12 Replies Latest reply on May 14, 2018 3:53 PM by Greg Hertvik

    SolidWorks Sheet Metal

    Joseph Sarhadian

      Hi.

       

      I started learning about SolidWorks Sheet Metal, so I'm a bit confused about Base Flange feature in SolidWorks. Attached are the details of the part I supposed to create. I don't see any info about "Bend Allowance" or "K-Factor". What value am I suppose to enter?

       

      Thank you

        • Re: SolidWorks Sheet Metal
          Dennis Bacon

          Since the question is asking for the mass of the part (not the flat pattern) you can use anything that doesn't break the model. A good enough value for the k-factor would be just about anything (0-1). Go with ~.5

           

          Edit:... Further on down there is a question that requires you to flatten the part and does supply a value for the k-factor.

            • Re: SolidWorks Sheet Metal
              Joseph Sarhadian

              Dennis,

               

              It's absolutely correct. K-factor or bend allowance have zero effect on the mass I got all the values right!

               

              Thank you,

                • Re: SolidWorks Sheet Metal
                  Dennis Dohogne

                  Joseph Sarhadian wrote:

                   

                  Dennis,

                   

                  It's absolutely correct. K-factor or bend allowance have zero effect on the mass I got all the values right!

                   

                  Thank you,

                  This is not true for all cases and should be clarified.

                  Since the K-factor or bend allowance will affect the flat pattern the mass of the flat pattern will most certainly be affected.  However, for the finished part the K-factor or bend allowance is not used by the software, therefore the mass of the finished part is not affected.  It must be noted then that the finished part does not take into consideration the compression of material at the inside of the bends, nor the stretching of the material on the outside of the bends.  As a result the finished part will likely have a greater mass than the flat part.

                   

                  I just verified this with a simple right angle flange: 50mm legs, 25mm wide, 1mm thick (inside), 1.5mm IBR

                  Mass in bent state = 19.38g, Volume = 2453.54 mm^3 (regardless of K-factor)

                  Flattened with 0.4 K-factor:  Mass = 19.35g, Vol = 2449.61 mm^3

                  Flattened with 0.5 K-factor:  Mass = 19.38g, Vol = 2453.54 mm^3

                  Flattened with 0.6 K-factor:  Mass = 19.41g, Vol = 2457.47 mm^3

                   

                  Note the coincidence of the formed and flat having the same mass and volume when the K-factor is 0.5.

              • Re: SolidWorks Sheet Metal
                Kevin Chandler

                Hello,

                 

                As a followup to what Mr. Bacon posted, given the relatively minor affect the K-factor will have on the mass and that the answer choices for mass are well spaced, I suggest you do your best on modelling the example correctly.

                Be sure to read the question correctly (they'll even remind you of this too, come exam time).

                If you're confident that your model is correct, then in this case, being exact may not matter (especially since the density is 0.0027 and the thickness is 1.2, I think it'd be coincidental that the flat pattern area would be such that the resultant mass is an integer).

                 

                Exam tip:

                Beware! For multiple choice exam questions, all of the incorrect answers provided may not be "randomly" generated.

                One or two of the incorrect answers might be valid choices if you've made an incorrect choice in your modelling somewhere along the way.

                SW has been doing this long enough to know where people may deviate and they have crafted answers accordingly.

                 

                So, just because you "got" one of the multiple choices is not a guarantee that it's correct.

                 

                Practice. Practice. Practice. Maximize your confidence. And minimize your overconfidence.

                 

                Good luck and cheeers,

                 

                Kevin

                • Re: SolidWorks Sheet Metal
                  Deepak Gupta

                  Joseph, it seems like these are sheet metal exam questions.

                   

                  If these are from actual exam then kindly remove them as that violates the T&C of exams.

                   

                  If not then you're fine