On Monday, July 15, 2019 at 8:45:05 AM UTC-4, Michael Opitz wrote:
At 08:44 11 July 2019, Senna Van den Bosch wrote:
I've been flying my DG-101 for a year now and really love it.
However,
there are some gaps which haven't been sealed and I'd like to give
tuning a
shot.

Does anyone have experience using aileron fences? Would it be
worth using
to increase handling?

My rudder has no gap sealing to transition from tail to rudder. Is
this
advised to still have that sealed?

Is turbulator tape something interesting? I have seen some articles
on this
for a Standard Cirrus but can't seem to find a definitive answer.

Last but not least, winglets. I know there are no factory upgrade
winglets
available for a DG-100/101, but could it be possible to add the DG-
300
winglets?

Every % of performance is welcome, feel free to add your options



There is one glaring omission in this discussion, and it that is the
issue of post-mold cure and spar waves on the wing surfaces. DG
was better than most, but most gliders of that generation suffered
from the thick resin in the wing spar caps continuing to cure (and
thus shrink) over a period of ~2 years after manufacture. This
process creates spar waves which will act to trip the laminar
boundary layer to turbulent at a point on the wing chord well before
the intended design transition point, thus significantly reducing
performance. If you have a wave gauge, you can measure the
waviness of the wing profile. If you don't have a wave gauge, you
can simply take a handkerchief, (or paper towel, or a very thin
plastic shopping bag, etc) and use it flat underneath your
outstretched flat hand to rub chord-wise across the wing surface.
Some designers have also commented that spar waves on the under
surface of the wings are at least as important as those on the upper
surfaces, if not more so, due to large lower surface laminar
separation bubbles on that generation of airfoils. You will feel any
significant waves this way. If you want to improve performance and
you have spar waves, then you will need to get rid of them. If the
waves are not too big, and if the gel-coat was applied thick enough
at manufacture, then judicious sanding and polishing might be able
to remove most of them. Probably best to check with your CAMO or
someone who has done this more than a few times already, because
if you are not careful, you can go through the gel-coat. If you are
very lucky, the glider won't have much for spar waves, or a previous
owner had already fixed the issue at another time before you bought
it. While you are at it, make sure the dive brake caps are flush too,
and by all means do seal the glider up... Basic glider tuning course
"101" :-) Smoothing wings that were previously wavy will lead to a
noticeable performance improvement when flying alongside other
similar gliders, like if you were to want to race in Club Class, etc.

RO

Phase 2 after all the easy stuff has been done.
I agree with checking the drive brakes. Another easy job.
BTDT
UH