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  1. wdornfeld

    Any Details on Acela Brake Cracks?

    It was news in May that the Acela trains had "cracked brake disks", but there haven't been many details. About the best I have seen are: http://host18.hrwebservices.net/~myjackp/may1205.html and http://www.washingtonpost.com/wp-dyn/content/article/2005/05/11/AR2005051102089.html Can anyone...
  2. wdornfeld

    Flex Fatigue of PFA Tubing - Relating MIT Tester Results to Reality

    I have an application where one end of a ~12" length of 8x6mm Perfluoralkoxy PFA ultra high purity tubing is continuously cycled about 3/4" sideways (+/- 3/8"). I can find "MIT Flexural Life" (ASTM D2176) properties of PFA that report 200,000 cycles of life. I believe that the MIT tester is...
  3. wdornfeld

    "Cryo" Tempered Razor Blades for Longer Life??

    I just ordered my Cryo's - let's compare notes to see how they perform. Even with shipping, they aren't that much more expensive than the non-Cryos in the stores. The prices are starting to make electric shavers look pretty competitive. But I miss my old Braun with the non-pivotting head.
  4. wdornfeld

    "Cryo" Tempered Razor Blades for Longer Life??

    Thanks all for your replies. Since the blades remain in their sealed boxes, the cooling and warming rates must be essentially as in air. It is good to hear that this isn't apparently a scam. BRT549 - I did find the thread338-53716 "Keep razor blades sharp" once I opened up my search...
  5. wdornfeld

    "Cryo" Tempered Razor Blades for Longer Life??

    I was web-shopping for cheap Gillette Mach3 razor blades, and ran across the site http://greatrazors.zoovy.com/category/xx/ that advertises long lasting razor blades that are simply Gillette blades that have been cooled to -300°F for 24 hours (in the original box, no less! Read the site FAQ.)...
  6. wdornfeld

    Journal Bearing Design - Does anyone use Raimondi & Boyd?

    I suggest that you get a good clean copy of the Min Film Thickness chart and build a table in Excel. Maybe see http://www.utm.edu/departments/engin/lemaster/machine_design.htm and click the 26th class notes, slide 13, which is Shigley 6Ed Figure 12-14. The Min Film Thickness variable h0/c = 1 -...
  7. wdornfeld

    NonMagnetic Replacement for 440C (Sy > 250ksi)?

    TVP & TEV - Thanks for your inputs. CarTech actually had five alloys that were >250ksi and Mu<25: BioDur 108, Custom Age 625 Plus, 18-18 Plus, MP35N, and 20Mo-6 HS. The first three were described by CarTech as &quot;rare&quot;. The MP35N (and, I think, the 20Mo-6 HS) were 500 lb min orders...
  8. wdornfeld

    NonMagnetic Replacement for 440C (Sy &gt; 250ksi)?

    I have an application where I need a nonmagnetic (or very low permeability) bar with a yield strength of at least 250ksi (but 275 would be better). The bar is 0.25 x 0.4 x 6 inches, and is currently 440C. I've seen a few possibilities that have the strength and low permeability (PH15-7Mo) but...
  9. wdornfeld

    Journal Bearing Design - Does anyone use Raimondi &amp; Boyd?

    Mr. Woodward - I looked at Shigley (5th Ed) on page 504, and it looks like equations a. and c. when combined will give the same deltaT equation in the link's Step 13. Shigley uses C sub H for specific heat, while the UTM equation uses C sub p. And Shigley uses gamma for weight per unit volume...
  10. wdornfeld

    Journal Bearing Design - Does anyone use Raimondi &amp; Boyd?

    Could you share (roughly) what range of speeds, bores, loads, lubricants, and/or temperatures that you work with? Thanks.
  11. wdornfeld

    Journal Bearing Design - Does anyone use Raimondi &amp; Boyd?

    Thanks for your input. Raimondi & Boyd charts are for continuously rotating shafts riding on hydrodynamic films, so they are for a quite different application than the almost static bearing joints that you work with. A very nice summary of the use of these charts is at...
  12. wdornfeld

    Journal Bearing Design - Does anyone use Raimondi &amp; Boyd?

    I've been teaching ME students the use of Raimondi & Boyd's Sommerfeld number -> dimensionless variable charts for years. The method is in every machine design text, but I am curious as to if anyone actually uses it in practice. It doesn't appear to have changed much since 1958 (not that...
  13. wdornfeld

    Journal Bearing Design - Does anyone use Raimondi &amp; Boyd?

    I've been teaching ME students the use of Raimondi & Boyd's Sommerfeld number -> dimensionless variable charts for years. The method is in every machine design text, but I am curious as to if anyone actually uses it in practice. It doesn't appear to have changed much since 1958 (not that...
  14. wdornfeld

    Journal Bearing Design - Does anyone use Raimondi &amp; Boyd?

    I've been teaching ME students the use of Raimondi & Boyd's Sommerfeld number -> dimensionless variable charts for years. The method is in every machine design text, but I am curious as to if anyone actually uses it in practice. It doesn't appear to have changed much since 1958. I would...
  15. wdornfeld

    Ling Shaker wiring diagram

    Try these guys. They specialize in rebuilding old shakers and will likely have the info that you need - or know where to find it. Good luck. ACG INC. 232 Front Avenue West Haven, CT 06516 USA 800-842-8378 Fax: 203-932-5608 Contact: Mr. Andrew C. Grimaldi, President Engineering...
  16. wdornfeld

    Guidelines for Press Fitting Knurled Parts?

    Has anyone seen rules of thumb or calculations for designing press fits for putting a knurled metal post into a smooth metal hole? Thanks
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