|Finished Allegro Lite RC Sailplane|
|Allegro in Flight|
With the all the plans and instructions downloaded from the Charles Rivers website I started the construction of the Allegro Lite on a glass surface using bags of bird shot for weight as recommended. Building the wing was an overwhelming task for me, it is a combination of balsa and composite materials. Spar construction consists of end grain balsa sandwiched between carbon fiber strips. This is wrapped with Kevlar tow (loose fibers) and then painted with a slow curing epoxy. The design objective for this sailplane was for it to be able to withstand any flying load including full-pedal winch launches. A friend of mine did manage to break the tailboom on a particularly brutal launch with his Allegro Lite.
|Wing Spar and Tip|
|Another View of Spar After Sheeting|
Obtaining the special components needed for this project was somewhat easier in that I obtained a partial kit that had those composite components and laser-cut ribs. Building the wing was such a task that at some point I felt like if I finished this plane and it crashed it I would be devastated. It sat for years at about 90% complete and then I started slowly working on it again last winter. Just within the last couple of weeks have I started flying the glider. It flies very well but somewhat faster than I had anticipated. Still nervous flying my pride and joy I have only made thermal flights of no more than 5 minutes by making big circles over the field.
|Hatch Held With Magnets|
If more nose weight could be crammed in the tiny nose pod it would be good to try because the CG is slightly behind the recommended spot and it seems to be close to tip-stalling occasionally. I used powerful tiny magnets to hold on the nose hatch this has worked very well.
What a feeling of accomplishment I have from building this model airplane.
Charles River RC Article and Plans for Allegro Lite
Dr. Mark Drela MIT
XFOIL Airfoil Program
Daedalus Human-powered Record Setting Airplane
Download Plans for Rubber Power Free Flight Corsair Designed by Mark Drela
Human Powered Speed Record Set on Water - Decavitator