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Recent content by Steven_D_P

  1. Steven_D_P

    Interesting drawing

    @3DDave There's an email of the designer on the drawings. You can tell him how his drawing are absolute crap and that your car is faster 0-60.
  2. Steven_D_P

    Selection of spline module

    DIN 5466-1 only deals with the strength of the splines themselves and not the fatigue strength of the shaft. In that case I would look into not just how the cross-section of the shaft changes with the module of the splines, but also the fatigue notch factor if you can find some information about...
  3. Steven_D_P

    Shaft to Gear Connection

    Some simple options are: 1. Shrink-fit the gear on the shaft. Usually it's easiest if the shaft has shoulders to axially locate the gear or other elements on it (or you can use sleeves as well). It's also easier to mount a shrink-fit if the shaft in front of the gear is slightly smaller so it...
  4. Steven_D_P

    Hydraulic Drive vs. Direct drive vs, Diesel Electric Drive -- Overall Efficiency Comparison

    Well, you asked about the efficiency of the diesel-hydraulic option so I replied w.r.t. the efficiency of a diesel-hydraulic system. Whether it's lower cost is worth it's lower efficiency is a trade-off you or your client will have to make. W.r.t. the ease of varying engine loads at different...
  5. Steven_D_P

    Hydraulic Drive vs. Direct drive vs, Diesel Electric Drive -- Overall Efficiency Comparison

    The hydraulic option should not just picture the losses because of the pump and motor but because of the lines, fittings and any valves in-between as well as these losses will be higher compared to "transporting electricity". Furthermore, if you're using a variable displacement pump or motor the...
  6. Steven_D_P

    Planetary Gear Material- 9310, any tool steel viable?

    Ring gears are usually not case hardened because (usually) after hardening they need to be ground which is often not possible (or at least hard to do) for internal gears. Therefore they are either through hardened or QT and nitrided. Nitriding them will not lead to large distortions which means...
  7. Steven_D_P

    Concentricity with common axis A-B?

    Yeah, I was thinking it only is useful if it's less than half of the size tolerance since it's radial and not diametrical. But you're correct that there are certain specific exceptions that would fit the size tolerance without fitting the circularity tolerance so it rules out those.
  8. Steven_D_P

    GD&T position Mutiple segment - Calculating min and max span of bolt holes.

    ^I think there's 1 little mistake and that's that the maximum span would be 304.14 + 3.7 = 307.84 (since both holes can be a distance of 1.85 away from their ideal location). Same goes for the minimum span which would be 300.44. This is only taking the tolerance w.r.t. datums X, Y, Z into...
  9. Steven_D_P

    Natural frequency of clamped-hinged column

    @dyahaw._ You say you used the BC that resembles a roller to take the external load into account but the external loads shouldn't have an influence on the natural frequency. Furthermore, a beam is loaded in pure compression only theoretically, in reality the force will be off-center from the...
  10. Steven_D_P

    Concentricity with common axis A-B?

    When I look at this drawing the only thing that seems strange to me is to have a 0.1 circularity tolerance on a feature that has a size tolerance of +/- 0.1. This size tolerance should automatically make the circularity within 0.1. It's not wrong but unless I'm mistaken it's unnecessary...
  11. Steven_D_P

    Natural frequency of clamped-hinged column

    If you calculate the clamped-clamped condition you should get a higher natural frequency than the FEA result and not a lower one. There are a lot of ways to calculate the natural frequency. Here's one based on the maximum deflection because of it's own weight. n = k*946*SQRT(1/f) with n =...
  12. Steven_D_P

    Webster Hardness conversion to Brinell HBW

    @Dhurjati Sen If you want to convert accurately you'd need testing strips of the same material class.
  13. Steven_D_P

    Do I have the correct Idea for Position tolerance

    Yes, the total perpendicularity tolerance w.r.t. datum A in the worst case is 0.2 + the size tolerance of the hole.
  14. Steven_D_P

    Do I have the correct Idea for Position tolerance

    You have a MMC so if the hole is larger than the minimum size tolerance the position tolerance will be more than 0.2. (This is usually the design intent so I'm not saying it's wrong, just making sure you know.) The allowed distance from the B datum is also allowed to change based on the position...
  15. Steven_D_P

    Mechanical Design of industrial equipment - disagreements on design timelines and methods

    Well, we all hear the story from you, so we're biased by your opinion and your explanation. But you say this position has physically and mentally worn you down so at the very minimum it's time to have a talk about this with your boss or manager and explain your viewpoint. That's the minimum...

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