DG-300 Wing fore/aft pin slop

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I'm a new owner of a 1984 DG-300 with 700 hrs. Upon first assembly,
it is apparent there is approximately 1/8" gap between the wing root
and fuse. Also there is what appears to be a moderate amount of
movement of the wings fore/aft when moderate force is applied. What is
the acceptable amount of movement? Is there an adjustment, or shim
placement that could be expected?? I'll could feel "bumping" of the
wings in turbulent air. thanks...

[5Z]

We used shims on my ASW-20B to eliminate the slop.

On the '20B, the fore and aft pins in the fuselage can be knocked out
using a steel rod through a hole in the pin on the other side, and
gentle tapping with a hammer. Thin metal shim "washers" were installed
until the clunk went away.

Fly straight at 60 knots and wag the rudder slowly. If there's no
clunk, then slop is gone.

Beware, on some ships (PIK-20D) the spars and carry through tubes have
different coefficient of expansion. If you get rid of the clunk on a
cold day, you may never be able to assemble on a hot day. In this case
you can't completely get rid of the little bit of play.

Also, the gap between fibreglass parts on fuselage and wing is really
inumportant - it's the gap between the metal parts. That's why we have
tape! :)

-Tom

[John C]

I own an 1985 DG-300 3e127 with 1350 hrs. I too have a sizeable gap
between the wings and fuse (~1/8") after assembly. However, my wings
have virtually no freeplay or movement at the tips. The maintenance
manual does call for installing shim washers on the pin(s) when there
is freeplay (sec 1.10). With the amount of motion you describe I would
get it looked at. After consulting with your local A&I you could
contact DG's service dept via email for washers (and/or specifications
on max allowable freeplay). They have always been very helpful for me.

John Cotter (XJ)

[Marc Ramsey]

wrote:
> I'm a new owner of a 1984 DG-300 with 700 hrs. Upon first assembly,
> it is apparent there is approximately 1/8" gap between the wing root
> and fuse. Also there is what appears to be a moderate amount of
> movement of the wings fore/aft when moderate force is applied. What is
> the acceptable amount of movement? Is there an adjustment, or shim
> placement that could be expected?? I'll could feel "bumping" of the
> wings in turbulent air. thanks...
>

There should be essentially no fore/aft movement of the wings. First
and most importantly, look at the two brass bushings in each spar end to
make sure they are not obviously worn or distorted. The bushings can be
replaced, if needed. If that is not the problem, get some shim washers
for the drag pins (your local DG rep will have them in the right size).
Stand near the fuselage and have someone move each tip fore/aft, it
should be obvious where the shim(s) need to go (at least it was to me).
Pull the wings out, slip the shims on for a trial fitting, push in and
pin the wings, and try again. If you need more than one shim on a drag
pin, try to evenly distribute them on both sides of the fuselage. When
it is set up to you liking, you can use a small amount RTV sealant to
glue the shims on semi-permanently. Remember, though, if it is winter
where you are, the fit will be noticeably tighter when the weather gets
warmer. So, leave a bit of slop now, if you don't want to be tearing
your hair out come summer...

Marc

[Andy]

You put the shims on the load bearing face of the lift pins??? On
Schleichers the shims have to go behind the lift pin shoulders. A
trial fit can be done on the font face but then the lift pins must be
removed and the shims placed behind.

Andy

[Marc Ramsey]

Andy wrote:
> You put the shims on the load bearing face of the lift pins??? On
> Schleichers the shims have to go behind the lift pin shoulders. A
> trial fit can be done on the font face but then the lift pins must be
> removed and the shims placed behind.

This is the standard way it is done with DGs, they even supply a few
shims along with other parts when it is purchased new. The supplied
shims will not fit on the back face of the pin.

Marc

[Bill Daniels]

"Marc Ramsey" > wrote in message
...
> Andy wrote:
>> You put the shims on the load bearing face of the lift pins??? On
>> Schleichers the shims have to go behind the lift pin shoulders. A
>> trial fit can be done on the font face but then the lift pins must be
>> removed and the shims placed behind.
>
> This is the standard way it is done with DGs, they even supply a few shims
> along with other parts when it is purchased new. The supplied shims will
> not fit on the back face of the pin.
>
> Marc
>

From an unnamed glider maintenance manual:

"Tangential backlash (Movement back and forth at the wing tip.) can occur
due to the wear of the washers which are pressed onto the wing attachment
pins. If the movement exceeds 45mm (!) additional washers can be pressed
onto the pins." Talk about a glider being a loose formation of parts.

Bill Daniels

Bill Daniels

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Thanks, that's very helpful, it's still it bit cool out here in AZ. I
might wait a couple months to see how the wings install when its
warmer.

I have another question in regards to the Tech note regarding the
landing gear down/lock modification. I forget the T/N #, but DG sells
the kit for approx 70 euro. Has anyone installed this mod, how are the
results..

[John C]

I just had that T/N installed last month. My gear handle was not yet
very loose, but if you talk to other owners, it is just a matter of
time before that handle gets so loose as to flop out of the gear down
position. The T/N fix is very nice in terms of how positive the action
is when reaching both the up and down positions. IMHO the torsion
spring weight they chose is just right.

John Cotter (XJ)