Today's Message Index:
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1. 12:57 AM - Can anybody confirm this? (mark_trickel)
2. 08:46 AM - Re: Can anybody confirm this? (Owen Baker)
3. 09:30 AM - Re: Can anybody confirm this? (M Ketteing)
4. 03:30 PM - Re: Can anybody confirm this? (Owen Baker)
5. 06:33 PM - Re: Can anybody confirm this? (Tim Yoder)
Message 1
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| Subject: | Can anybody confirm this? |
http://www.kathrynsreport.com/2016/08/kis-tr-1-n660c-incident-occurred-august.html
OC?
MT
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=467622#467622
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| Subject: | Re: Can anybody confirm this? |
3/26/2017
Hello Mark, Yes. I can confirm this event. Here is the back story:
1) I was never happy with my first (#1) Lyle Hendricks round tube nose gear
strut. It was very sturdy, but it had two manufacturing / design defects in
my opinion.
a) The bottom vertical 3/4-16 threaded stud potion was too short. This meant
that a thin AN320-12 castle nut must be used instead of the normal
thickness AN310-12 castle nut. This further meant that the total nut-to-stud
thread interface holding the aluminum shoe and any washer stack up into
place was pretty limited. I was concerned that that interface could fail and
the entire shoe and nose wheel could fall off in flight.
b) The cotter pin hole through the bottom of that stud did not pass through
the center of the stud. This off set meant that the pin would not pass
through the normal castle notches in the AN320-12 nut. A person had to grind
/ file the nut notches wider in order for the cotter pin to pass through the
nut. This had two effects: ONE) The nut could not be rotated one notch at a
time to adjust the friction keeping the shoe from shimmying on landing roll
out unless each pair of notches was ground or filed wider. TWO) Grinding or
filing all pairs of notches wider further reduced the nut-to-stud thread
interface.
2) So my solution after over 500 flight hours with no problems other than
dealing with the two irritating issues described above was to have Lyle make
for me a new nose gear strut (#2) with modifications to eliminate the two
issues. I also had Lyle make some other design modifications to this #2
strut assembly such as a longer threaded portion at the top of the
compression rod and a welded cross bar at the bottom of the rod. The longer
threaded portion at the top of the rod gave more vertical adjustment
opportunity for the rod and the welded bar permitted one to hold the rod
from rotating when wrenching nuts at the top of the rod.
3) The #2 strut assembly was installed and I set off on its first test
flight. Unfortunately, not having any numerical figure available to measure
the shimmy prevention friction for the shoe, I used the TFAR (That Feels
About Right) criteria in tightening the AN310-12 nut holding the (new to me)
two Belleville washers up against the aluminum shoe. TFAR worked fine for a
few touch and go landings at an outlying field, but when I returned to my
home field (KHEF Manassas Virginia) for one final landing trouble showed up.
4) At a very slow speed on the final landing roll out the nose wheel began
to shimmy violently from side to side. This shimmy broke the two aluminum
nose wheel brackets at the bottom of the fire wall and allowed the strut
assembly to flop over sideways and the airplane nose to be lowered to the
runway surface. The damage consisted of grinding off a small portion of the
bottom of the #2 strut weldment, grinding off a bit of each wooden propeller
tip, and some scrapes off the bottom of the spinner, lower engine cowl, and
one of the main landing gear wheel pants. This event falls into the
categories of: "No good deed goes unpunished" or "If it ain't broke, don't
fix it". Take your choice.
5) The airplane was recovered to my hangar, Lyle graciously agreed to build
me strut assembly #3, Prince Aircraft repaired the propeller tips, I
replaced the spinner, repaired the engine cowling and the wheel pants, and
had them painted. I put everything back together once I had all pieces in
hand and used a 27 pound pull at the axle as my base figure for measuring
the friction for tightening the AN310-12 nut. I flew again for the first
time since the reported event on 10/18/2016. No nose wheel strut problems
since then. Thanks again go to Lyle.
Any questions?
OC
====================================
From: mark_trickel
Sent: Sunday, March 26, 2017 3:57 AM
Subject: KIS-List: Can anybody confirm this?
http://www.kathrynsreport.com/2016/08/kis-tr-1-n660c-incident-occurred-august.html
OC?
MT
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| Subject: | Re: Can anybody confirm this? |
Hello OC,
How much weight do you have on your nose gear? Have you moved you main gear forward?
As you may know the more weight on the nose the more energy to the shimmy.
With more energy the less effective the friction damping. The geometry
(pivot axis angle) could maybe use some tweaking to reduce shimmy.
Mark K.
--------------------------------------------
On Sun, 3/26/17, Owen Baker <bakerocb@cox.net> wrote:
Subject: Re: KIS-List: Can anybody confirm this?
To: kis-list@matronics.com, "TRICKEL MARK" <marktrickel@gmail.com>
Date: Sunday, March 26, 2017, 11:45 AM
"Owen Baker " <bakerocb@cox.net>
3/26/2017
Hello Mark, Yes. I can confirm this event. Here is the back
story:
1) I was never happy with my first (#1) Lyle Hendricks round
tube nose gear
strut. It was very sturdy, but it had two manufacturing /
design defects in
my opinion.
a) The bottom vertical 3/4-16 threaded stud potion was too
short. This meant
that a thin AN320-12 castle nut must be used instead
of the normal
thickness AN310-12 castle nut. This further meant that the
total nut-to-stud
thread interface holding the aluminum shoe and any washer
stack up into
place was pretty limited. I was concerned that that
interface could fail and
the entire shoe and nose wheel could fall off in flight.
b) The cotter pin hole through the bottom of that stud did
not pass through
the center of the stud. This off set meant that the pin
would not pass
through the normal castle notches in the AN320-12 nut. A
person had to grind
/ file the nut notches wider in order for the cotter pin to
pass through the
nut. This had two effects: ONE) The nut could not be rotated
one notch at a
time to adjust the friction keeping the shoe from shimmying
on landing roll
out unless each pair of notches was ground or filed wider.
TWO) Grinding or
filing all pairs of notches wider further reduced the
nut-to-stud thread
interface.
2) So my solution after over 500 flight hours with no
problems other than
dealing with the two irritating issues described above was
to have Lyle make
for me a new nose gear strut (#2) with modifications to
eliminate the two
issues. I also had Lyle make some other design modifications
to this #2
strut assembly such as a longer threaded portion at the top
of the
compression rod and a welded cross bar at the bottom of the
rod. The longer
threaded portion at the top of the rod gave more vertical
adjustment
opportunity for the rod and the welded bar permitted one to
hold the rod
from rotating when wrenching nuts at the top of the rod.
3) The #2 strut assembly was installed and I set off on its
first test
flight. Unfortunately, not having any numerical figure
available to measure
the shimmy prevention friction for the shoe, I used the TFAR
(That Feels
About Right) criteria in tightening the AN310-12 nut holding
the (new to me)
two Belleville washers up against the aluminum shoe. TFAR
worked fine for a
few touch and go landings at an outlying field, but when I
returned to my
home field (KHEF Manassas Virginia) for one final landing
trouble showed up.
4) At a very slow speed on the final landing roll out the
nose wheel began
to shimmy violently from side to side. This shimmy broke the
two aluminum
nose wheel brackets at the bottom of the fire wall and
allowed the strut
assembly to flop over sideways and the airplane nose to be
lowered to the
runway surface. The damage consisted of grinding off a small
portion of the
bottom of the #2 strut weldment, grinding off a bit of each
wooden propeller
tip, and some scrapes off the bottom of the spinner, lower
engine cowl, and
one of the main landing gear wheel pants. This event falls
into the
categories of: "No good deed goes unpunished" or "If it
ain't broke, don't
fix it". Take your choice.
5) The airplane was recovered to my hangar, Lyle graciously
agreed to build
me strut assembly #3, Prince Aircraft repaired the propeller
tips, I
replaced the spinner, repaired the engine cowling and the
wheel pants, and
had them painted. I put everything back together once I had
all pieces in
hand and used a 27 pound pull at the axle as my base figure
for measuring
the friction for tightening the AN310-12 nut. I flew again
for the first
time since the reported event on 10/18/2016. No nose wheel
strut problems
since then. Thanks again go to Lyle.
Any questions?
OC
====================================
From: mark_trickel
Sent: Sunday, March 26, 2017 3:57 AM
To: kis-list@matronics.com
Subject: KIS-List: Can anybody confirm this?
http://www.kathrynsreport.com/2016/08/kis-tr-1-n660c-incident-occurred-august.html
OC?
MT
Forum -
- MATRONICS WEB FORUMS -
MATRONICS LIST WIKI -
List Contribution Web Site -
-Matt
Dralle, List Admin.
Message 4
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| Subject: | Re: Can anybody confirm this? |
3/26/2017
Hello Mark K, Thanks for your input. You wrote:
1) "Have you moved you main gear forward?"
Yes, I wedged it forward with flox. The main landing gear axles are 72.25
inches aft of the 0.00 datum point.
That datum point is, in turn, 32.00 inches forward of the engine cowling
joggle on the fuselage.
2) "How much weight do you have on your nose gear?"
Right now, in operational configuration and without reweighing, I don't
know.
The original empty aircraft weighing showed 242 pounds on the nose gear.
Since then there have been a few misc items (quart of oil, jar for fuel
testing, rags, etc.)
that are normally kept in the right baggage well.
Also there are some other misc items (hand held radio, small tool bag, water
bottle, roll of tape, etc.) that have taken up permanent lodging on the hat
shelf aft of the seats.
Not too long ago I double bagged sand into two kitchen sliding lock plastic
gallon bags (they totaled 23 pounds) and placed them over the battery box in
the far right rear corner of the right baggage well (I mostly fly solo in
the left seat) because I was unhappy that the nose gear was descending to
meet the runway too quickly after the main gear touched down. I am not sure
if that has helped, or if so how much.
3) "The geometry (pivot axis angle) could maybe use some tweaking to reduce
shimmy."
Can you please elaborate on the contribution of the pivot angle axis on
shimmy and how one would go about tweaking that angle in a KIS TR-1? Thanks.
Also a reminder that my shimmy problem with strut #2 was my fault for not
tightening the friction nut enough and I have had no shimmy problems since
installing strut #3 and using 27 pounds as a base figure for setting the
friction nut.
Also in my listing of the design / manufacturing defects in the #1 strut in
paragraph 1 below I forget to mention that the off center cotter pin hole
was also so close to the end of the vertical stub that I was concerned about
the possibility of break out.
OC
PS: I have your last name spelled Kettering in some old places in my
computer. Has there been a change?
=======================================
From: M Ketteing
Sent: Sunday, March 26, 2017 12:30 PM
Subject: Re: KIS-List: Can anybody confirm this?
Hello OC,
How much weight do you have on your nose gear? Have you moved you main gear
forward? As you may know the more weight on the nose the more energy to the
shimmy. With more energy the less effective the friction damping. The
geometry (pivot axis angle) could maybe use some tweaking to reduce shimmy.
Mark K.
--------------------------------------------
On Sun, 3/26/17, Owen Baker <bakerocb@cox.net> wrote:
Subject: Re: KIS-List: Can anybody confirm this?
"Owen Baker " <bakerocb@cox.net>
3/26/2017
Hello Mark, Yes. I can confirm this event. Here is the back
story:
1) I was never happy with my first (#1) Lyle Hendricks round
tube nose gear
strut. It was very sturdy, but it had two manufacturing /
design defects in
my opinion.
a) The bottom vertical 3/4-16 threaded stud potion was too
short. This meant
that a thin AN320-12 castle nut must be used instead
of the normal
thickness AN310-12 castle nut. This further meant that the
total nut-to-stud
thread interface holding the aluminum shoe and any washer
stack up into
place was pretty limited. I was concerned that that
interface could fail and
the entire shoe and nose wheel could fall off in flight.
b) The cotter pin hole through the bottom of that stud did
not pass through
the center of the stud. This off set meant that the pin
would not pass
through the normal castle notches in the AN320-12 nut. A
person had to grind
/ file the nut notches wider in order for the cotter pin to
pass through the
nut. This had two effects: ONE) The nut could not be rotated
one notch at a
time to adjust the friction keeping the shoe from shimmying
on landing roll
out unless each pair of notches was ground or filed wider.
TWO) Grinding or
filing all pairs of notches wider further reduced the
nut-to-stud thread
interface.
2) So my solution after over 500 flight hours with no
problems other than
dealing with the two irritating issues described above was
to have Lyle make
for me a new nose gear strut (#2) with modifications to
eliminate the two
issues. I also had Lyle make some other design modifications
to this #2
strut assembly such as a longer threaded portion at the top
of the
compression rod and a welded cross bar at the bottom of the
rod. The longer
threaded portion at the top of the rod gave more vertical
adjustment
opportunity for the rod and the welded bar permitted one to
hold the rod
from rotating when wrenching nuts at the top of the rod.
3) The #2 strut assembly was installed and I set off on its
first test
flight. Unfortunately, not having any numerical figure
available to measure
the shimmy prevention friction for the shoe, I used the TFAR
(That Feels
About Right) criteria in tightening the AN310-12 nut holding
the (new to me)
two Belleville washers up against the aluminum shoe. TFAR
worked fine for a
few touch and go landings at an outlying field, but when I
returned to my
home field (KHEF Manassas Virginia) for one final landing
trouble showed up.
4) At a very slow speed on the final landing roll out the
nose wheel began
to shimmy violently from side to side. This shimmy broke the
two aluminum
nose wheel brackets at the bottom of the fire wall and
allowed the strut
assembly to flop over sideways and the airplane nose to be
lowered to the
runway surface. The damage consisted of grinding off a small
portion of the
bottom of the #2 strut weldment, grinding off a bit of each
wooden propeller
tip, and some scrapes off the bottom of the spinner, lower
engine cowl, and
one of the main landing gear wheel pants. This event falls
into the
categories of: "No good deed goes unpunished" or "If it
ain't broke, don't
fix it". Take your choice.
5) The airplane was recovered to my hangar, Lyle graciously
agreed to build
me strut assembly #3, Prince Aircraft repaired the propeller
tips, I
replaced the spinner, repaired the engine cowling and the
wheel pants, and
had them painted. I put everything back together once I had
all pieces in
hand and used a 27 pound pull at the axle as my base figure
for measuring
the friction for tightening the AN310-12 nut. I flew again
for the first
time since the reported event on 10/18/2016. No nose wheel
strut problems
since then. Thanks again go to Lyle.
Any questions?
OC
====================================
From: mark_trickel
Sent: Sunday, March 26, 2017 3:57 AM
Subject: KIS-List: Can anybody confirm this?
http://www.kathrynsreport.com/2016/08/kis-tr-1-n660c-incident-occurred-august.html
OC?
MT
Message 5
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| Subject: | Can anybody confirm this? |
OC,
My main gear on N52TY are 74.25" aft of the 0.00 datum point and the nose
gear weighs 245#. I added 1 1/2" to my elevator cord which helps hold the
nose gear off at touch down.
Tim
-----Original Message-----
From: owner-kis-list-server@matronics.com
[mailto:owner-kis-list-server@matronics.com] On Behalf Of Owen Baker
Sent: Sunday, March 26, 2017 3:30 PM
Subject: Re: KIS-List: Can anybody confirm this?
3/26/2017
Hello Mark K, Thanks for your input. You wrote:
1) "Have you moved you main gear forward?"
Yes, I wedged it forward with flox. The main landing gear axles are 72.25
inches aft of the 0.00 datum point.
That datum point is, in turn, 32.00 inches forward of the engine cowling
joggle on the fuselage.
2) "How much weight do you have on your nose gear?"
Right now, in operational configuration and without reweighing, I don't
know.
The original empty aircraft weighing showed 242 pounds on the nose gear.
Since then there have been a few misc items (quart of oil, jar for fuel
testing, rags, etc.) that are normally kept in the right baggage well.
Also there are some other misc items (hand held radio, small tool bag, water
bottle, roll of tape, etc.) that have taken up permanent lodging on the hat
shelf aft of the seats.
Not too long ago I double bagged sand into two kitchen sliding lock plastic
gallon bags (they totaled 23 pounds) and placed them over the battery box in
the far right rear corner of the right baggage well (I mostly fly solo in
the left seat) because I was unhappy that the nose gear was descending to
meet the runway too quickly after the main gear touched down. I am not sure
if that has helped, or if so how much.
3) "The geometry (pivot axis angle) could maybe use some tweaking to reduce
shimmy."
Can you please elaborate on the contribution of the pivot angle axis on
shimmy and how one would go about tweaking that angle in a KIS TR-1? Thanks.
Also a reminder that my shimmy problem with strut #2 was my fault for not
tightening the friction nut enough and I have had no shimmy problems since
installing strut #3 and using 27 pounds as a base figure for setting the
friction nut.
Also in my listing of the design / manufacturing defects in the #1 strut in
paragraph 1 below I forget to mention that the off center cotter pin hole
was also so close to the end of the vertical stub that I was concerned about
the possibility of break out.
OC
PS: I have your last name spelled Kettering in some old places in my
computer. Has there been a change?
=======================================
From: M Ketteing
Sent: Sunday, March 26, 2017 12:30 PM
Subject: Re: KIS-List: Can anybody confirm this?
Hello OC,
How much weight do you have on your nose gear? Have you moved you main gear
forward? As you may know the more weight on the nose the more energy to the
shimmy. With more energy the less effective the friction damping. The
geometry (pivot axis angle) could maybe use some tweaking to reduce shimmy.
Mark K.
--------------------------------------------
On Sun, 3/26/17, Owen Baker <bakerocb@cox.net> wrote:
Subject: Re: KIS-List: Can anybody confirm this?
"Owen Baker " <bakerocb@cox.net>
3/26/2017
Hello Mark, Yes. I can confirm this event. Here is the back
story:
1) I was never happy with my first (#1) Lyle Hendricks round
tube nose gear
strut. It was very sturdy, but it had two manufacturing /
design defects in
my opinion.
a) The bottom vertical 3/4-16 threaded stud potion was too
short. This meant
that a thin AN320-12 castle nut must be used instead
of the normal
thickness AN310-12 castle nut. This further meant that the
total nut-to-stud
thread interface holding the aluminum shoe and any washer
stack up into
place was pretty limited. I was concerned that that
interface could fail and
the entire shoe and nose wheel could fall off in flight.
b) The cotter pin hole through the bottom of that stud did
not pass through
the center of the stud. This off set meant that the pin
would not pass
through the normal castle notches in the AN320-12 nut. A
person had to grind
/ file the nut notches wider in order for the cotter pin to
pass through the
nut. This had two effects: ONE) The nut could not be rotated
one notch at a
time to adjust the friction keeping the shoe from shimmying
on landing roll
out unless each pair of notches was ground or filed wider.
TWO) Grinding or
filing all pairs of notches wider further reduced the
nut-to-stud thread
interface.
2) So my solution after over 500 flight hours with no
problems other than
dealing with the two irritating issues described above was
to have Lyle make
for me a new nose gear strut (#2) with modifications to
eliminate the two
issues. I also had Lyle make some other design modifications
to this #2
strut assembly such as a longer threaded portion at the top
of the
compression rod and a welded cross bar at the bottom of the
rod. The longer
threaded portion at the top of the rod gave more vertical
adjustment
opportunity for the rod and the welded bar permitted one to
hold the rod
from rotating when wrenching nuts at the top of the rod.
3) The #2 strut assembly was installed and I set off on its
first test
flight. Unfortunately, not having any numerical figure
available to measure
the shimmy prevention friction for the shoe, I used the TFAR
(That Feels
About Right) criteria in tightening the AN310-12 nut holding
the (new to me)
two Belleville washers up against the aluminum shoe. TFAR
worked fine for a
few touch and go landings at an outlying field, but when I
returned to my
home field (KHEF Manassas Virginia) for one final landing
trouble showed up.
4) At a very slow speed on the final landing roll out the
nose wheel began
to shimmy violently from side to side. This shimmy broke the
two aluminum
nose wheel brackets at the bottom of the fire wall and
allowed the strut
assembly to flop over sideways and the airplane nose to be
lowered to the
runway surface. The damage consisted of grinding off a small
portion of the
bottom of the #2 strut weldment, grinding off a bit of each
wooden propeller
tip, and some scrapes off the bottom of the spinner, lower
engine cowl, and
one of the main landing gear wheel pants. This event falls
into the
categories of: "No good deed goes unpunished" or "If it
ain't broke, don't
fix it". Take your choice.
5) The airplane was recovered to my hangar, Lyle graciously
agreed to build
me strut assembly #3, Prince Aircraft repaired the propeller
tips, I
replaced the spinner, repaired the engine cowling and the
wheel pants, and
had them painted. I put everything back together once I had
all pieces in
hand and used a 27 pound pull at the axle as my base figure
for measuring
the friction for tightening the AN310-12 nut. I flew again
for the first
time since the reported event on 10/18/2016. No nose wheel
strut problems
since then. Thanks again go to Lyle.
Any questions?
OC
====================================
From: mark_trickel
Sent: Sunday, March 26, 2017 3:57 AM
Subject: KIS-List: Can anybody confirm this?
http://www.kathrynsreport.com/2016/08/kis-tr-1-n660c-incident-occurred-augus
t.html
OC?
MT
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