Today's Message Index:
----------------------
1. 04:54 AM - Re: Re: Control Stick Slop - Bushings ()
2. 05:11 AM - Re: Re: Control Stick Slop - Bushings (Rob Kermanj)
3. 07:14 AM - Re: Re: Control Stick Slop - Bushings (Carl Froehlich)
4. 07:46 AM - Re: Re: Control Stick Slop - Bushings (Phillip Perry)
5. 07:50 AM - Re: Re: Control Stick Slop - Bushings (Phillip Perry)
6. 08:20 AM - Re: Re: Control Stick Slop - Bushings (Tim Olson)
7. 08:28 AM - Re: Re: Control Stick Slop - Bushings (Carl Froehlich)
8. 08:36 AM - Re: Re: Control Stick Slop - Bushings (Phillip Perry)
9. 08:47 AM - Re: Re: Control Stick Slop - Bushings (Tim Olson)
10. 08:54 AM - Re: Re: Control Stick Slop - Bushings (Phillip Perry)
11. 09:25 AM - Re: Re: Control Stick Slop - Bushings (Carl Froehlich)
12. 09:45 AM - Re: Re: Control Stick Slop - Bushings (Tim Olson)
13. 09:50 AM - Re: Re: Control Stick Slop - Bushings (Phillip Perry)
14. 11:14 AM - Re: Re: Control Stick Slop - Bushings (Carl Froehlich)
15. 12:08 PM - Re: Control Stick Slop - Bushings (Strasnuts)
16. 06:44 PM - Re: Re: Control Stick Slop - Bushings (Kelly McMullen)
17. 08:55 PM - P Mags (Albert)
Message 1
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| Subject: | Re: Control Stick Slop - Bushings |
Well done, Phil! Don=99t ya just love it when you find the
correct diagnosis, come up with a solution (with a little help from your
friends), and it works. On to the next challenge! I enjoy these
threads that lead to happy endings.
Later, =93 Lew
do not archive
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| Subject: | Re: Control Stick Slop - Bushings |
+1.
Rob Kermanj
> On Feb 25, 2016, at 7:53 AM, lewgall@charter.net wrote:
>
> Well done, Phil! Don=99t ya just love it when you find the
correct diagnosis, come up with a solution (with a little help from your
friends), and it works. On to the next challenge! I enjoy these
threads that lead to happy endings.
>
> Later, =93 Lew
>
> do not archive
>
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| Subject: | Re: Control Stick Slop - Bushings |
=9DI tuned this part of the system like you would a wheel bearing.
I rotated the sticks left and right while tightening the nut one flat
at a time. Once I began to feel tension on the sticks, I stopped and
backed off one flat where I then dropped in the cotter key in to lock it
into position.=9D
Perhaps I=99m reading this wrong. I thought the objective was for
the bolt to capture the bushing so that there is no relative motion
between the bolt and the bushing. All relative motion should be between
the outside of the bushing and the weldment (in this case the Control
Stick Base Pivot Tube).
I also believe adding a light grease for the bushing to weldment
provides for reduced corrosion between the dissimilar metals =93
obviously not an issue when using delrin but perhaps would help keep
dirt out of the bearing surface.
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 12:53 AM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
I thought I'd follow up on the control stick slop issue that I had in my
system since I promised a post-bushing report. I had some major play in
my control sticks and ended up following Sean's advice and replaced the
brass bushings with delrin. I attached a couple of photos of the plans
to help with the explanation.
After discovering the slop, I ordered delrin rods from Aircraft Spruce.
I ordered 3/8" hoping they'd be a drop-in replacement for a tight fit
without any machining and 7/16" in case I had to machine them down to
something closer to proper size for a good fit in the control stick
base. Each stick was about $3 for a 3 ft stick, so there was no harm in
ordering both.
I pulled the sticks, stick bases, and control column out of the plane
and put it on the bench. On disassembly, I found that there was play
between the brass bushing and the welded part of the stick bases. I
tried the 3/8" rod to see how well it fit and it dropped straight
through unrestricted. The inside of the welded stick bases were way
more than the spec'd 3/8". That was one part of the problem. The other
part of the problem was the slop on the inside of the bushing between
the bushing and the 1/4" bolt. That slop was worse than the welded
part. Additionally I found one more location for slop and that was the
ability to slide the stick forward and aft on the 1/4" bolt between the
stick bases and the control column that the stick bases mount to.
The first order of business was to get new bushings machined out.
Since the stick bases were more than 3/8" I used the 7/16" delrin rod
and turned it down on a lathe that another guy on the airport had. It
was turned down until it was a thumb-press fit into the stick bases.
The next step was to drill and ream the hole for the 1/4" bolt down the
center. I initially tried to ream it to 15/64 (1/64" undersized for
the 1/4" bolt) to get a snug fit in the event that the bolt was on the
skinny side of the tolerance. That didn't work out and I ultimately had
to open it to a full 1/4" to get the bolt to slide through.
Back to the work bench where I installed the new bushings. The fit was
free of any play between that bases and the bushing and between the
bushing and the bolt.
The final task was to eliminate the sliding motion of the sticks forward
and aft on the 1/4" bolt between the stick bases and the control column.
This was a pretty simple task of inserting AN960-416 and 416L washers
to shim as much of the gaps away as possible. Obviously you can't get
all of the gap out, so you have to take care of the last little bit by
tightening the nut and pulling the control column in tighter on the
stick bases.
I tuned this part of the system like you would a wheel bearing. I
rotated the sticks left and right while tightening the nut one flat at a
time. Once I began to feel tension on the sticks, I stopped and backed
off one flat where I then dropped in the cotter key in to lock it into
position.
The system linkages are tight (meaning no play) and very smooth (minus
the drag of the TruTrak servos). You can work the left and right sticks
in opposition directions, like driving a bull dozer, and you won't find
any play. You can go all the way out to the control surface and hold
it tight while wiggling the stick and not find any play between the
control surface and stick. I'm very happy with the outcome.
This wasn't a terrible change to make and if you have the seats out and
access to a lathe, you could probably do it in less than a day. You
certainly could do it on a drill press with some forethought. creative
jigs, patience, and a few sacrificed pieces of delrin while you traverse
the learning curve, but the lathe is certainly the fastest and easiest.
I'd do it again... Glad it turned out the way it did.
Phil
Inline image 1
Inline image 2
On Sat, Feb 13, 2016 at 8:08 PM, Phillip Perry <philperry9@gmail.com>
wrote:
I have some delrin coming and I'm planning on making them for my
sloppiness.
I'm planning on reaming the bell crank to 3/8 and then seeing how well a
3/8 delrin rod fits. If it's still too loose, I have a 7/16 rod coming
in the mail too. I'll be able turn it down to fit or possibly it would
fit without any working (though I doubt it).
Once I find the rod that fits best, then I'll ream the center on a
friends lathe. I have a 3/16" reamer that will work, but I plan on using
another reamer that's 11/64 (1/64 under sized) to see how it fits first.
Then if it's too tight I'll open it up to the full 3/16 with the other
reamer.
I'll probably have a report on how well it works in the next 2 weeks or
possibly late next week.
Phil
Sent from my iPhone
> On Feb 13, 2016, at 5:29 PM, rvdave <rv610dave@gmail.com> wrote:
>
>
> I thought about that and wondered about the possibility of sanding
them down a little bit if oversized since the delrin does compress a
little.
>
> --------
> Dave Ford
> RV6 for sale
> RV10 building
> Cadillac, MI
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=452802#452802
>
>
============
h --
EE Gifts!)
on
r> ed
://www.buildersbooks.com" rel="noreferrer"
target="_blank">www.buildersbooks.com
ion" rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
============
br> ?RV10-List" rel="noreferrer"
target="_blank">http://www.matronics.com/Navigator?RV10-List
============
S WEB FORUMS -
="noreferrer" target="_blank">http://forums.matronics.com
============
on Web Site -
-Matt Dralle, List Admin.
ion" rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
============
>
>
Message 4
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| Subject: | Re: Control Stick Slop - Bushings |
You want the pivot point on the bolt and not the steel welded part. That we
lded part isn't perfectly round (oblong) from the heat and it's also rough, a
brasive, and susceptible to rust - contributing for abrasion and wear.
If you keep the motion on the bolt, you have a perfectly round and smooth pi
vot point. The nut is pinned so there's no chance of running the nut off.
Phil
Sent from my iPhone
> On Feb 25, 2016, at 9:10 AM, Carl Froehlich <carl.froehlich@verizon.net> w
rote:
>
> =9DI tuned this part of the system like you would a wheel bearing. I
rotated the sticks left and right while tightening the nut one flat at a ti
me. Once I began to feel tension on the sticks, I stopped and backed off on
e flat where I then dropped in the cotter key in to lock it into position.
=9D
>
> Perhaps I=99m reading this wrong. I thought the objective was for t
he bolt to capture the bushing so that there is no relative motion between t
he bolt and the bushing. All relative motion should be between the outside o
f the bushing and the weldment (in this case the Control Stick Base Pivot Tu
be).
>
> I also believe adding a light grease for the bushing to weldment provides f
or reduced corrosion between the dissimilar metals =93 obviously not a
n issue when using delrin but perhaps would help keep dirt out of the bearin
g surface.
>
> Carl
>
>
> From: owner-rv10-list-server@matronics.com [mailto:owner-rv10-list-server@
matronics.com] On Behalf Of Phillip Perry
> Sent: Thursday, February 25, 2016 12:53 AM
> To: rv10-list@matronics.com
> Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
>
> I thought I'd follow up on the control stick slop issue that I had in my s
ystem since I promised a post-bushing report. I had some major play in my c
ontrol sticks and ended up following Sean's advice and replaced the brass bu
shings with delrin. I attached a couple of photos of the plans to help wit
h the explanation.
>
> After discovering the slop, I ordered delrin rods from Aircraft Spruce. I
ordered 3/8" hoping they'd be a drop-in replacement for a tight fit without
any machining and 7/16" in case I had to machine them down to something clo
ser to proper size for a good fit in the control stick base. Each stick was
about $3 for a 3 ft stick, so there was no harm in ordering both.
>
> I pulled the sticks, stick bases, and control column out of the plane and p
ut it on the bench. On disassembly, I found that there was play between the
brass bushing and the welded part of the stick bases. I tried the 3/8" ro
d to see how well it fit and it dropped straight through unrestricted. The i
nside of the welded stick bases were way more than the spec'd 3/8". That wa
s one part of the problem. The other part of the problem was the slop on th
e inside of the bushing between the bushing and the 1/4" bolt. That slop wa
s worse than the welded part. Additionally I found one more location for sl
op and that was the ability to slide the stick forward and aft on the 1/4" b
olt between the stick bases and the control column that the stick bases moun
t to.
>
> The first order of business was to get new bushings machined out. Since t
he stick bases were more than 3/8" I used the 7/16" delrin rod and turned it
down on a lathe that another guy on the airport had. It was turned down u
ntil it was a thumb-press fit into the stick bases.
>
> The next step was to drill and ream the hole for the 1/4" bolt down the ce
nter. I initially tried to ream it to 15/64 (1/64" undersized for the 1/4"
bolt) to get a snug fit in the event that the bolt was on the skinny side o
f the tolerance. That didn't work out and I ultimately had to open it to a f
ull 1/4" to get the bolt to slide through.
>
> Back to the work bench where I installed the new bushings. The fit was fr
ee of any play between that bases and the bushing and between the bushing an
d the bolt.
>
> The final task was to eliminate the sliding motion of the sticks forward a
nd aft on the 1/4" bolt between the stick bases and the control column. Th
is was a pretty simple task of inserting AN960-416 and 416L washers to shim a
s much of the gaps away as possible. Obviously you can't get all of the ga
p out, so you have to take care of the last little bit by tightening the nut
and pulling the control column in tighter on the stick bases.
>
> I tuned this part of the system like you would a wheel bearing. I rotated
the sticks left and right while tightening the nut one flat at a time. Onc
e I began to feel tension on the sticks, I stopped and backed off one flat w
here I then dropped in the cotter key in to lock it into position.
>
> The system linkages are tight (meaning no play) and very smooth (minus the
drag of the TruTrak servos). You can work the left and right sticks in opp
osition directions, like driving a bull dozer, and you won't find any play.
You can go all the way out to the control surface and hold it tight while w
iggling the stick and not find any play between the control surface and stic
k. I'm very happy with the outcome.
>
> This wasn't a terrible change to make and if you have the seats out and ac
cess to a lathe, you could probably do it in less than a day. You certainl
y could do it on a drill press with some forethought. creative jigs, patienc
e, and a few sacrificed pieces of delrin while you traverse the learning cur
ve, but the lathe is certainly the fastest and easiest.
>
> I'd do it again... Glad it turned out the way it did.
>
> Phil
>
>
> <image001.png>
>
> <image002.png>
>
>
>
>
>
> On Sat, Feb 13, 2016 at 8:08 PM, Phillip Perry <philperry9@gmail.com> wrot
e:
> I have some delrin coming and I'm planning on making them for my sloppines
s.
>
> I'm planning on reaming the bell crank to 3/8 and then seeing how well a 3
/8 delrin rod fits. If it's still too loose, I have a 7/16 rod coming in t
he mail too. I'll be able turn it down to fit or possibly it would fit with
out any working (though I doubt it).
>
> Once I find the rod that fits best, then I'll ream the center on a friends
lathe. I have a 3/16" reamer that will work, but I plan on using another re
amer that's 11/64 (1/64 under sized) to see how it fits first. Then if it'
s too tight I'll open it up to the full 3/16 with the other reamer.
>
> I'll probably have a report on how well it works in the next 2 weeks or po
ssibly late next week.
>
> Phil
>
> Sent from my iPhone
>
> > On Feb 13, 2016, at 5:29 PM, rvdave <rv610dave@gmail.com> wrote:
> >
> >
> > I thought about that and wondered about the possibility of sanding them d
own a little bit if oversized since the delrin does compress a little.
> >
> > --------
> > Dave Ford
> > RV6 for sale
> > RV10 building
> > Cadillac, MI
> >
> >
> >
> >
> > Read this topic online here:
> >
> > http://forums.matronics.com/viewtopic.php?p=452802#452802
> >
> >
> >
> >
> >
> >
> >
> ============
> h --
> EE Gifts!)
> on
> r> ed
> ://www.buildersbooks.com" rel="noreferrer" target="_blank">www.builder
sbooks.com
> ion" rel="noreferrer" target="_blank">http://www.matronics.com/contrib
ution
> -Matt Dralle, List Admin.
> ============
> br> ?RV10-List" rel="noreferrer" target="_blank">http://www.matronics.
com/Navigator?RV10-List
> ============
> S WEB FORUMS -
> ="noreferrer" target="_blank">http://forums.matronics.com
> ============
> on Web Site -
> -Matt Dralle, List Admin.
> ion" rel="noreferrer" target="_blank">http://www.matronics.com/contrib
ution
> ============
> >
> >
> >
>
Message 5
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| Subject: | Re: Control Stick Slop - Bushings |
Also, by putting the motion on the bolt, any future replacement of parts fro
m wear would involve a new bushing and potentially new bolt. Cheap and easy t
o replace.
Putting be motion on the welded piece would lead to a new bushing and potent
ially new weldment. Expensive and more complex to repair.
Phil
Sent from my iPhone
> On Feb 25, 2016, at 9:45 AM, Phillip Perry <philperry9@gmail.com> wrote:
>
> You want the pivot point on the bolt and not the steel welded part. That w
elded part isn't perfectly round (oblong) from the heat and it's also rough,
abrasive, and susceptible to rust - contributing for abrasion and wear.
>
> If you keep the motion on the bolt, you have a perfectly round and smooth p
ivot point. The nut is pinned so there's no chance of running the nut off.
>
> Phil
>
> Sent from my iPhone
>
>> On Feb 25, 2016, at 9:10 AM, Carl Froehlich <carl.froehlich@verizon.net> w
rote:
>>
>> =9DI tuned this part of the system like you would a wheel bearing.
I rotated the sticks left and right while tightening the nut one flat at a t
ime. Once I began to feel tension on the sticks, I stopped and backed off o
ne flat where I then dropped in the cotter key in to lock it into position.
=9D
>>
>> Perhaps I=99m reading this wrong. I thought the objective was for t
he bolt to capture the bushing so that there is no relative motion between t
he bolt and the bushing. All relative motion should be between the outside o
f the bushing and the weldment (in this case the Control Stick Base Pivot Tu
be).
>>
>> I also believe adding a light grease for the bushing to weldment provides
for reduced corrosion between the dissimilar metals =93 obviously not
an issue when using delrin but perhaps would help keep dirt out of the bear
ing surface.
>>
>> Carl
>>
>>
>> From: owner-rv10-list-server@matronics.com [mailto:owner-rv10-list-server
@matronics.com] On Behalf Of Phillip Perry
>> Sent: Thursday, February 25, 2016 12:53 AM
>> To: rv10-list@matronics.com
>> Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
>>
>> I thought I'd follow up on the control stick slop issue that I had in my s
ystem since I promised a post-bushing report. I had some major play in my c
ontrol sticks and ended up following Sean's advice and replaced the brass bu
shings with delrin. I attached a couple of photos of the plans to help wit
h the explanation.
>>
>> After discovering the slop, I ordered delrin rods from Aircraft Spruce. I
ordered 3/8" hoping they'd be a drop-in replacement for a tight fit without
any machining and 7/16" in case I had to machine them down to something clo
ser to proper size for a good fit in the control stick base. Each stick was
about $3 for a 3 ft stick, so there was no harm in ordering both.
>>
>> I pulled the sticks, stick bases, and control column out of the plane and
put it on the bench. On disassembly, I found that there was play between t
he brass bushing and the welded part of the stick bases. I tried the 3/8" r
od to see how well it fit and it dropped straight through unrestricted. The
inside of the welded stick bases were way more than the spec'd 3/8". That w
as one part of the problem. The other part of the problem was the slop on t
he inside of the bushing between the bushing and the 1/4" bolt. That slop w
as worse than the welded part. Additionally I found one more location for s
lop and that was the ability to slide the stick forward and aft on the 1/4" b
olt between the stick bases and the control column that the stick bases moun
t to.
>>
>> The first order of business was to get new bushings machined out. Since
the stick bases were more than 3/8" I used the 7/16" delrin rod and turned i
t down on a lathe that another guy on the airport had. It was turned down u
ntil it was a thumb-press fit into the stick bases.
>>
>> The next step was to drill and ream the hole for the 1/4" bolt down the c
enter. I initially tried to ream it to 15/64 (1/64" undersized for the 1/4
" bolt) to get a snug fit in the event that the bolt was on the skinny side o
f the tolerance. That didn't work out and I ultimately had to open it to a f
ull 1/4" to get the bolt to slide through.
>>
>> Back to the work bench where I installed the new bushings. The fit was f
ree of any play between that bases and the bushing and between the bushing a
nd the bolt.
>>
>> The final task was to eliminate the sliding motion of the sticks forward a
nd aft on the 1/4" bolt between the stick bases and the control column. Th
is was a pretty simple task of inserting AN960-416 and 416L washers to shim a
s much of the gaps away as possible. Obviously you can't get all of the ga
p out, so you have to take care of the last little bit by tightening the nut
and pulling the control column in tighter on the stick bases.
>>
>> I tuned this part of the system like you would a wheel bearing. I rotate
d the sticks left and right while tightening the nut one flat at a time. On
ce I began to feel tension on the sticks, I stopped and backed off one flat w
here I then dropped in the cotter key in to lock it into position.
>>
>> The system linkages are tight (meaning no play) and very smooth (minus th
e drag of the TruTrak servos). You can work the left and right sticks in op
position directions, like driving a bull dozer, and you won't find any play.
You can go all the way out to the control surface and hold it tight while
wiggling the stick and not find any play between the control surface and st
ick. I'm very happy with the outcome.
>>
>> This wasn't a terrible change to make and if you have the seats out and a
ccess to a lathe, you could probably do it in less than a day. You certain
ly could do it on a drill press with some forethought. creative jigs, patien
ce, and a few sacrificed pieces of delrin while you traverse the learning cu
rve, but the lathe is certainly the fastest and easiest.
>>
>> I'd do it again... Glad it turned out the way it did.
>>
>> Phil
>>
>>
>> <image001.png>
>>
>> <image002.png>
>>
>>
>>
>>
>>
>> On Sat, Feb 13, 2016 at 8:08 PM, Phillip Perry <philperry9@gmail.com> wro
te:
>> I have some delrin coming and I'm planning on making them for my sloppine
ss.
>>
>> I'm planning on reaming the bell crank to 3/8 and then seeing how well a 3
/8 delrin rod fits. If it's still too loose, I have a 7/16 rod coming in t
he mail too. I'll be able turn it down to fit or possibly it would fit with
out any working (though I doubt it).
>>
>> Once I find the rod that fits best, then I'll ream the center on a friend
s lathe. I have a 3/16" reamer that will work, but I plan on using another r
eamer that's 11/64 (1/64 under sized) to see how it fits first. Then if it
's too tight I'll open it up to the full 3/16 with the other reamer.
>>
>> I'll probably have a report on how well it works in the next 2 weeks or p
ossibly late next week.
>>
>> Phil
>>
>> Sent from my iPhone
>>
>> > On Feb 13, 2016, at 5:29 PM, rvdave <rv610dave@gmail.com> wrote:
>> >
>> >
>> > I thought about that and wondered about the possibility of sanding them
down a little bit if oversized since the delrin does compress a little.
>> >
>> > --------
>> > Dave Ford
>> > RV6 for sale
>> > RV10 building
>> > Cadillac, MI
>> >
>> >
>> >
>> >
>> > Read this topic online here:
>> >
>> > http://forums.matronics.com/viewtopic.php?p=452802#452802
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> ============
>> h --
>> EE Gifts!)
>> on
>> r> ed
>> ://www.buildersbooks.com" rel="noreferrer" target="_blank">www.builde
rsbooks.com
>> ion" rel="noreferrer" target="_blank">http://www.matronics.com/contri
bution
>> -Matt Dralle, List Admin.
>> ============
>> br> ?RV10-List" rel="noreferrer" target="_blank">http://www.matronics
.com/Navigator?RV10-List
>> ============
>> S WEB FORUMS -
>> ="noreferrer" target="_blank">http://forums.matronics.com
>> ============
>> on Web Site -
>> -Matt Dralle, List Admin.
>> ion" rel="noreferrer" target="_blank">http://www.matronics.com/contri
bution
>> ============
>> >
>> >
>> >
>>
Message 6
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| Subject: | Re: Control Stick Slop - Bushings |
Phil beat me to it. You're absolutely right.
(I like yours and Seans solution by the way)
The housing on the outside of the bushing isn't
really round, so you wouldn't want it to rotate on the
bushing there. If it DID wear, it could potentially wear
a larger hole in the housing, which would then be harder
to fix later. If you rotate it on the bolt, a simple
change of bolt and you're back to normal specs. The
Delrin should work real well.
This whole mess happened on mine, and I used a filler to
surround the bushing and basically "epoxy" it in to the
weldment. That way it can only rotate on the bolt.
And I took up the end slop as well...also out in the
aileron bellcranks. You should look at those areas and
think about where wear is going to happen, and try to
ensure that any surface that will wear, is a replaceable
part. You will find there are a few places that can
be improved upon from the plans...just like the
original nose gear axle...that was a horrible design
until they went with thicker spacer...then it was just
a bad design. The Matco axle is a great improvement.
Tim
On 2/25/2016 9:50 AM, Phillip Perry wrote:
> Also, by putting the motion on the bolt, any future replacement of parts
> from wear would involve a new bushing and potentially new bolt. Cheap
> and easy to replace.
>
> Putting be motion on the welded piece would lead to a new bushing and
> potentially new weldment. Expensive and more complex to repair.
>
> Phil
>
>
> Sent from my iPhone
>
> On Feb 25, 2016, at 9:45 AM, Phillip Perry <philperry9@gmail.com
> <mailto:philperry9@gmail.com>> wrote:
>
>> You want the pivot point on the bolt and not the steel welded part.
>> That welded part isn't perfectly round (oblong) from the heat and
>> it's also rough, abrasive, and susceptible to rust - contributing for
>> abrasion and wear.
>>
>> If you keep the motion on the bolt, you have a perfectly round and
>> smooth pivot point. The nut is pinned so there's no chance of running
>> the nut off.
>>
>> PhilI'm very happy with the
>>> outcome.
>>>
>>> This wasn't a terrible change to make and if you have the seats out
>>> and access to a lathe, you could probably do it in less than a day.
>>> You certainly could do it on a drill press with some forethought.
>>> creative jigs, patience, and a few sacrificed pieces of delrin while
>>> you traverse the learning curve, but the lathe is certainly the
>>> fastest and easiest.
>>>
>>> I'd do it again... Glad it turned out the way it did.
>>>
>>> Phil
>>>
Message 7
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| Subject: | Re: Control Stick Slop - Bushings |
Thanks Phil =93 but I=99ll have to disagree.
Relative motion between the bushing and bolt means you have small
bearing surfaces, and a nice hard steel bolt wearing steel mating
surfaces (the bolt holes in the weldment). The function of the bushing
is to provide a large bearing surface (between the bushing and the pivot
tube). The larger surface area contributes to why we enjoy such smooth
controls in our RVs. The same principle applies to bell cranks and rod
end bearings =93 no relative motion around the bolt.
There is need from time to time to shorten either the pivot tube or
bushing to achieve slop free operation. You rare cases you may also
find need to ream out the pivot tube. The bushing, when firmly captured
in the weldment, should have perhaps 1/32=9D exposed on each side
of the pivot tube. If needed washers are added to make sure the
weldment is not deformed when the bolt is tightened =93 thus
maintaining this small gap and preventing binding. Again a little
grease between the bushing and pivot tube is recommended.
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 10:50 AM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
Also, by putting the motion on the bolt, any future replacement of parts
from wear would involve a new bushing and potentially new bolt. Cheap
and easy to replace.
Putting be motion on the welded piece would lead to a new bushing and
potentially new weldment. Expensive and more complex to repair.
Phil
Sent from my iPhone
On Feb 25, 2016, at 9:45 AM, Phillip Perry <philperry9@gmail.com> wrote:
You want the pivot point on the bolt and not the steel welded part.
That welded part isn't perfectly round (oblong) from the heat and it's
also rough, abrasive, and susceptible to rust - contributing for
abrasion and wear.
If you keep the motion on the bolt, you have a perfectly round and
smooth pivot point. The nut is pinned so there's no chance of running
the nut off.
Phil
Sent from my iPhone
On Feb 25, 2016, at 9:10 AM, Carl Froehlich <carl.froehlich@verizon.net>
wrote:
=9DI tuned this part of the system like you would a wheel bearing.
I rotated the sticks left and right while tightening the nut one flat
at a time. Once I began to feel tension on the sticks, I stopped and
backed off one flat where I then dropped in the cotter key in to lock it
into position.=9D
Perhaps I=99m reading this wrong. I thought the objective was for
the bolt to capture the bushing so that there is no relative motion
between the bolt and the bushing. All relative motion should be between
the outside of the bushing and the weldment (in this case the Control
Stick Base Pivot Tube).
I also believe adding a light grease for the bushing to weldment
provides for reduced corrosion between the dissimilar metals =93
obviously not an issue when using delrin but perhaps would help keep
dirt out of the bearing surface.
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 12:53 AM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
I thought I'd follow up on the control stick slop issue that I had in my
system since I promised a post-bushing report. I had some major play in
my control sticks and ended up following Sean's advice and replaced the
brass bushings with delrin. I attached a couple of photos of the plans
to help with the explanation.
After discovering the slop, I ordered delrin rods from Aircraft Spruce.
I ordered 3/8" hoping they'd be a drop-in replacement for a tight fit
without any machining and 7/16" in case I had to machine them down to
something closer to proper size for a good fit in the control stick
base. Each stick was about $3 for a 3 ft stick, so there was no harm in
ordering both.
I pulled the sticks, stick bases, and control column out of the plane
and put it on the bench. On disassembly, I found that there was play
between the brass bushing and the welded part of the stick bases. I
tried the 3/8" rod to see how well it fit and it dropped straight
through unrestricted. The inside of the welded stick bases were way
more than the spec'd 3/8". That was one part of the problem. The other
part of the problem was the slop on the inside of the bushing between
the bushing and the 1/4" bolt. That slop was worse than the welded
part. Additionally I found one more location for slop and that was the
ability to slide the stick forward and aft on the 1/4" bolt between the
stick bases and the control column that the stick bases mount to.
The first order of business was to get new bushings machined out.
Since the stick bases were more than 3/8" I used the 7/16" delrin rod
and turned it down on a lathe that another guy on the airport had. It
was turned down until it was a thumb-press fit into the stick bases.
The next step was to drill and ream the hole for the 1/4" bolt down the
center. I initially tried to ream it to 15/64 (1/64" undersized for
the 1/4" bolt) to get a snug fit in the event that the bolt was on the
skinny side of the tolerance. That didn't work out and I ultimately had
to open it to a full 1/4" to get the bolt to slide through.
Back to the work bench where I installed the new bushings. The fit was
free of any play between that bases and the bushing and between the
bushing and the bolt.
The final task was to eliminate the sliding motion of the sticks forward
and aft on the 1/4" bolt between the stick bases and the control column.
This was a pretty simple task of inserting AN960-416 and 416L washers
to shim as much of the gaps away as possible. Obviously you can't get
all of the gap out, so you have to take care of the last little bit by
tightening the nut and pulling the control column in tighter on the
stick bases.
I tuned this part of the system like you would a wheel bearing. I
rotated the sticks left and right while tightening the nut one flat at a
time. Once I began to feel tension on the sticks, I stopped and backed
off one flat where I then dropped in the cotter key in to lock it into
position.
The system linkages are tight (meaning no play) and very smooth (minus
the drag of the TruTrak servos). You can work the left and right sticks
in opposition directions, like driving a bull dozer, and you won't find
any play. You can go all the way out to the control surface and hold
it tight while wiggling the stick and not find any play between the
control surface and stick. I'm very happy with the outcome.
This wasn't a terrible change to make and if you have the seats out and
access to a lathe, you could probably do it in less than a day. You
certainly could do it on a drill press with some forethought. creative
jigs, patience, and a few sacrificed pieces of delrin while you traverse
the learning curve, but the lathe is certainly the fastest and easiest.
I'd do it again... Glad it turned out the way it did.
Phil
<image001.png>
<image002.png>
On Sat, Feb 13, 2016 at 8:08 PM, Phillip Perry <philperry9@gmail.com>
wrote:
I have some delrin coming and I'm planning on making them for my
sloppiness.
I'm planning on reaming the bell crank to 3/8 and then seeing how well a
3/8 delrin rod fits. If it's still too loose, I have a 7/16 rod coming
in the mail too. I'll be able turn it down to fit or possibly it would
fit without any working (though I doubt it).
Once I find the rod that fits best, then I'll ream the center on a
friends lathe. I have a 3/16" reamer that will work, but I plan on using
another reamer that's 11/64 (1/64 under sized) to see how it fits first.
Then if it's too tight I'll open it up to the full 3/16 with the other
reamer.
I'll probably have a report on how well it works in the next 2 weeks or
possibly late next week.
Phil
Sent from my iPhone
> On Feb 13, 2016, at 5:29 PM, rvdave <rv610dave@gmail.com> wrote:
>
>
> I thought about that and wondered about the possibility of sanding
them down a little bit if oversized since the delrin does compress a
little.
>
> --------
> Dave Ford
> RV6 for sale
> RV10 building
> Cadillac, MI
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=452802#452802
>
>
============
h --
EE Gifts!)
on
r> ed
://www.buildersbooks.com" rel="noreferrer"
target="_blank">www.buildersbooks.com
ion" rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
============
br> ?RV10-List" rel="noreferrer"
target="_blank">http://www.matronics.com/Navigator?RV10-List
============
S WEB FORUMS -
="noreferrer" target="_blank">http://forums.matronics.com
============
on Web Site -
-Matt Dralle, List Admin.
ion" rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
============
>
>
Message 8
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| Subject: | Re: Control Stick Slop - Bushings |
I thought about JB welding my bushing to the weldment or Lok-Tite. Both would have
helped significantly reduce the play. But I had so much slop on the inside
of the bushing that it still would have been notable.
If you don't have that much slop on the inside of the bushing, Tim's solution to
permanently place the bushing inside he weldment could work really well for
you.
Phil
Sent from my iPhone
> On Feb 25, 2016, at 10:19 AM, Tim Olson <Tim@MyRV10.com> wrote:
>
>
> Phil beat me to it. You're absolutely right.
> (I like yours and Seans solution by the way)
> The housing on the outside of the bushing isn't
> really round, so you wouldn't want it to rotate on the
> bushing there. If it DID wear, it could potentially wear
> a larger hole in the housing, which would then be harder
> to fix later. If you rotate it on the bolt, a simple
> change of bolt and you're back to normal specs. The
> Delrin should work real well.
>
> This whole mess happened on mine, and I used a filler to
> surround the bushing and basically "epoxy" it in to the
> weldment. That way it can only rotate on the bolt.
> And I took up the end slop as well...also out in the
> aileron bellcranks. You should look at those areas and
> think about where wear is going to happen, and try to
> ensure that any surface that will wear, is a replaceable
> part. You will find there are a few places that can
> be improved upon from the plans...just like the
> original nose gear axle...that was a horrible design
> until they went with thicker spacer...then it was just
> a bad design. The Matco axle is a great improvement.
> Tim
>
>
>> On 2/25/2016 9:50 AM, Phillip Perry wrote:
>> Also, by putting the motion on the bolt, any future replacement of parts
>> from wear would involve a new bushing and potentially new bolt. Cheap
>> and easy to replace.
>>
>> Putting be motion on the welded piece would lead to a new bushing and
>> potentially new weldment. Expensive and more complex to repair.
>>
>> Phil
>>
>>
>>
>> Sent from my iPhone
>>
>> On Feb 25, 2016, at 9:45 AM, Phillip Perry <philperry9@gmail.com
>> <mailto:philperry9@gmail.com>> wrote:
>>
>>> You want the pivot point on the bolt and not the steel welded part.
>>> That welded part isn't perfectly round (oblong) from the heat and
>>> it's also rough, abrasive, and susceptible to rust - contributing for
>>> abrasion and wear.
>>>
>>> If you keep the motion on the bolt, you have a perfectly round and
>>> smooth pivot point. The nut is pinned so there's no chance of running
>>> the nut off.
>>>
>>> PhilI'm very happy with the
>>>> outcome.
>>>>
>>>> This wasn't a terrible change to make and if you have the seats out
>>>> and access to a lathe, you could probably do it in less than a day.
>>>> You certainly could do it on a drill press with some forethought.
>>>> creative jigs, patience, and a few sacrificed pieces of delrin while
>>>> you traverse the learning curve, but the lathe is certainly the
>>>> fastest and easiest.
>>>>
>>>> I'd do it again... Glad it turned out the way it did.
>>>>
>>>> Phil
>
>
>
>
Message 9
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|
| Subject: | Re: Control Stick Slop - Bushings |
Yeah, except I think Delrin is a better solution for the long
term. Cheap, and easy to replace.
I did see Carl's reply about the outer surface being required
to be the pivot point for smooth control operation, but I
just have to totally disagree. The controls when pivoting
on the bolt are very very smooth. And when you get the play
out of the system it's just sweet. My sticks flop around
easily with no effort. And, if the bolt does start to wear,
it will be easy to detect because the slop will come back.
In either the case of the Delrin, or the brass/bronze,
I think it'll be a long long time to wait to worry
about it. I lube mine occasionally but I'm up to over
1100 hours and have found no slop yet. I'll be surprised
if the bolt doesn't last 2000+ hours.
Tim
On 2/25/2016 10:34 AM, Phillip Perry wrote:
> <philperry9@gmail.com>
>
> I thought about JB welding my bushing to the weldment or Lok-Tite.
> Both would have helped significantly reduce the play. But I had so
> much slop on the inside of the bushing that it still would have been
> notable.
>
> If you don't have that much slop on the inside of the bushing, Tim's
> solution to permanently place the bushing inside he weldment could
> work really well for you.
>
> Phil
>
>
> Sent from my iPhone
>
>> On Feb 25, 2016, at 10:19 AM, Tim Olson <Tim@MyRV10.com> wrote:
>>
>>
>> Phil beat me to it. You're absolutely right. (I like yours and
>> Seans solution by the way) The housing on the outside of the
>> bushing isn't really round, so you wouldn't want it to rotate on
>> the bushing there. If it DID wear, it could potentially wear a
>> larger hole in the housing, which would then be harder to fix
>> later. If you rotate it on the bolt, a simple change of bolt and
>> you're back to normal specs. The Delrin should work real well.
>>
>> This whole mess happened on mine, and I used a filler to surround
>> the bushing and basically "epoxy" it in to the weldment. That way
>> it can only rotate on the bolt. And I took up the end slop as
>> well...also out in the aileron bellcranks. You should look at
>> those areas and think about where wear is going to happen, and try
>> to ensure that any surface that will wear, is a replaceable part.
>> You will find there are a few places that can be improved upon from
>> the plans...just like the original nose gear axle...that was a
>> horrible design until they went with thicker spacer...then it was
>> just a bad design. The Matco axle is a great improvement. Tim
>>
>>
Message 10
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|
| Subject: | Re: Control Stick Slop - Bushings |
As Tim said, according to the plans you're right.
But after digging into the problem in more detail and understanding the issu
es with the inconsistent weldment and poor fit of the bushing, I believe the
plans are the worst possible solution and can be improved on.
Will the plans work? Yes, for most people. But in my case I had tolerance s
tacking with multiple loose surfaces compounding into a more significant and
noticeable problem.
Now the controls have zero slop and are silky smooth and consistent through f
ull movement in all directions.
There's no doubt that the modification to the plans improved the control sys
tem in my plane greatly.
Phil
Sent from my iPhone
> On Feb 25, 2016, at 10:28 AM, Carl Froehlich <carl.froehlich@verizon.net> w
rote:
>
> Thanks Phil =93 but I=99ll have to disagree.
>
> Relative motion between the bushing and bolt means you have small bearing s
urfaces, and a nice hard steel bolt wearing steel mating surfaces (the bolt h
oles in the weldment). The function of the bushing is to provide a large be
aring surface (between the bushing and the pivot tube). The larger surface a
rea contributes to why we enjoy such smooth controls in our RVs. The same p
rinciple applies to bell cranks and rod end bearings =93 no relative m
otion around the bolt.
>
> There is need from time to time to shorten either the pivot tube or bushin
g to achieve slop free operation. You rare cases you may also find need to r
eam out the pivot tube. The bushing, when firmly captured in the weldment, s
hould have perhaps 1/32=9D exposed on each side of the pivot tube. If
needed washers are added to make sure the weldment is not deformed when the
bolt is tightened =93 thus maintaining this small gap and preventing b
inding. Again a little grease between the bushing and pivot tube is recomme
nded.
>
> Carl
>
>
> From: owner-rv10-list-server@matronics.com [mailto:owner-rv10-list-server@
matronics.com] On Behalf Of Phillip Perry
> Sent: Thursday, February 25, 2016 10:50 AM
> To: rv10-list@matronics.com
> Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
>
> Also, by putting the motion on the bolt, any future replacement of parts f
rom wear would involve a new bushing and potentially new bolt. Cheap and eas
y to replace.
>
> Putting be motion on the welded piece would lead to a new bushing and pote
ntially new weldment. Expensive and more complex to repair.
>
> Phil
>
>
>
> Sent from my iPhone
>
> On Feb 25, 2016, at 9:45 AM, Phillip Perry <philperry9@gmail.com> wrote:
>
> You want the pivot point on the bolt and not the steel welded part. That w
elded part isn't perfectly round (oblong) from the heat and it's also rough,
abrasive, and susceptible to rust - contributing for abrasion and wear.
>
> If you keep the motion on the bolt, you have a perfectly round and smooth p
ivot point. The nut is pinned so there's no chance of running the nut off.
>
> Phil
>
> Sent from my iPhone
>
> On Feb 25, 2016, at 9:10 AM, Carl Froehlich <carl.froehlich@verizon.net> w
rote:
>
> =9DI tuned this part of the system like you would a wheel bearing. I
rotated the sticks left and right while tightening the nut one flat at a ti
me. Once I began to feel tension on the sticks, I stopped and backed off on
e flat where I then dropped in the cotter key in to lock it into position.
=9D
>
> Perhaps I=99m reading this wrong. I thought the objective was for t
he bolt to capture the bushing so that there is no relative motion between t
he bolt and the bushing. All relative motion should be between the outside o
f the bushing and the weldment (in this case the Control Stick Base Pivot Tu
be).
>
> I also believe adding a light grease for the bushing to weldment provides f
or reduced corrosion between the dissimilar metals =93 obviously not a
n issue when using delrin but perhaps would help keep dirt out of the bearin
g surface.
>
> Carl
>
>
>
> From: owner-rv10-list-server@matronics.com [mailto:owner-rv10-list-server@
matronics.com] On Behalf Of Phillip Perry
> Sent: Thursday, February 25, 2016 12:53 AM
> To: rv10-list@matronics.com
> Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
>
> I thought I'd follow up on the control stick slop issue that I had in my s
ystem since I promised a post-bushing report. I had some major play in my c
ontrol sticks and ended up following Sean's advice and replaced the brass bu
shings with delrin. I attached a couple of photos of the plans to help wit
h the explanation.
>
> After discovering the slop, I ordered delrin rods from Aircraft Spruce. I
ordered 3/8" hoping they'd be a drop-in replacement for a tight fit without
any machining and 7/16" in case I had to machine them down to something clo
ser to proper size for a good fit in the control stick base. Each stick was
about $3 for a 3 ft stick, so there was no harm in ordering both.
>
> I pulled the sticks, stick bases, and control column out of the plane and p
ut it on the bench. On disassembly, I found that there was play between the
brass bushing and the welded part of the stick bases. I tried the 3/8" ro
d to see how well it fit and it dropped straight through unrestricted. The i
nside of the welded stick bases were way more than the spec'd 3/8". That wa
s one part of the problem. The other part of the problem was the slop on th
e inside of the bushing between the bushing and the 1/4" bolt. That slop wa
s worse than the welded part. Additionally I found one more location for sl
op and that was the ability to slide the stick forward and aft on the 1/4" b
olt between the stick bases and the control column that the stick bases moun
t to.
>
> The first order of business was to get new bushings machined out. Since t
he stick bases were more than 3/8" I used the 7/16" delrin rod and turned it
down on a lathe that another guy on the airport had. It was turned down u
ntil it was a thumb-press fit into the stick bases.
>
> The next step was to drill and ream the hole for the 1/4" bolt down the ce
nter. I initially tried to ream it to 15/64 (1/64" undersized for the 1/4"
bolt) to get a snug fit in the event that the bolt was on the skinny side o
f the tolerance. That didn't work out and I ultimately had to open it to a f
ull 1/4" to get the bolt to slide through.
>
> Back to the work bench where I installed the new bushings. The fit was fr
ee of any play between that bases and the bushing and between the bushing an
d the bolt.
>
> The final task was to eliminate the sliding motion of the sticks forward a
nd aft on the 1/4" bolt between the stick bases and the control column. Th
is was a pretty simple task of inserting AN960-416 and 416L washers to shim a
s much of the gaps away as possible. Obviously you can't get all of the ga
p out, so you have to take care of the last little bit by tightening the nut
and pulling the control column in tighter on the stick bases.
>
> I tuned this part of the system like you would a wheel bearing. I rotated
the sticks left and right while tightening the nut one flat at a time. Onc
e I began to feel tension on the sticks, I stopped and backed off one flat w
here I then dropped in the cotter key in to lock it into position.
>
> The system linkages are tight (meaning no play) and very smooth (minus the
drag of the TruTrak servos). You can work the left and right sticks in opp
osition directions, like driving a bull dozer, and you won't find any play.
You can go all the way out to the control surface and hold it tight while w
iggling the stick and not find any play between the control surface and stic
k. I'm very happy with the outcome.
>
> This wasn't a terrible change to make and if you have the seats out and ac
cess to a lathe, you could probably do it in less than a day. You certainl
y could do it on a drill press with some forethought. creative jigs, patienc
e, and a few sacrificed pieces of delrin while you traverse the learning cur
ve, but the lathe is certainly the fastest and easiest.
>
> I'd do it again... Glad it turned out the way it did.
>
> Phil
>
>
> <image001.png>
>
> <image002.png>
>
>
>
>
>
>
> On Sat, Feb 13, 2016 at 8:08 PM, Phillip Perry <philperry9@gmail.com> wrot
e:
> I have some delrin coming and I'm planning on making them for my sloppines
s.
>
> I'm planning on reaming the bell crank to 3/8 and then seeing how well a 3
/8 delrin rod fits. If it's still too loose, I have a 7/16 rod coming in t
he mail too. I'll be able turn it down to fit or possibly it would fit with
out any working (though I doubt it).
>
> Once I find the rod that fits best, then I'll ream the center on a friends
lathe. I have a 3/16" reamer that will work, but I plan on using another re
amer that's 11/64 (1/64 under sized) to see how it fits first. Then if it'
s too tight I'll open it up to the full 3/16 with the other reamer.
>
> I'll probably have a report on how well it works in the next 2 weeks or po
ssibly late next week.
>
> Phil
>
> Sent from my iPhone
>
> > On Feb 13, 2016, at 5:29 PM, rvdave <rv610dave@gmail.com> wrote:
> >
> >
> > I thought about that and wondered about the possibility of sanding them d
own a little bit if oversized since the delrin does compress a little.
> >
> > --------
> > Dave Ford
> > RV6 for sale
> > RV10 building
> > Cadillac, MI
> >
> >
> >
> >
> > Read this topic online here:
> >
> > http://forums.matronics.com/viewtopic.php?p=452802#452802
> >
> >
> >
> >
> >
> >
> >
> ============
> h --
> EE Gifts!)
> on
> r> ed
> ://www.buildersbooks.com" rel="noreferrer" target="_blank">www.builder
sbooks.com
> ion" rel="noreferrer" target="_blank">http://www.matronics.com/contrib
ution
> -Matt Dralle, List Admin.
> ============
> br> ?RV10-List" rel="noreferrer" target="_blank">http://www.matronics.
com/Navigator?RV10-List
> ============
> S WEB FORUMS -
> ="noreferrer" target="_blank">http://forums.matronics.com
> ============
> on Web Site -
> -Matt Dralle, List Admin.
> ion" rel="noreferrer" target="_blank">http://www.matronics.com/contrib
ution
> ============
> >
> >
> >
>
Message 11
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| Subject: | Re: Control Stick Slop - Bushings |
Ok Phil & Tim.
For those reading however I want to emphasize you have transformed a
large surface area soft brass bushing (the wear element) in a steel tube
bearing to a =9Cknife edge=9D bearing with a steel bolt
riding on the small steel weldment bolt hole tabs. It will work, but
for most I offer careful assembly of these bearings, bell cranks and
such per plans would be the best option. For both of my planes I too
enjoy smooth, no slop controls.
Now going back into the woodwork..
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 11:54 AM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
As Tim said, according to the plans you're right.
But after digging into the problem in more detail and understanding the
issues with the inconsistent weldment and poor fit of the bushing, I
believe the plans are the worst possible solution and can be improved
on.
Will the plans work? Yes, for most people. But in my case I had
tolerance stacking with multiple loose surfaces compounding into a more
significant and noticeable problem.
Now the controls have zero slop and are silky smooth and consistent
through full movement in all directions.
There's no doubt that the modification to the plans improved the control
system in my plane greatly.
Phil
Sent from my iPhone
On Feb 25, 2016, at 10:28 AM, Carl Froehlich
<carl.froehlich@verizon.net> wrote:
Thanks Phil =93 but I=99ll have to disagree.
Relative motion between the bushing and bolt means you have small
bearing surfaces, and a nice hard steel bolt wearing steel mating
surfaces (the bolt holes in the weldment). The function of the bushing
is to provide a large bearing surface (between the bushing and the pivot
tube). The larger surface area contributes to why we enjoy such smooth
controls in our RVs. The same principle applies to bell cranks and rod
end bearings =93 no relative motion around the bolt.
There is need from time to time to shorten either the pivot tube or
bushing to achieve slop free operation. You rare cases you may also
find need to ream out the pivot tube. The bushing, when firmly captured
in the weldment, should have perhaps 1/32=9D exposed on each side
of the pivot tube. If needed washers are added to make sure the
weldment is not deformed when the bolt is tightened =93 thus
maintaining this small gap and preventing binding. Again a little
grease between the bushing and pivot tube is recommended.
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 10:50 AM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
Also, by putting the motion on the bolt, any future replacement of parts
from wear would involve a new bushing and potentially new bolt. Cheap
and easy to replace.
Putting be motion on the welded piece would lead to a new bushing and
potentially new weldment. Expensive and more complex to repair.
Phil
Sent from my iPhone
On Feb 25, 2016, at 9:45 AM, Phillip Perry <philperry9@gmail.com> wrote:
You want the pivot point on the bolt and not the steel welded part.
That welded part isn't perfectly round (oblong) from the heat and it's
also rough, abrasive, and susceptible to rust - contributing for
abrasion and wear.
If you keep the motion on the bolt, you have a perfectly round and
smooth pivot point. The nut is pinned so there's no chance of running
the nut off.
Phil
Sent from my iPhone
On Feb 25, 2016, at 9:10 AM, Carl Froehlich <carl.froehlich@verizon.net>
wrote:
=9DI tuned this part of the system like you would a wheel bearing.
I rotated the sticks left and right while tightening the nut one flat
at a time. Once I began to feel tension on the sticks, I stopped and
backed off one flat where I then dropped in the cotter key in to lock it
into position.=9D
Perhaps I=99m reading this wrong. I thought the objective was for
the bolt to capture the bushing so that there is no relative motion
between the bolt and the bushing. All relative motion should be between
the outside of the bushing and the weldment (in this case the Control
Stick Base Pivot Tube).
I also believe adding a light grease for the bushing to weldment
provides for reduced corrosion between the dissimilar metals =93
obviously not an issue when using delrin but perhaps would help keep
dirt out of the bearing surface.
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 12:53 AM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
I thought I'd follow up on the control stick slop issue that I had in my
system since I promised a post-bushing report. I had some major play in
my control sticks and ended up following Sean's advice and replaced the
brass bushings with delrin. I attached a couple of photos of the plans
to help with the explanation.
After discovering the slop, I ordered delrin rods from Aircraft Spruce.
I ordered 3/8" hoping they'd be a drop-in replacement for a tight fit
without any machining and 7/16" in case I had to machine them down to
something closer to proper size for a good fit in the control stick
base. Each stick was about $3 for a 3 ft stick, so there was no harm in
ordering both.
I pulled the sticks, stick bases, and control column out of the plane
and put it on the bench. On disassembly, I found that there was play
between the brass bushing and the welded part of the stick bases. I
tried the 3/8" rod to see how well it fit and it dropped straight
through unrestricted. The inside of the welded stick bases were way
more than the spec'd 3/8". That was one part of the problem. The other
part of the problem was the slop on the inside of the bushing between
the bushing and the 1/4" bolt. That slop was worse than the welded
part. Additionally I found one more location for slop and that was the
ability to slide the stick forward and aft on the 1/4" bolt between the
stick bases and the control column that the stick bases mount to.
The first order of business was to get new bushings machined out.
Since the stick bases were more than 3/8" I used the 7/16" delrin rod
and turned it down on a lathe that another guy on the airport had. It
was turned down until it was a thumb-press fit into the stick bases.
The next step was to drill and ream the hole for the 1/4" bolt down the
center. I initially tried to ream it to 15/64 (1/64" undersized for
the 1/4" bolt) to get a snug fit in the event that the bolt was on the
skinny side of the tolerance. That didn't work out and I ultimately had
to open it to a full 1/4" to get the bolt to slide through.
Back to the work bench where I installed the new bushings. The fit was
free of any play between that bases and the bushing and between the
bushing and the bolt.
The final task was to eliminate the sliding motion of the sticks forward
and aft on the 1/4" bolt between the stick bases and the control column.
This was a pretty simple task of inserting AN960-416 and 416L washers
to shim as much of the gaps away as possible. Obviously you can't get
all of the gap out, so you have to take care of the last little bit by
tightening the nut and pulling the control column in tighter on the
stick bases.
I tuned this part of the system like you would a wheel bearing. I
rotated the sticks left and right while tightening the nut one flat at a
time. Once I began to feel tension on the sticks, I stopped and backed
off one flat where I then dropped in the cotter key in to lock it into
position.
The system linkages are tight (meaning no play) and very smooth (minus
the drag of the TruTrak servos). You can work the left and right sticks
in opposition directions, like driving a bull dozer, and you won't find
any play. You can go all the way out to the control surface and hold
it tight while wiggling the stick and not find any play between the
control surface and stick. I'm very happy with the outcome.
This wasn't a terrible change to make and if you have the seats out and
access to a lathe, you could probably do it in less than a day. You
certainly could do it on a drill press with some forethought. creative
jigs, patience, and a few sacrificed pieces of delrin while you traverse
the learning curve, but the lathe is certainly the fastest and easiest.
I'd do it again... Glad it turned out the way it did.
Phil
<image001.png>
<image002.png>
On Sat, Feb 13, 2016 at 8:08 PM, Phillip Perry <philperry9@gmail.com>
wrote:
I have some delrin coming and I'm planning on making them for my
sloppiness.
I'm planning on reaming the bell crank to 3/8 and then seeing how well a
3/8 delrin rod fits. If it's still too loose, I have a 7/16 rod coming
in the mail too. I'll be able turn it down to fit or possibly it would
fit without any working (though I doubt it).
Once I find the rod that fits best, then I'll ream the center on a
friends lathe. I have a 3/16" reamer that will work, but I plan on using
another reamer that's 11/64 (1/64 under sized) to see how it fits first.
Then if it's too tight I'll open it up to the full 3/16 with the other
reamer.
I'll probably have a report on how well it works in the next 2 weeks or
possibly late next week.
Phil
Sent from my iPhone
> On Feb 13, 2016, at 5:29 PM, rvdave <rv610dave@gmail.com> wrote:
>
>
> I thought about that and wondered about the possibility of sanding
them down a little bit if oversized since the delrin does compress a
little.
>
> --------
> Dave Ford
> RV6 for sale
> RV10 building
> Cadillac, MI
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=452802#452802
>
>
============
h --
EE Gifts!)
on
r> ed
://www.buildersbooks.com" rel="noreferrer"
target="_blank">www.buildersbooks.com
ion" rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
============
br> ?RV10-List" rel="noreferrer"
target="_blank">http://www.matronics.com/Navigator?RV10-List
============
S WEB FORUMS -
="noreferrer" target="_blank">http://forums.matronics.com
============
on Web Site -
-Matt Dralle, List Admin.
ion" rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
============
>
>
Message 12
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|
| Subject: | Re: Control Stick Slop - Bushings |
I think if they REALLY wanted it to be that way, the way
the weldment is produced is very poor. They should have a
machined hole through the weldment, not that bent metal
seam where the parts come together. It would need to be
made with much more precision. If nothing else, a
different solution would be to glue in a stainless or
steel sleeve of some sort, that is thinner, to provide a
nice consistent bore. Then the bushing could be sized to
fit and it would be more precise. But the weldment isn't
a precision bore of any sort.
And so, as we talked about, you consider the long term wear
implications, it's just much easier for long term maintenance
to make the bolt (and bushing) be the easily replaceable items.
And, while I haven't tried this, it certainly would be possible
to use a larger diameter bolt and bore out the delrin bushing,
if you want to use a thicker bolt...but I see no point in that.
Tim
On 2/25/2016 10:54 AM, Phillip Perry wrote:
> As Tim said, according to the plans you're right.
>
> But after digging into the problem in more detail and understanding the
> issues with the inconsistent weldment and poor fit of the bushing, I
> believe the plans are the worst possible solution and can be improved on.
>
> Will the plans work? Yes, for most people. But in my case I had
> tolerance stacking with multiple loose surfaces compounding into a more
> significant and noticeable problem.
>
> Now the controls have zero slop and are silky smooth and consistent
> through full movement in all directions.
>
> There's no doubt that the modification to the plans improved the control
> system in my plane greatly.
>
> Phil
>
Message 13
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|
| Subject: | Re: Control Stick Slop - Bushings |
I understand what you're saying now. You're worried about he bolt rotating o
n the steel weldment and having a knife edge wear point. That makes sense.
However, I should point out that the bolt is not rotating at all. Just like
the plans.
Because the bolt doesn't rotate, all of the rotation occurs inside the bushi
ng. The wear surface is the smooth interface between the bolt and the bush
ing and not the bolt and the weldment edges. That would be a mistake as yo
u could saw the bolt right in two and it would be inconsistent too.
The case you're describing isn't an issue.
Here's a video I just shot showing where the rotation occurs.
http://youtu.be/SaywmrHZW24
Phil
Sent from my iPhone
> On Feb 25, 2016, at 11:24 AM, Carl Froehlich <carl.froehlich@verizon.net> w
rote:
>
> Ok Phil & Tim.
>
> For those reading however I want to emphasize you have transformed a large
surface area soft brass bushing (the wear element) in a steel tube bearing t
o a =9Cknife edge=9D bearing with a steel bolt riding on the sma
ll steel weldment bolt hole tabs. It will work, but for most I offer carefu
l assembly of these bearings, bell cranks and such per plans would be the be
st option. For both of my planes I too enjoy smooth, no slop controls.
>
> Now going back into the woodwork..
>
> Carl
>
> From: owner-rv10-list-server@matronics.com [mailto:owner-rv10-list-server@
matronics.com] On Behalf Of Phillip Perry
> Sent: Thursday, February 25, 2016 11:54 AM
> To: rv10-list@matronics.com
> Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
>
> As Tim said, according to the plans you're right.
>
> But after digging into the problem in more detail and understanding the is
sues with the inconsistent weldment and poor fit of the bushing, I believe t
he plans are the worst possible solution and can be improved on.
>
> Will the plans work? Yes, for most people. But in my case I had toleranc
e stacking with multiple loose surfaces compounding into a more significant a
nd noticeable problem.
>
> Now the controls have zero slop and are silky smooth and consistent throug
h full movement in all directions.
>
> There's no doubt that the modification to the plans improved the control s
ystem in my plane greatly.
>
> Phil
>
> Sent from my iPhone
>
> On Feb 25, 2016, at 10:28 AM, Carl Froehlich <carl.froehlich@verizon.net> w
rote:
>
> Thanks Phil =93 but I=99ll have to disagree.
>
> Relative motion between the bushing and bolt means you have small bearing s
urfaces, and a nice hard steel bolt wearing steel mating surfaces (the bolt h
oles in the weldment). The function of the bushing is to provide a large be
aring surface (between the bushing and the pivot tube). The larger surface a
rea contributes to why we enjoy such smooth controls in our RVs. The same p
rinciple applies to bell cranks and rod end bearings =93 no relative m
otion around the bolt.
>
> There is need from time to time to shorten either the pivot tube or bushin
g to achieve slop free operation. You rare cases you may also find need to r
eam out the pivot tube. The bushing, when firmly captured in the weldment, s
hould have perhaps 1/32=9D exposed on each side of the pivot tube. If
needed washers are added to make sure the weldment is not deformed when the
bolt is tightened =93 thus maintaining this small gap and preventing b
inding. Again a little grease between the bushing and pivot tube is recomme
nded.
>
> Carl
>
>
> From: owner-rv10-list-server@matronics.com [mailto:owner-rv10-list-server@
matronics.com] On Behalf Of Phillip Perry
> Sent: Thursday, February 25, 2016 10:50 AM
> To: rv10-list@matronics.com
> Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
>
> Also, by putting the motion on the bolt, any future replacement of parts f
rom wear would involve a new bushing and potentially new bolt. Cheap and eas
y to replace.
>
> Putting be motion on the welded piece would lead to a new bushing and pote
ntially new weldment. Expensive and more complex to repair.
>
> Phil
>
>
>
> Sent from my iPhone
>
> On Feb 25, 2016, at 9:45 AM, Phillip Perry <philperry9@gmail.com> wrote:
>
> You want the pivot point on the bolt and not the steel welded part. That w
elded part isn't perfectly round (oblong) from the heat and it's also rough,
abrasive, and susceptible to rust - contributing for abrasion and wear.
>
> If you keep the motion on the bolt, you have a perfectly round and smooth p
ivot point. The nut is pinned so there's no chance of running the nut off.
>
> Phil
>
> Sent from my iPhone
>
> On Feb 25, 2016, at 9:10 AM, Carl Froehlich <carl.froehlich@verizon.net> w
rote:
>
> =9DI tuned this part of the system like you would a wheel bearing. I
rotated the sticks left and right while tightening the nut one flat at a ti
me. Once I began to feel tension on the sticks, I stopped and backed off on
e flat where I then dropped in the cotter key in to lock it into position.
=9D
>
> Perhaps I=99m reading this wrong. I thought the objective was for t
he bolt to capture the bushing so that there is no relative motion between t
he bolt and the bushing. All relative motion should be between the outside o
f the bushing and the weldment (in this case the Control Stick Base Pivot Tu
be).
>
> I also believe adding a light grease for the bushing to weldment provides f
or reduced corrosion between the dissimilar metals =93 obviously not a
n issue when using delrin but perhaps would help keep dirt out of the bearin
g surface.
>
> Carl
>
>
>
>
> From: owner-rv10-list-server@matronics.com [mailto:owner-rv10-list-server@
matronics.com] On Behalf Of Phillip Perry
> Sent: Thursday, February 25, 2016 12:53 AM
> To: rv10-list@matronics.com
> Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
>
> I thought I'd follow up on the control stick slop issue that I had in my s
ystem since I promised a post-bushing report. I had some major play in my c
ontrol sticks and ended up following Sean's advice and replaced the brass bu
shings with delrin. I attached a couple of photos of the plans to help wit
h the explanation.
>
> After discovering the slop, I ordered delrin rods from Aircraft Spruce. I
ordered 3/8" hoping they'd be a drop-in replacement for a tight fit without
any machining and 7/16" in case I had to machine them down to something clo
ser to proper size for a good fit in the control stick base. Each stick was
about $3 for a 3 ft stick, so there was no harm in ordering both.
>
> I pulled the sticks, stick bases, and control column out of the plane and p
ut it on the bench. On disassembly, I found that there was play between the
brass bushing and the welded part of the stick bases. I tried the 3/8" ro
d to see how well it fit and it dropped straight through unrestricted. The i
nside of the welded stick bases were way more than the spec'd 3/8". That wa
s one part of the problem. The other part of the problem was the slop on th
e inside of the bushing between the bushing and the 1/4" bolt. That slop wa
s worse than the welded part. Additionally I found one more location for sl
op and that was the ability to slide the stick forward and aft on the 1/4" b
olt between the stick bases and the control column that the stick bases moun
t to.
>
> The first order of business was to get new bushings machined out. Since t
he stick bases were more than 3/8" I used the 7/16" delrin rod and turned it
down on a lathe that another guy on the airport had. It was turned down u
ntil it was a thumb-press fit into the stick bases.
>
> The next step was to drill and ream the hole for the 1/4" bolt down the ce
nter. I initially tried to ream it to 15/64 (1/64" undersized for the 1/4"
bolt) to get a snug fit in the event that the bolt was on the skinny side o
f the tolerance. That didn't work out and I ultimately had to open it to a f
ull 1/4" to get the bolt to slide through.
>
> Back to the work bench where I installed the new bushings. The fit was fr
ee of any play between that bases and the bushing and between the bushing an
d the bolt.
>
> The final task was to eliminate the sliding motion of the sticks forward a
nd aft on the 1/4" bolt between the stick bases and the control column. Th
is was a pretty simple task of inserting AN960-416 and 416L washers to shim a
s much of the gaps away as possible. Obviously you can't get all of the ga
p out, so you have to take care of the last little bit by tightening the nut
and pulling the control column in tighter on the stick bases.
>
> I tuned this part of the system like you would a wheel bearing. I rotated
the sticks left and right while tightening the nut one flat at a time. Onc
e I began to feel tension on the sticks, I stopped and backed off one flat w
here I then dropped in the cotter key in to lock it into position.
>
> The system linkages are tight (meaning no play) and very smooth (minus the
drag of the TruTrak servos). You can work the left and right sticks in opp
osition directions, like driving a bull dozer, and you won't find any play.
You can go all the way out to the control surface and hold it tight while w
iggling the stick and not find any play between the control surface and stic
k. I'm very happy with the outcome.
>
> This wasn't a terrible change to make and if you have the seats out and ac
cess to a lathe, you could probably do it in less than a day. You certainl
y could do it on a drill press with some forethought. creative jigs, patienc
e, and a few sacrificed pieces of delrin while you traverse the learning cur
ve, but the lathe is certainly the fastest and easiest.
>
> I'd do it again... Glad it turned out the way it did.
>
> Phil
>
>
> <image001.png>
>
> <image002.png>
>
>
>
>
>
>
>
> On Sat, Feb 13, 2016 at 8:08 PM, Phillip Perry <philperry9@gmail.com> wrot
e:
> I have some delrin coming and I'm planning on making them for my sloppines
s.
>
> I'm planning on reaming the bell crank to 3/8 and then seeing how well a 3
/8 delrin rod fits. If it's still too loose, I have a 7/16 rod coming in t
he mail too. I'll be able turn it down to fit or possibly it would fit with
out any working (though I doubt it).
>
> Once I find the rod that fits best, then I'll ream the center on a friends
lathe. I have a 3/16" reamer that will work, but I plan on using another re
amer that's 11/64 (1/64 under sized) to see how it fits first. Then if it'
s too tight I'll open it up to the full 3/16 with the other reamer.
>
> I'll probably have a report on how well it works in the next 2 weeks or po
ssibly late next week.
>
> Phil
>
> Sent from my iPhone
>
> > On Feb 13, 2016, at 5:29 PM, rvdave <rv610dave@gmail.com> wrote:
> >
> >
> > I thought about that and wondered about the possibility of sanding them d
own a little bit if oversized since the delrin does compress a little.
> >
> > --------
> > Dave Ford
> > RV6 for sale
> > RV10 building
> > Cadillac, MI
> >
> >
> >
> >
> > Read this topic online here:
> >
> > http://forums.matronics.com/viewtopic.php?p=452802#452802
> >
> >
> >
> >
> >
> >
> >
> ============
> h --
> EE Gifts!)
> on
> r> ed
> ://www.buildersbooks.com" rel="noreferrer" target="_blank">www.builder
sbooks.com
> ion" rel="noreferrer" target="_blank">http://www.matronics.com/contrib
ution
> -Matt Dralle, List Admin.
> ============
> br> ?RV10-List" rel="noreferrer" target="_blank">http://www.matronics.
com/Navigator?RV10-List
> ============
> S WEB FORUMS -
> ="noreferrer" target="_blank">http://forums.matronics.com
> ============
> on Web Site -
> -Matt Dralle, List Admin.
> ion" rel="noreferrer" target="_blank">http://www.matronics.com/contrib
ution
> ============
> >
> >
> >
>
Message 14
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| Subject: | Re: Control Stick Slop - Bushings |
Ok =93 again thanks Phil for the explanation, but you pulled me
back out of the woodwork.
You now have the soft delrin rubbing against the steel tabs on the
weldment. The fact that you have no rotation between the bolt and the
steel weldment tabs is by your careful application of torque on the nut.
The delrin rotates around the bolt only because you have, right now,
more friction between the bolt head and nut and the weldment tabs than
you do between the delrin ends and the weldment tabs. Perhaps this
stays the same but I=99d be surprised if the delrin rod end wear
does not open up the joint =93 leaving the bolt loose and free to
rotate in the tabs and end up as I described.
I assume the reason why you did not simply make the delrin as a
replacement for the brass bushing is that you did not like the inside of
the steel bearing tube. You would have a much larger bearing surface
area between the delrin and the steel bearing tube, and a much larger
wear area. Perhaps you got a bad one. I=99ve seen some that
needed to be reamed to size but none that where so bad not to use.
But =93 we all get to build the planes as we want. I have also
deviated from the plans when I did not like a particular design element.
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 12:50 PM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
I understand what you're saying now. You're worried about he bolt
rotating on the steel weldment and having a knife edge wear point.
That makes sense.
However, I should point out that the bolt is not rotating at all. Just
like the plans.
Because the bolt doesn't rotate, all of the rotation occurs inside the
bushing. The wear surface is the smooth interface between the bolt and
the bushing and not the bolt and the weldment edges. That would be a
mistake as you could saw the bolt right in two and it would be
inconsistent too.
The case you're describing isn't an issue.
Here's a video I just shot showing where the rotation occurs.
http://youtu.be/SaywmrHZW24
Phil
Sent from my iPhone
On Feb 25, 2016, at 11:24 AM, Carl Froehlich
<carl.froehlich@verizon.net> wrote:
Ok Phil & Tim.
For those reading however I want to emphasize you have transformed a
large surface area soft brass bushing (the wear element) in a steel tube
bearing to a =9Cknife edge=9D bearing with a steel bolt
riding on the small steel weldment bolt hole tabs. It will work, but
for most I offer careful assembly of these bearings, bell cranks and
such per plans would be the best option. For both of my planes I too
enjoy smooth, no slop controls.
Now going back into the woodwork..
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 11:54 AM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
As Tim said, according to the plans you're right.
But after digging into the problem in more detail and understanding the
issues with the inconsistent weldment and poor fit of the bushing, I
believe the plans are the worst possible solution and can be improved
on.
Will the plans work? Yes, for most people. But in my case I had
tolerance stacking with multiple loose surfaces compounding into a more
significant and noticeable problem.
Now the controls have zero slop and are silky smooth and consistent
through full movement in all directions.
There's no doubt that the modification to the plans improved the control
system in my plane greatly.
Phil
Sent from my iPhone
On Feb 25, 2016, at 10:28 AM, Carl Froehlich
<carl.froehlich@verizon.net> wrote:
Thanks Phil =93 but I=99ll have to disagree.
Relative motion between the bushing and bolt means you have small
bearing surfaces, and a nice hard steel bolt wearing steel mating
surfaces (the bolt holes in the weldment). The function of the bushing
is to provide a large bearing surface (between the bushing and the pivot
tube). The larger surface area contributes to why we enjoy such smooth
controls in our RVs. The same principle applies to bell cranks and rod
end bearings =93 no relative motion around the bolt.
There is need from time to time to shorten either the pivot tube or
bushing to achieve slop free operation. You rare cases you may also
find need to ream out the pivot tube. The bushing, when firmly captured
in the weldment, should have perhaps 1/32=9D exposed on each side
of the pivot tube. If needed washers are added to make sure the
weldment is not deformed when the bolt is tightened =93 thus
maintaining this small gap and preventing binding. Again a little
grease between the bushing and pivot tube is recommended.
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 10:50 AM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
Also, by putting the motion on the bolt, any future replacement of parts
from wear would involve a new bushing and potentially new bolt. Cheap
and easy to replace.
Putting be motion on the welded piece would lead to a new bushing and
potentially new weldment. Expensive and more complex to repair.
Phil
Sent from my iPhone
On Feb 25, 2016, at 9:45 AM, Phillip Perry <philperry9@gmail.com> wrote:
You want the pivot point on the bolt and not the steel welded part.
That welded part isn't perfectly round (oblong) from the heat and it's
also rough, abrasive, and susceptible to rust - contributing for
abrasion and wear.
If you keep the motion on the bolt, you have a perfectly round and
smooth pivot point. The nut is pinned so there's no chance of running
the nut off.
Phil
Sent from my iPhone
On Feb 25, 2016, at 9:10 AM, Carl Froehlich <carl.froehlich@verizon.net>
wrote:
=9DI tuned this part of the system like you would a wheel bearing.
I rotated the sticks left and right while tightening the nut one flat
at a time. Once I began to feel tension on the sticks, I stopped and
backed off one flat where I then dropped in the cotter key in to lock it
into position.=9D
Perhaps I=99m reading this wrong. I thought the objective was for
the bolt to capture the bushing so that there is no relative motion
between the bolt and the bushing. All relative motion should be between
the outside of the bushing and the weldment (in this case the Control
Stick Base Pivot Tube).
I also believe adding a light grease for the bushing to weldment
provides for reduced corrosion between the dissimilar metals =93
obviously not an issue when using delrin but perhaps would help keep
dirt out of the bearing surface.
Carl
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Phillip Perry
Sent: Thursday, February 25, 2016 12:53 AM
Subject: Re: RV10-List: Re: Control Stick Slop - Bushings
I thought I'd follow up on the control stick slop issue that I had in my
system since I promised a post-bushing report. I had some major play in
my control sticks and ended up following Sean's advice and replaced the
brass bushings with delrin. I attached a couple of photos of the plans
to help with the explanation.
After discovering the slop, I ordered delrin rods from Aircraft Spruce.
I ordered 3/8" hoping they'd be a drop-in replacement for a tight fit
without any machining and 7/16" in case I had to machine them down to
something closer to proper size for a good fit in the control stick
base. Each stick was about $3 for a 3 ft stick, so there was no harm in
ordering both.
I pulled the sticks, stick bases, and control column out of the plane
and put it on the bench. On disassembly, I found that there was play
between the brass bushing and the welded part of the stick bases. I
tried the 3/8" rod to see how well it fit and it dropped straight
through unrestricted. The inside of the welded stick bases were way
more than the spec'd 3/8". That was one part of the problem. The other
part of the problem was the slop on the inside of the bushing between
the bushing and the 1/4" bolt. That slop was worse than the welded
part. Additionally I found one more location for slop and that was the
ability to slide the stick forward and aft on the 1/4" bolt between the
stick bases and the control column that the stick bases mount to.
The first order of business was to get new bushings machined out.
Since the stick bases were more than 3/8" I used the 7/16" delrin rod
and turned it down on a lathe that another guy on the airport had. It
was turned down until it was a thumb-press fit into the stick bases.
The next step was to drill and ream the hole for the 1/4" bolt down the
center. I initially tried to ream it to 15/64 (1/64" undersized for
the 1/4" bolt) to get a snug fit in the event that the bolt was on the
skinny side of the tolerance. That didn't work out and I ultimately had
to open it to a full 1/4" to get the bolt to slide through.
Back to the work bench where I installed the new bushings. The fit was
free of any play between that bases and the bushing and between the
bushing and the bolt.
The final task was to eliminate the sliding motion of the sticks forward
and aft on the 1/4" bolt between the stick bases and the control column.
This was a pretty simple task of inserting AN960-416 and 416L washers
to shim as much of the gaps away as possible. Obviously you can't get
all of the gap out, so you have to take care of the last little bit by
tightening the nut and pulling the control column in tighter on the
stick bases.
I tuned this part of the system like you would a wheel bearing. I
rotated the sticks left and right while tightening the nut one flat at a
time. Once I began to feel tension on the sticks, I stopped and backed
off one flat where I then dropped in the cotter key in to lock it into
position.
The system linkages are tight (meaning no play) and very smooth (minus
the drag of the TruTrak servos). You can work the left and right sticks
in opposition directions, like driving a bull dozer, and you won't find
any play. You can go all the way out to the control surface and hold
it tight while wiggling the stick and not find any play between the
control surface and stick. I'm very happy with the outcome.
This wasn't a terrible change to make and if you have the seats out and
access to a lathe, you could probably do it in less than a day. You
certainly could do it on a drill press with some forethought. creative
jigs, patience, and a few sacrificed pieces of delrin while you traverse
the learning curve, but the lathe is certainly the fastest and easiest.
I'd do it again... Glad it turned out the way it did.
Phil
<image001.png>
<image002.png>
On Sat, Feb 13, 2016 at 8:08 PM, Phillip Perry <philperry9@gmail.com>
wrote:
I have some delrin coming and I'm planning on making them for my
sloppiness.
I'm planning on reaming the bell crank to 3/8 and then seeing how well a
3/8 delrin rod fits. If it's still too loose, I have a 7/16 rod coming
in the mail too. I'll be able turn it down to fit or possibly it would
fit without any working (though I doubt it).
Once I find the rod that fits best, then I'll ream the center on a
friends lathe. I have a 3/16" reamer that will work, but I plan on using
another reamer that's 11/64 (1/64 under sized) to see how it fits first.
Then if it's too tight I'll open it up to the full 3/16 with the other
reamer.
I'll probably have a report on how well it works in the next 2 weeks or
possibly late next week.
Phil
Sent from my iPhone
> On Feb 13, 2016, at 5:29 PM, rvdave <rv610dave@gmail.com> wrote:
>
>
> I thought about that and wondered about the possibility of sanding
them down a little bit if oversized since the delrin does compress a
little.
>
> --------
> Dave Ford
> RV6 for sale
> RV10 building
> Cadillac, MI
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=452802#452802
>
>
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| Subject: | Re: Control Stick Slop - Bushings |
Nice work Phil!
Delrin is an amazing material in my opinion. I really don't think mine will ever
wear out. I bet I did the swap more than 350 hours ago and mine feels EXACTLY
the same as it did after installation. If anything was wearing down I think
you would instantly feel the slop again.
--------
40936
RV-10 SB N801VR Flying
530 hours
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=453187#453187
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| Subject: | Re: Control Stick Slop - Bushings |
I agree, Delrin is an amazing material, and it is rather hard as a
plastic goes. Certainly harder than the UHMW that Vans uses for some
friction sizes to prevent wear.
It also has had weird uses, like the Army had disks molded from Delrin
with a knife edge on the inner diameter. Purpose was to allow you to
light it on the knife edge to use as a heating element to warm C rations
in the winter.
On 2/25/2016 1:08 PM, Strasnuts wrote:
>
> Nice work Phil!
>
> Delrin is an amazing material in my opinion. I really don't think mine will
ever wear out. I bet I did the swap more than 350 hours ago and mine feels EXACTLY
the same as it did after installation. If anything was wearing down I think
you would instantly feel the slop again.
>
> --------
> 40936
> RV-10 SB N801VR Flying
> 530 hours
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=453187#453187
>
>
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The 6 cylinder P Mags have been out for a while-has anyone on the list
used them and have a report?
Albert Gardner
RV-10 N991RV
Yuma, AZ
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