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Everything posted by onetrack
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Close. The term reputedly comes from referring to the River Dart, whereupon the Britannia Royal Naval College Dartmouth was situated, overlooking the River estuary. Sailors were reputed to have said they were "returning to the Old Dart", as a reference to returning to the U.K. after extended voyages. The Britannia Royal Naval College Dartmouth trained RN officers from 1863, and was apparently an institution which was held in respect by the RN officers. The younger RN officers likely returned to the BRNCD to do further RN officer training.
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......question to the group. "Why do the aliens found on the crashed Roswell UFO, look so much like Turbo?" The revelation brought out mixed levels of concern amongst the others. Could Turbo have come from an alien family, and perhaps even just be a humanoid, not a genuine homo sapiens? The thought brought disquiet upon many of the assembled gathering, and one of the group spoke up, "I'd heard before, that Turbo had the ability to put a level of terrifying fear into anyone who crossed him, but this revelation is.......
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SE-XFV is a completely different aircraft to the others pictured. It has the canard wing mounted forward of the pilot, whereas all the other photos show an aircraft with a canard mounted behind the pilot. Plus, the fuselage appears to be more squared off at the bottom. Even the wing is different, with the vertical stabilisers mounted inboard, as compared to the others where the VS's are mounted at the ends of the wings.
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There's too much emphasis placed on bore condition. You can have all kinds of patterns, wear, gouges, scores and problems with the bore - and the engine will still run reasonably well. But the major weakness of IC engines is poppet valves. 95% of your engines problems will come back to valve sealing and seating and valve head condition. Valves are the most heavily worked part of any IC engine. Sleeve valves and porting really are a much more durable arrangement, but the drive mechanism and clearances are critical areas, and they can't handle high RPM's. In tests of the early sleeve valve car engines in the late 1920's, the sleeve valve engines were still reliable, and still producing 99% of their power output after 80,000-100,000 miles - unlike their poppet valve cousins, which were suffering serious power losses and valve sealing problems, in as little as 40,000 miles. I would have liked to have seen the rotary valve head become more developed and widespread, but inertia and lack of funding, often stopped many good ideas. The Deane Rotary Valve, an extremely promising Australian invention by three Aussie engineers, was proven to work, and be exceptionally efficient and reliable, when tested on a motorcycle engine - but it failed to gain financial backing, and fell by the wayside, as with many good design ideas. Rotary-Valve Internal Combustion Engines. WWW.DOUGLAS-SELF.COM Douglas Self, rotary valve engines, Minerva, Aspin valve, Cross valve, Froede valve, Wankel valve, Mellors Rotary Valve
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That's a bearly believable photo.
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Well, it appears that Wisk Aero is gradually closing in on the pilotless, eVTOL, air taxi dream. As a fully-owned subsidiary of Boeing, they have a fraction more street cred than the usual Internet/YooToob startups. However, even Wisk won't be drawn into a specific date when their product is finally guaranteed to be safe, and receives certification - but they coyly state they hope that event is, "before the end of this decade". Discover Wisk's Self-Flying eVTOL Air Taxi WISK.AERO Our self-flying, eVTOL air taxi will set the standard for the Advanced Air Mobility Industry and transform the future of mobility. Wisk Partners with Airservices Australia | Wisk WISK.AERO Wisk Partners with Airservices Australia to Incorporate Autonomous Air Taxi Network into National Airspace.
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Leaf springs are normally heat-treated in the following manner, which produces the toughness needed. They are heated to 780°C, then quenched in an oil bath. A brine bath can also be used, instead of oil - although oil is generally regarded as superior. This process hardens the steel. Then the hardened leaf or leaves are placed in a furnace, and evenly heated to 380°C, and then allowed to cool naturally. This is called "tempering", and it lowers the hardness and toughens the steel. The leaf or leaves need to be restrained in a jig when being hardened and tempered, as they will normally buckle or curl out of the desired shape.
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Try this spring manufacturer, they say they'll manufacture custom springs. Leaf Springs WWW.DOBINSONS.COM Upgrade your vehicle with Dobinsons' high-quality leaf springs for superior load-carrying capacity, enhanced ride comfort, and stability. Ideal for 4x4 and off-road adventures, these durable springs undergo...
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Bathurst Mt Panorama incident 13th Oct 2024.
onetrack replied to Thruster88's topic in Aircraft Incidents and Accidents
Did anyone see how close he came to hitting the wall with the wing? I reckon there's only a few centimetres between the wall and the wingtip, just before he clobbered it with the tail. -
I like this part of the description - "The control is done by means of a radio control on a desk in front of the pilot (on the prototype)" Now, where have we seen this dodgy style of control setup before? 😞
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Red, the placard is pretty fine print for my aging eyes - but the gist of it is, he's using 62cc Zenoah R/C engines (model G620PU-1) running Walbro carburettors, which are each driving the props through a RADNE centrifugal clutch and a gearbox with a 45mm primary pulley and a 180mm secondary pully, using poly V-belts. The engines use servomotors on the carbies for control. He says the engines produce "6 CV" ("Cheval-vapeur", the French word for HP) each - but that's at odds with Zenoahs website, which says the engine gross HP is 5.46. The French bloke also claims 8000RPM for his Zenoah engines, yet Zenoah say the maximum output is "around 7600RPM". He's really winding those little Zenoahs out! The Frenchman claims the engines produce 25kg of thrust each and therefore a combined total thrust of 300kgs. Not too bad I suppose, if they all keep going at maximum power! He outlines that 6 props runs clockwise and 6 run anti-clockwise, so thus negating any torque issues. He says the frame weighs less than 30kgs and the total mass is less than 100kgs - although above that, he has 105kgs, so some variation in his stats there. The engines are started by flipping the prop or by "an electric device" (type not known). All in all, not too much inherent strength or redundancy there, so I'm inclined to agree with Facthunters, "Pass"! http://www.hobbysupplies.com.au/Zenoah Engines.HTM
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A 12 rope-pull engine start, would make for an interesting takeoff experience!
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The work going into non-pneumatic tyre research is quite amazing. There's actually an improved Tweel-2 now. And Michelin and GM have collaborated to produce a non-pneumatic combined tyre and wheel called Uptis, which is supposed to be getting fitted to new road-going vehicles this year. They'd better get a move on, there's not much left of 2024. The research article below will keep you fully updated, Skippy - but be prepared to burn some midnight oil reading the entire article! You might be able to go non-pneumatic, sooner than you think! A comprehensive review on non-pneumatic tyre research - ScienceDirect WWW.SCIENCEDIRECT.COM Non-pneumatic tyre technology can overcome the safety problems of traditional pneumatic tyres. Hence, it is expected to improve driving safety signifi… Promo for the Uptis tyre ... MICHELIN UPTIS tyre prototype, an airless tyre | Michelin Australia WWW.MICHELIN.COM.AU
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Skippy, I guess you could always be the Tweel test pilot! However, the cost of the Tweels appears to be considerably more than a pneumatic tyre, a factor which might put you off! Another point I just thought of - wouldn't the ribs act as vanes when airborne, and start the wheels spinning, thus acting as somewhat destabilising gyros? Are Michelin Tweels worth the upfront cost and do they last longer? - Darra Tyres, Brisbane WWW.DARRATYRES.COM.AU Michelin Tweel tyres are a type of non-pneumatic tyre that consists of a rigid hub connected to a shear band, which is made of rubber and acts as the tyre's
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I can't, despite going through the whole thread and all the links carefully. I've never seen a starter shaft with a pin in the end - a circlip groove and circlip, yes - but never a pin. However, I'm always open to being proved wrong, and just as you think you've seen it all, some engineer decides it has to be done differently.
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Skippy, the increased rolling resistance of the Tweel comes from the fact it flattens out more on the bottom than a conventional pneumatic tyre. I'd have to opine a radial tyre has less wall flexing resistance than the tread supports or ribs in the Tweel, which are quite stiff material.
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Skippy, the lightest weight gas turbine APU I can find is the one on the Bombardier/DHC Dash-8 100 series, and it weighs 115lbs (52kgs). That's the basic twin turbine unit - add in accessories and a fuel supply, and you're probably looking at over 100kgs additional weight. Not exactly a practical proposition, I'd have to say.
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Weight gain would make the addition of a small genset impractical. Even a camping genset is heavy for its size. No-one has yet been able to produce a very light generator.
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The turf equipment tweels are rated for a maximum speed of 25mph (40kmh), and the tweels for ATV/UTV's are rated for a maximum speed of 50mph (80kmh). No model of tweel is approved for highway use yet. There's a considerable increase in rolling resistance with a tweel, as compared to a pneumatic tyre. So, I'd have to opine that tweels are unsuitable for any aircraft. The fact that the manufacturer hasn't sought to produce a tweel specifically for aircraft, tells me that the tweel is limited to off-road, low-speed vehicles only.
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"But is it safe, and does it come in more than one colour?" 😄("Bubbles" Fisher, of the ABC Inventors programme)
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50 Gallon Motorized Gas Caddy -- The Smart Ass Fuel Mule
onetrack commented on DonkeyBrains's classified in Pilot Supplies
Yes, the forum is based in and run from Australia, but users from all countries come here, and are welcome if they provide content that is interesting, informative, and which adds to our combined aviation and engineering knowledge. I wish you well with your product, it looks good, and is likely to be acceptable in many countries. I just felt the need to address the issues associated with private (i.e. non-commercial) fuel transport within Australia and its territories, and point out the risks associated with highly combustible fuel transport, which risks are regarded as serious ones by the relevant authorities here. Fuel transport containers must meet the relevant Australian/New Zealand Standard, which is - "AS/NZ 2906: Fuel containers – portable – plastic and metal". Below is a link to one of the Australian States, Workplace Health and Safety (equivalent to OSHA) guidance booklets, for the storage and transport of flammable and combustible liquids. https://www.worksafe.qld.gov.au/__data/assets/pdf_file/0024/22866/guide-for-flammable-and-combustible-liquids.pdf All of our legislation and regulations regarding fuel transport and storage, are centred around risk reduction and education of end-users, to minimise accidents and disasters. -
50 Gallon Motorized Gas Caddy -- The Smart Ass Fuel Mule
onetrack commented on DonkeyBrains's classified in Pilot Supplies
You might want to get a handle on the fact that Australia uses 240V power, not 110V, it has different power plugs and wiring as compared to the U.S. - and all containers for carrying fuel in vehicles in Australia must be approved by Govt authority, under the Transport of Dangerous Goods Act - with each State having slightly different regulations, as regards fuel transport in vehicles. In addition, all containers carrying Hazardous or Dangerous goods must be labelled under the GHS (Globally Harmonised System) labelling regulations. Most Western countries (including the U.S. and Australia) are party to the GHS labelling system. This system clearly identifies the hazardous substance with pictograms on the containers or vessels and also provides readily provides MSDS information for first responders to fires and crashes. 250 litres is the maximum allowable volume to be carried in private vehicles in Australia - above that amount, you need to have a commercial Dangerous Goods transport permit, and your vehicle must carry standardised U.N.-markings - the Dangerous Goods diamond-shaped warning plates, front and rear. Documentation for the DG load must also be carried in the vehicle, relating to the supplier and carrier, and responsible persons contact details. This type of DG load is referred to as a "placarded load". 50 U.S. gallons is approximately 190 litres. Note that the 250 litre transport limit for vehicles in Australia, includes the fuel in your vehicle fuel tank. A fuel transport container on wheels may not get approval to transport in a vehicle in Australia, as fuel transport containers are required to "be properly secured" in a vehicle. Adding substantial tie-down points to your Fuel Mule would be advisable, to ensure it received official transport approval in Australia. There is an important distinction between petrol fuels (avgas and gasoline) and diesel-based fuels in Australia. All fuels with a flashpoint below 60°C are classed as "Flammable liquids", but fuels based on petrol are classed as Combustible liquids, because their flashpoint is around -43°C, and they will ignite easily from a single spark, at well below room temperature, thanks to the large volume of volatile fumes these fuels produce. Diesel or kerosene-based fuels do not pose such a severe flammability danger as petrol-based fuels, because they do not produce the same level of volatile fumes as petrol-based fuels. If you own a boat, you are no doubt well aware of the dangers of refuelling with volatile fuels, and the need to avoid containment of the fumes produced. I have seen an entire major fuel storage depot burn to the ground, simply because a customer refuelling his car and caravan (trailer home) out front of the depot (via a depot fuel bowser), spilled some petrol, due to overfilling his (petrol) fuel tank. The petrol fumes wafted into his caravan, where he'd left his LPG fridge burning. The petrol fumes ignited via the gas burner flame, the caravan went up in flames, the car joined it, then the fuel depot caught fire, too! It ended up a multi-million dollar fire, and it wasn't even in a built-up urban area, it was in a small country town, where the depot was located in an isolated industrial area of town. A strong, steady wind aided the fire to take hold rapidly. There's a general official attitude discouraging the transport of any more than about 50 litres of petrol-based fuels in vehicles, in Australia. This is because of the severe level of danger involved in the case of a vehicle crash, where a vehicle is carrying more than about 50 litres of petrol-based fuels, in portable containers (or container). Fuel tanks built into vehicles have a major level of protection built into their design, such as their location, plus protective shields around the tank. This is not the case with volatile fuels being carried in bulk containers in vehicles. Finally, service stations (gas stations) in Australia will generally not allow the filling of portable fuel transport containers in vehicles, due to static ignition fire potential. All portable fuel-carrying containers must be removed from the vehicle and placed on the ground for filling, and the container size being filled is not allowed to be larger than 25 litres. -
....."Spare Prawns", as there's always plenty of prawns to spare, whenever bull pulls into the fishing boat harbour. But bull ran into a problem when he visited a publisher. "Who the **** wrote this ****?", the publisher said, using words that he knew bull would understand, straight up. "The punctuation is terrible!", he went on. "The paragraphs all run into one another, there's long blank bits with rows of dots - and to make it even worse, no-one would be able to follow the plot, it's so rambling, it makes......