Who pays follow-up

Threw the belt again after twenty minutes in IMC on the way to the avionics
shop. Destination was VMC, so elected to continue rather than turn around or
land, and the other alternator was handling the load easily.

Avionics guy fixed the radar (took three guys around 30 minutes). Belt
replaced.

Flew 1.5 hours back- no problems. After return I tightened belt again, and
then flew another 1.6 hours doing LNAV/VNAV approaches in IMC (much
smoother than ILS).

Checked belt again, which appeared tight. So, last belt has now gone over
three hours, where the others have all thrown in less than 30 minutes.

What gives- can a new belt stretch so much that it gets thrown that easily,
or should I still suspect that the engine is detuned and has a sticking
counterweight?

The engine shop quoted a cost of over $3,000 as a minimum to change the
counterweight bearings, plus any costs associated with finding something
wrong with the cylinders.

It's hard for me to let go of my single-engine, single-alternator mentality.
I read "Threw the belt again after twenty minutes in IMC..." and I'm
immediately thinking what is he thinking going back into IMC until that
problem is solved for sure? I forget that you carry around a spare.

Again, I'm no A&P but I agree with the thought you expressed in one of your
earlier posts. The question in my mind would be, "What's changed?" Before
tearing the engine apart, I sure would make sure that it isn't just a washer
put back on the wrong side of a bracket or a bent bracket causing the
Alternator to be mis-aligned.

--
-------------------------------
Travis
Lake N3094P
PWK
"Viperdoc" wrote in message
...
Threw the belt again after twenty minutes in IMC on the way to the
avionics shop. Destination was VMC, so elected to continue rather than
turn around or land, and the other alternator was handling the load
easily.

Avionics guy fixed the radar (took three guys around 30 minutes). Belt
replaced.

Flew 1.5 hours back- no problems. After return I tightened belt again, and
then flew another 1.6 hours doing LNAV/VNAV approaches in IMC (much
smoother than ILS).

Checked belt again, which appeared tight. So, last belt has now gone over
three hours, where the others have all thrown in less than 30 minutes.

What gives- can a new belt stretch so much that it gets thrown that
easily, or should I still suspect that the engine is detuned and has a
sticking counterweight?

The engine shop quoted a cost of over $3,000 as a minimum to change the
counterweight bearings, plus any costs associated with finding something
wrong with the cylinders.

Unrelated, but are you still happy with your eFlyBook? I rode along with a
friend to do some of the same approaches using the EFB. It is a major pain
switching approaches and trying to tap in the identifier on the little
keyboard in even minimal turbulence.

They need a function to simply go back one page using the flipper. Hopefully
Arinc will drive the customer service end for them- MA.com is at a critical
juncture regarding their future success.

I'll throw a few things out there based on my experience with v-belts. We
have literally thousands of v-belts on a wide variety of equipment. Our
mechanics have become very picky about which belts they use. Sometimes we
run into a change that the manufacturer has made that causes the same brand
and part numbered belt to do strange things. We've seen things such as a
change in the composition of the rubber of the belting material causing
additional friction and "pulley climb" and changes in the number of layers
of reinforcing fabric and changes to the hardness of the belts causing
problems because it is either more or less flexible than the previous belt.

Do you still have the old belt(s)? Are the belts that were being thrown off
worn, chaffed, or stretched unusually? Polished or shiny spots on the sides
of the belt will indicate slipping. Cracks and fraying will indicate that
the belt was either overtight and/or old when installed. Do they lay flat
when you simply lay them on the floor? Twisted belts can indicate
misalignment. I'm just wondering if there was something wrong with those
specific belts. How old where they when installed? Brand and part number
identical to the latest 3 hour belt? Can you measure them to check them
against the original length and what the belt number states?

Could either pulley have slipped on the shafts? Do you have room to run a
straight edge across and between the faces of each pulley to check for
alignment?

Too tight? Too loose? Rule of thumb tension is a deflection mid way
between the pulleys of 1/2 the thickness of the belt, but check your MM.

Jim

"Viperdoc" wrote in message
...
Threw the belt again after twenty minutes in IMC on the way to the
avionics shop. Destination was VMC, so elected to continue rather than
turn around or land, and the other alternator was handling the load
easily.

Avionics guy fixed the radar (took three guys around 30 minutes). Belt
replaced.

Flew 1.5 hours back- no problems. After return I tightened belt again, and
then flew another 1.6 hours doing LNAV/VNAV approaches in IMC (much
smoother than ILS).

Checked belt again, which appeared tight. So, last belt has now gone over
three hours, where the others have all thrown in less than 30 minutes.

What gives- can a new belt stretch so much that it gets thrown that
easily, or should I still suspect that the engine is detuned and has a
sticking counterweight?

The engine shop quoted a cost of over $3,000 as a minimum to change the
counterweight bearings, plus any costs associated with finding something
wrong with the cylinders.

All of the belts that were thrown no longer lay flat- they looked like they
were stretched on one side. This, I was told, was due to some of the cords
being broken on one side versus the other.

One episode found the belt actually inside out on the pulleys, but still in
place. Yet, the overall alignment looks good to everyone who has inspected
the system.

The only difference so far is that at the last belt change, we noted that
the lower (non-tensioning) alternator bolt was very loose.

I bought two spares, and one of them is now on the plane. I forget the
source, and didn't save any of the old belts, but clearly they were all
"warped" and didn't lay flat.

Again, this was attributed to "whipping" of the belts by two mechanics, as a
result of the engine being detuned due to a sticking crankshaft
counterweight.

I again questioned why this should occur all of a sudden after changing the
belt at annual, since the previous belt had gone for hundreds of hours
without any indication of a problem. No one had a good answer for this, so
somehow the logic of the crankshaft counterweights being the source of the
problem is a little suspicious.
"Jim Burns" wrote in message
...
I'll throw a few things out there based on my experience with v-belts. We
have literally thousands of v-belts on a wide variety of equipment. Our
mechanics have become very picky about which belts they use. Sometimes we
run into a change that the manufacturer has made that causes the same
brand and part numbered belt to do strange things. We've seen things such
as a change in the composition of the rubber of the belting material
causing additional friction and "pulley climb" and changes in the number
of layers of reinforcing fabric and changes to the hardness of the belts
causing problems because it is either more or less flexible than the
previous belt.

Do you still have the old belt(s)? Are the belts that were being thrown
off worn, chaffed, or stretched unusually? Polished or shiny spots on the
sides of the belt will indicate slipping. Cracks and fraying will
indicate that the belt was either overtight and/or old when installed. Do
they lay flat when you simply lay them on the floor? Twisted belts can
indicate misalignment. I'm just wondering if there was something wrong
with those specific belts. How old where they when installed? Brand and
part number identical to the latest 3 hour belt? Can you measure them to
check them against the original length and what the belt number states?

Could either pulley have slipped on the shafts? Do you have room to run a
straight edge across and between the faces of each pulley to check for
alignment?

Too tight? Too loose? Rule of thumb tension is a deflection mid way
between the pulleys of 1/2 the thickness of the belt, but check your MM.

Jim

"Viperdoc" wrote in message
...
Threw the belt again after twenty minutes in IMC on the way to the
avionics shop. Destination was VMC, so elected to continue rather than
turn around or land, and the other alternator was handling the load
easily.

Avionics guy fixed the radar (took three guys around 30 minutes). Belt
replaced.

Flew 1.5 hours back- no problems. After return I tightened belt again,
and then flew another 1.6 hours doing LNAV/VNAV approaches in IMC (much
smoother than ILS).

Checked belt again, which appeared tight. So, last belt has now gone over
three hours, where the others have all thrown in less than 30 minutes.

What gives- can a new belt stretch so much that it gets thrown that
easily, or should I still suspect that the engine is detuned and has a
sticking counterweight?

The engine shop quoted a cost of over $3,000 as a minimum to change the
counterweight bearings, plus any costs associated with finding something
wrong with the cylinders.

("Viperdoc" wrote)
Again, this was attributed to "whipping" of the belts by two mechanics, as
a result of the engine being detuned due to a sticking crankshaft
counterweight.

I again questioned why this should occur all of a sudden after changing
the belt at annual, since the previous belt had gone for hundreds of hours
without any indication of a problem. No one had a good answer for this, so
somehow the logic of the crankshaft counterweights being the source of the
problem is a little suspicious.


This sounds like a case for "House" ...or in your case, "Hangar". :-)

If it's easy to get at, and all other things being equal, can you swap
alternators with a known good one (meaning pulley)?


Montblack
http://www.fox.com/house/features/houseisms.htm
"Twenty-year olds fall in and out of love more often than they change their
oil filters. Which they should do more often."
- Fools For Love

"Take this four times a day. And stay off airplanes. They're flying
cesspools."
- Informed Consent

I am still happy. I have flown quite a few approaches in VMC and about 15 in
real IMC using the eFB. I have gained enough confidence with it that it is
now my sole reference. When I know where I am going in advance, I do print
the destination charts for backup and so that I have the airport diagram and
FBO info easily accessible but I have also flown to places with no paper
backup. And, I no longer print out any enroute airports - which I used to do
just in case of a need to divert.

You are right, of course. Some things are not as easy as they could be. I
don't find selecting an approach using the stylus to be difficult - even in
turbulence. But, it does take a little patience and timing. As in, bounce -
float - touch the screen - bounce - float - touch the screen. Entering an
airport ID, however, can be pretty tough. But, I find that the eFB can be
used effectively step by step. That is, you can enter a letter - scan -
enter another letter - scan - enter the final letter - scan - pick the
approach - scan.

For normal operation, that's OK. There is plenty of time to bring up the
right chart. The tough scenarios are the practice ones where it is one
approach after another and maybe quickly switching airports. I tend to
practice at Kenosha. With a safety pilot, I did the ILS, the VOR, then
switched to Waukegan and did the ILS there. It is tempting to panic but it
really only takes about 10 seconds to bring up another approach and about 30
seconds to bring up an approach at another airport.

The cool thing is that any airport is just as accessible as the next. No
more fumbling for the right binder or thumbing through a pile of charts.

I have a hard cover folder for mine. I do one of two things. Either fold the
front cover behind and clip it onto my kneeboard or leave it open and clip
the back cover onto my kneeboard. The stylus goes into an elastic holder
when not in use - all the time, any time. I've never been a clip the paper
chart to the yoke kind of guy. I don't why. I have always clipped paper
charts onto my kneeboard so there is no adjustment for me to have the eFB
there instead.

Going to Sun n' Fun?

--
-------------------------------
Travis
Lake N3094P
PWK


"Viperdoc" wrote in message
...
Unrelated, but are you still happy with your eFlyBook? I rode along with a
friend to do some of the same approaches using the EFB. It is a major pain
switching approaches and trying to tap in the identifier on the little
keyboard in even minimal turbulence.

They need a function to simply go back one page using the flipper.
Hopefully Arinc will drive the customer service end for them- MA.com is at
a critical juncture regarding their future success.

I'm no expert but it occurs to me that if you checked your prop
balance and it was good then it's unlikely your counterweights are
sticking.

On Sun, 1 Apr 2007 07:20:49 -0500, "Viperdoc"
wrote:

Threw the belt again after twenty minutes in IMC on the way to the avionics
shop. Destination was VMC, so elected to continue rather than turn around or
land, and the other alternator was handling the load easily.

Avionics guy fixed the radar (took three guys around 30 minutes). Belt
replaced.

Flew 1.5 hours back- no problems. After return I tightened belt again, and
then flew another 1.6 hours doing LNAV/VNAV approaches in IMC (much
smoother than ILS).

Checked belt again, which appeared tight. So, last belt has now gone over
three hours, where the others have all thrown in less than 30 minutes.

What gives- can a new belt stretch so much that it gets thrown that easily,
or should I still suspect that the engine is detuned and has a sticking
counterweight?

The engine shop quoted a cost of over $3,000 as a minimum to change the
counterweight bearings, plus any costs associated with finding something
wrong with the cylinders.

"Montblack" writes:



This sounds like a case for "House" ...or in your case, "Hangar". :-)

If it's easy to get at, and all other things being equal, can you swap
alternators with a known good one (meaning pulley)?

I've wondered about the whole idea of belt drive; given that you must pull
the prop to change same.

I've pondered a smooth pulley in place of the existing one, then a
rubber drive wheel on the alternator/vacuum pump etc.... I suppose
icing may be an issue, as well as having to locate the accessories
directly adjacent to the engine axis.

The other way would be driving the belt with the back of engine
pulley, but that has other issues...

BTW, Real Soon Now, Detroit is promising everything will be
electric-driven; water pump, power steering, air conditioning, you
name it. They'll build a starter/ alternator into the flywheel/bell
housing area. The engine won't idle; it will stop at red lights
and restart when you hit the gas...
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

Dave,
My bonanza has a 70A alternator that is belt driven off the back of the
engine, IO470.

Toyota already offers what Detroit is promising - actually I think Ford
does too. My Camry Hybrid has electric power steering, electric power
assist brakes, electric AC, etc. The engine only runs when it needs
to. Very clever car. I've put about 1400 miles on it and so far so good.

Dave
M35

David Lesher wrote:
"Montblack" writes:



This sounds like a case for "House" ...or in your case, "Hangar". :-)

If it's easy to get at, and all other things being equal, can you swap
alternators with a known good one (meaning pulley)?

I've wondered about the whole idea of belt drive; given that you must pull
the prop to change same.

I've pondered a smooth pulley in place of the existing one, then a
rubber drive wheel on the alternator/vacuum pump etc.... I suppose
icing may be an issue, as well as having to locate the accessories
directly adjacent to the engine axis.

The other way would be driving the belt with the back of engine
pulley, but that has other issues...

BTW, Real Soon Now, Detroit is promising everything will be
electric-driven; water pump, power steering, air conditioning, you
name it. They'll build a starter/ alternator into the flywheel/bell
housing area. The engine won't idle; it will stop at red lights
and restart when you hit the gas...