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    Whether A Pump with Gear Box (to increase pump speed) is Feasible?

    If the curve is relatively flat, then yeah you really shouldn't have recirculation running back a little bit (though I've seen it before). Most manufacturers allow for you to run about 70-110% of BEP. But he's talking all the way back to 50% (assuming he's at 100% now). Even on a flat curve...
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    Whether A Pump with Gear Box (to increase pump speed) is Feasible?

    I cannot begin to tell you how bad of an idea this is. Really. Very. Bad. If you run a pump like this back on the curve that far, you will almost certainly experience higher vibrations, most likely due to discharge recirculation, and that could have a significant impact on pump...
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    Whether A Pump with Gear Box (to increase pump speed) is Feasible?

    Are you sure on that flowrate? There's only a handful of pumps in the world that can push that amount, and last I checked none of them ran at 3000 rpm. In my experience, you have 3 options. 1) Gearbox. Yes, it is done, but normally not for something like this. I usually see it in instances...
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    Head for a Pump

    It can be done, but it's not very straightforward. There are several "modeling" equations that can be used to predict performance based on the geometry of the impeller (or plungers if a piston pump), but you are correct, the only real way to know how a pump will perform is to test it. That...
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    Programming Languages used in High School Robotics

    Yeah, Python's probably the easiest to learn and apply to robotics, as jedi pointed out. However, if you find yourself wanting to get really hardcore and want a more difficult challenge, C++ would probably be my second choice.
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    Igntion system suggestions/considerations

    I suppose you would need a lot of other parts if you really want this to look nice, but if you're just concerned with lighting it up, you can probably take the coil from an automotive ignition system and rig a switch and a wire to it. Just run to the local automotive junkyard and rob the...
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    Shaft Critical Speed Considerations

    There's a lot of stuff to deal with here... Let me define what I mean by "dynamic." What I mean to say is that it is a force that only occurs when the system is in operation, not static or motionless. Let's think on this force some more (by the way, I got confused in my last post, I was...
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    Shaft Critical Speed Considerations

    I'll take a stab at this, though I'm still pretty early on in my rotordynamics analysis career, so I wouldn't call anything I say gospel without fact-checking. I think you're getting some stuff mixed up. The natural frequency of the rotor is a property inherent to the design of that rotor...
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    Need some good books on these subjects (Mech)

    JE Shigley's "Mechanical Engineering Design" occupies a prominent place on my bookshelf. Learned a ton from this book that I use on a daily basis at work. For Eng. Math, I used Stewart for Calc. Don't remember who wrote my Diff Eq book. Dynamics: if you find a good book, let me know, because...
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    Help with springs

    To clarify, you're scenario is a spring with a rate of 4 lbs per inch compressed one inch, held in place at its compressed state, and then released, and you want to know the maximum load it could move back to its uncompressed state? I will assume that the spring is also acting against gravity...
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    Help with springs

    What you're looking for is the spring rate. In English units (like you're using above), it is generally listed as pounds per inch. For example, if I have a 4 inch long compression spring with a spring rate of 4 pounds per inch, and I put a 4 pound weight on top of it, the spring will compress...
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    Small wheel folding bike, which rc engine best for lightweight n performance ?

    I'm really fairly certain that you'd be better off rigging a brushless electric motor or something to your bike instead. The only way you're gonna be able to get an R/C engine to power a bike is with some very severe gear reduction. The smallest motor off hand that I would go with would be O.S...
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    Which is cheap and suitable pump?

    Well, even if he is selecting a pump, you have to know a TON of information. Generally you can't even get an applications engineer at the companies to quote you without: 1) Desired Head 2) Suction Head Available 3) Desired Flowrate 4) Fluid service (more often than not they want the...
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    Gears in transmission

    Your notion of the bicycle is wrong. Turn a bicycle with multiple gears upside down and turn the pedal with your hand. Every single gear moves, whether it is engaged or not.
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    Which is cheap and suitable pump?

    This. It's complicated enough selecting a premade pump for a particular application, there's no need to try to design one from scratch when there are multiple different brands that have pumps for nearly every possible situation.
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    Innovative ideas(devices) for common problems

    One of the largest problems in the world is the lack of drinking water in many developing countries. They have the water, but it's not clean, which can lead to all sorts of diseases, many of which can be fatal when nutrition is also an issue (and it usually is). Maybe you can devise a means to...
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    Fuel System

    And to make things even more off topic, this answers why in the movie "Battle of Britain," you always saw the Spits rolling over before diving into attack. Before, I always thought that they just did that to show the gracefulness of the airplane.
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    Fuel System

    I had assumed we were looking at a carburetor concept and had ditched the injector idea, should have clarified, I suppose.
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    I want to make put a control package on a R/C plane

    "Make" magazine did an article on this not too long ago. Might see if I can find it tonight. In general you're gonna wind up putting some micro-gyros and a small PIC controller on the fuselage.
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    Fuel System

    If you elevate the fuel source enough, no, you won't need the pump or regulator. I've actually gotten a 400 cubic inch V-8 to run off a milk jug full of gas with a rubber hose connected to the carburetor.
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    Fuel System

    1) Kinda depends on the engine itself, as well as the injector valve. In automobiles, the injectors are somewhere around the 15-25 lbs/hr (the standard measure for injectors). This requires a fuel pump, and also a fuel pressure regulator (which you didn't list). If you were to use a small enough...