On Fri, 02 Apr 2010 15:35:51 -0500, Barnyard BOb
wrote:


The McCreary tires [tyres] furnished by Van's are NOT the way to go.

Remember the name... CONDOR.
They are priced about the same, but are twice the tire [tyre].
I'm told these are made by Michelin. No idea if specs are are same or
not. Cheap tires have weak walls, track poorly and wear fast. Not
Condors.

I use lower 22 lbs pressure... for better shock absorbtion.


Condor. yep they're the ones I was referring to.

if you get any shimmy in the main gear on landing the cause is
brinelling of the single bolt at the top of the leg causing it to
become a loose fit. sure sign of this is the shimmy vanishing on the
application of light braking. replace the bolt and it should be sweet
again.

Thanks for the advice.
I'll definitely try that.

the ground handling is interesting. I will not be using the tailwheel
chain arrangement on the plans. mine will be a solid rod as per my
Tailwind. Originally the Tailwind had the Wittman plans tailwheel
arrangement and was rated as a good flying aircraft but a nightmare in
the ground handling. When I first taxyied the aircraft I recognised a
problem with overgearing of the tailwheel immediately. I made a simple
change that halved the tailwheel movement and the aircraft has been a
pussycat in the ground handling ever since. the plans indicate the the
same gearing problem on the RV3 but it is probably masked by the
sloppiness in the chain and spring arrangement.

From past experiences....
a bit of slop has normally produced best results for me.

However:
With my RV3, no slop has proven best. The springs tho, are anythiing
but stiff and stretch with little force/effort.

What I've been told that makes for a pussycat is TOW OUT.
With TOW IN... you have one mean TIGER.

ZERO would be best, if you can achieve it.

I don't mean to start a war with the above tidbit...
I mean it as a fact of life for taildraggers. g


tailwheel gearing and toe out come into play at different times.
I think both are important.

directional control is definately made easier if the tailwheel
"ruddering" is made just right. on the tailwind the link rod sat
parallel to the tailspring and was overgeared to blazes.
I halved the distance out on the rudder arm which effectively reduced
the throw by half. I wouldnt use anything but a solid link rod because
it allows for such positive correction between the time that the
tailwheel is on the ground and the time that the mains touch.
you can completely straighten a gusted landing before the mains touch
and have a totally uneventful roll out.

toe out works.
if the aircraft is in a swerve to the right (as sensed by the pilot)
inertia will have the left side tyre pressed hard on the ground and
often the right side tyre will be almost off the ground. the right
side tyre could be pointing anywhere because it isnt contributing
much. if the left side tyre in this swerve is toed out then it will be
pointing almost in the direction of movement and it wont contribute
much adverse input.
if it was toed in it would be adding to the forces trying to roll the
aircraft over. ...not what you want.

swerve the other way and the situation is mirror imaged.

I once bent an undercarriage leg with the effect that the right leg
had something like 15 to 20 degrees of toe out. the left leg was
undamaged. on takeoff as you lifted the tail the aircraft would yaw
slightly until the drag off each wheel equalised and in this condition
would quite happily complete the takeoff. I flew back across australia
with the gear like that. it demonstrated to me that an aircraft can
have quite large amounts of toe out with no detriment to the ground
handling.

Stealth Pilot