LASER CUTTING BASICS FOR SHEET METAL DESIGN

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LASER CUTTING BASICS

       

                Laser Cutting is often utilized in prototyping and production parts of sheet metal. This process is good for intricate details and irregular contours.

       a)                 Tolerances:-

         Feature to feature tolerance on for the laser cutter is +/- .004”. The smallest cut is determined by beam width or .008” wide.

       b)                Material Restrictions:-

         There are three factors depending on material restrictions for laser cutting:-                                 1.      Reflectivity:-    Cutting beam gets scattered due to reflectivity.                                                                2.      Thickness:-      Molten metal scatters the beam before part is fully cut, due to                      
                              thicker materials. It is possible to cut thicker metals of 3/8” but
                              the edge quality suffers greatly. 
       3.      Flammability:- The degree of flammability is considered as factor. Some parts
                             considered flammable can be used. 
             The acceptable materials are any raw Steel (Stainless, CRS, HRS), Aluminum (some deburring issues), Plastic (check heat and flammability), Cardstock (check heat and flammability), Galvanized, Galvaneal.
              The unacceptable materials are Copper (highly reflective), Paperstock (unless treated with flame retardant), Silver and other precision metals (highly reflective).
   

       c)                 Localized Hardening:-

                The edges of material become hardened due to intense heat of laser cutting. This area is referred as heat affected zone (HAZ). This is important for secondary operations such as reaming and tapping. The HAZ increases in thicker materials.

       d)                Hole Dia:-

                The entry dia is greater than exit dia, creating slightly tapered hole. Minimum hole sizes are related to stock thickness and can be as low as 20% of stock thickness.

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