RE: Mass balance boxes

[James Thursby <JThursby@tampabay.rr.com>]

I have found that it is best to leave the mass balance weights off  the
ailerons, until ready to mount them to the wing. Some of the early XS wings
that I have seen, the box recess in the top wing skin did not line up with
the balance position on the aileron. You can make a temporary balance arm
out of foam to simulate the foam and lead portion of the weight. Sand and
carve this one to proper shape, and THEN make the actual arm for mounting.
You will probably need to shave quite a bit off  the top of the arm. Don't
worry, they are way over balanced as supplied.  Try to get the box as tight
on the upper skin as possible. Hope this helps.


                      Jim Thursby
                          N814AT
    -----Original Message-----
    From: owner-europa@ns1.avnet.co.uk
    Subject: RE: Mass balance boxes


    I hadn't noticed the "T" and "R" markings - I'll look for them tonight.
    I'm currently at the same step - putting on the boxes, but I did not
    make the mass balance weights until now so I'm not having any fit
    problems. My manual makes no mention at all of the size and shape of
    the wing cutouts for the weights, and the section on mounting the
    mass balance boxes is very short, with one extremely illegible
    photo-copied photograph and very little text. No mention is made of
    a root and tip box.

    Unfortunately, getting a very early XS has meant that my wing manual
    is all but useless.

    David

    -----Original Message-----
    Subject: Mass balance boxes


    Everyone else probably already knew , but since I just "discovered" this
    little tidbit I thought I'd throw it out.

    I'm (attempting) to fit the mass balance boxes to the port wing and,
    quite by accident, noticed the letter "T" scratched into the underside
    of the top of two boxes and "R" likewise on the other two.  I had
    noticed a slight difference in fit, but there's no mention in the manual
    that there are two root  and two tip boxes.  Did I miss another
    newsletter entry?

    Speaking of fit, when I set my root balance box hard against the
    trailing edge closeout, the root mass balance arm's tip hits the box's
    closeout.  I need about 5 mm to get them to clear.  I see three options
    here: trim the end of the weight to fit (repairing the removed uni and
    bid when done), cut out the end of the balance box and lengthen it
    sufficiently to clear the weight, or affix the box so the weight is
    clear and fill the gap (again, about 5 mm.) at the trailing edge with
    flox.  A fourth option would be to use the remaining tip box, but that
    would leave me with two root boxes for the starboard wing and I'm unsure
    how well that would work.

    Thanks in advance,

    Steve G.