Rahul's RC Aircraft and other designs

A fast composite aircraft  Span : 48" Root Cord : 14" Tip Cord : 7 & 3/4" Sweep : 3/4" AUW = 74 oz This build stared much earlier but had stalled after the wings were made.. finally after delay of around 6 months the work on the fuselage was resumed.  This was also a my experimentation with different aerodynamics and materials  and construction techniques... From an aerodynamic perspective, choice of airfoil, multiple control surfaces in each wing and their inter-relatedness in the control of the aircraft, factoring the fuselage for CG considerations .. From construction, materials, use of  composite uni Carbon fiber tape as the wing spar. Kevlar hinges, refinement of my fiber glassing technique, Undercarriage mounting, thin fiberglass cowl molding There were many learnings, specially how the weight went much higher than expected due to wrong decisions and construction techniques, and how to avoid damaging kevlar hinges,  The airfoil preparation for hotwire ...

This is a 1000 mm span aerobatic aircraft, in the lines of a pattern ship built during covid lockdown The wing is symmetrical , constant cord Span : 1000 mm Cord : 200 mm + 40mm aileron Airfoil :FX 77080 and 15% thickness The wing is hotwired, and the leading edge is fiberglassed with 100 gsm FG, upto 25%. This itself acts as a spar. Something like a D box.  The full length ailerons are 5mm depron covered with paper for stiffness The tail assembly, horizontal and vertical stabilizer, are constructed our of 5mm depron , with the leading edge (upto 25%) covered with paper Fuselage is box construction out of 5mm depron. The underside is fiber glassed  with 100 gsm FG The cowl was modified and the ailerons were trimmed to align with the wing tips She is beautiful .. both in looks as well as in flight characteristics.. hammerheads are perfect, rolls are controlled , it flies as if on rails..  

A pivoting wing design in the lines of Mignet's Flying Flea Front wing : Span : 755 mm Cord : 155 mm Airfoil : NACA 23112 Dihedral Rear wing Span : 510 Cord : 155 mm Airfoil : NACA 23112 No Dihedral Motor : 2204, 1400kv, 3s 1500 bty, 30A ESC, 7x4.8 prop, 2x 9gm servos. All these are reused components , and specially the motor/bty/esc combination could have been much smaller and lighter Horizontal separation of wings 15 mm, Vertical Separation of wings 85 mm Wanted to keep the construction  simple Both the wings have the same cord and airfoil. This makes construction easy in terms of hotwire airfoil template / ribs> The wings are hotwired out of EPS, and the leading and training edge have been laminated. There is a 3/4 span 3 mm CF road in the front wing.  Two thin Aluminium "L" section have been epoxied at 20% of the cord, on the bottom surface of the front wing. The lower prong of the "L" have holes through which a bolt attaches it to ...

This is a 40" span KF flying wing Airfoil is KF2, 50% top and 7.5% Root Cord - 25cm, Tip Cord - 25cm , sweep distance -25cm CG -17.5 cm from wing leading edge It has one CF spaning the whole wing.. Latter version had 2 X 3mm spars Bty- 1000mah 3S 2228, 1400kv 7X5 prop AUW with cam - 465gms I did not quite believe in the advantages of a KF airfoil .. but this aircraft flies (glide ratio, and sink rate)  much better than a flat plate wing... and the difference is quite noticeable .. She is a great flyer.. good climb, good glide.. very stable, once trimmed can fly in a thermal with  minimal inputs. Stalls are predictable A video from a on-board cam https://www.youtube.com/watch?v=3VPjojkbF04 The first aircraft broke apart in mid flight when trying to pull up after a high speed pass..  as the design was very good was tempted , and built a second aircraft  on the same lines .. more strengthened (with 2 X 3mm CF  spars in the wing.. the e...