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Hydro & Marine Redbird Construction - Part 1 Photos and text by Miha Holc

Boat: Hydromarine Redbird Motor: Speed 400 4.8 V Race Cells: 7 x Sanyo 700 AR unmatched/unzapped Servo: Graupner C261 Receiver: Decased Graupner R600 Hardware: Custom stainless steel/brass/aluminium/carbonfiber Drive: 1.2 mm piano wire RTR Weight: 480 grams Speed: Flies like a bird ;) OK, let's begin! First: Electronic components Motor is Speed 400 4.8 V Race with underwater brush seating procedure. This procedure is described on http://www.rccaraction.com but note that the brushes are quite hard and I needed almost 10 minutes @ 5 V to get them in full contact with the comm. Next is the cooling & iron flux ring install. The photo shows only one flux ring (can be obtained from Graupner part No. 1794.1, but I made it from scrap plate of thin iron) but I installed two to get max. torque from the motor. Adding third ring won't help much anymore it is just adding weight. The cooling is very simple and effective À thin brass plate with soldered brass tubes and for sealing there is thin rubber coated with silicone grease. On the ends there are two scres and nuts that squeeze the plate when it is installed and thin fiberglass plates serving as washers. On this photo I made also soldered short brass tubes to the brush tabs but later removed them due to lack of space. On the first runs the can cooling was enough effective enough. 1 2 3 4 5 6 7