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1 13th August 19:33
tommy
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Default Bell Cranks- which is best


Forget about bellcranks, Install some small servos out in the wings. Much
better.
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2 13th August 19:33
dbdorton@hotmail.com (doug
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Default Bell Cranks- which is best


Bellcrank? You said bellcrank, right?

I didn't think anybody used them anymore.

I certainly wouldn't use them on a '90' size warplane. Use a servo. It
will save you money in the long run when you don't have to replace the
plane due to loosing a aileron, because of fludder.
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3 13th August 19:33
micheal h. gordon
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Default Bell Cranks- which is best


Fludder? Is that a Spirit of Utah term? I not familiar with that one
Doug . Saw yer show in Heber. I liked it!

snip a lot of stuff


--
Mike Gordon AMA 320990
Remember; RC Pylon Racing, the Ultimate Thrill,
when *** and drugs just ain't enough
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4 14th August 03:22
mjc
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Default Bell Cranks- which is best


Bellcranks will double the slop and halve the fun (as in watching your
ailerons flutter away at altitude). Servo's just don't weigh that much so
put it out in the bay ahead of the aileron arm and you'll only have about 4"
of straight control rod to mess with.

MJC
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5 14th August 03:22
fred mcclellan
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Default Bell Cranks- which is best


Nope, none of those bell cranks will do. _WAY_ too sloppy.

http://nelsonhobby.com/ make serious bell cranks.

Nelson have purportedly changed the design, going from double truss to
single truss, and I've not used any of the new offerings, but the
originals are somethin' else !

The Nelson bell cranks are supported by ball bearings and use ball
joint connectors. Zero, and I mean _zero_, slop.

I'll be adding photos of a bell crank aileron installation in a 1/3
scale L-4 when TD Bill gets past and I can get out to the building
shed. There is one photo of a Nelson bell crank setup in the photo
album "Split Elevator Linkage", third photo, at
http://home.bellsouth.net/p/pwp-modebof

Not the best photo in the world, but you can see the double-truss bell
crank. First class setup, _if you have the room_.
Cheers,
Fred McClellan
the dash plumber at mindspring dot com
AMA L180201
IMAA LM 090
NASA 6512
LHA 3
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6 14th August 11:21
dbdorton@hotmail.com (doug
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Default Bell Cranks- which is best


Hi Gordo,

Glad you liked it. It was probably the best show we've done in quite a
while. Short and sincere. I didn't know that my combat ship would flat
spin like that.

Fludder is what the rudder does. Doesn't do it very often and is very
difficult to detect.

How'd you like the "The Dragon and His Tail?" The 'Morning Deseret
News' said that it's the last B-24 flying.
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7 20th August 09:58
m dennett
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Posts: 1
Default Bell Cranks- which is best


There may have been a bit, IIRC there was a tiny "click-click" when I
wiggled the ailerons, but the connectors and holes were properly sized.
However there are twice as many connection points and it stands to reason
that slop will be more of a problem than with a short direct connection. The
hinge gaps were reasonable. This was a Sig Kommander (I think - it was a
shoulder wing right?) kit, that I flipped upside down into a low winger and
flew with a .60, so it moved pretty fast and I beat it up every chance I got
too. These were lightweight barn-door type ailerons, so that likely
contributed to a propensity for flutter. I didn't dork it that time btw,
managed to get it down on the remaining aileron. Before I realized I was
near sighted and my depth perception was less than perfect though, I flew it
through a dead tree at >100mph after pulling out of a vertical WOT dive.
That was entertaining - the engine and fuselage stayed in the tree but a
shower of foam and covering sprayed out the other side. A stick rammed
itself down through the carburetor throat and into the crankshaft port and
ther cooling fins were plugged with wood and bark. Oops.

I guess my main point was that right after this episode (circa 1985) I
started using twin servos and right awaysensed an improvement in control
feel, and never went back. I immediately retrofitted a couple of aircraft
with outboard servos and things were better. Thus I can't see why I would
choose bellcranks versus twin servos, as it seems hard to make a case that
bellcranks have any functional benefit in comparison.

Mike D.
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