Dr Kiwi
11-12-2002, 09:49 PM
Building the Herr StarLite
I have recently completed a Herr StarLite and thought I could share with you the minor modifications I made during construction. The kit goes together in very straightforward fashion but I departed from the party line in a couple of places. Wing center section: I used 1/32" sheet between the central ribs above and below on the center section of the wing - I felt that the recommended tissue alone might easily be damaged by the hold-down rubber bands. Push-rods: I went the easy route and used a Du-Bro Micro push-rod system, rather than the complex, wire-bound to carbon rod-bound to wire, system supplied. Covering: an interesting comparative exercise. I initially covered with the supplied tissue and two coats of thinned dope. The tissue wing covering tended to warp the frame and was not as drum-tight as I would have liked, so having weighed the wing (36g), I then re-covered in SoLite. Easier to apply, drum-tight without warps, and weight the same at 36g! Motor mount: I screwed, rather than glued, the motor to its ply mount. Battery and servo position: The plan shows a long flat pack battery which extends rearward into the underwing compartment, and the servos as far aft as they'll go, but this produced a CG far too far aft. I moved the receiver and servos as far forward as they'd go in the underwing compartment, and placed the folded battery (in a foam tray, cut from GWS receiver packing) immediately behind the motor (photo below). CG was now spot on. A comment on RTF weight - how do they do it? The motor (geared Wes-Tech Micro DC 5-2.4 with carbon fiber prop - 12g), the radio gear (R-4P receiver in foam, Pico servos, and 2amp ESC - 24g), and battery pack (folded 8-cell,120mAh NiMH - 28g), produced a total of 64g (63g max recommended). With a 36g wing and 50g fuselage/uc/pushrods etc my RTF weight was 150g (5.3oz). The recommended weight, however, is only 114g (4oz), with an absolute maximum of 142g (5oz) - there is even a suggestion in the instructions that "with careful wood selection" one should be able get the whole thing down to 100g (3.5oz)! Yes, I suppose one could use slightly lighter radio gear, but I'd like to know how one takes another 40-50g from a plane this size by using lighter wood!
I have recently completed a Herr StarLite and thought I could share with you the minor modifications I made during construction. The kit goes together in very straightforward fashion but I departed from the party line in a couple of places. Wing center section: I used 1/32" sheet between the central ribs above and below on the center section of the wing - I felt that the recommended tissue alone might easily be damaged by the hold-down rubber bands. Push-rods: I went the easy route and used a Du-Bro Micro push-rod system, rather than the complex, wire-bound to carbon rod-bound to wire, system supplied. Covering: an interesting comparative exercise. I initially covered with the supplied tissue and two coats of thinned dope. The tissue wing covering tended to warp the frame and was not as drum-tight as I would have liked, so having weighed the wing (36g), I then re-covered in SoLite. Easier to apply, drum-tight without warps, and weight the same at 36g! Motor mount: I screwed, rather than glued, the motor to its ply mount. Battery and servo position: The plan shows a long flat pack battery which extends rearward into the underwing compartment, and the servos as far aft as they'll go, but this produced a CG far too far aft. I moved the receiver and servos as far forward as they'd go in the underwing compartment, and placed the folded battery (in a foam tray, cut from GWS receiver packing) immediately behind the motor (photo below). CG was now spot on. A comment on RTF weight - how do they do it? The motor (geared Wes-Tech Micro DC 5-2.4 with carbon fiber prop - 12g), the radio gear (R-4P receiver in foam, Pico servos, and 2amp ESC - 24g), and battery pack (folded 8-cell,120mAh NiMH - 28g), produced a total of 64g (63g max recommended). With a 36g wing and 50g fuselage/uc/pushrods etc my RTF weight was 150g (5.3oz). The recommended weight, however, is only 114g (4oz), with an absolute maximum of 142g (5oz) - there is even a suggestion in the instructions that "with careful wood selection" one should be able get the whole thing down to 100g (3.5oz)! Yes, I suppose one could use slightly lighter radio gear, but I'd like to know how one takes another 40-50g from a plane this size by using lighter wood!