Conference vmszoo::rc

    
    Jim,  A common method used in years past was to use 45 wadcutter ammo
    from a 45 auto.  They are reasonably flat on both ends. Are very
    adjustable and easily housed in a brass tube installed in the wing.
    I've seen them added and the a small balsa stick slipped in to take
    up the excess area.  Then the weight and balsa is removed and
    reinstalled, balsa first and then the bullets. A small piece of tape
    seals the end of the tube.  This keeps the weight close to the fuse.
    
    Tom

    The Airtronics Adante I picked up has ballast tubes in the wing. They
    are installed right next to the wing rod tube and is just a piece of
    brass tubing. It's probably about a half inch diameter. The plans
    basically just show sheeting one side of the wing, cutting a notch out
    of the foam for the tubes, gluing them in, and sheeting the other
    side.
    
    Actually I lied. It doesn't have ballast tubes. What it has is the hole
    cut into the root rib for the insertion of a balast tube. Everything 
    else I said is still true.
    
    Another method I've seen is to put the ballast tubes along side the
    fuse (internally) just a hair longer then the wing saddle. The claim
    is that there is no added "dead weight" strain on the wing and it
    helps stiffen the fuse sides in an area that usually suffers damage.
    
    Steve

    I have used cardboard model rocket tubes glued through holes cut in
    the wing spars, or buried in a hole bore into the wing foam.  My
    Algebra came with a 1/2" aluminum tube which was to be sharpened on
    one end and used to bore holes in the foam, then it was cut in half
    and each piece epoxied into the wing next to the spar.  Solid bar
    stock of a slightly smaller diameter works pretty well as the ballast.
    If possible I would attempt to put the ballast in the wing, rather the
    fuse, I think this puts less stress on the wings.  Another thing I have
    learned about ballast is that you should attempt to increase the wing
    loading by a noticeable difference, I used to add a 4 0z. weight  in
    the fuselage of my 2-meter Sagitta and it really wasn't noticeable. The
    13 oz. weight I used to put in my Paragon did make a noticeable
    difference.  After reading Martin Simon's articles, I am not sure that
    ballasting works well for high lift/high drag ships, they may penetrate
    better, but lose a lot of altitude doing so.
    
                                                    Regards,
    
                                                    Jim

    Any light tube will do, typically alloy, but even glass fibre spiral
    wound round a suitable former and coated in resin has been successfully
    used. Make sure that the former is well coated in some form of release
    agent though.
    
    A trick often used here in the UK if you have spoilers is to load the 
    ballast in short lengths from the spoiler end - the tube being accessed
    when the spoiler is open. This means that, with suitable lengths of
    wood dowel as spacers it is possible to vary the amount of ballast
    quite precisely, and you don't have to unplug the wings each time.
    
    Hope that makes sense,
    
    Malcolm

    Hi there,
    I don't know much about this subject. This the reason for this
    question. What do you the ballast for?
    
    Curious
    

    Adding ballast increases the wing loading.
    
    Increasing the wing loading forces the airplane to fly faster in order
    to maintain the same L/D.
    
    Flying faster means that the plane will penetrate higher headwinds
    better.
    
    Or, if wind is not a factor, the higher speed can be advantageous
    in speed events such as the F3B speed task, but this is not invariably
    true.
    
    Do not feel deprived if you don't need/use ballast. If you rarely or
    never fly in conditions that might need ballast, as I do, the subject
    will remain academic.
    
    Terry

    We fly in various conditions in the New England area. I find that there
    are gas bag days and lead sled days. If you build light but strong you
    can vary the wing loading to overlap both types. You can add weight to
    a gas bag but it's a little harder if you initially build a lead sled.
    You need a little extra when the wind starts hitting 25mph but you want
    to be ready for the calm days.