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Recent content by arbreen

  1. arbreen

    V-belt slipping - material selection?

    tbuelna, can you elaborate on that last point? Do you mean because of backlash? Tensile modulus?
  2. arbreen

    Zincated Steel Sheets for the Casing of an AC Machine

    I occasionally specify nitrited parts for use in submarines. They are easily identified by their deep pink color and delicious, salty flavor [pig]
  3. arbreen

    Plate Deflection Calulation help

    @IFRs, the OP's not hydroforming. My quick FEA spits out around .25" max deflection for a 18"x36" steel plate (roughly scaled from illustration). Unless the plate's in danger of buckling or yielding, that's definitely a small deflection. If you got a large deflection for a result, you'd know it...
  4. arbreen

    Plate Deflection Calulation help

    What I'd really do is create a complete 3D model with proper loads and constraints, run FEA, and just use Roark/Moody to validate the results. Now that everyone and their mother has FEA built into their CAD system, it's so quick and easy it seems foolish not to use it for quick iteration of your...
  5. arbreen

    Plate Deflection Calulation help

    @kingnero, Because OP's loading is even pressure and not a concentrated load, the deflection is the same for the beam method no matter the width. I would choose a width of 1 inch to drop a dimension out of the calculations.
  6. arbreen

    Plate Deflection Calulation help

    You need a copy of Roark's Formulas for Stress and Strain.
  7. arbreen

    Update position mirrored assembly

    While the mirror tool in a part creates a constraint, mirror in an assembly just creates new parts and does not constrain them. So, after you have used the mirror tool to create the new parts, you will still have to go in and manually constrain the L and R parts to each other. I'm guessing that...
  8. arbreen

    Standard Timing Model AKA Mechanical Minimizer test?

    I read an article about something like this, I think in Wired magazine. The employer had a slew of engineering knick knacks and the prompt was just "tell me everything you can about this object." There was no way to study for it except to get practical experience in your field. One of the...
  9. arbreen

    Mandatory Use of PE

    Bridgebuster, I was browsing through this old thread and took a look at the document you posted. The title text of that official document is totally written in one of the fonts from Star Trek! I was tickled.
  10. arbreen

    Electrically non-conductive but thermally highly conductive material

    Overrun, we didn't use thermal grease, at least in part because they're messy and these assemblies were in optics. Based on experience installing computer heatsinks with silver grease it may be difficult to get a thin, even application of grease or adhesive with such a large surface. Heat...
  11. arbreen

    mechanism for angular stroke

    It looks like a gimbal arm would also be too big. The arm would be something like the attached picture, coming into or out of the page w.r.t. your diagram so as to dodge your target, but the overall envelope of the machine still have to go to center, just on a different plane. You won't need to...
  12. arbreen

    mechanism for angular stroke

    Does this linkage need to control both position and angle? At least it would be possible to use a pantograph linkage to translate circular motion, but it would be necessarily very large. It does appear that any linkage that traces an arc will not also point your block at the correct angle. Can...
  13. arbreen

    mechanism for angular stroke

    It sounds like you're looking for a goniometer stage: https://www.google.com/search?q=goniometer+stage&espv=2&biw=1920&bih=995&tbm=isch&tbo=u&source=univ&sa=X&ei=WhmdVfiEOozfoAT7y7uQBg&ved=0CDQQsAQ
  14. arbreen

    Electrically non-conductive but thermally highly conductive material

    I worked with power electronics packaging in a past life, so here's my two cents. You can't just sandwich a ceramic block in there and expect to get good heat transfer at the interfaces because they're not compliant. I would use a copper sheet (or aluminum for cost) for the bulk of the material...
  15. arbreen

    Flywheel Inertia with chamfer

    I was able to arrive at a solution through two methods. First, I used a combination of simple moment of inertia equations for cylinders and cones to get to the shape of a chamfer. Second, I integrated over the radius with a thin tube as my differential element. I was able to get identical...

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