12 Replies Latest reply on Mar 23, 2010 9:08 PM by 1-MPPC4D

    Perimeter measurements in drawings

      Ok lets say I have a long slot that I want to determine the dimensions based on the end radius's and the perimeter. AKA you pick the size of the end rounds and the perimeter and it comes up with the lenght based on that. In pro/E this is really easy and extremly usful for the things I design which happen to use rubber tracks. Is there a way to do this in solidworks. I am trying to determine the program I am going to buy for my business and this is a very important feature to me.

       

       

      Thanks!

        • Re: Perimeter measurements in drawings
          Wayne Tiffany

          In an interactive mode, it's easy to do.  RMB on an edge of the slot, pick Select Loop, then open the measure box where it tells you the total length of the selected entities.

           

          If it would be a part that you would use multiple times, you could identify the slot and have a property that is filled in with the calculated length.  Then use that length in a drawing.  You might also be able to just run a macro against a slot an have it grab the total length and use that.  Just thoughts.

           

          WT

          • Re: Perimeter measurements in drawings

            What exactly is an RMB.

             

            Oh and I should have menstioned that the slots will not always be just a normal slot. Sometimes there has to be more rounded areas aka idler wheels to make the track change its attack angle.

              • Re: Perimeter measurements in drawings
                Wayne Tiffany
                Right Mouse Button
                  • Re: Perimeter measurements in drawings

                    Ok I figured out what you meant by selecting them but the only measurement I get is down in the lower right it tells me the length but is there a way to make the deminsions based on that. If I click the smart measure tool it just unselects everything and works like usual.

                     

                     

                     

                    I did manage to make it work by measureing all of the arcs and sraight segments one by one and making them all driven measurements and then making an equation to set the last one to a certain length to make a full loop of the required size but it is really messy and looks very error prone. Also in the equation place there is and red ! mark.

                     

                    There has got to be a better way of doing this

                     

                     

                     

                    Thanks!

                      • Re: Perimeter measurements in drawings
                        Wayne Tiffany

                        I have the measure box set to a hotkey of D (for Determine a Distance) so I just select the loop in question and then hit the hotkey.  The measure box then shows the total length.

                         

                        But that doesn't capture it to a variable as you have found.  In cases of a lifting belt or chain going around bends, I have done the equation route in order to set the belt to a given length and then worked out the geometry of the bends, etc.

                         

                        Sorry, not much more help.  If you think I'm missing what you wish to do, can you post a picture?

                         

                          WT

                          • Re: Perimeter measurements in drawings

                            I have done some research and I don't think you can do it. It pro engineer you can select the loop much the same way and get a measurement that you can change. So lets say you have a slot define completely except for the length of the slot you could use the perimeter measurement and then when you change the length of the perimeter the length of the slot would change. I don't think SolidWorks has the capability as it doesn't seem to have some other sketch functions the pro E does espesially when it comes to arcs and circles.

                              • Re: Perimeter measurements in drawings
                                Deepak Gupta
                                Randy, I just looked at this capability/option of perimeter dimensioning in Pro E but I'm still not able to make as how it can be useful. I haven't seen any slot defined in this fashion. Can you please give an example or case where this kind of dimensioning is helpful.
                                  • Re: Perimeter measurements in drawings

                                    Ok so let me explain.

                                     

                                    I design and build things that use a rubber track. For instance snowmobiles. I said a slot because of simplicity but for what I do it is rarely a normal slot. I have attached a pic from pro/e of a current project.

                                     

                                    In the pic you can see that all of the round part which in this case is things like idler wheels and track drivers. In pro/e I can take the inside perimeter of the entire loop and then set that to any dimension I want. In the example I used the distance from the front driver to the rear(aka the length of the track between front and rear centers). Now I know my track is 101.6 inches long and so I set the perimeter to be this long. Then I set the upper dimension that says 38.45var to be the dimension to change when I change the perimeter. In other words If I change the perimeter to said 110 inches then the 38.45 dimension when change and get longer to compensate the change in perimeter.

                                     

                                    This is extremely useful for this application and many others like chains for instance. I can build something to fit a set number of chain links as opposed to just trying to get close.

                                     

                                    If you need further explanation I can try but I thing you can see what I mean now.

                        • Re: Perimeter measurements in drawings
                          Gerald Davis

                          ...things I design which happen to use rubber tracks....

                          SolidWorks has a very useful tool for designing tracks (belts).

                           

                          The attached example is in SW09.  I set the belt length to 15".  The location of the pulleys floats to match since the belt drives the show.  If you select to create a driven belt, then the location and size of the pulleys take precident.

                           

                          In this example, I'm using a sketch in a part.  You can do a similar thing by inserting a belt into an assembly, which more closely resembles a manufacturing process.

                           

                          For the devoted, the use of layout sketches and blocks is a great way to develop belt driven mechanisms.  Check out SWW presentations by Bruce Holway for outstanding tutorials on this.

                           

                          Driven Belt.jpg

                            • Re: Perimeter measurements in drawings

                              I tried it and I think it might work but I do have a question. After I made the sketch and added the belt there is still a - in front of the sketch say that it is not defined but you can drag anyware on the sketch and nothing moves. Is this just a bug or what.

                               

                               

                              Thats alot and I will use the feature a little more when I get some time to see how well it works. I have narrowed down the pros and cons of each and for a smaller bussiness I am really leaning toward Solidworks as it is much cheaper for what you get and I dont need surfacing. But this might be the deciding factor. Thanks!