Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Simple Design Project: 'Walnut Cracker'

  1. Feb 27, 2009 #1
    Here's what I need to do:

    Walnuts are an important cash crop in Yolo County and are popular to consume around the holidays. To give the market a boost, it would be useful to have a device which would facilitate walnut cracking and also be fun to use. Recognizing this need, the objective of this design project is to design an impact walnut cracker which meets the following design criteria:

    1. The device must operate in the horizontal position.

    2. Impact must be provided by a mass sliding on a track which is accelerated by a linear spring(s).

    3. The mass must strike a ‘firing pin’ which slides in a bushing and applies the impact load to the walnut.

    4. The nut must be temporarily encased during impact to prevent the nut shell fragments from scattering.

    5. The device must be designed to crack an infinite number of walnuts.

    Some of the primary design considerations include the slider mass, the sliding distance, and the spring rate. Specifying these quantitatively depends on the energy required to crack a walnut shell. To determine this energy, you will need to devise a simple test to determine the average and standard deviation of the energy required to crack 10 nuts. This data will then be used for the design.

    Your assignment is to conceive a device which meets the above criteria, perform the necessary calculations to select both material and geometry so that none of the structural components experiences fatigue failure, generate the working drawings to manufacture the design, and finally to communicate your design through the preparation of a design project report. The contents and format of the report are described in a separate handout.

    To get started, I need to determine the energy needed with an experiment. Anyone have any ideas for how I should do this?
  2. jcsd
  3. Feb 27, 2009 #2


    User Avatar
    Gold Member

    This seems to be a homework assignment. As such, it's in the wrong place.
    I hate walnuts with a burning passion, but if I have to crack one for the wife I use a hammer.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook