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Mechanical Engineering


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DrD last won the day on July 28

DrD had the most liked content!

About DrD

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  • Gender
  • Location
    Iowa, USA
  • Interests
    Kinematics, dynamics, mechanics of materials, Theory of Machines, machine design, vibrations
  • Present Company
    Machinery Dynamics Research
  • Highest Qualification
  • Engineering Qualification
    Registered Professional Engineer, TX, WI (Ret'd)

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  • Achievement /recognition/ Certifications
    Consulting work for a variety of industries, particularly in the IC engine related area (Torsional vibration analysis, shaking force analysis, engine cam design, system simulation).

    Author of several books, including one widely used textbook for Theory of Machines.

    Life Member ASME
    Member SAE
    Member SNAME

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  1. Dear Alban, Absolute symmetry is truly rare. Consider the case of a table on four legs of equal length. By your argument, all four legs each carry 1/4 of the total weight. Everything is perfect, the floor is level, the table is flat, the legs are all equally long. But now enter a tiny bit of reality (ever so slightly!). One of the legs is short by 0.0001 mm. To the eye, it appears that perfect symmetry still exists, but in actual fact, one of the four legs no even longer touches the floor. Do you still think that each leg in contact with the floor carries only 1/4 of the weight? What holds up the remaining quarter of the weight? DrD
  2. If you are serious about this, why not design a better screw and have a machine shop make some for you?
  3. Looks to me like the kinetic energy of your systems is T=(1/2)*m1*xdot^2+(1/2)*m2*ydot^2 and the potential energy is V=(1/2)*K1*(x-xc)^2+(1/2)*K2*(y-x)^2+(1/2)*K3*y^2 if we understand that all springs are relaxed when xc=x=y=0. All of this raises a question for me. Why do you want this if you did not know how to develop it in the first place? DrD
  4. Do you know about Newton's Second Law? If so, start there. DrD
  5. Whatever in the world is meant by "inverting the rotation" of the turbine? I have no idea what this question is about. DrD
  6. Whatever in the world does it mean to "invert the rotation"? I've never heard such a term, and I cannot imagine what it means. DrD
  7. When I suggested a picture, I was referring to a drawing, not a photograph. DrD
  8. Who said there was a screw? Did I miss something? DrD
  9. This is a really fine post by JAG, and I'm sorry I only saw it so late (today). That said, I would add just a little bit. Lawyers are only lawyers because the choose to be lawyers. This is a free choice. They volunteer for that sort of work. In making that choice, volunteering as it were, they abandon morality and make themselves volunteer hostages to a system that has no interest in truth, only an interest in winning. In my view, to make that choice, and those who make it, completely immoral. I have to add that my sister is a lawyer, and we have had many battle over this matter. Now, we rarely speak about it because there is no resolution possible. In life, that is how things work. Those who sell their souls to the devil cannot be talked back. DrD
  10. It would help if you posted a picture of the situation with dimensions, wind load direction, etc. DrD
  11. I think it was Einstein who said, "Everything should be explained as simply as possible, but no more so." DrD PS: I'm sorry it is all Greek to you. Perhaps you should not call yourself a mechanical engineer?
  12. Looks like you have identified the key items you need to learn in this internship. Now it is up to you to investigate and learn them. DrD
  13. DrD

    gearbox lubrication

    I think Sergio may have missed the point (or else I have). As I understand the question, the concern is lubrication of the external gear train. No oil will get to it unless you provide oil to it. The crankcase oil cannot get there. DrD
  14. Sinar memuai jalan - What does this mean in English? DrD
  15. The motor you describe is probably very large and heavy. Consider instead going with a small, lighter, less expensive motor and a speed reduction (gears, belts, etc). DrD
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