Tailwheel question

[Steve B]

I have a Starduster SA100 with a Scotts tailwheel. The tailwheel is
not tight on the springs it is loose and the wheel can be moved a few
inches each direction before the springs make contact.

I would think that there should be no play in the springs... my
thought is that it could cause shimmy and also make it unstable on the
ground?

The person that I bought the plane from has been flying it that way
and made no comments about the tention.

Any thoughts would be appreciated.

Steve

[ShawnD2112]

The Taylorcraft I fly is like that and presents no problems. My Pitts, on
the other hand, used to have springs like you describe and shimmied like all
hell on landing. I took all the slack out and tightened them up and not
only has the shimmy gone away but ground steering is much more positive.
Try it. If you don't like the results, you can always put them back the way
they were.

Shawn
"Steve B" > wrote in message
om...
> I have a Starduster SA100 with a Scotts tailwheel. The tailwheel is
> not tight on the springs it is loose and the wheel can be moved a few
> inches each direction before the springs make contact.
>
> I would think that there should be no play in the springs... my
> thought is that it could cause shimmy and also make it unstable on the
> ground?
>
> The person that I bought the plane from has been flying it that way
> and made no comments about the tention.
>
> Any thoughts would be appreciated.
>
> Steve

[Andrew Boyd]

(Steve B) wrote:

> The tailwheel is not tight on the springs it is loose
> and the wheel can be moved a few inches each direction
> before the springs make contact.

These springs stretch over time, and gradually you end
up with what you're seeing. The slop in the controls
makes it harder to control the aircraft on the ground.

On both sides, take links out to get rid of the slop, or
consider replacing the springs if they've gone too soft,
which is common with the compression-type.

Don't overtighten, though - it will increase wear, and
might not be controllable if something in the linkage
on one side breaks.

--
ATP

[Steve Beaver]

Adding a couple of extra points:

If you decide to replace the springs, the compresion style springs are
considerd better than the expansion type and
don't be surprised if the spring on one side is larger than that on the
other. - This is done to eliminate the resonance that would occur with two
identiacal springs.

With an American engine, the heavier spring goes on the right. A European
engine (Yak52TW for example) requires the heavy spring on the left.


"Steve B" > wrote in message
om...
> I have a Starduster SA100 with a Scotts tailwheel. The tailwheel is
> not tight on the springs it is loose and the wheel can be moved a few
> inches each direction before the springs make contact.
>
> I would think that there should be no play in the springs... my
> thought is that it could cause shimmy and also make it unstable on the
> ground?
>
> The person that I bought the plane from has been flying it that way
> and made no comments about the tention.
>
> Any thoughts would be appreciated.
>
> Steve

[Dave Swartz]

The ideal setup, which is difficult to achieve, is to adjust the
number of links such that all slack is removed but the springs are not
significantly compressed. If you put both springs in compression it
is true that you will find ground steering greatly improved.
Unfortunately, if one of the linkages should break (and they often
do), tight springs may make a groundloop almost impossible to avoid
since the remaining spring will pull the wheel on that side. I've
often wished for a simple turnbuckle arrangement in the linkage that
would allow the tension to be set right where you want it.


Dave Swartz
Fort Lauderdale, Florida
http://www.FlightFantastic.US