Today's Message Index:
----------------------
1. 05:46 AM - Re: Dynon Avionics Stuff (RV_8 Pilot)
2. 06:21 AM - Re: Dynon Avionics Stuff (Brian Lloyd)
3. 08:31 AM - Tire rubber comparison (Joe Howse)
4. 08:40 AM - Re: Tire rubber comparison (Richard Basiliere)
5. 08:52 AM - Re: Tire rubber comparison (Ernie)
6. 09:05 AM - Forward trim cable (jay reiter)
7. 09:50 AM - Tires (jay reiter)
8. 10:58 AM - Re: Tire rubber comparison (Joe Howse)
9. 10:59 AM - Re: Tires (Joe Howse)
10. 02:52 PM - Forward trim cable replacement. (jay reiter)
11. 03:06 PM - hole (jay reiter)
12. 07:33 PM - Worlds Most Powerfull Engine (Frank Haertlein)
Message 1
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| Subject: | Dynon Avionics Stuff |
--> Yak-List message posted by: "RV_8 Pilot" <rv_8pilot@hotmail.com>
Bryan or Brian?! ;)
Bryan Jones
do not archive
>>
>Bryan
>Imagine you have a randomly oriented, accelerometer stabilized,
>non-moving, inertial platform. Once level, remove the accelerometer
>correction signals and any gyro correction signals that take care of
>precession. The platform will now "find" or tilt in the northern
>direction. Of course you need to tell the platform what hemisphere you
>are in (GPS corrections here?) After a period of time what you wind up
>with is an acceleration signal in the Y axis proportional to latitude
>and the direction of true north. This is Ay Secant Phi as I know it.
>
>What you have now is a correction signal amplitude proportional to
>latitude that can be used to keep the platform stable and earth
>referenced over time using the gyro signals combined with the correction
>for latitude. Call it an initial reference point if you will. The
>platform now knows true north and you have max output from one gyro and
>min out from the other. Measured outputs from the gyros can thus be used
>to keep the platform level with earth allowing you to use accelerometer
>signals for pure acceleration measurements in the X, Y and Z plane.
>Rather than a mechanical system (iron gyros slaved for keeping level)
>all this can exist in software.
>
>One could use those same accelerometer signals to calculate position,
>and thus the correction signal amplitude required for maintaining a
>stable platform independent of GPS position information used for
>normally correcting the system. Provide GPS corrections and software
>lookup tables with known quantities of correction signals required for
>your latitude and you have a self correcting system platform. In the
>event of a failure of GPS, corrections to the system could be calculated
>based on current measurements of speed and direction to provide
>correction signals accurate to within some specified period of time and
>accuracy level.....probly enough to get you on the ground safely in IMC
>within a set period of time if it's implemented correctly.
>
>I understand this may be an oversimplification but I hope it gets the
>idea across. Your critique is welcome.
>Frank
>N911OM
>YAK-52
>
>-----Original Message-----
>From: owner-yak-list-server@matronics.com
>[mailto:owner-yak-list-server@matronics.com] On Behalf Of Brian Lloyd
>To: yak-list@matronics.com
>Subject: Re: Yak-List: Dynon Avionics Stuff
>
>
>--> Yak-List message posted by: Brian Lloyd <brianl@lloyd.com>
>
>Frank Haertlein wrote:
> > --> Yak-List message posted by: "Frank Haertlein"
> > --> <yak52driver@earthlink.net>
> >
> > Brian said
> >
> > "you need something to establish "down" to "erect" the gyro platform"
> >
> > How about Ay Secant Phi ?
>
>I am not sure what you are referring to. Sorry.
>
>The problem is that you have rate information. When you integrate rate
>to get displacement you end up with a constant factor you just don't
>know ahead of time. This means that while the platform can tell you how
>much you have displaced it from where it started (rotated about the X,
>Y, and Z axes), you don't know where you started from so you don't know
>where you are now. You just know by how much your attitude has changed.
>You need something that tells you your orientation right now, even if
>for only a moment. Once you have that you know how much you have
>displaced from that point in time. Since we live in a 1G field, it is
>natural to use that as our reference for the vertical axis. This gives
>me attitude in pitch and roll. If the vector sum of acceleration does
>not equal 1G, then I know that the airplane is accelerating about one or
>more axes and I can't use that information to provide a correction
>factor. Since no airplane remains in accelerated flight continuously
>eventually you get a good sample that lets you correct the platform's
>orientation.
>
>If you want heading you use the magnetometer. The three-axis magnetic
>vector is then projected on the horizontal plane to yield a magnetic
>heading. GPS gives you position, track, and groundspeed to reset the
>position in real space. Now the inertial reference platform provides
>short-term stabilization that is accurate.
>
>We do the same thing when we fly with traditional instruments (iron
>gyros, etc.). We just do it for the instruments instead of letting them
>figure it out for themselves. When we know we are flying straight and
>level we reset the vertical gyro either with a fast-erect button (caging
>knob, etc.) or it has a pendulum mechanism to always apply a slow but
>steady correction factor to the gyro. As for heading, we use the DG
>(HI) to provide short-term information and the magnetic compass to
>provide correction information when we are in straight-and-level flight.
>Regardless of who does the work, the principles remain the same.
>
>--
>Brian Lloyd 6501 Red Hook Plaza
>brianl@lloyd.com Suite 201
>http://www.lloyd.com St. Thomas, VI 00802
>+1.340.998.9447 (voice) +1.360.838.9669 (fax)
>
>There is a time to laud one's country and a time to protest.
>A good citizen is prepared to do either as the need arises.
>
>
>==
>direct advertising on the Matronics Forums.
>==
>==
>==
>
>
Message 2
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| Subject: | Re: Dynon Avionics Stuff |
--> Yak-List message posted by: Brian Lloyd <brianl@lloyd.com>
Frank Haertlein wrote:
> --> Yak-List message posted by: "Frank Haertlein" <yak52driver@earthlink.net>
>
> Bryan
> Imagine you have a randomly oriented, accelerometer stabilized,
> non-moving, inertial platform. Once level, remove the accelerometer
> correction signals and any gyro correction signals that take care of
> precession. The platform will now "find" or tilt in the northern
> direction. Of course you need to tell the platform what hemisphere you
> are in (GPS corrections here?) After a period of time what you wind up
> with is an acceleration signal in the Y axis proportional to latitude
> and the direction of true north. This is Ay Secant Phi as I know it.
Ding. The light dawns. You are correcting for the precession caused by the rotation
of the earth. I wasn't even considering that for short-term attitude stabilization.
Also, an inertial reference platform of sufficient sensitivity
using rate gyros, usually ring LASER gyros (RLGs) or interferometric fiber optic
gyros (IFOGs), just directly reads out the earth's rotation and doesn't precess.
This is a critical problem for a long-range INS but generally ignored for the platforms
used to provide attitude reference info. (Actually, it just looks like
another accumulated error that must be corrected.) The earth's rotation rate
(0.25 degree/min) is often at or below the limit of detection for these devices.
If you do have good gyros you can recognize that the platform is stable
and the earth is rotating so that the signal from the gyros is valid and not
drift or noise.
So the "cheap" rate gyros provide information about gross attitude changes but
must be continuously and frequently "reset" to maintain any semblance of accuracy.
This process of "resetting" eliminates the earth rotation factor and has
them performing like the traditional gyros in the panel.
> What you have now is a correction signal amplitude proportional to
> latitude that can be used to keep the platform stable and earth
> referenced over time using the gyro signals combined with the correction
> for latitude. Call it an initial reference point if you will. The
> platform now knows true north and you have max output from one gyro and
> min out from the other. Measured outputs from the gyros can thus be used
> to keep the platform level with earth allowing you to use accelerometer
> signals for pure acceleration measurements in the X, Y and Z plane.
> Rather than a mechanical system (iron gyros slaved for keeping level)
> all this can exist in software.
Right. There your interest is in knowing your location in space more than aircraft
attitude. (Although, if you know your location and the reference plane of
the instrument, you can calculate attitude.)
> One could use those same accelerometer signals to calculate position,
> and thus the correction signal amplitude required for maintaining a
> stable platform independent of GPS position information used for
> normally correcting the system. Provide GPS corrections and software
> lookup tables with known quantities of correction signals required for
> your latitude and you have a self correcting system platform. In the
> event of a failure of GPS, corrections to the system could be calculated
> based on current measurements of speed and direction to provide
> correction signals accurate to within some specified period of time and
> accuracy level.....probly enough to get you on the ground safely in IMC
> within a set period of time if it's implemented correctly.
Yes, but (how annoying that "but" is) it takes really good gyros. High-quality
iron gyros, RLGs and IFOGs can perform this function. As a practical matter
the solid-state rate gyros can not, any more than the iron gyros we fly behind
for attitude and heading would suffice in this application.
So I was ignoring it.
But your point is well taken and I thank you for reminding me.
> I understand this may be an oversimplification but I hope it gets the
> idea across. Your critique is welcome.
Offhand I can't think of anything to add right now.
--
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
http://www.lloyd.com St. Thomas, VI 00802
+1.340.998.9447 (voice) +1.360.838.9669 (fax)
There is a time to laud one's country and a time to protest.
A good citizen is prepared to do either as the need arises.
Message 3
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| Subject: | Tire rubber comparison |
--> Yak-List message posted by: Joe Howse <joeh@shaw.ca>
For info only on the difference between Chinese and Desser tire rubber thickness.
Not meant to be an endorsement for either.
Core samples taken from center of tread area of two 500X150 tires, one Chinese
and one Desser with about 50 hours use, gravel and hard surface.( both scrapped
for puncture damage ) both on CJ6 aircraft.
Chinese tire - Total thickness remaining 7/16" including cord .
Desser tire - Total thickness remaining 5/16" including cord, but only 3/16"
remaining under tread groove.
In short, I do not believe that remaining tread grooves on the Chinese or Russian
tires are a good indicator of remaining life.
Joe
Message 4
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| Subject: | Re: Tire rubber comparison |
--> Yak-List message posted by: "Richard Basiliere" <BasiliereR@ci.boulder.co.us>
Does this mean that the tires should be retired ( pun intended) prior to
smoothness (lack of grooves) or that the tire could be used for some
length of time while smooth prior to cord showing?
Thanks, Rick
>>> joeh@shaw.ca 6/25/2004 9:21:45 AM >>>
--> Yak-List message posted by: Joe Howse <joeh@shaw.ca>
For info only on the difference between Chinese and Desser tire rubber
thickness.
Not meant to be an endorsement for either.
Core samples taken from center of tread area of two 500X150 tires, one
Chinese and one Desser with about 50 hours use, gravel and hard
surface.( both scrapped for puncture damage ) both on CJ6 aircraft.
Chinese tire - Total thickness remaining 7/16" including cord .
Desser tire - Total thickness remaining 5/16" including cord, but
only 3/16" remaining under tread groove.
In short, I do not believe that remaining tread grooves on the Chinese
or Russian tires are a good indicator of remaining life.
Joe
Message 5
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| Subject: | Re: Tire rubber comparison |
--> Yak-List message posted by: "Ernie" <ernest.martinez@oracle.com>
You didnt specify remaining thickness remaining under the tread groove of
the chinese tire.
Additionally if you look at the Russian tires used on the Mig15 a visibly
exposed cord was not an indication of a tire worn to its limits.
Ernie
----- Original Message -----
From: "Joe Howse" <joeh@shaw.ca>
Subject: Yak-List: Tire rubber comparison
> --> Yak-List message posted by: Joe Howse <joeh@shaw.ca>
>
> For info only on the difference between Chinese and Desser tire rubber
thickness.
> Not meant to be an endorsement for either.
>
> Core samples taken from center of tread area of two 500X150 tires, one
Chinese and one Desser with about 50 hours use, gravel and hard surface.(
both scrapped for puncture damage ) both on CJ6 aircraft.
>
> Chinese tire - Total thickness remaining 7/16" including cord .
> Desser tire - Total thickness remaining 5/16" including cord, but only
3/16" remaining under tread groove.
>
> In short, I do not believe that remaining tread grooves on the Chinese or
Russian tires are a good indicator of remaining life.
>
> Joe
>
>
Message 6
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| Subject: | Forward trim cable |
--> Yak-List message posted by: "jay reiter" <jmreiter@adelphia.net>
Craig Eckner and I replaced his forward elevator trim cable. I sent some info to
Tom Johnson. Tom has suggested I post a detailed description. If there is any
interest I will write one. Here are the hints I sent Tom:
Craig and I replaced the forward half of the elevator trim cable. I have a much
better idea of the routing of the cable and I will not be so confused the next
time I have one of the basket cases. I safety wired the cables together below
each spool so they could not unravel before I was ready. I also used a bungee
at the ADF mount to hold and separate the aft upper and lower cables. I knew
I would forget which was which.
Message 7
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--> Yak-List message posted by: "jay reiter" <jmreiter@adelphia.net>
I bet Desser has someone that knows the tire construction of these tires.
On commercial aircraft some tires have two tread ply's that are not an indication
of excessive wear. Some tires are serviceable to the second ply of the main
core. Wear to that point scrapes the carcass. At TWA we were paying for the tires
by the landing so they were removed at recap limits.
Message 8
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| Subject: | Re: Tire rubber comparison |
--> Yak-List message posted by: Joe Howse <joeh@shaw.ca>
Ernie
The tread grooves on the Chinese tire were long gone
before the sample was taken, 7/16 " of rubber left.
I did not want to sample an unused tire. ( can't afford it )
Joe----- Original Message -----
From: "Ernie" <ernest.martinez@oracle.com>
Subject: Re: Yak-List: Tire rubber comparison
> --> Yak-List message posted by: "Ernie" <ernest.martinez@oracle.com>
>
> You didnt specify remaining thickness remaining under the tread groove of
> the chinese tire.
>
> Additionally if you look at the Russian tires used on the Mig15 a visibly
> exposed cord was not an indication of a tire worn to its limits.
>
> Ernie
>
>
> ----- Original Message -----
> From: "Joe Howse" <joeh@shaw.ca>
> To: <yak-list@matronics.com>
> Subject: Yak-List: Tire rubber comparison
>
>
> > --> Yak-List message posted by: Joe Howse <joeh@shaw.ca>
> >
> > For info only on the difference between Chinese and Desser tire rubber
> thickness.
> > Not meant to be an endorsement for either.
> >
> > Core samples taken from center of tread area of two 500X150 tires, one
> Chinese and one Desser with about 50 hours use, gravel and hard surface.(
> both scrapped for puncture damage ) both on CJ6 aircraft.
> >
> > Chinese tire - Total thickness remaining 7/16" including cord .
> > Desser tire - Total thickness remaining 5/16" including cord, but only
> 3/16" remaining under tread groove.
> >
> > In short, I do not believe that remaining tread grooves on the Chinese
or
> Russian tires are a good indicator of remaining life.
> >
> > Joe
> >
> >
>
>
Message 9
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--> Yak-List message posted by: Joe Howse <joeh@shaw.ca>
My choice will be to have Desser recap the Chinese tires.
Joe
----- Original Message -----
From: "jay reiter" <jmreiter@adelphia.net>
Subject: Yak-List: Tires
> --> Yak-List message posted by: "jay reiter" <jmreiter@adelphia.net>
>
> I bet Desser has someone that knows the tire construction of these tires.
> On commercial aircraft some tires have two tread ply's that are not an
indication of excessive wear. Some tires are serviceable to the second ply
of the main core. Wear to that point scrapes the carcass. At TWA we were
paying for the tires by the landing so they were removed at recap limits.
>
>
Message 10
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| Subject: | Forward trim cable replacement. |
--> Yak-List message posted by: "jay reiter" <jmreiter@adelphia.net>
I would like to thank Doug Sapp for the correct cable supplied a good three feet
longer than finished length. Bill Blackwell for the help on how to start. Craig
Eckner as this was a cooperative project and his work and ideas were equal
to mine.
Explanation:
The forward trim cable is one continuous cable. The cable starts at the lower turn
buckle runs forward to the front trim handle. At the handle spool it is wound
approximately three and one half turns. The cable passes thru two holes in
the spool and it then winds approximately three and one half turns to complete
the winding. The cable continues aft to the rear trim handle and is wound the
same as the front. The cable continues aft to the upper turn buckle and ends.
Open up:
1) Remove front and rear seats
2) Remove left front and rear side wall covers
3) Unhinge left aft compartment door
4) Remove left stabilizer fairing
5) Remove ADF loop (or what ever is in that position)
6) Open ADF door and remove receiver if installed.
Preparation:
1) Neutralize the trim
2) Safety wire the cables together at elevator mounted spool with two safeties
to keep windings intact
3) Safety the cables below the forward and aft trim handles in the same manner
4) At the turn buckles in aft compartment using a bungee or convenient ties, tie
off the aft upper and lower cable eyelets preserving their orientation. I used
the ADF mount.
Replacement:
1) Disconnect trim cable at lower turn buckle only
2) Build up eye on new cable ( original cable eye used wrap and solder method)
3) Assemble lower turn buckle
4) Arrange cable in random loop to avoid kinks
5) Pass cable free end thru first pulley. Be careful you are in the pulley grove
and under the small cable guide.
6) Connect the cable free end to the old cable
7) Thread the cable forward toward the front trim handle.
8) The bullet for the trim center switch will snag at the pulley below the trim
handle
9) Cut the old cable save the bullet
10) Thread the free end of the cable thru the pulley. Be careful you are in the
pulley grove and under the small cable guide.
11) Continue up to the trim handle opening
12) Before you cut the safeties at the trim handle take careful note of the direction
and amount of the turns.
13) Cut safeties remove handle
14) Unwind handle try to get approximate length of the cable used in the first
set of windings.
15) Remove old cable from forward handle
16) Insert free end of new cable into the cable whole closest to the handle
17) Thread the free end of the cable out the handle side, shaft bushing
18) Thread the free end back thru the shaft bushing and thru the second cable whole
19) Slide the handle down the cable till the approximate cable length to wind the
appropriate number of turns is left
20) Wind the proper amount of turns with the wheel turning in the nose up direction
21) Remember the spool at the stabilizer is safetied the turn buckle is connected
22) Make a trial fit to see if the cable length is correct to this point
23) Wind the second set of turns
24) Secure the front handle with safety wire to hold tension in the nose up direction.
25) Safety the cables to hold the pretty turns in place
26) Continue toward the second handle using the free end or old cable what ever
is convenient
27) Wind the aft handle as the front, safety the cables at the aft handle
28) Use the old cable thread the cable to the aft compartment.
29) Thread the free end of the cable thru the last pulley Be careful you are in
the pulley grove and under the small cable guide.
Be careful this is where we got a twist, the cables should be parallel
30) Assemble the upper turn buckle and cable eye.
Rig and close up:
I will leave the rest. You are checked out. If the cables are too tight the trim
will not be smooth. If you forget to remove the safety wire the trim will be
jammed. Our elapsed time to hook up was about 4.5 to 5 hours. We finished close
up and other jobs the next day. The job is not impossible but is tedious and
sometimes painful.
Message 11
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--> Yak-List message posted by: "jay reiter" <jmreiter@adelphia.net>
Just had to fire my proof reader I used the wrong word for the cable holes in the
handle spool. Correct the spelling on your copies.
Message 12
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| Subject: | Worlds Most Powerfull Engine |
--> Yak-List message posted by: "Frank Haertlein" <yak52driver@earthlink.net>
http://www.bath.ac.uk/~ccsshb/12cyl/
Towards the opposite scale:
http://www.nvbackflow.com/engines/index.html
http://www.conleyprecision.com/backdrop.htm
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