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Sandro Cacciola 1

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  1. Hello, work in progress... Let's go back a moment to the engine: the Kingtech K130G4+ turbine. Among the most interesting aspects such as the possibility of connecting the ECU to an optional Kingtech telemetry device which allows you to have essential information on the status, operation and fuel consumption of the turbine even during flight on the radio control, there is 'is another one that allows you to do without the engine Gsu display on the ground. This is "Kingtech Gsu Bluetooth module BDT” device which, coupled with the dedicated Android or IoS application downloadable on Google Play or Apple Store, allows you to have the Gsu functions on your smartphone without any cables around. Interesting. The BDT module contains the warning to “disconnect before flight” but I have not found any evidence that this could cause problems. The maximum reception distance of the BDT signal is 6 meters... The same Kingtech application can be used on the smartphone even without the BDT module o but by connecting the mobile phone to the ECU via a USB cable with micro USB connector on the ECU side and normal USB socket but with an Otg adapter that connects to the smartphone's charging socket.
  2. For the servos control power unit I chose a Pioneer Powerbox because I had already tried it on another model and it is, as well as cheap, light, small and easy to adjust. A "power unit" which can manage up to 14 channels and which (deliberately) does not provide for any regulation of the supply voltage because it was expressly designed for HV (high voltage) servos. So the output voltage will be exactly identical to the input voltage but stabilized and with power supply redundancy as it manages two 2S Lipo packs (or Lithium, Ni-Mh, Life-Po) with a 4-9 Volt range. The equipment is completed by a pressure or (optional) magnetic MicroMag switch. All servo outputs can handle currents of 10 amps. continuous and 20 amps. up to 30 seconds while inputs are provided for the two receivers. The Pioneer Powerbox ((63x44x12mm for 44g of weight) has no display or visual signals on its case but all the information, programming, battery charge data, etc. are transmitted telemetrically to the transmitter (PowerBox, Futaba, Jeti and Spektrum selectable from the menu control unit configuration); obviously to do this you will need either the PowerBox USB interface or the “BlueCom” programmer which can be purchased separately. But the surprises don't end there: a feature that makes the Pioneer unique in its category is its integrated iGyro technology that requires only the iGyro SAT (optional) as a motion sensor. Once connected, the sensor transforms the Powerbox into a powerful 9-axis gyro of the latest generation (3x aileron, 3x elevator, 3x rudder). Powerbox has tried to simplify the programming of this gyroscope as much as possible which can be configured in a few minutes (so to speak, you will have to lose some time...). All the setting characteristics present in all the gyroscopic devices of the PowerBox remain unchanged.
  3. The Predator 2.2 PiloRc in the fuselage has two plywood bases covered in black PVC: a fixed one where the tank, the pump, the ECU, the filter and possibly the turbine battery are located, and a raised removable one where the servo control unit is located. that of the retractable landing gear, the receivers, ignition switch, gyro, refueling point (included in the kit) and the batteries for the landing gear and control unit. I moved all three 2S 2600Mah Li-Ion batteries (Sony 18650 VTC5A 2600mAh 35A/90W) as far forward as possible. And still with regard to batteries, it should be emphasized that Kingtech specifies that for its turbine it is necessary to use 3S LiFe batteries with a voltage of 9.9v. I specifically asked Kingtech if I could use the classic 2S lipo and they answered me “strictly LiFe 9.9v”…!
  4. Good... When assembling the two-piece fuselage, I recommend first inserting the double chamber exhaust pipe (included in the kit) into the tail section and then tightening the two parts (in this case you will find it a bit difficult to reach the bolts underneath and above the drain pipe). The same exhaust already has two "L" flanges inserted in the funnel and which are screwed into the base of the turbine. The Kingtech K130G4+ fits well to the base in the turbine compartment without the need for adjustments. The connections of the Kingtech turbine with the ECU are reduced to only the data cable and the fuel line. Solenoid valves and part of the electronics are inserted in the turbine itself. The el Predator 2.2 kit includes the fiber bin tank and the Uat but the kevlar tank is also available as an accessory. I dedicated myself to its “Home made” construction after having printed the negative mold in 3D (…!). While for the arrangement of the turbine we are obliged to the position, for the tank we have more room to maneuver and it is important for the balance of the weights (like any Jet, this too will need weight at the tip...).
  5. But let's get back to the Predator. The Jet arrives in a huge, ultra-strong, protected cardboard box. Fuselage divided in two to facilitate transport, wings with new locking system with Allen bolt drowned in the trailing edge in the attachment rib, same system for the altitude planes: excellent and fast. Good paintwork and friezes and adhesive writings applied before the transparent (passing the hand you can feel the slight step). Complete the electric trolley kit with brakes, exhaust pipe, fiber tank and Uat. Assembly without particular problems thanks to the two large openings both in the turbine compartment and in the one for the electronics (on two levels). You need 7 standard 25/30kg servos plus a mini for front steering. Wide range of accessories such as adjustable tie rods, brackets, uniball, nuts, bolts, cable clamps, etc. The servos are fixed on the lids of the servo compartments with 4 generously sized self-tapping screws and the same thing for the trolleys (marked PilotRc but which I doubt are JP Hobby…) which are well made and robust. A little disappointing is the trolley control unit which appears to be "chinese" (it also has a small key to test the opening and closing without connecting the Rx but not used because it messes up the opening and closing coordination (I asked Pilot for guidance and I they said they are thinking about removing this feature…). To be continue
  6. The occasion was also good to test the G4+ generation of Kingtech turbines which was waiting for a jet to host it: the K130G4+. A compromise between power (money) and lightness and which should be perfect for this jet which in flight order (with kero) should be around 13/14kg. Kingtech 130 turbine has a diameter: 94.5mm, length: 220 mm and weight of 1270 grams and maximum thrust at 142,000 rpm. It has food as standard and requires 9.9v or 3S Li-Fe batteries. Specific accessory parts supplied include the KP-500BL brushless fuel pump developed and manufactured by King Tech complete with bracket, this pump is one of the major differences between the G4 and G4+ turbines, as older G4 turbines use fuel pumps with brushes. As with all of the new G4+ range, a DRM (Data Relay Module) has replaced the ECU, as the turbines themselves now incorporate much of what was previously included in the ECU such as all operating parameters including total run time etc.
  7. Hi friends, today I want to share with you my first experience with a turbine jet made by the PilotRC company. I have already bought several models from Pilot but to date only with 4 stroke and 2 stroke engine prop. This "Predator" sport jet had already struck me for some time and I decided to buy it thanks also to a tempting offer from Mattfly on the occasion of the last Black Friday. I was aware of the forthcoming release of the new PilotRc “Matrix” but I liked the Predator more…
  8. Better late than never! After years of using surgical masks or FP2, I decided to buy a professional product for individual protection from dust, glass or carbon fibers and to avoid harmful fumes in the event of painting or the use of resins in perhaps insufficiently ventilated environments. You know, even in our hobby of model makers (especially those who love to build models from scratch) we often find ourselves having to deal with materials and processes that are potentially harmful to health. I bought a professional mask from GVS, a Bolognese company that I've read has over 40 years of history and that from a supplier of components for the healthcare sector has become a global group that supplies a series of highly technological filtration solutions. And since as you know by now I like to share my experiences with you readers, here I am writing a "mini review" of this product. The mask I bought (there are several models on the market) is an "Elipse P3 RD", medium range, with interchangeable filters. As soon as I put it on, I was able to appreciate its compact and light shape, good wearability, it does not obstruct the view and, more importantly, it does not bother any protective glasses or noise canceling headphones. Thanks to the adjustable non-slip sealing band, it is possible to find the best comfort in its use (the mask can be purchased in different sizes). The first time I put it, I have to tell the truth, it had a certain effect on me as I was not used to wearing professional respirators for my hobby (and more...) but I must admit that after 5 minutes the "strange" sensation it disappeared and I was able to appreciate the ease of breathing that is not hindered by the filter media, the lightness and, most importantly, the fact that you feel protected. Reading on the GVS website I had read the company certifies this mask to be effective against dusts and fumes containing substances such as microorganisms, marble, plaster, titanium oxides, steatite, rock wool, wood, detergents, textile fibers, spices, etc. And, what interests us all, also from dusts that can cause lung diseases. In particular against dusts of coal, silica, cotton, iron ore, graphite, kaolin, zinc, aluminium, asbestos, bauxite, coal, silica, iron and against toxic dusts such as manganese, lead and chromium. There's nothing to say! For fans of numbers, here are two interesting facts: the interchangeable pleated P3 filters have a minimum efficiency of 99.95%, porosity of 0.3 microns and a mechanical resistance of 4.2 mbar at a flow of 47.5 l/min for each virgin filter. For certifications, the mask body is certified EN140: 1998. The filters P3 RD EN143: 2000 + A1: 2006. CE 2797. The materials are hypoallergenic TPE (thermoelastomer) compliant with ISO 10993-10:2010 for irritations. Latex-free, silicone-free and odourless. There is very little left to say: I consider my purchase more than satisfactory and I think that from now on I won't be able to do without it. If anyone is interested, just do some research on the web to find the dealer who can satisfy your requests. Until next time!
  9. Hi, true, kevlar costs money, but I liked trying to make my first kevlar tank... Let us conclude the brief summary. We had remained at the cutting of the fabrics, solved the problem before starting the lamination (spreading of the fabric and then of the resin) you will have to prepare pieces of kevlar and glass fabric that best adapt to the mold and that cover it all overhanging a a little (you will trim the excess once all the fabric has been placed on the mould). I leave the choice of epoxy resin to you (never use polyester because it shrinks and stinks to death) but I recommend specialized shops (cost of 1kg of resin + catalyst from 20 to 30 euros depending on the brand). For this tank I used about 160 grams of which 10/15% is lost with excess fabric. The lamination work starts now (try to work in an environment with a temperature not lower than 18 degrees otherwise the catalyst will be slowed down): mix the resin and the catalyst with a precision scale (once the resin has been mixed I usually pour it from paper cup in a plastic saucer to prevent it from catalyzing sooner than expected (too much resin in a small container has a faster chemical reaction); once this is done, start spreading the resin inside the mold with a soft brush; take the first piece of Kevlar that you have cut and arrange it with your hands inside the mold making it adhere well with your fingers to the walls (use latex gloves!!), then with the brush lightly soaked in resin dab on the fabric impregnating it well (you will notice where it is impregnated and where not by the change of color which will become dark where it has absorbed the resin.After this, go on to spread the second layer with the piece of glass fabric and with the same procedure make it adhere to the mold and impregnate it well. Once this is done, the work is almost completed for the third layer as well. To make the inside of the tank as smooth and uniform as possible you will need to use a piece of Peelply fabric which is a synthetic fabric which has the particularity of not sticking permanently to the resin but can be removed once the piece has dried, taking away the resin in excess and making the surfaces uniform (cost a few euros per 1m2). You spread it like the previous layers in the mold without however sprinkling it with resin: you lay it down with your hands and with a brush without resin you make it adhere well. Now you have two options: either leave the mold as it is making sure that all the fabric adheres well to the walls of the mold to avoid bubbles, or get yourself a vacuum device and put all the pieces inside a special nylon bag and let the vacuum press all the fabric against the mold reproducing exactly its surface. But here a separate chapter opens that we will see in another article. Laminated everything we let it catalyze for 12/24 hours depending on the ambient temperature and then we remove the pieces from the moulds. If the wax and the polyvinyl have been given well, you won't have much difficulty getting the piece out. A little more complicated to get it out of the Uat mold which has a deeper part. Help yourself with a plastic spatula and slowly detach the walls first and then the whole piece should come out. Done! now you have the two shells of the tanks which, once trimmed, you will join and glue with epoxy glue. Once glued, for safety, a small strip of Kevlar is glued over the joint to reinforce the coupling point of the two shells. Finally choose the petrol (or kerosene) feed connectors and always glue them with epoxy. I recommend gluing all the power lines except the main front ones (tank and Uat) before joining the two shells, you work better from the inside. Before mounting it on the model, I recommend you do a leak test in a basin of water by putting it under pressure by blowing into it. You never know! I hope I have been clear enough. My tank came out quite well, not perfect, but being the first tank I'm happy with it. You learn by making mistakes.
  10. Hello, The resin sticks, just enough to never remove the piece from the mold... We continue... At this point you will be ready to start preparing the resin and fabric for the tank lamination. For the fabric I decided to use a first layer of 170gmq Kevlar and two layers of 160gmq glass fabric. The choice proved to be right as I got a light and resistant tank. And here, however, the first problem arose that I hadn't considered: when I went to cut the Kevlar I found myself with scissors and an electric cutter that I normally use which are unusable. I tried with different types of scissors but without being able to cut the kevlar. I started looking for an effective system and I discovered that special scissors are needed for this type of aramid fabric (as well as carbon in part). By pure chance, I found on the web a company with 100% certified Italian products that only produces scissors (it's called "Millemetri" - https://millemetri.it). It offers a wide range of scissors but what interested me was the specific "Technik" line for industrial use in cutting composite fibers such as Kevlar, glass fiber and carbon fiber. I contacted them and they recommended the “Art. 329 - Tailor 9.5 Aramid” 24cm (9.5 inches) long. Tailor shears, size 9.5" (24.5 cm) with blades and screws in special 62 HRC steel with micro-toothing (on one or both blades of your choice) ideal for cutting aramid fibers - Kevlar, glass fiber, fiber of carbon. I ordered them and… show! Perfect, precise cut, without filleting of the fabric, a pleasure ... But be careful because the company has recommended itself (as I later discovered it is also reported on the site) that maintenance is of fundamental importance for these scissors (and for all of them in general) : simple tricks that can avoid annoying long-term problems. After use, it is recommended to avoid leaving residues of any kind on the blade, including water or dirt in general; periodically clean the blades by opening the scissors and oiling them in the sliding points between the blades with lubricating oil (pharmaceutical grade vaseline oil is excellent). I am also attaching a short video (forgive the quality...) https://www.youtube.com/watch?v=yFyBbSrGpMU
  11. Hello, lt's Go on. yes it is true, there are ready-made fuel tank but I wanted to try to make something I had never done before...🤣 The pieces printed with the 3D printer, however precise and of quality they are, have small jaggies which, if not corrected, would leave fingerprints on the printed piece. So I sanded the interior first with 120 sandpaper, then 200 and finally 360. I then gave a nice coat of catalyzed spray filler and then a varnish with 2K acrylic paint. The result was mirror surfaces! Those who are somewhat familiar with composite molds know that every new mold must be treated with a release agent before molding. So you need to get a release wax for molds (you can find it in all online shops of modeling or composite processing items (I use Sorvolando Compositi "sorvolandocompositi.it" cost about 25 euros for a 400/500 gram jar which will lasts a lifetime and, which creates added value, a person who knows how to give you lots of useful advice). This wax must be applied inside the mold with a soft cotton cloth with circular movements being careful to treat all points of the mold and the upper part where the fabric and the resin will overflow). 7/8 coats of wax (each coat interspersed with air drying for about twenty minutes and light polishing) for a new mold are sufficient. In subsequent pressings he was able to give only a couple of coats of wax. After the wax, I also use polyvinyl alcohol given with a spray gun / airbrush: it is an additional release agent that forms a water-soluble film and which helps the extraction of the molded piece (someone does not use it).
  12. Slightly reduced to have a capacity of about 3.5 liters (more than enough for my 120N turbine) the main part of the tank has been designed in 4 shells (two halves for the lower part (which also has a flare where the upper to close the two shells with a perfect joint) and two halves for the upper one to allow the shot to be easily extracted from the master. Once the files were obtained, I started to do some printing tests on my Artillery Sidewinder X2 to find (I use “Cura” as the slicer) the right parameters that would allow for the smoothest internal mold surface possible. Once I found the optimal configuration I started printing the molds. It took about 55 hours of printing to get all the pieces and at this point I dedicated myself to the finishing work. (continued)
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