taildragger toe-in vs toe-out AGAIN

On Sat, 15 Nov 2003 20:49:41 GMT, Ron Wanttaja
wrote:

On Sat, 15 Nov 2003 20:39:29 GMT, Jerry Springer
wrote:

Another consideration for spring
tension is whether you can get full rudder deflection in both directions with
tight springs.

And yet ANOTHER consideration (depending upon aircraft type) is whether the
tailwheel-mounting spring relaxes when the tailwheel is off the ground.
That may increase the distance between your rudder horn and your tailwheel
horn, not a good situation if your link between the two is tight on the
ground.

Ron Wanttaja

these experiences are interesting. I guess you sort it out by having a
fly of typical aircraft to see whether the results match your flying
style.

on my Tailwind the link rod and taper spring are pretty well together
and parallel when you look at them in elevation.
bouncing the tail up and down doesnt produce any noticeable movement
of the tailwheel.

tailwheels are like yellow volkswagens. you only start noticing them
when you have one at the top of your mental focus. after I sorted out
my tailwheel I started noticing them in photos. Pitts Specials quite
often have the same setup, and in articles in Sport Aviation I notice
that the setup is preferred by others with short coupled frisky
aircraft.

A friend building a Sonerai did some comparisons with all the
homebuilts on our airfield (probably 50 or so) and showed me his wing
tip rock test. you hold the wing tip and rock it up and down while
watching the tailwheel. his target was a tailwheel which didnt move
because of the rocking. of all the aircraft he looked at he said that
mine was the most rigid of the setups and the only one that didnt
wobble all over the place. oddly it is one of the lighest. it is a bog
standard Wittman tapered spring tailwheel setup in tempered SAE4140
steel. works well (though I'm not starting a religion over it :-) )

I hope the guy who posed the original question got something useful
from all of this. I thought he deserved a decent reply.
Stealth Pilot
Australia.

All I need now is 10 extra hours in a day.

Quit wasting time on this newsgroup!! :-)

Ed "not practicing what I preach" Wischmeyer

I think all this toein/toeout stuff comes into play before the tailwheel is
even down.--
walt evans
NX140DL

"Stealth Pilot" wrote in message
...
I should add that in the considerations regarding handling of a
taildragger tyre pressure and tailwheel alignment and gearing are
quite critical as well.

25psi on my tailwind has as much bearing as anything regarding
handling. below 25psi and it is directionally interesting, much above
25psi and it is a bugger to land but very easy to bounce, and bounce,
and bounce.

having the neutral point of the rudder and tailwheel together is
critical. if they are offset from each other you get this very
squirrelly roll out as one has effect, then the other, then the other
until you finally run out of rudder.

the gearing of the tailwheel is important to relaxed landing as well.
having the tailwheel overgeared makes the landing a nightmare.
I tamed mine by moving the link arm in to about half the prior
distance where it attaches to the rudder.


these are all items just as important as toe in/out when considering
taildragger gear.

Stealth Pilot

btw how anyone lands a taildragger with sloppy spring links to the
tailwheel is beyond me.

It depends on whether you have a front or rear wheel drive car,
toe-out for front wheel drive and toe-in for rear wheel drive,
generally speaking anyway. Just because I can't think of a car with
something quite different doesn't mean that it isn't the case, just
that I can't think of it.:-))

OK, just to add more fuel to the fire. As I said I had 20 years of doing car
alignments with repete customers so I got many chances to see "long term"
results. If a car "needs" some sort of "preset" (toe in or toe out) to
compensate for what will happen when it is driven then experience has tought me
that something is generally loose that needs fixing first. Customers want two
things; First they want the car to go down the road straight when they take
their hands off the wheel. (don't ask me why the hell they are taking their
hands off the wheel, I couldn't figure that one out). They also want their
tires to wear evenly. End of story. Tried many manufacturer's recommendations
over the years but zero toe in always proved the best to keep them happy and
coming back.
The inner side of the right tire always seems to wear more on my RV. Don't know
why and don't care. Rotating them and flipping them on the wheels each odd year
gets me 200 hours out of a set. Can't complain; cheap tires and it's the most
stable tail dragger I've ever landed. (my tail wheel springs are snug and the
wheel is the old non-pivoting type. couldn't tell you if that's good or bad)

Jim

On 18 Nov 2003 00:51:52 GMT, (JFLEISC) wrote:

Customers want two
things; First they want the car to go down the road straight when they take
their hands off the wheel. (don't ask me why the hell they are taking their
hands off the wheel, I couldn't figure that one out).
Jim

It's not that they want to drive with their hands off the steering
wheel Jim, it's that they don't want the car pulling to one side or
the other. I don't like that either. When I find that happening to
my car it drives me to distraction. I don't want to have to hold
constant pressure on the steering wheel to make sure the car is
tracking straight down the road (unless the road is crowned, or there
is a steady side wind).

I used to do alignments too. I remember one guy who came in with a
Datsun 2000Z and was complaining about it pulling to one side. Z
cars, like many Japanese cars and a lot of cars now, don't have any
adjustments for castor or camber. All I could do was adjust toe-in,
and that would not correct for a pulling condition. So I took the car
out on the road to find out if it really was pulling. The wind was
blowing strongly directly out of the west that day and the interstate
heads north and south. The car veered to the left when heading south,
and veered to the right when heading north. It COULD NOT be a
mechanical pulling problem or the car would have veered only one way.

I explained that the high winds were simply blowing his car to one
side. He didn't believe me. I suggested we go for a test drive. He
drove. We went south on the interstate, I told him to let go of the
wheel. Sure enough, it veered left. I pointed out the bending
treetops, which were showing us which way the wind was blowing. We
turned around and headed north. Same thing, let go of the wheel and
the car now veered to the right.

I explained that there was no adjustment I could make to correct for a
pulling condition, that the wind was causing his problem that day.

I still did not believe me. Drove away convinced I was just trying to
avoid doing a good alignment.

Corky Scott

On Mon, 17 Nov 2003 17:37:52 -0500, "w b evans"
wrote:

I think all this toein/toeout stuff comes into play before the tailwheel is
even down.--
walt evans
NX140DL

comes into play at any time you get the aircraft off line and are
recovering to straight. regardless of where the tailwheel is.
if you keep it dead straight it is all insignificant.
Stealth Pilot

it's that they don't want the car pulling to one side or
the other.

Ya think?

Ed Wischmeyer wrote:
Suffice to unscientificlly say that
20 years in the automotive alignment business has shown me that cars with toe
out tend to be a bit more twitchy than those with toe in. Have no idea if that
translates to aircraft


It does not. You want a small amount of toe out with the weight on the
wheels. Do a deja search and find some good posts on the topic.

One of the key points has to do with which way the wheels point when one
wing is up.

Ed Wischmeyer

Having had 2 A/C that were a nightmare on the ground until changing the
geometry I wholeheartedly agree.

Note the the aforementioned "wing up" condition can be from a crosswind
landing (take off), you are coming down from a bounce or a bunch of others.

There have been a bunch of comments about other factors, and they make
sense. However in my case I had a Rans Chaos and a Pitts S1-S that were
both more than a handful. Both had toe in. The previous owner of the
Pitts had never been seen to do a good landing but was an excellent
pilot. After setting them up with 0.5 deg of toe out (3 point attitude
with flying weight, set up on greased plates for acuracy) they were both
fabulous to land. Note that I made no other change in either case.

My Pitts only deviates (on the runway..) with the first input of power
on takeoff or if I push on a pedal.

Darrol Stinton in "The Design of the Aeroplane" (excellent book) clearly
states that taildraggers should be set up at 0 deg or some toe out.
NEVER toe in.

A previous comment mentioned that the Pitts factory set their a/c up
with toe in. Given than all Pitts a/c have an evil repution on the
ground (and that mine is now excellent with this one change) do you
think that this is good thing?

Regards

Martin Morgan

On Mon, 24 Nov 2003 12:22:05 +1100, Martin Morgan
wrote:


Darrol Stinton in "The Design of the Aeroplane" (excellent book) clearly
states that taildraggers should be set up at 0 deg or some toe out.
NEVER toe in.

A previous comment mentioned that the Pitts factory set their a/c up
with toe in. Given than all Pitts a/c have an evil repution on the
ground (and that mine is now excellent with this one change) do you
think that this is good thing?

Regards

Martin Morgan
++++++++++++++++++++++++++++++++++++++

Plain or plane truth....

No matter how much testimony is given from those
of us with multiple decades and thousands of hours
of success, there remains that ever present vocal
minority which only finds solace in opposition. They
can be convinced of nothing. For these tortured
souls, the wheel MUST be reinvented and history
MUST be repeated.... usually by somebody else
that they will never believe, either.

Barnyard BOb -- over 50 years of successful flight

- Barnyard BOb - wrote:

On Mon, 24 Nov 2003 12:22:05 +1100, Martin Morgan
wrote:


Darrol Stinton in "The Design of the Aeroplane" (excellent book) clearly
states that taildraggers should be set up at 0 deg or some toe out.
NEVER toe in.

A previous comment mentioned that the Pitts factory set their a/c up
with toe in. Given than all Pitts a/c have an evil repution on the
ground (and that mine is now excellent with this one change) do you
think that this is good thing?

Regards

Martin Morgan
++++++++++++++++++++++++++++++++++++++

Plain or plane truth....

No matter how much testimony is given from those
of us with multiple decades and thousands of hours
of success, there remains that ever present vocal
minority which only finds solace in opposition. They
can be convinced of nothing. For these tortured
souls, the wheel MUST be reinvented and history
MUST be repeated.... usually by somebody else
that they will never believe, either.

Who are you accusing of reinventing the wheel? The Pitts factory, or
the person who improved the landings by removing the toe in?