's RF noise.
But I can't see that being self-powered.


The receiver could be, but not the transmitter. An antenna wire is probably
a lot lighter than running power out, so I guess that would need to stay in
the cockpit.

Well, I did suggest (kinda tongue-in-cheek) using RF to power the radio
transmitter, as Nicola Tesla proposed way back in the (IIRC) 1930s.

Yeah, I know that none of these things is quite right, right now.
There's lots of engineering to be done to make it workable. But I think
we *probably* have enough technology to be able to begin implementing
this kind of stuff.

Frank

Scott Skylane wrote:
Prop blade pitch control... a motor in the spinner to adjust pitch,
controlled via Bluetooth. No hollow crankshafts and oil pressure
systems, no slip-rings.

Eh? How would the motor be powered, batteries? I'm not sure how long
reasonably sized batteries would work. And what about centrifugal force
issues?...

If I was totally serious about this, I wouldn't tell you... I'd go and
make a huge fortune. Or lose a small one.

How about this... mount some permanent magnets on the front of the cowl,
right behind the spinner. In the rear face of the spinner, embed some
coils. In effect, the spinner becomes a generator. This electricity is
used to run the motor inside the spinner that adjusts blade pitch.
Probably include a small battery to allow pitch adjustment when the
engine isn't running.

Feasible? Dunno. But if you use this idea to make a large fortune, could
you please just send me a small fortune? In advance?

Thanks

Frank

Frank van der Hulst wrote:

snippo

"Frank van der Hulst" wrote in message
...

First thing would be Bluetooth headsets... no more cords tangling round
the cockpit.



Not to change the subject but where did they come up with
'Bluetooth anyway?... (just lucky maybe?)
--

-Gord.
(use gordon in email)

"Frank van der Hulst" wrote in message
...
Yeah. I wonder whether head movement would produce enough power... like
the 'self-winding' watches of the 1970s.

Probably not, but you don't need a lot. I guess it depends on how long you
need it to operate. Using modern digital amp chips (which are amazingly
efficient), you can keep consumption down. A couple of gumstick batteries
might be alright.

Not necessarily... I guess you're talking about a metal firewall
shielding the signals, right? But, assuming a fibreglass cowl, mount a
self-powered repeater someplace where the engine instruments can see it,

That kinda goes against my "as few possible components between the source
and the destination" philosophy. I think you'd have to just locate the
receiver on the firewall and put an antenna through.

Yeah, I know that none of these things is quite right, right now.

If you don't keep working through the possibilities, you might miss an
opportunity to invent that new gadget that everybody just has to have.
Personally, I'm not hopeful that there's a big opportunity for blue tooth on
home-built airplanes, but there might be a couple of really good
applications.

Pete

Pete Schaefer wrote:
So, what things on the airplane are you guys going to replace with
self-powered blue tooth devices?

I'm typing out loud here...

When I suggested bluetooth the other day, what I had in mind was a kit
that you would temporarily hang on an airplane for specific tests, much
like we hang all the orange on Navy aircraft for flight tests. Much more
accurate pitot-static, vib sensors, postion sensors, data loggers, etc.
You could, for example, have a kit for flight testing an RV-8. Pop it
on, do the tests, and remove it. Or it could be used for "external
stores" such as a camera.

Afterward, I contemplated replacing all signal wires with wireless. So
any wire not carrying power could be replaced. This might be especially
useful for a refit, where access is far more difficult than during
initial construction.

Other harebrained ideas...two planes in semi-close formation could
network via bluetooth. Why? Could be low prob. of intercept comms on a
private channel, sharing of nav data, text messaging, ipod music files.

There's an ongoing thread on rec.aviation.soaring on bluetooth and
cellphones aboard planes.

nafod40 wrote:
Pete Schaefer wrote:

So, what things on the airplane are you guys going to replace with
self-powered blue tooth devices?


I'm typing out loud here...

When I suggested bluetooth the other day, what I had in mind was a kit
that you would temporarily hang on an airplane for specific tests, much
like we hang all the orange on Navy aircraft for flight tests. Much more
accurate pitot-static, vib sensors, postion sensors, data loggers, etc.
You could, for example, have a kit for flight testing an RV-8. Pop it
on, do the tests, and remove it. Or it could be used for "external
stores" such as a camera.

Afterward, I contemplated replacing all signal wires with wireless. So
any wire not carrying power could be replaced. This might be especially
useful for a refit, where access is far more difficult than during
initial construction.

Other harebrained ideas...two planes in semi-close formation could
network via bluetooth. Why? Could be low prob. of intercept comms on a
private channel, sharing of nav data, text messaging, ipod music files.

There's an ongoing thread on rec.aviation.soaring on bluetooth and
cellphones aboard planes.

Bluetooth: a solution in search of a problem

Pete Schaefer wrote:
"Ernest Christley" wrote in message
om...

How about stress monitors built into the prop (I have no idea if anyone
makes such a thing). Would help you to carve a perfect prop.


How much would someone pay for the software to analyze this data? Also,
you'd probably need structurally integrated sensors, which would have to be
strong enough to support the loads. This would be a pretty tough engineering
problem in itself.



??? analyze ???
What analysis would you want to do other than to look a the relative
strains at a few distinct points. You'd like a bell shaped lift curve
on the prop, same as for a wing. I would pay $0 dollars for software
analysis, and opt for plotting the values on a sheet of graph paper with
a pencil. Well, that's not EXACTLY true. I'd probably use Gnumeric
(open source spreadsheet), as it would produce a much prettier graph
that I would.

Mind you, I'm talking a home carved wood prop here. Build in a little
pocket for the probe. Keep carving until one gives you the perfect profile.


Miniature temp probes and air pressure sensors that you can stick all
over the place.


More software. Sure it could be done, but cheaply enough for the average
home builder?

Why the software again. Danm, man, what do you think people did before
Intel came along with their little 4-bit wonder. You're engine isn't
cooling like you want it to. The way to see what you need to fix is to
map out pressures in and around the radiator system (I'm building a
water cooled auto-conversion. Please be patient with the radiator
thing.) The current way is to run water lines all over the place, duct
taping them to the side of the plane to get them back to the cockpit so
that you can measure all the relative water columns. No fancy analysis
is needed. Either you have a few inches of pressure across the radiator
cores, or you don't. Move the sensors around to find out where the high
pressure areas are.



Vibration sensors stuck inside control surfaces and different parts of
the skin. Early warning system for flutter.


Might be really expensive to get the signals characterized well enough for a
warning system.

Do you have a squelch knob on your radio? Do you have to run incoming
signals through a laborious data analysis before you decide where to set
said squelch? No! You just turn it up till the background noise stops.
Same here. If you hit flutter, the intensity will increase
dramatically, just like the occasionaly noise gets through the squelch.

As I said in my original post, it will probably give you just enough
time to kiss your butt goodbye, but flutter isn't always noticed for
what it really is and it does't always catastrophically destroy the
airplane. Sometimes it beats the airplane to death slowly. If the
'flutter squelch' from the t-tail always goes off as you hit 140kts and
dies back down as you pass through 150kts, it might be a clue that you
should rebalance the t-tail or avoid 145kts as a minimum.



Nothing is stopping anyone from doing any of this with wired sensors.
It would just be cleaner and easier if the wire can be left on the spool.


There's a ton of stuff stopping people from doing this right now. It's
money. None of the stuff you've mentioned is even remotely innexpensive. I
know people who've researched this stuff with the wired sensors for several
years, and haven't gotten much of it out of the lab. Yeah, with steady
improvements in computational fluids, finite element, mems tech, sensing
tech, etc., this stuff will be eventually packaged into something us
home-builder types can afford to use. However, most of it is still too
damned expensive, manpower intensive, and technically immature for even the
military to employ on huge aircraft development programs like JSF. By the
time this stuff really becomes generally available, I'm sure there will be
something better than blue tooth around.


I say those people are asking for too much. If you want the computer to
tell you exactly what's wrong, I'll agree with you all day long that
it's not economically possible with todays technology. If all you want
is a little information about what's going on around you (with the human
doing the divining), the cost is well under $500 (for wired sensors,
don't know about BlueTooth).


--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

William W. Plummer wrote:
Bluetooth: a solution in search of a problem

So was the internet for a while.

I'm thinking of just wireless in general, of which bluetooth is an
implementation (with a really catchy name.)

nafod40 wrote:

William W. Plummer wrote:

Bluetooth: a solution in search of a problem


So was the internet for a while.

Not at all. TCP, the original name for "TCP/IP" that we know today,
was designed to meet certain military needs but the bigger issue of how
to communicate through widely-disparate networks was _THE_ problem.
You can look up the IEEE Trans. on Communications paper by Kahn and
Cerf. 1974 as I recall.