1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

Caterpillar Performance Handbook Edition 36 Questions

Discussion in 'General Industry Questions' started by fensoncont., Feb 17, 2007.

  1. fensoncont.

    fensoncont. New Member

    Joined:
    Jan 2, 2007
    Messages:
    286
    Likes Received:
    0
    Hey guys,

    I am having some problems with the Caterpillar Performance Handbook. I don't understand some things.

    First, on the "Effective Grade" Charts (Grade Assistance minus Rolling), what if I have a grade assistance of 2% and a rolling resistance of 4%?? I get -2%, how do I do that?? Also according to the way to do that a steeper grade would be a higher Total Resistance, how is that, more retarding??

    I have some more questions, but lets take care of that one first.
     
    Last edited: Feb 17, 2007
  2. JDOFMEMI

    JDOFMEMI New Member

    Joined:
    Jan 4, 2007
    Messages:
    3,060
    Likes Received:
    0
    Nolan

    Treat roling resistance like it is a negative, and grade assistance like it is a positive. Assistance of +2% and resistance of -4% equals a total resistance of 2%. Your answer is correct, just think of resistance as always negative, as it always slows you down.
    When you start figuring this, you will only ever get close, as conditions on most jobs change often enough that you need to figure an average.
    You could take a full year course, and still not cover all the variables on cycle times.
     
  3. fensoncont.

    fensoncont. New Member

    Joined:
    Jan 2, 2007
    Messages:
    286
    Likes Received:
    0
    Jerry,

    Thank you for your reply. What are you doing to get 2% from 2% and -4%?? Can you give me some more example problems so I understand it better to?? In the examples how about have some that are Grade Resistance to. And wouldn't a steeper grade help the machine going downhill?? Also what do you do if you have Total Assistance, if there is such a thing?? Example, your rolling is low and grade assiatance is high. After that I will proceed with my other questions everyone.
     
    Last edited: Feb 17, 2007
  4. JDOFMEMI

    JDOFMEMI New Member

    Joined:
    Jan 4, 2007
    Messages:
    3,060
    Likes Received:
    0
    Nolan
    It is really -2%, but as I said before, resistance is always a negative effect, so standard practice is to simply call it resistance, then the "-" sign is redundant.
     
  5. fensoncont.

    fensoncont. New Member

    Joined:
    Jan 2, 2007
    Messages:
    286
    Likes Received:
    0
    Thanks Jerry. I understand it now. That clears that up.

    Next question gentleman. On the "Rimpull-Speed-Gradeability Curves" charts I seem to get slower speed for empty machines than loaded. I followed the example they give you, but if you do the same exact problem empty you get the same speed. And in some situations like I said you get slower speeds on empty than loaded, why is that, or what am I doing wrong?? Same goes for the "Retarder Curves" charts.
     
  6. surfer-joe

    surfer-joe New Member

    Joined:
    Mar 25, 2007
    Messages:
    1,400
    Likes Received:
    0
    Best check with your Cat dealer PSR guy for more answers to questions regarding charts and graphs in the Cat handbooks. He will have all the answers for you, or he will check with the factory and get back to you in short order. That's if you aren't running a bunch of Komatsu's or Volvo's.
     
  7. Countryboy

    Countryboy New Member

    Joined:
    Jun 8, 2006
    Messages:
    3,276
    Likes Received:
    0
    Welcome to HEF surfer-joe! :drinkup
     
  8. lpcubo

    lpcubo New Member

    Joined:
    Apr 15, 2009
    Messages:
    3
    Likes Received:
    0
  9. fensoncont.

    fensoncont. New Member

    Joined:
    Jan 2, 2007
    Messages:
    286
    Likes Received:
    0
    I don't have a copy of the manual online. I only have the hard copy.
     
  10. JimBruce42

    JimBruce42 New Member

    Joined:
    Jan 15, 2006
    Messages:
    965
    Likes Received:
    0
    I'm probably way off, but I think a big part of the reason for that Nolan is that extra weight. On trucks for example the drive wheels (or 2/3 of them on ADT's) are under the bed of the truck, so when they are loaded you have more weight pushing down to give added traction effort, course if you're on some soft spongey crap you just sink.:Banghead
     

Share This Page