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Plastic Bottle and Aluminum can crusher

  1. Dec 5, 2011 #1
    I created a plastic bottle and aluminum can crusher. I researched and found out that my crusher should apply at least 175 lbf - 200lbf in order to crush the beverage container. My design idea is very similar to that of a cold rolling manufacturing process. Although I have research the cold rolling process and the calculations involved, I am still having trouble relating it to my design. As you can see from the attached image, the crusher will do a best effort attempt at crushing the article, if the force excedes that of the rollers then the springs attached (with a particular k value) will compress resulting in an increase in the gap between the rollers.

    To clarify, my issues are...

    Calculating the force of the drums on the can

    Calculating the k value of the springs in order to allow them to only compress once the force of the rollers exceeds about 175 lbf

    Calculating the torque needed out of a pair of DC motors in order to power the rollers

    If you need more information please let me know and I will do the best I can to answer

    Attached Files:

  2. jcsd
  3. Dec 6, 2011 #2
    First of all, convert your units to SI units. I have no idea what a lbf is.
  4. Dec 6, 2011 #3
    I apologize for the unit confusion, 175lbf = 778.44N, 200lbf = 889.64N. Also the diameter of the rollers is equal to .127meters with a length of .4064 meters. The gap between the rollers is equal to .019meters. Although the springs depicted are small, they will need to widen the gap from .019meters to about .0762meters.
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