Inside F5J 2.9m

The Inside F5J is a lovely built up laser cut balsa, ply, and carbon kit for competitive F5J flying without breaking the bank. The Inside F5J has been developed from the Introduction F5J with the major changes being improved structure giving a lower weight, six servo wings with outer ailerons, inner ailerons, and flaps and reduced dihedral to give more precise control in windier flying conditions. The reason for the three control surfaces in each wing half is to keep each control surface structure reasonably short so that it does not deform and twist under load, even when using all balsa construction

The Inside F5J is extremely good-natured in climb, in thermals and when landing. It has a good speed range through the use of the AG35mod profile with outstanding cruise and thermal characteristics. Its good control response allows accurate positioning in a thermal and allows the thermal to be tracked easily as it drifts downwind, giving great climbs. The fully articulated wing allows the camber to be decreased when increased speed is required when returning to the field from far downwind.

The 2866 mm (113 in) easy build wing with full camber control and a flying weight from 1100 g makes the Inside-F5J an ideal model for an aeromodeller looking for a high performance F5J plane without breaking the bank. The recommended Hacker A20-22 brushless motor, a 3-cell LiPo with 900mAh – 1300mAh capacity and an Aeronaut CamCarbon 11×6 prop gives many climbs to thermal altitudes. Due to the low flying weight 5s -10s motor runs per climb are usually sufficient.

The central design feature of the wings is the carbon fiber tube, onto which the laser-cut ribs are threaded. Stylish wingtips ensure an elegant surface finish. The balsa fuselage is reinforced in the front area with light plywood. A milled firewall is already prepared for the Hacker A20-22L evo. Apart from the laser-cut components, the kit also includes CFRP spars, GRP nose strips, as well as control rods and small parts. An excellent full scale full colour plan and a richly illustrated German construction manual is supplied. An English translation is here and an improved one is here – print it double sided.

Not included in the kit are adhesives, covering material, powertrain and RC components. For covering the model we recommend Oracover Light film. Lots more info in this Inside F5J RCGroups thread. Thanks to Lauri Maalismaa and RCGroups members for use of the photos.

Inside F5J Specifications
Wing span	2.9 m	113 in
Wing area	65.0 dm2	1008 sq in
Length inc spinner	143 cm	56.4 in
Flying weight from	1100 g	38.8 oz
Wing loading	16.9 g/dm	5.5 oz/sq ft
Aspect ratio	12.6
Wing airfoil	AG35 Mod
EDA (dihedral)	6.6º
Spinner Diameter	38 mm
Centre of Gravity	87-90 mm from wing leading edge
Controls	Rudder, elevator, outer ailerons,inner ailerons, flaps, throttle

Inside F5J Typical Weights
Structure	790 g	27.9 oz
Wiring	25 g	0.9 oz
Receiver	10 g	0.4 oz
Rudder servo	11 g	0.4 oz
Elevator servo	11 g	0.4 oz
Wing servos (6)	60 g	2.1 oz
Speed control	30 g	1.1 oz
Motor	43 g	1.5 oz
Prop & spinner	20 g	0.7 oz
Battery	100 g	3.5 oz
Flying weight	1100 g	38.8 oz

Recommended RC
Rudder & Elevator	KST X06, KST X08, MKS DS6100, MKS HV6100, Blue Bird BMS-125, Blue Bird BMS-126, Graupner DES 427BB
Outer ailerons	Ripmax SD100, KST X06H, KST X08H, MKS DS6100, MKS HV6100, MKS HV6110, Blue Bird BMS-101DMG, Blue Bird BMS-101HV, Blue Bird BMS-125, Blue Bird BMS-126, Graupner DES 427BB
Inner ailerons	KST X08H, MKS DS6100, MKS HV6100, MKS HV6110, Blue Bird BMS-115, Blue Bird BMS-125, Graupner DES 427BB
Flaps	MKS DS6100, MKS HV6100, MKS HV6110, Blue Bird BMS-115, Blue Bird BMS-125, Graupner DES 427BB
Receiver	9+ channel rx to match your transmitter
Power	30A – 40A ESC with 4A – 5A uBEC

Powertrain Recommendations
Axi 2217/16 V2 Long	2S 900mAh LiPo, 12×6
Axi 2217/20 V2 Long	3S 900mAh LiPo, 12×6
Axi 2220/16 V2 Long	2S 900mAh LiPo, 12×6 or 12×7
Axi 2220/20 V2 Long	3S 900mAh LiPo, 12×6 or 12×7
Hacker A20-22L	3S 900mAh LiPo, 11×6
Hacker A20-20L	3S 900mAh LiPo, 10×7
Dualsky XM2826EA-10 45g outrunner	2S 900mAh LiPo, 10×7
Turnigy C2826-1350	3S 900mAh LiPo, 9×4.5
Mega 16/15/4	2S 900mAh LiPo, 8×4
Mega 16/15/5	3S 900mAh LiPo, 7×5