Hi,
     Can any one clarify/suggest if dihedral is needed for low-winger sport planes. I have a foam (blue-foam) kit that I purchased long back and have sketchy instructions from the manufacturer. Pls. advise on whether dihedral is essential/preferred on a low-winger.

Also, the wing span of this plane is 48 inches (chord is 6.5 inches semi-symmetrical, without ailerons)while the fuse length is 26 inches. Put together (not glued) the wing and fuse assembly looks awkward with the outsized wing and the short fuse. Is there any issue with such dimensions. Pls. advise.

It is not essential, but dihedral does help stability and is used in a lot of sport models.

Low wing airplanes "should" be given a slight dihedral (1-2 degrees).
Dihedral adds roll stability (or instability), ie if you roll the plane, without dihedral the plan would track straight, and with dihedral it would auto level.  Anhedral is opposite.

Now if you have a low wing airplane, and do not give it any dihedral, then it will have anhedral properties. Therefore to correct this you need to give a slight dihedral.

High wingers do not need this, in fact, a slight anhedral can make them track straight ( not recommended for beginners though ) .

-Gaurav

as far dihedral is concerned a low wing airplane needs more dihedral than a high wing airplane to achive same dihedral effect,
dihedral adds self correcting ability to the airplane , i suggest a littile dihedral, for me a dihedral of 3 degrees with high wing airplanes do the job.

but don't give too much of dihedral..or you will loose roll rate...spoiling the fun a sports plane should give