Today's Message Index:
----------------------
1. 03:27 AM - Re: generator intermittent (Vic)
2. 05:36 AM - Re: Re: generator intermittent (George Coy)
3. 05:44 AM - test only (DAVID STROUD)
4. 07:19 AM - Re: Gill shutters and powder coating (jetjockey)
5. 11:16 AM - Re: Re: generator intermittent (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E)
6. 02:18 PM - Re: Re: generator intermittent (Gill Gutierrez)
7. 04:49 PM - Yak 55M Tail Wheel (Flightbag)
8. 06:26 PM - Nanchang Youtube movie (Pete Fowler)
9. 08:12 PM - Re: Re: generator intermittent (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E)
Message 1
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| Subject: | Re: generator intermittent |
Hi Jon,
basically I dont think that flashing the dynamo will do the trick because you say
it works normally in times. So there is no reason to believe that polarity
was wrong or has changed in the past. But certainly you could try Marks method
at first before digging deeper. I suspect some fault in the wiring in the regulator
etc. . If you decide to take the generator off the plane you could try
to run it like an electric motor by connecting the field wire to the positive
brush and hook the lot to a battery, maybe with a big bulb in series to keep the
amps low. Then, in the same configuration the dynamo should produce more than
30 V and amps when you speed it up to 2000 - 3000 revs. Maybe Mark would check
this advice because I am not completely familiar with the wiring around the
dynamo and regulator.
Good luck in your failure hunting.
Electricity is a strange material, you dont see it but it does all sorts of funny
things.
Vic
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313182#313182
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| Subject: | Re: generator intermittent |
I do not know if the CJ has a similar system to the Yaks. If so the problem
is with the reverse current relay. They are the failure point in the Yak
generating system. You can sometimes take them apart and rescue them. They
are made of "un-obtainiam" (the replacements are impossible to find) so the
usual fix it to replace the generating system with a western alternator. I
know many CJ's have installed B&C alternators. We often supply the parts for
the conversion.
George Coy
Motorstar NA
714 Airport Rd.
Swanton VT 05488
802-868-5633 off
802-363-5782 cell
george.coy@gmail.com
SKYPE george.coy
motorstarna.com
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Vic
Sent: Tuesday, September 21, 2010 6:25 AM
Subject: Yak-List: Re: generator intermittent
Hi Jon,
basically I dont think that flashing the dynamo will do the trick because
you say it works normally in times. So there is no reason to believe that
polarity was wrong or has changed in the past. But certainly you could try
Marks method at first before digging deeper. I suspect some fault in the
wiring in the regulator etc. . If you decide to take the generator off the
plane you could try to run it like an electric motor by connecting the field
wire to the positive brush and hook the lot to a battery, maybe with a big
bulb in series to keep the amps low. Then, in the same configuration the
dynamo should produce more than 30 V and amps when you speed it up to 2000 -
3000 revs. Maybe Mark would check this advice because I am not completely
familiar with the wiring around the dynamo and regulator.
Good luck in your failure hunting.
Electricity is a strange material, you dont see it but it does all sorts
of funny things.
Vic
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313182#313182
Message 3
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test only
David Stroud Ottawa, Canada
Christavia C-FDWS
Fairchild 51 replica
under construction C-FYXV
Message 4
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| Subject: | Re: Gill shutters and powder coating |
My CJ vanes were powder coated years ago and I have had no problems whatsoever
with them.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313207#313207
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| Subject: | Re: generator intermittent |
To Vic (and Jon),
The generators on these aircraft are self-exciting. As such, they require a residual
magnetic field in order to start outputting voltage. A generator that
works sometimes and totally does not work at other times is a candidate for this
type of failure. As generators of this type age, and especially if they are
not run on a regular basis, the magnetic field can become weak. They do not
"change polarity" per se.
This is not "my method" by the way, it is an established procedure for re-establishing
a magnetic field in a generator, and is sometimes called "Flashing the
Field". It is not well known in today's world due to the abundance of alternators.
Just FYI, it just worked on another YAK aircraft just two weeks ago handled
off-line.
So that said, yes there is a very "reasonable belief" that this gents generator
has a weak magnetic field that could be causing his problem, and it is a very
easy, cheap and foolproof first step, as long as it is done correctly.
The regulator itself is not likely the bad actor, because once the generator comes
on line, it stays on line. Bad regulators of the carbon pile type used in
this system will typically display incorrect regulating voltage at full output
when they fail. However, there is a fault area NEAR the voltage regulator with
the method used to mount it in the aircraft. The voltage regulator is attached
to a MOUNT, and there are some wires that occasionally rub on that mount
and short out. That can be inspected for when the voltage regulator is removed
and inspected. However it is rare and is a last ditch kind of inspection,
but something to be kept in mind.
I would not recommend trying to run the generator like a motor by removing it and
connecting it to a battery. A generator can easily become a motor, but making
it into one does not really solve the issue of what is wrong with the aircraft.
George Coy goes on in another message to discuss the possibility that this problem
could be caused by a reverse current relay. And he is totally correct. It
very well could be. There are some troubleshooting steps that can be used to
help identify that as the problem as well. If the DMR-200 relay is indeed bad,
they are (as he mentions) difficult to find and expensive to replace, although
they can indeed be repaired SOMETIMES.
However, "we are not there yet" if you are willing to learn how this system works
and take the time to troubleshoot it.
Any electrical or electronics system is approached in logical steps when it comes
to repairing it. A lot of people like to dive-bomb what might be wrong in
a hit and miss fashion. I do not do that.
In this case, the first thing to verify is that the generator itself is working
properly. These generators can be purchased cheaply, typically around $100 or
so, so we start there. Flashing the field is a 30 minute job with very little
effort and could easily fix your problem. However, it might not... but we
start there.
Then we move to check to see that the generator puts out when it is totally isolated
from the rest of the aircraft. If it works there, then we move on.
If it is the reverse current relay, there is a trick to check that out too.
Keep in mind that the DMR-200 is indeed a reverse current relay, but it is also
the main contactor relay, the source for how your cockpit generator light works,
and a whole lot more. It is actually called the Combined Device. It is made
up of a very special reverse current relay with a primary and counter magnetic
field and two additional stand alone relays, plus the main power contactor
relay as I said.
One last thing please.
How are the batteries in your aircraft? Go out to your aircraft and read the
battery voltage with everything turned on. Is it below 20 volts? Please pass
this on.
Mark Bitterlich
________________________________
From: owner-yak-list-server@matronics.com on behalf of Vic
Sent: Tue 9/21/2010 6:25 AM
Subject: Yak-List: Re: generator intermittent
Hi Jon,
basically I dont think that flashing the dynamo will do the trick because you say
it works normally in times. So there is no reason to believe that polarity
was wrong or has changed in the past. But certainly you could try Marks method
at first before digging deeper. I suspect some fault in the wiring in the regulator
etc. . If you decide to take the generator off the plane you could try
to run it like an electric motor by connecting the field wire to the positive
brush and hook the lot to a battery, maybe with a big bulb in series to keep the
amps low. Then, in the same configuration the dynamo should produce more than
30 V and amps when you speed it up to 2000 - 3000 revs. Maybe Mark would check
this advice because I am not completely familiar with the wiring around the
dynamo and regulator.
Good luck in your failure hunting.
Electricity is a strange material, you dont see it but it does all sorts of funny
things.
Vic
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313182#313182
Message 6
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| Subject: | Re: generator intermittent |
Mark,
I was of the understanding that the CJ generator was not self exciting, i.e.
power to the fields is provided externally by the regulator, similar to how
alternators are regulated. It's been a while since I have looked into this,
so I could be wrong. I assume the YAK generator is the same.
Gill
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Bitterlich, Mark G
CIV Det Cherry Point, MALS-14 64E
Sent: Tuesday, September 21, 2010 11:12 AM
Subject: RE: Yak-List: Re: generator intermittent
MALS-14 64E" <mark.bitterlich@navy.mil>
To Vic (and Jon),
The generators on these aircraft are self-exciting. As such, they require a
residual magnetic field in order to start outputting voltage. A generator
that works sometimes and totally does not work at other times is a candidate
for this type of failure. As generators of this type age, and especially if
they are not run on a regular basis, the magnetic field can become weak.
They do not "change polarity" per se.
This is not "my method" by the way, it is an established procedure for
re-establishing a magnetic field in a generator, and is sometimes called
"Flashing the Field". It is not well known in today's world due to the
abundance of alternators. Just FYI, it just worked on another YAK aircraft
just two weeks ago handled off-line.
So that said, yes there is a very "reasonable belief" that this gents
generator has a weak magnetic field that could be causing his problem, and
it is a very easy, cheap and foolproof first step, as long as it is done
correctly.
The regulator itself is not likely the bad actor, because once the generator
comes on line, it stays on line. Bad regulators of the carbon pile type
used in this system will typically display incorrect regulating voltage at
full output when they fail. However, there is a fault area NEAR the voltage
regulator with the method used to mount it in the aircraft. The voltage
regulator is attached to a MOUNT, and there are some wires that occasionally
rub on that mount and short out. That can be inspected for when the voltage
regulator is removed and inspected. However it is rare and is a last ditch
kind of inspection, but something to be kept in mind.
I would not recommend trying to run the generator like a motor by removing
it and connecting it to a battery. A generator can easily become a motor,
but making it into one does not really solve the issue of what is wrong with
the aircraft.
George Coy goes on in another message to discuss the possibility that this
problem could be caused by a reverse current relay. And he is totally
correct. It very well could be. There are some troubleshooting steps that
can be used to help identify that as the problem as well. If the DMR-200
relay is indeed bad, they are (as he mentions) difficult to find and
expensive to replace, although they can indeed be repaired SOMETIMES.
However, "we are not there yet" if you are willing to learn how this system
works and take the time to troubleshoot it.
Any electrical or electronics system is approached in logical steps when it
comes to repairing it. A lot of people like to dive-bomb what might be
wrong in a hit and miss fashion. I do not do that.
In this case, the first thing to verify is that the generator itself is
working properly. These generators can be purchased cheaply, typically
around $100 or so, so we start there. Flashing the field is a 30 minute job
with very little effort and could easily fix your problem. However, it
might not... but we start there.
Then we move to check to see that the generator puts out when it is totally
isolated from the rest of the aircraft. If it works there, then we move on.
If it is the reverse current relay, there is a trick to check that out too.
Keep in mind that the DMR-200 is indeed a reverse current relay, but it is
also the main contactor relay, the source for how your cockpit generator
light works, and a whole lot more. It is actually called the Combined
Device. It is made up of a very special reverse current relay with a
primary and counter magnetic field and two additional stand alone relays,
plus the main power contactor relay as I said.
One last thing please.
How are the batteries in your aircraft? Go out to your aircraft and read
the battery voltage with everything turned on. Is it below 20 volts?
Please pass this on.
Mark Bitterlich
________________________________
From: owner-yak-list-server@matronics.com on behalf of Vic
Sent: Tue 9/21/2010 6:25 AM
Subject: Yak-List: Re: generator intermittent
Hi Jon,
basically I dont think that flashing the dynamo will do the trick because
you say it works normally in times. So there is no reason to believe that
polarity was wrong or has changed in the past. But certainly you could try
Marks method at first before digging deeper. I suspect some fault in the
wiring in the regulator etc. . If you decide to take the generator off the
plane you could try to run it like an electric motor by connecting the field
wire to the positive brush and hook the lot to a battery, maybe with a big
bulb in series to keep the amps low. Then, in the same configuration the
dynamo should produce more than 30 V and amps when you speed it up to 2000 -
3000 revs. Maybe Mark would check this advice because I am not completely
familiar with the wiring around the dynamo and regulator.
Good luck in your failure hunting.
Electricity is a strange material, you dont see it but it does all sorts
of funny things.
Vic
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313182#313182
Message 7
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| Subject: | Yak 55M Tail Wheel |
On my Yak-55, one of the stops that prevents the tail wheel from swiveling broke
off.
Obviously I need to repair it.
Any suggestions?
Thanks...............Flightbag
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313293#313293
Message 8
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| Subject: | Nanchang Youtube movie |
After 9 months of Nanchang ownership, I decided to consolidate some of the video
footage I had (mostly shot by GIB's) and made a film that condenses the crazy
last 9 months of ownership. It's been no bed of roses but I've packed 70 hours
of Nanchang flying in and have had experiences I would never have dreamed would
have been possible. Mostly it's the formation flying and camaraderie that
have been amazing and thanks to the many people who helped me during purchase,
training, maintenance and beyond.
It's set to "Dreamers" by Jack Savoretti. I discovered that song as it was the
background to a beautiful film of some jets flying that someone posted several
months ago.
Enjoy!
http://www.youtube.com/watch?v=24HG3qK0jRg
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313308#313308
Message 9
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| Subject: | Re: generator intermittent |
I know zero about CJ's. The only electrical systems I have worked on extensively
have been Yak's and Sukhoi's.
The YAK generator can power up completely without a battery.
The "field" input connection to the YAK generator is supplied from the output of
the generator itself fed back from a carbon pile regulator.
This is not to say that it uses permanent magnets such as what are found in B&C's
small 10 amp unit. Instead it relies on a residual magnetic field. If left
to sit for a long period, this field can reduce in intensity to where initial
operation can become intermittent and fail to come "on-line" predictably. This
is where the "flashing the field" procedure comes into play. Following that
procedure attempts to restore that residual field to regain reliable operation.
In the Sukhoi manual, there are actual specs on when the DMR-200 relay will close
with the battery removed and with the battery operational. I am in Yuma right
now and do not have access to that data, but will be glad to send it to you
when I return.
Mark Bitterlich
________________________________
From: owner-yak-list-server@matronics.com on behalf of Gill Gutierrez
Sent: Tue 9/21/2010 5:14 PM
Subject: RE: Yak-List: Re: generator intermittent
Mark,
I was of the understanding that the CJ generator was not self exciting, i.e.
power to the fields is provided externally by the regulator, similar to how
alternators are regulated. It's been a while since I have looked into this,
so I could be wrong. I assume the YAK generator is the same.
Gill
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Bitterlich, Mark G
CIV Det Cherry Point, MALS-14 64E
Sent: Tuesday, September 21, 2010 11:12 AM
Subject: RE: Yak-List: Re: generator intermittent
MALS-14 64E" <mark.bitterlich@navy.mil>
To Vic (and Jon),
The generators on these aircraft are self-exciting. As such, they require a
residual magnetic field in order to start outputting voltage. A generator
that works sometimes and totally does not work at other times is a candidate
for this type of failure. As generators of this type age, and especially if
they are not run on a regular basis, the magnetic field can become weak.
They do not "change polarity" per se.
This is not "my method" by the way, it is an established procedure for
re-establishing a magnetic field in a generator, and is sometimes called
"Flashing the Field". It is not well known in today's world due to the
abundance of alternators. Just FYI, it just worked on another YAK aircraft
just two weeks ago handled off-line.
So that said, yes there is a very "reasonable belief" that this gents
generator has a weak magnetic field that could be causing his problem, and
it is a very easy, cheap and foolproof first step, as long as it is done
correctly.
The regulator itself is not likely the bad actor, because once the generator
comes on line, it stays on line. Bad regulators of the carbon pile type
used in this system will typically display incorrect regulating voltage at
full output when they fail. However, there is a fault area NEAR the voltage
regulator with the method used to mount it in the aircraft. The voltage
regulator is attached to a MOUNT, and there are some wires that occasionally
rub on that mount and short out. That can be inspected for when the voltage
regulator is removed and inspected. However it is rare and is a last ditch
kind of inspection, but something to be kept in mind.
I would not recommend trying to run the generator like a motor by removing
it and connecting it to a battery. A generator can easily become a motor,
but making it into one does not really solve the issue of what is wrong with
the aircraft.
George Coy goes on in another message to discuss the possibility that this
problem could be caused by a reverse current relay. And he is totally
correct. It very well could be. There are some troubleshooting steps that
can be used to help identify that as the problem as well. If the DMR-200
relay is indeed bad, they are (as he mentions) difficult to find and
expensive to replace, although they can indeed be repaired SOMETIMES.
However, "we are not there yet" if you are willing to learn how this system
works and take the time to troubleshoot it.
Any electrical or electronics system is approached in logical steps when it
comes to repairing it. A lot of people like to dive-bomb what might be
wrong in a hit and miss fashion. I do not do that.
In this case, the first thing to verify is that the generator itself is
working properly. These generators can be purchased cheaply, typically
around $100 or so, so we start there. Flashing the field is a 30 minute job
with very little effort and could easily fix your problem. However, it
might not... but we start there.
Then we move to check to see that the generator puts out when it is totally
isolated from the rest of the aircraft. If it works there, then we move on.
If it is the reverse current relay, there is a trick to check that out too.
Keep in mind that the DMR-200 is indeed a reverse current relay, but it is
also the main contactor relay, the source for how your cockpit generator
light works, and a whole lot more. It is actually called the Combined
Device. It is made up of a very special reverse current relay with a
primary and counter magnetic field and two additional stand alone relays,
plus the main power contactor relay as I said.
One last thing please.
How are the batteries in your aircraft? Go out to your aircraft and read
the battery voltage with everything turned on. Is it below 20 volts?
Please pass this on.
Mark Bitterlich
________________________________
From: owner-yak-list-server@matronics.com on behalf of Vic
Sent: Tue 9/21/2010 6:25 AM
Subject: Yak-List: Re: generator intermittent
Hi Jon,
basically I dont think that flashing the dynamo will do the trick because
you say it works normally in times. So there is no reason to believe that
polarity was wrong or has changed in the past. But certainly you could try
Marks method at first before digging deeper. I suspect some fault in the
wiring in the regulator etc. . If you decide to take the generator off the
plane you could try to run it like an electric motor by connecting the field
wire to the positive brush and hook the lot to a battery, maybe with a big
bulb in series to keep the amps low. Then, in the same configuration the
dynamo should produce more than 30 V and amps when you speed it up to 2000 -
3000 revs. Maybe Mark would check this advice because I am not completely
familiar with the wiring around the dynamo and regulator.
Good luck in your failure hunting.
Electricity is a strange material, you dont see it but it does all sorts
of funny things.
Vic
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313182#313182
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