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Geoff_H

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Everything posted by Geoff_H

  1. Geoff_H
    Mooney have a power earth with one connection to the airframe and at the other end of the earth strip a connection to the instrument earth bar. Instrument earth isolated from the frame. It stops earth loops and allows you to hear over the radio squark. All shield conductors MUST be only connected at one end. Same reason as above. I did a nice income getting communication systems to work that had been installed by others, usual problem was shield earthed both ends.
  2. Geoff_H
    The attached PDF shows the increased current carrying capacity for Teflon wire vs other insulation. Tefzel is similar to Teflon but is significantly lighter. If you were designing an electric aircraft Tefzel would contribute significantly to weight reduction. WIREMAX-conductor-CURRENT--2- (1).pdf
  3. Geoff_H
    From memory the FAA require at least 10pound of stick force per g of aircraft load. With a stick it would appear easier to pull 6g, 60lb with your arm free to move. My question is is that still the case with a sidestick when you appear to be just rotating your wrist. Or Have I got the sidestick wrong?
  4. Geoff_H
    The current carrying capacity of a conductor is limited by the maximum temperature that the insulation can take. Smaller conductors generate more heat so a higher temperature insulation can carry more current for the conductor
  5. Geoff_H
    Yes but the FAA dictate that you must have to use a given force for a g pulled on the aircraft. So you don't accidentally pull 12g etc. Is that requirement still the same for a sidestick where you have significantly less movement.
  6. Geoff_H
    What is the feedback force of a sidestick. I know the force per g for stick and yoke, but not sidestick. I am designing my aircraft to be able to adjust this force through a huge range. It would be nice to know around now ( designing the trim systems)
  7. Geoff_H
    Tefzel and Teflon give off more harmful smoke than PVC, if that is possible. Probabily dead either way. Believe me the only advantage of Tefzel and Teflon is weight. Significant weight reduction.
  8. Geoff_H
    Tefzel uses tin plated copper as a conductor. Tefzel is used because you can get a much lighter wiring system than PVC insulated wire. You can use a conductor that is smaller in size than with PVC insulated wire. Any copper reduction can make a sizeable weight reduction. Tefzel insulation is lighter than Teflon (although it has many similarities), so it is the lightest weight for any conductor. It is difficult to work, being slippery skinning and mechanical connection to the insulation is difficult and must be done with the highest quality crimpers. I would just use PVC insulated wire in a small aircraft.
  9. Geoff_H
    Oil pressure has little to do with the load carrying capacity of a journal bearing. Oil pressure just ensures that there is oil between the journal and the bearing. The load carrying capacity is a function of the oil wedge formed between the bearing and the journal.
  10. Geoff_H
    Lycoming did change their design they put in roller followers. I chose not to go this way because if you have a prop strike you have a sizeable bill because they have to be either inspected or replaced I can't remember, but it wouldn't involve more cost over the straight engine disassembly on a prop strike. Getting old so sure of my memory anymore
  11. Geoff_H
    Sorry for the few errors in the previous post I'm using voice to text because I'm a bit pressed for time. Please use your imagination
  12. Geoff_H
    I could have found the Lycoming camshaft wear problem before I bought the aircraft had I done an oil condition check. we picked up the problem because we found an enormous amount of metal filings in the oil filter at the oil change. We found this metal with a magnet full stop when we found it there was an enormous amount of wear but how do I have a check for metals in oil we would have found it's a wrong before I bought it and I probably would have saved myself the $40,000 the engine overhaul cost. engine oil condition monitoring tells you many many things about the engine I I would recommend it to everyone who owns an engine particularly a person who owns an aircraft engine.
  13. Geoff_H
    There only needs to be the smallest amount of oil between the bearing and the journal for an oil wedge to happen. So as long as the wedge is higher than the roughness of the bearing and journal no wear should happen. Having said that I paid $1800 to have oil supposed to the camshaft on my Lycoming IO360. The standard arrangement is that splashing from oil in the engine lubricates the lifter/camshaft area. My engine had a valve lift around have the design lift from wear. The oil was wearing off the camshaft after sitting for extended periods of time. Hence no wedge on startup. Lycoming suggests that you use a "magnetic" oil to solve this problem. So I really wasted my money, I lost confidence in my judgement lol. My father used to say that if his car ran out of oil he would put water in his sump to get him home. I once thought that it was a great idea, after all both form a wedge in the journal/bearing area. How once the fluid shearing heat had raised the temperature of the water steam would have formed. With steam's lower viscosity a very weak wedge would have formed. Steam also has much lower heat transfer coefficient than water so it would only have worked for a very short distance. OK if very close to home, maybe easier to push the car, ?
  14. Geoff_H
    I have never used a side stick but my project involves one. Maybe a mistake. I have been wondering about the requirements for control force verses pilot g force. I have assumed that the stick force should be less than for a centre long stick, am I wrong. The design is for me to be recumbent, should that influence anything of the control situation?
  15. Geoff_H
    I got 260kts from Kalgoorlie to the middle of the bight. What a disappointment when the tailwind went from over 100kts to zero. Mooney NWF.
  16. Geoff_H
    In the 70's when I was starting out in computer control systems we had many plug system faults. We discovered that any connection where the stress at the connection was less than 30,000psi would get oxidation at the connection and develop a high resistance. Long term reliability was achieved with edge design point of contact and gold plating. Today crimping uses galvanic bond and the removable connections are a sophisticated design. I would not trust doing the plug connector nor the pin connection myself. I would never solder. I have learnt through experience!
  17. Geoff_H
    After watching Landline yesterday it appears that the agricultural equipment manufacturers have systems that prevent the owner from doing any maintenance. Often a machine will break down in the field and wait days for the manufacturer to come and repair it, this comes with large production losses. Particularly if a crop is deteriorating. They have software locks on the machines. Spare parts must be purchased by the manufacturer under the contract of sale. The issue is being taken up by the consumer affairs guys, looks like going to court. It reminds me of the Mirage aircraft contract where we had to buy ammunition from France.
  18. Geoff_H
    From all I read Winston Churchill was able to assess good ideas from bad. It was probably his greatest skill. I don't think that he was landed gentry.
  19. Geoff_H
    For 25 years I wrote control strategies for steam power, before switching to gas turbines. The control of boilers uses steam pressure for fuel control and water desuperheating for temperature control. Well it is much more complicated than that but steam controllers are available across the counter
  20. Geoff_H
    Definitely a water tube, they are much lighter with much larger surface area
  21. Geoff_H
    If I was doing a steam project I would use a vane motor for the propeller I would make the boiler the main item of concern. I also would make it closed loop. For the boiler would use very small bore high pressure tube because that is the lightest weight for the biggest surface area and power at using gasoline. I would definitely have a superheater in the boiler. Because it's a closed system I would need a condenser this would be some type of air condenser which is less efficient than a water condenser but that's all we have.
  22. Geoff_H
    Bunker C is solid at room temperature. A reasonably large heating system would required for the fuel tanks and feed system. You can walk on it and not leave an impression. Ships and power stations use it as it is very cheap.
  23. Geoff_H
    I don't know the horsepower of steam engine with the same displacement as a diesel, but it's output would depend upon the steam pressure. I would guess that the efficiency of the steam engine would be less than 5% if it was an open cycle and around 8% for a closed cycle. But so much depends upon the boiler. It's temperature and pressure delivered to the engine
  24. Geoff_H
    A steam power station with sub critical point operation would be around 34% efficient. A supercritical would get to around 60%. Please note that the combined cycle efficiency uses a gas turbine with a class C or D design and the exhaust from the gas turbine makes steam that uses a steam turbine to augment the output. Class H gas turbine will have around 60%=efficiency itself
  25. Geoff_H
    A condenser running close to a vacuum adds 33% to the power. Sub critical maximum efficiency is approx 34%. Super critical is up to around 50%. Why not burn a liquid fuel, much lighter and easier to handle
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