On Wed, 11 May 2016 15:55:18 -0700, MNLou wrote:

I will by flying my LAK17at at contests and camps this summer. I will
need to tie out the glider.

I am trying to figure out a good way to tie down the wings. With 18m
wingtips, the ailerons extend almost to the end of the wingtip. I am
concerned about damaging the aileron if I just throw a strap over the
top and tighten down.

Don't know whether this helps, but....

I made a pair tip caps. These are glass+carbon mouldings. The top and
bottom surfaces are joined at the TE and round the end of the tip. They
are handed and slip onto the wingtips from behind. There's an alloy
bobbin mounted on a piece of 1.5mm epoxy plate and glued onto the upper
surface of the mouldings. Each tip-cap is lined with pieces cut from 6mm
foam-rubber camping mat that is glued in so it won't fall out and get
lost.

To use them, I put trestles under both wings to steady them, slip a tip
cap over each and run soft climbing rope round the bobbin, forward over
the LE and down to a Claw tiedown placed directly under the LE and with
the top rope angled 45 degrees inward where it is on top of the wing. The
rope is snugged down to hold the wings firmly on the trestles. Angling
the rope in makes sure the tip-caps cant work off outwards and puting the
centre of the Claw directly below the LE minimises fore/aft loading on
the wings.

These work well on my Libelle and fit nicely with wing covers on or off.
I've seen no sign of the ropes getting pulled loose, even in quite a lot
of wind.

If you want the tip caps to stop ailerons/flaperons from flapping, make
them long enough spanwise to fit over the control surface' outer ends and
deep enough chordwise to extend 1.5 to 2 times the width of the control
surface. By putting the bobbins well outboard you should be able to feed
the rope tension onto the fixed TE outboard on the control surface and
avoid loading its hinges.

Any ideas would be greatly appreciated.

If you like this idea and would like to see pictures, just ask: there are
none online at present but putting them up is no problem. I made pics of
the bits while I was assembling them.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |