16 Replies Latest reply on Sep 6, 2018 5:08 PM by Anna Wood

    Arc Length

    Brian Kelly

      On most or all sketch entities that create arcs...the length of the arc is determined by entereing an angle.  Is there a way to draw an arc where I can enter its length rather than an angle?

        • Re: Arc Length
          Wayne Matus

          You cannot draw it by length, but you can dimension the length. Select one end point, then the next end point, then the arc itself, and  finally select the location to place the dimension.

            • Re: Arc Length
              Kelvin Lamport

              ... and after being placed, the dimension can be adjusted to suit.

              • Re: Arc Length
                Dennis Dohogne

                Wayne Matus wrote:

                 

                You cannot draw it by length, but you can dimension the length. Select one end point, then the next end point, then the arc itself, and finally select the location to place the dimension.

                Actually, you can pick the endpoints and arc in any order.  I find I usually pick the arc first then the endpoints.  It's all good.

                 

                Fun Fact:  Starting in SWX2016 you could set the length of an arc equal to the length of another line segment in a sketch.  This has turned out to be quite handy for several situations for me.

                  • Re: Arc Length
                    Anna Wood

                    Dennis Dohogne wrote:

                     

                    Fun Fact: Starting in SWX2016 you could set the length of an arc equal to the length of another line segment in a sketch. This has turned out to be quite handy for several situations for me.

                    This is a huge timesaver for me.  I use this functionality quite often.  It is bidirectional for which is driving, arc or line segment.

                      • Re: Arc Length
                        Alex Lachance

                        May I ask, how do you and Dennis Dohogne use that functionality? Is it when you draw flat patterns for things such as rods? That is pretty much the only use I've ever had of it.

                          • Re: Arc Length
                            Dennis Dohogne

                            Alex Lachance wrote:

                             

                            May I ask, how do you and Dennis Dohogne use that functionality? Is it when you draw flat patterns for things such as rods? That is pretty much the only use I've ever had of it.

                            A lot of times I use it while in development.  The arc might represent the range of motion of a certain point and I need to achieve that with another component or linkage.  I also made extensive use of the equal relationship between arcs and line segments in my parametric involute gear files.

                            • Re: Arc Length
                              Anna Wood

                              I use it for sheet metal strip layouts / flat patterns.

                                • Re: Arc Length
                                  Alex Lachance

                                  For flat patterns? Is it because you build from a flat pattern and then fold it?

                                    • Re: Arc Length
                                      Anna Wood

                                      Not everything that is formed or needs flat patterns works well with SolidWorks forming tools.

                                       

                                      Parts where I only get a step file or parts that have complex bends that are created with more than one hit.  I use old school methods and bury a lot of information in sketches when working out the form tooling; overbends, spring back, using up all the material appropriately.

                                       

                                      1st form is pink, second form is cyan, 3rd/final form is green/yellow.  There is a ton of info buried in the sketchs to work out the form design.  Across the opening of the final form is only .020" to give you an idea of the scale of this part.

                                       

                                      Form Sketches.jpg

                                        • Re: Arc Length
                                          Alex Lachance

                                          I wish I could sit down with you for a day to understand the methodology through this, it is rather interesting to see the method you use.

                                           

                                          So guessing from the opening, these are very small gauges plates?Are all 3 of the forms directly linked? My guess is the folded is the master that controls a flattened.

                                           

                                          I love learning new methods of working

                                            • Re: Arc Length
                                              Anna Wood

                                              Wired form punches and inserts out of D-2 steel.

                                               

                                              Yes the final, folded form (green sketch) controls the other two sketches.  There are quite a few equal relations between the base sketch (green) for the arc lengths and straight lengths.  I have to start the bend in the appropriate location on the tip to use the material up correctly to get the last form and overall height and tip length.

                              • Re: Arc Length
                                Mike Price

                                Arc length = radius * angle (in radians)

                                • Re: Arc Length
                                  Brian Kelly

                                  OK...thanks guys......clicking on the 2 end points then the arc is the correct answer.  I have been using this software for over 10 years and I still learn new things about it.