Recent content by Feodalherren

  1. Feodalherren

    Torque to force conversion (from a motor)

    So this is a silly problem that I ran into at work which made me realize that I have all but forgotten Newton's laws of motion after years of working with just hardware and software. I am in the middle of programming a robot for an industrial application and I realized that I have no clue how...
  2. Feodalherren

    Code / Software for Dynamic Balancing (Free / Open Source)

    I have been known to look for my keys while holding them in my hand. On Topic: I have created micro controllers for similar applications. I obviously can't share proprietary code but I can tell you that our design process is to first model the system in MATLAB Simulink or SimScape Mechanics...
  3. Feodalherren

    Simple Linear DiffEq, not understanding the book

    Ah, of course! Thank you very much. I vaguely remembered from my DiffEq class that you can 'play around' with C because it's just some constant. But of course you can't just ignore the algebraic rules for it, duh! Once I saw what you did with e^2C I remembered what 'play around with C' means...
  4. Feodalherren

    Simple Linear DiffEq, not understanding the book

    The way I want to solve it is the way that I always want to solve separable linear diffEqs: after some trivial algebra and an easy integral I end up with t = (-1/2) ln (20-2x) +C Easy enough, solve for x(t) yields x(t) = 10 - (1/2)e^(-2t) + C Solve for C when x(0) = 3 yields C = -13/2 But...
  5. Feodalherren

    Admissions Accepted at Caltech - what should I do to be best prepared?

    Congrats. I had a friend who went there and he said the hardest part was accepting the fact that he was no longer always the smartest kid in the room. As for what he did between high school and college, nothing academic. We traveled through western Europe together with some other friends from...
  6. Feodalherren

    Help replicating Eratosthenes' experiment

    Guys.. They are in the 11th grade, you're over complicating it.
  7. Feodalherren

    First natural frequency for bending, axial and torsion modes

    Does this seem correct to you? https://pasteboard.co/GX52epp.jpg https://pasteboard.co/GX526h9.jpg Edit: It didn't want to attach the images on the post. Don't know why.
  8. Feodalherren

    First natural frequency for bending, axial and torsion modes

    Bending k = EA/L Axial load k = EA/L Torsional k = πGD4 / 32L
  9. Feodalherren

    First natural frequency for bending, axial and torsion modes

    Thanks. I know how to find the formulas for k, it's not a problem. I just wanted to make sure that I had the basic problem down. It's not really a point mass. I was just simplifying it to see if what I was doing was accurate. The mass is an AISI 1005 steel ball with diameter of 8 mm. So it's...
  10. Feodalherren

    First natural frequency for bending, axial and torsion modes

    Homework Statement We have a rod of length L fixed to a rigid support. At the end of the rod there is a mass, m. Assume that the rod has no mass. Find the first natural frequency for the bending, axial and torsion modes. Homework EquationsThe Attempt at a Solution So I'm reviewing some stuff...
  11. Feodalherren

    Is My Understanding of Spring Energy Conversions Accurate?

    You already answered your own question. If it's an ideal spring the question you're asking does not make sense. It's like asking "what does blue taste like"? When you're dealing with the spring you're using Newtonian physics in which mass is conserved and energy and mass are not two sides of the...
  12. Feodalherren

    Vibrations in cantilever beams

    Thank you, that was very helpful!
  13. Feodalherren

    Making Energy Generating Gym Equipment

    I agree but since it is a school project those restrictions may be valid - i.e. it may be all that he has access to without pouring money into the project.
  14. Feodalherren

    Vibrations in cantilever beams

    Hi fellow mechanical engineers, I am designing a rather simple excel program for work that deals with vibrations in robots. Imagine a robot that is made up of linear axes that can move in x,y,z sort of like a 3D printer, take a look at this picture: https://pasteboard.co/8hvV5vf.png Focusing...
  15. Feodalherren

    Undamped Harmonic Motion of a rod

    So then by the principle of superpositioning it should be x(t)= [(P/k) / (1-(Wn/Ω)^2)]sin(Ωt) + Acos(Wn*t) + Bsin(Wn*t) - mg/k but then I arrive back at my original issue - how do I find A and B. I only have one initial condition?
Back
Top