Anurous - Side Arm Launched (SAL) plank glider... AND ..converted to a powered glider

-

 Here are the details of a SAL 1m plank wing glider

The airfoil is PW1211. The wing is hotwired out of high density EPS. It has a 1mm CF rod epoxied to the underside , and a 5mm  wide CF tow lamination on the LE underside.. these act as spars. The TE has a 2 mm balsa 30mm wide, part of which is also the elevons, and balsa wing tips

Fuselage is a 3 mm CF rod .. with some scrap balsa glued onto it to in front to act as the place to attach the RX and the battery.. the front part of the fuse is covered by a PET sleeve

The wings are but joined with the 3mm CF rod sandwiched in between  and have two additional balsa joiners glued from top

The whole wing and elevons are finished and coated with water based PU sealer mixed with light weight crack seal. 

The rudder is glued onto the 3mm CF rod sticking out behind the TE

It has two 4.5 gms servos controlling the elevons , and the 1s 350 mah bty directly plugs into the Rx.




Dimensions

Root Cord - 230mm (220 mm foam)

Tip Cord - 130mm (115mm foam)

Span - 900 mm (840mm foam)

Sweep forward measured at the foam tips  - 20mm (-ve)

Elevon length - 300mm

AUW with a 1s 350mah bty is 126 gms

2 x 4.5 servos. 1S 300mah battery. Since the battery was 1S, it was plugged straight into the Rx .

The vertical tail kept on breaking after landing.. it was changed to a transparent plastic sheet.

Other than  fine tuning the CG .. one major learning was the tuning of elevon throws, specially elevator, during "launch", "glide" and "thermal"... The plane was very sensitive to these settings..  It is imp to have a bit to down elevator (compared to glide) during launch , else it would loop.. in addition, for launch, a small amount of up aileron has to be applied on the outboard wing, to prevent it rolling up during launch. ... these settings are configured in flight modes on a switch 

Here is a flight video of it as a side arm launched Glider : 

https://www.youtube.com/watch?v=aATh3hIu50Y

CONVERSION TO A POWERED GLIDER

The nose was shortened

electronics : 1811 2000kv motor, 12A ESC, 2S 350 mah bty, 2X 4.5 gms servos

AUW with battery is 185 gms... So the wing loading is 11 gms/dm sq or 3.73 oz/sq ft.. and the wing cubic loading at 2.84... 😁...




The motor had to be kept at min throttle (5%) as it does not have a folding prop... and with the small motor the braking does not work

Got a 33 min flight on a calm day .. 

Flight video link :
https://www.youtube.com/watch?v=BZ6FNMgFH9Q




Comments

Post a Comment

Popular posts from this blog

Flipper - Plank flying wing SAL

-
Image
 This is a Plank flying wing for SAL or bungee The dimensions are  Span = 875mm, Root cord = 260mm, Tip cord = 160mm, sweep = 60mm. 20mm constant cord full length elevons The wing is hotwired out of EPP and then laminated with thin iron-on laminating film. The airfoil is PW51 7% thick at the root and PW51 7.5% thick at the tip. It has a 1.5 degree washout and a 45mm dihedral at the tips.  It has one 2mmCF spar glued to the bottom positioned at 40% cord. There is also a spar on the top surface biased to the rear to avoid elevon reversal. Two 9g servos are positioned vertically into slots cut on the top of the wing. The position of the servos are driven by the thickness of the wing at that part and distance from CG. The full length elevon is a tapered 3mm balsa with fiberglass lamination. ....Note I had to increase the elevon cord at the tips by 12mmto improve the control response (after the first flight trials) The fuselage is a 3mm CF rod glued onto the bottom of the wing...
Read more

Angor-Rot & Hot-Rod hotliner RC plane

-
Image
 Fast, hotliner design These two are built for speed, and unlike a 3 surface (wing , tailplane and rudder) design, they are wings (delta). The thought was having the max wing area for a given wt and strength and with the least friction/profile drag, and of course ease of construction. (ignoring  difference in Induced drag). Construction is composite, foam, glass fibre, carbon fibre and vacuum bagged,  resulting  in a very strong lightweight structure for its wt. Airfoil is PW 51, with a 1.5 degree washout at the tips. Small wing tips are added to draw out the tip vortex. The LE is reinforced with CF. The wings tips and the centre section of the underbelly has some CF  reinforcements built in. It has 2 layers CF tow of different lengths acting as spar. The paint pattern has been painted directly onto the skin and then vacuum bagged. The control surface hinges are live hinges built into the glass fibre skin. The servos and push-rods are embedded with the wing. All...
Read more

WitchCraft

-
Image
DESIGN This design explores the region between a plank and a swept wing flying wing, and to try and get the best of both worlds to whatever extent possible.... The major balancing acts were being efficient across a large speed range, good C l /C d , less twist, and maintaining good flight characteristics. PLAN & DIMENSIONS A span of 1200mm was chosen to keep it a one-piece plane.  - Sweep is a very moderate 13 degrees measured at LE, and even lesser when measured at 1/4 AC line. - - Aspect ratio =- 6.3... (adequate wing loading with the set span of 1200mm span) - Taper ratio= 0.65 and Twist - (-)1 degree..... (close to elliptical lift distribution, less induced drag, while maintaining decent Re and flow characteristics at the tips, good stall characteristics) - Airfoil is PW51.. (good cl/cd, adequate +ve cm, and minimum trim losses).  - A central tailfin is chosen over wing tip fins.... (due the the less moment arm and the issues arising out of a badly designed wing tip ta...
Read more