onetrack

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.

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...

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? 😞

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

Contributors commenting 31,000 times? If I've told you once, I've told you a million times!! - don't exaggerate!! 😄

A 12 rope-pull engine start, would make for an interesting takeoff experience!

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

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

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.

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.

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.

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.

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.

"But is it safe, and does it come in more than one colour?" 😄("Bubbles" Fisher, of the ABC Inventors programme)

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.

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.

The BMW F650 starter is most certainly CCW rotation. https://www.ebay.com/itm/305041039675

....."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......

......immediately surrounded by 72 virgins - a real surprise to bull, as in the suburb he was raised in, virgins were virtually unknown, and bull had only encountered one or two in his lifetime - whereupon he instantly understood why they were still virgins. Still reeling from the shock of reaching for a choccy and suddenly being surrounded by virgins, bull was at a loss as to what...........

Who's to say it wasn't a mechanical failure of the nose gear?

Dave, the alternator specs are in the link below; SD8 Alternator, 8 Amps (Homebuilt) - B&C Specialty Products BANDC.COM The spline-driven SD8 alternator offers the benefits of an exceptionally lightweight alternator, and a design with proven durability in the rugged world of aerobatic aircraft. Weighing just 2.9 lbs., with a rated output...

The primary factor involved, is whether any medication affects brain function, and in what manner. There's a substantial number of medications that affect your driving/operating/piloting skills - and this information is readily available from the drug manufacturers, and the medical profession. However, just in my personal opinion, I believe a lot of drug manufacturers, and even medical professionals often downplay the full effect of medications. I know I've taken medications that adversely affected my skills and decision-making, and I wasn't advised fully on all the side-effects. I would hazard a guess this is because everyone is affected a little differently by various medications. From what little I've read about ADHD medications, they're touted as a gift from God, with amazing results, and little side effects. I'd have a more reserved opinion on that angle, purely because of the power of drug manufacturers, and how they can influence even medical professionals. I was under the impression that the main drugs used to treat ADHD are all from the amphetamine family. These drugs are commonly nicknamed "speed" drugs, simply because they stimulate brain function. In the case of ADHD, it appears the amphetamine drugs operate on brain function in a highly beneficial manner - unlike the illegal methamphetamine drugs. Naturally, the legal drugs are produced to a medical standard with proper QC, unlike the illegal ones. However, the bottom line with amphetamines is, they are addictive - and the other question also remains, with regard to someone needing to take a legal prescription of amphetamine, is - what happens when they're piloting, and they forget to take their medication? I believe the situation as regards someone piloting with a need to medicate, to function effectively, is a question that needs to be addressed on a simple case-by-case basis, with extensive medical professional input, and not a "one case fits all" scenario. Just my .02c worth.

The very first Douglas DST, and the first Douglas aircraft with sleeper berths. But it wasn't the first aircraft with sleeper berths, that claim to fame goes to the Curtiss Condor (in 1932).

I don't think there's any sniggering needed if someone has studied up and learnt to fly, and has passed the tests to acquire a licence, it's something to be proud of, and I for one would not be sniggering at anyone wearing a set of wings that has been earned, I'd respect their effort and achievement. But if someone was wearing a set of wings that hasn't been earned, and they were just trying to impress - well, there's a name for that character deficiency.