http://www.aircraftspruce.com/catalog/a ... s21260.php
Date: Mon, 28 Dec 2009 19:54:48 -0500
From: klehman@albedo.net
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] control cable thimble
I have never hesitated to advertise any weakness or maintenance issues
in aircraft but I consider it to be a severe over reaction to call MAM's
controls "dangerous". Certainly they are not designed to be maintenance
free and certainly there are several upgrades possible. IMO they are a
reasonable compromise of cost vs. quality especially when you consider
how few homebuilts in general actually accumulate more than 3 or 4
hundred hours lifetime total.
This thread was a reminder that I have been neglecting lubricating the
rear elevator cable connections though. Thank you for that. I did put an
aluminum bushings between the AN4 bolts and the cable thimbles to
hopefully reduce future maintenance in that area. I would not hesitate
to use a steel AN111 bushing there and yes it would still benefit from
periodic lubrication or an occasional shot of corrosion-x. These are
inside the fuselage. I wouldn't consider them "out in the elements". I
decided to lube all other bushings every 10 to 20 hours instead of
upgrading the AIL26 steel bushings to stainless. Yes you need a
precision oiler or a small syringe to oil them. I might have upgraded to
stainless bushings if I had planned to store the airframe outdoors or
neglect keeping them lubed.
The largest maintenance bushing issue AFAIK is the lower rudder bushing
so I did put a bronze bushing in the aluminum bracket there. Those of us
with big feet can put a lot of pressure on the rudder cables.
What else - there has been mention of how to use a few spacers to keep
the rod end from rotating in the push tube threads between the front
aileron control horn and the left control stick.
Ken
119R
art_spangler@dcsol.com wrote:Doug,
I too have been running into the same problem. On my Cessna 140, I believe
that its cable controls are better constructed than the Murphy's (not to
insult those who love Murphy) and its a 1947! I see what you are concerned
about. After some careful inspection, I have already seen wear on the bolt
that the thimble is wearing on. When I put it together I lubricated it but there
is pressure on the back side of the bolt from the cable tension and it has
started to cut the bolt. I am glad you brought this to my attention, you are a
very observant person to catch this.
Art Spangler
Texas
On 12/9/2009 4:38 PM, fastback-1@hotmail.com wrote to rebel-builders:
->
-> My concern is about the whole planes surface controls.No bearing or
proper bushing.Bolts through aluminum,steel bushing in brass.Planes in 1946
had better technology.When you look at every link and joint for the controls
this thing is dangerous.And where I am concerned on this thimble,it is hidden,
if there is no lube between the insert and bolt.The insert will eventually cut
the bolt .There is constant pressure on the cable 30lbs. so wear on the bolt
is hard to define .If it was anything but steel to steel I would not be overly
concerned but to the unwary and left out in the elements and no lube I
repeat dangerous I lost rudder one time on a real plane(180) ,it wasn't fun
flying it with the doors .I never lost a elevator I guess that is why I am still
here.Another concern Chapter 12 pge. 3 tangs attached to torque tube I
used a offset No. 80 real chain link not something you can bend by hand.All
bushing running in brass were made out of stainless.For insert i wish to
replace it with a sealed ball bearing
-> 1/4 inch bore if anyone has done it I would appreciate where you got it.I
will Sleeve the outer race and machine a cable groove around it
->
-> And by the way no offence wayne i give my information for free so nobody
dies .What do you charge for your professionalism if you don't know say so .
->
-> > Date: Wed, 9 Dec 2009 15:48:46 -0800
-> > Subject: Re: [rebel-builders] control cable thimble
-> > From: westcoastkitplanes@gmail.com
-> > To: rebel-builders@dcsol.com
-> >
-> > Doug,
-> >
-> > Is your concern that the insert rotates or that the thimble and insert are
-> > dissimilar metals ?
-> >
-> > Cheers,
-> > Jeff
-> >
-> >
-> > On Wed, Dec 9, 2009 at 1:31 PM, doug wilson <fastback-
1@hotmail.com> wrote:
-> >
-> > >
-> > > I guess You can't answer or don't know .I figured you had seen
enough dum
-> > > shit you might know and have changed it.ANYBODY ELSE CARE TO
TAKE A STAB AT
-> > > IT.
-> > >
-> > >
-> > >
-> > > thanks Doug
-> > >
-> > > > From: oifa@irishfield.on.ca
-> > > > To: rebel-builders@dcsol.com
-> > > > Subject: Re: [rebel-builders] control cable thimble
-> > > > Date: Wed, 9 Dec 2009 16:14:51 -0500
-> > > >
-> > > > I'm at a lose as to why this was directed to me??.. and not the
Moose
-> > > > builders/fliers in general.
-> > > >
-> > > > ----- Original Message -----
-> > > > From: "Mike Davis" <mike.davis@dcsol.com>
-> > > > To: <rebel-builders@dcsol.com>
-> > > > Sent: Wednesday, December 09, 2009 4:07 PM
-> > > > Subject: [rebel-builders] control cable thimble
-> > > >
-> > > >
-> > > > > Wayne G O'shea
-> > > > > Wayne, on the elevator control cables (moose) murphy used a
machined
-> > > > > grooved steel insert inside the thimble for the elevator. Insert
-> > > rotates
-> > > > > in the thimble .I would use this if it wasn't hid. this is a perfect
-> > > > > setup for rust corrosion and seizure and rotation on the bolt .I
know
-> > > its
-> > > > > there but if someone acquires the aircraft they don't. What did
you
-> > > change
-> > > > > this to .
-> > > > >
-> > > > > thanks
-> > > > >
-> > > > > Doug Wilson
-
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