Piranha 3D Hydro Plane Dear customer, congratulations on the purchase of the Pirañha model. To enjoy building and flying the model most, please read carefully the building instructions before you begin and make sure that you understand the building process. Parts list Part name Pcs Part name Pcs Fuselage main part of EPP 2 Elevator and rudder interconnecting rods/bell 4 cranks Elevator control rod 2 Motor mount 3 Floats of EPP 2 Rudder arm 2 Elevator of EPP 1 Instructions 1 Vertical tail of EPP 2 Elevator arm 2 Rudder control rod 2 Fuselage 1 Auxiliary surfaces 2 Elevators connecting pieces 2 Rudder control bell crank 1 Doubler of the fuselage main part 1 You will need the following tools and materials: CA glue, CA glue accelerator, UHU POR can be used for some of the foam to foam joins, a sharp (modelling) knife, and sandpaper. To complete the model you need the following: a receiver (4ch), three servos (2x5.6g & 1x9g), an Brushless controller (10-12amp), a battery pack (3 LiPo cells of 640-1200 mah), a motor (HCS-80/2E or similar of about 80 W power output) Description of the model: The model is completely made of the EPP, strong enough to enable the Piranha to be used on the water, on the ground and in the air. Due to its revolutionary concept it gives the pilot the choice of pleasures among skimming above the ground or water surface or flying in the air. It is meant not only for experienced pilots, but also for modellers of average skill. You can power the Piranha with a brushless outrunner motor that has about 80W (or more) power & that weighs 35-45g, can be powered by 3 LiPo cells & an 8x4.3 or 8x4DD propeller. Thanks to the well thought out design you should be able to have this plane ready within 3-4 hours. Building the model: Unless otherwise stated, all parts are to be glued by the medium-thick CA glue. Start the building of the model by gluing both fuselage halves (Fig. 1). According to Fig. 2, cut a slit through the fuselage, then glue into it the glass fibre stiffener, using thin CA glue. If you have purchased an unpainted kit, you can paint it prior to construction, or after it is however easier to paint it before assembly. Make sure that you read through the instructions fully before painting to understand how it all fits together also note that the floats need trimming. Now glue the floats in place (Fig. 3) UHU POR is best for this, and sand their front parts to mate with the fuselage. If you plan to operate the model mainly on the water, devote a special attention to the surface finish of the floats. Spray on them the 3M contact glue and, once the glue slightly sets, apply the coloured self-adhesive tape to the surface. Crop the protruding part of the floats (Fig. 4). EPP on it s own is not waterproof & will need some protection if you are planning on using it on water. Glue the vertical tail surfaces along the bottom edge of the fuselage (Fig. 5) so that the hinge axes of both elevators and rudders are perpendicular. Then glue the top elevator in place (Fig. 6), ensuring at the same time that the elevator is parallel to the fuselage. According to the Fig. 7, glue the auxiliary fins in place, so that their rear edges end at the hinge point of the rudders Now glue together the motor mount according to the Figs. 8 and 9, ensuring the axis of the motor shaft is offset by some 3 to the right. It is best to also have a small amount of up thrust (ensure that there is no down thrust, this will prevent your piranha from flying!). Using a sharp knife, cut a 10 mm deep slit in the fuselage parallel to the fuselage axis and glue the assembled motor mount in place (Fig. 10). Glue the servos carefully by their mounting flanges and secure them. It is a good idea to wrap the servos with tape before gluing (masking tape or pvc tape both work fine) this prevents glue entering the servo & also makes it easier to remove the servo in the future should you need to (Fig. 11). If you are planning to use the Piranha on water, you can waterproof the speed controller by sealing the ends carefully with hot glue or a small amount of silicon sealant. Using the Fig.12 as a guide, glue the controller to the motor bulkhead (it is possible to attach it with a Velcro strip or cable tie). Bolt the motor flange in place and secure the motor. Using the five-minute epoxy, glue the rudder servo arm (bell crank) to the rudder servo (Fig. 13). The receiver may be also waterproofed by inserting it into a rubber balloon and tying the end (this measure would ensure complete waterproofing of the model). Then glue the fuselage top to its lower (float) part. Glue the V-shaped bell cranks into the rudders (Fig. 14). Now finish the model using any spray paint (the EPP does not degrade from any spray-can paint, enamel spray paint works very well). Piranha build manual www.robotbirds.com page: 1 / 5
Install the rudder control rods (Fig. 15). Glue the cross-shaped braces of aluminium wire (Fig. 16) according to the detailed drawing on the Figs. 17 and 18. Glue the elevator arm in place (Fig 19) and install the control rods (Fig. 20). Cut slits in the elevators and insert the connector levers to them (Fig. 21). Using the interconnection rods, joint the upper and lower elevators (Fig. 22), checking and ensuring, that the control surfaces are in a neutral position!! Final steps - the model is built. Now check the position of the centre of gravity (CG), which should be 291 mm from the model s nose. By moving the C of G. to the rear, the model becomes more nimble (therefore this modification is recommended to the more experienced pilots only)) and vice versa the more the C of G forward, the more stable is the model. For the initial flights, set the control surface deflection to about 50 %; the elevator servos should be programmed for a delta-winged model (elevon mixing). The rudders serve mainly to control the direction of movement on the surface (both ground and water), but they are effective also in the air. The properly balanced model takes-off in a few metres. Bear in mind, please, that when throttling back, the model does not glide, it sort of sags to ground. If throttled back in horizontal flight attitude, the Piranha lands by itself. The recommended equipment: Battery pack 3s1p 640 mah (Kokam) Motor choice: HCS C 80W/2, HCS23/8/12E, Hyperion 2209 (26 or 32), AXI 2208/34 motor or similar Motor mount you may wish to use a tube type motor mount instead of the included one. GWS 8x4 Direct Drive propeller Castle Creations Phoenix 10 brushless speed controller, Hyperion Titan 10 or equivalent. This model is not a toy therefore avoid flying in crowded places or such areas where you may cause damage/injury to yourself, others or their property. Lots of fun and many happy landings Robotbirds.com Piranha build manual www.robotbirds.com page: 2 / 5
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