Recent content by lr27


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  1. L

    CVT belt for Reduction Drive

    Where in your analysis do you account for changes in airspeed and air density? At lower airspeed and higher density, the prop will absorb a lot more power for a given rpm than it will in cruise.
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    CVT belt for Reduction Drive

    I'm not arguing about practicality, but about what you get out of the prop. Let's say you have an airplane with a cruise prop which works best at 8,000 feet, at about 75 percent of rated power because you don't have a turbo. You would like to climb at a significantly lower speed so you get a...
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    Mark Stull - outside the box designer

    If the risk to the airframe is twice as much, but the risk to the pilot is 0.1 percent, I think RC test flying would be a good deal. Modern RC sensors and telemetry are inexpensive. Obviously you'd want to do this out in the middle of nowhere instead of at a normal airport. Also, you'd want to...
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    CVT belt for Reduction Drive

    Oops. I meant to say leave in, not take out. Here's another way to say the above. Let's optimize the prop for cruise at 100 knots at 8,000 feet. Now we want to climb at sea level at 75 knots. The engine can't reach full power rpm. Now we gear things down a bit. Now the engine CAN reach full rpm...
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    CVT belt for Reduction Drive

    I don't think it's advantageous to select a climb prop for use with a CVT unless the rpm anticipated is low enough to keep the tip speed down. Better to use a cruise prop, and then use the CVT to low the full power of the,engine to be used during the climb. I imagine that it doesn't make sense...
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    CVT belt for Reduction Drive

    P.S. I'm only talking about relatively small differences in gearing. Like maybe 2:1 for cruise and 2.5:1 for climb. Assuming an automotive engine with the CVT being used as a redrive.
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    CVT belt for Reduction Drive

    Dan: What you're saying is equivalent to saying that somewhat lower rpm engines won't work well in aircraft. I don't believe it. Lower rpm engines have lower rpm's but more torque, just like an engine with a CVT geared down for climbing. I can believe that getting a CVT to work with a propeller...
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    Basic Woodworking Book for New Builders?

    I poked around a bit in Google Books and Amazon and found what's supposed to be a facsimile of the book. If I was on my PC instead of my Stoopidfone (R), I'd give you a link. Also ran across a publication of the same name by the War Department from the early 1940's. If I recall correctly, you...
  9. L

    Golden age classics in tube and gusset

    Sure it is. Just find a good medium and consult Eugene Larrabee.
  10. L

    Steve Henry's 2.5' take-off

    I suspect a very light cowl would help with the takeoff more than the weight would hurt. Plus it would reduce fuel consumption. But it wouldn't help with the landing.
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    Dream workshop?

    PMD: If the city water is too slow, could you just run it into a big tank which you could drain faster when needed? Maybe on a tower like you see on top of big buildings in Manhattan. Or is there a code problem? You could claim it was an enormous water heater for filling your hot hub.
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    looking for a fishing plane

    BJC: Buying a ticket doesn't significantly change your chances of winning a big prize like that. - ---- I'm sure manners while trolling or even when anchored would be greatly improved by a detachable centerboard. Possibly also by attaching a big vertical plate to the lower unit of the trolling...
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    CVT belt for Reduction Drive

    It can't be too bad, if done right, since they use it in some cars that get very good mileage. If you can keep the CVT feature, it may be like having variable pitch. If it was my project, I think I'd be looking into how heavy and/or big a flywheel would be required.
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    Promise me you will finish one of your airplane projects before before starting another one! Of...

    Promise me you will finish one of your airplane projects before before starting another one! Of course I start a dozen hobby projects for every one I finish, but do what I say not what I do. BTW, I hope you're taking medical advice from doctors rather than judges. And I hope your daughter has...
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    Composite wing spar web design - composite webs, foam webs, etc.

    Billski: A bit of fiddling with a calculator suggests that the carbon part of a spar cap can be made to fail at about the same strain as the wood part, if the wood species and the type of carbon are selected carefully. However, I can't see an advantage in doing so. I could understand using a...