29 Replies Latest reply on Oct 29, 2009 3:55 PM by Lenny Bucholz

    STEP conversion problems

    Scott Bruins

      I need to convert a model to STEP for one of our quality control guys but every time i save it as a STEP AP203 I get a lot of geometry problems. The model was originally an IGES we received from the customer that was then put in SW and then saved as a STEP file. Any Ideas?

       

       

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        • Re: STEP conversion problems
          Kevin De Smet

          That does seem pretty bad. Try opening your .IGS file you received into Solidworks and before doing anything go to: Tools -> Import Diagnostics.

           

          This is only available to you once and only if you haven't modified the file yet. Step through the feature and try "attempt to heal all" to get rid of none, some, most or all problems.

           

          Once through that I would attempt using the commands under Insert -> Surface... and use boundaries, delete face, fill surface and so on to repair the geometry. If you haven't used those much there are people here (including myself) that would be happy to give it a shot - upload your .IGS file if you are allowed to

          • Re: STEP conversion problems
            Phil Marra
            Can you post the file?
            • Re: STEP conversion problems
              Scott Bruins
              I can not post the original file sorry. I checked the IGES files and they have import errors so I requested new files from the customer. Ill just have to wait and see if the new files are any better. I did ask for the origional SolidWorks file so maybe ill get lucky and not have to mess with importing the IGES.
                • Re: STEP conversion problems
                  Phil Marra

                  So what you are saying is that file was originally created in SW then iges-ed out, then imported into SW, and exported out again as a step format?

                  If it was created in SW and for what ever reason they felt the need to export a "dumb solid" to you rather than just sending a native SW format, it should have been in the parasolid flavoring, and iges should never be the choice for SW to SW translation.

                  The problems I can see from the attached pics looks to be with surfaces not behaving and not being able to knit. I may be wrong but Im betting it wasnt created in SW.

                  Let me know how you make out

                    • Re: STEP conversion problems
                      Scott Bruins
                      The company uses SolidWorks but its 2007 (were running 2009, not really sure if it makes a differance). As for exporting as .iges that was not up to me, we asked for models and thats what we got. If the new set of models doesn't work I will ask for parasolid files. Thanks for your help.
                    • Re: STEP conversion problems
                      Kevin De Smet

                      Phil is exactly right, if it was modeled in Solidworks then ask your customer if they can send you a parasolid (.x_t) version. That's a neutral format that Solidworks is based on for its modeling kernel, it takes all the geometry and dumps all the rest like parametrics and history.

                       

                      It should be a very accurate file and your customer can be sure you can't really alter much because the history, featurs, sketches, parameters are still completely gone.

                       

                      Ask your customer if they can't give you a STEP if that's what your engineering guys are asking for. STEP should also be a good format, I've really never had trouble with STEP but I have with IGES, so I know it be a bit of trouble. It's like, surfaces with to many sides or to much curvature and things can get the IGES format confused, or maybe the IGES translator in software packages I don't know.

                        • Re: STEP conversion problems
                          Phil Marra

                          Scott,

                           

                          Your best bet and the only good solution to this question is get the 2007 native SW files, you can open them in 09 it is reverse compatibility (09 to 07) that can not be done.

                          I have the same problem no matter how many times I tell sales guys the prefered  formats (and I have at times made a list) I still get IGES. Almost every job I do has to have a file from the customer and probably 80% of the time it is from a software other than SW. Even when it is a SW user, I get the program manager or sales guy asking "they use SW what foemat would you like?"

                          • Re: STEP conversion problems
                            Kevin De Smet

                            I would like to correct myself for my previous post saying IGES seems to be always worse than STEP, I was messing around in Autodesk Alias making myself a little teapot and I tried importing that as an IGES and a STEP into Solidworks, the IGES actually had less errors. The STEP had a lot of problems but IGES was actually fairly good except for degree 7 surfaces missing, can someone shed some light on that if possible?

                             

                            Anyway - I guess it's not so much which format is better, but what the geometry is and where it comes from. That's in regards to how the surfaces were constructed and what tolerance settings were and a host of other variables to difficult to predict until you just give it a try. Of course you got your parasolid now and that's awesome

                        • Re: STEP conversion problems
                          Scott Bruins

                          Well I recieved parasolids of the parts i needed and everything worked beautifully this time. Im going to have to talk to our sales guy and have him start requesting parts as parasolids. Thanks for all your help guys.

                          • Re: STEP conversion problems

                            Scott,

                             

                            Glad that others here have offered sound advice by going to the source and requesting another translation type - Parasolid is the best solution. If you have further issues with imported geometry like this and cannot request or get anything other than what you've received from your client or vendor, and you suspect there are problems with the imported geometry, first do a Tools>check and look for invalid faces and short edges. If all passes and you still have trouble exporting/reimporting then do a Insert>face>Heal edges on the suspected faces of the model where Import translation is missing faces. In face even before doing Heal edges, run your cursor over the edges of the model that are suspect and as they highlight, you might discover some microscopic gaps or what I call "dirty edges" in the model. If they occur around the end points of face boundaries, it can result in mismatched vertices and can wacked out the surface or flip it's normal. I'm considering doing a session at SWW2010 on importing geometry.

                             

                            Regards

                             

                            Mark

                              • Re: STEP conversion problems
                                Kevin De Smet
                                I'm curious, is there a tool in Solidworks that allows you to see and flip a normal manually, if you do get problems with imported geometry and flipped normals?
                                • Re: STEP conversion problems
                                  Jerry Steiger

                                  Mark,

                                   

                                  A session on import/export would be great!

                                   

                                  Jerry Steiger

                                    • Re: STEP conversion problems

                                      Hi Jerry,

                                       

                                      I'm using Inventor 2010 and used to have pretty good luck with STEP files from Solidworks; however, I have several vendors and clients that use SW and the STEP files now are often plagued with problems.  These are usually missing faces.  I called my Autodesk tech up and asked what the issue was; apparently SW converts with significantly lower accuracy than INV, and you end up with faces not meeting and holes in the models.

                                       

                                      I downloaded  IDA-STEP which is a free STEP viewer and you can see the same problems with the model using that.  So I would definitely say the problem is with SW and its STEP converter.

                                       

                                      I'm currently looking for a good way to get solid data out of SW into INV.  I've tried using the INV solidworks import, but that also has holes in it.

                                       

                                      Regards,

                                      Jim

                                        • Re: STEP conversion problems
                                          Phil Marra

                                          Jim,

                                          Not knowing anything about Inventor, I did a quick google to see if they offer parasolid (x_t) or (x_b)  as an export/import flavor. Seems as if this might be, and if so stop using step when working with SW clients.

                                          Also can you post a sample file? Id be curious to see if some of the usual bad siuations are causing your problems.

                                            • Re: STEP conversion problems

                                              Hi Phil,

                                               

                                              Unfortunately, I can't post a file since they are all proprietary.  If you look below, you'll see that the *.x_t worked.  I googled and found a similar suggestion for Pro/E.  I'm not sure why the native SW parts have holes in them though.

                                               

                                              Jim

                                            • Re: STEP conversion problems
                                              Kevin De Smet

                                              Autodesk tech saying their software does a better job?

                                              Dear lord, I am amazed to the extreme!

                                               

                                              But yeah, try parasolid if you can. Sticking to well know kernel formats such as ACIS (which Inventor is largely based on I believe) and Parasolid (which Solidworks is entirely based on meaning completely compatible) are good bets for translating from one application, to the other.

                                               

                                              .x_t is the parasolid format that Solidworks natively works with, that will give the best results.

                                              Best of luck!

                                                • Re: STEP conversion problems
                                                  Bernard Julien

                                                  Kevin,

                                                   

                                                  Sometimes Autoesk sftware does a better job than Solidworks. I have files from a supplier (a parts catalog) done in Pro/e and converted to STEP. Most of the files will not come clean into Solidworks no matter how I try. All of them come clean into Inventor, and into AutoCAD Mechanical.

                                                   

                                                  That is pretty frustrating since we have to import files quite regularly. I filed an enhancement request asking that they improve the Step import functionnality. Step is a standard format and most of the time, it should work fine. With all the other softwares that I used so far, it generally worked well .

                                                    • Re: STEP conversion problems

                                                      The tech did actually have a reason, whether it's fact or not who knows.  He said that basically SW uses fewer significant digits.  I think the more basic answer is SW broke their STEP translator.

                                                       

                                                      I can't say I can directly compare against SW, but I have worked on a couple projects that Autocad could do that SW had problems with.  Sometimes, it required the use of Mechanical instead of Inventor; sometimes you just have to work in real 3D without worrying about sketches, constraints, and the CAD program making tweaks.  I also remember seeing the 2D drawings SW generated and noticing that the dashes in the hidden lines didn't match up or weren't symetric at corners; basically, something that you would fail first year drafting for. 

                                                       

                                                      Ok, so my solution was to use *.x_t for conversion from SW to INV; everything comes in fine.  Conversion from INV2010 to SW 9.5 using the default for *.x_t resulted in an error, I went into the options and selected an earlier Parasolid version (I haven't heard back from my SW counterpart on whether that was successful or not)  SW9.5 did like the STEP from INV2010 (including the colors, though not the transparency)

                                                       

                                                      So to summarize, looks like SW STEP translator is broken.  I've noticed this several times with surfaces associated with embossed text; though bottoms of the cross of philips screws have had problems, as have tops of pins.  If you'd like to check it out, download IDA-STEP http://www.ida-step.net/ and check out your STEP models before you send them off.

                                                       

                                                      Cheers,

                                                      Jim

                                            • Re: STEP conversion problems
                                              Lenny Bucholz
                                              remember all of autodesk  uses the asics kernal, so have you tried the sat conversion?
                                              • Re: STEP conversion problems
                                                Lenny Bucholz

                                                info on invetor and cad system comparisons

                                                 

                                                http://en.wikipedia.org/wiki/Autodesk_Inventor

                                                http://en.wikipedia.org/wiki/Comparison_of_CAD_software

                                                 

                                                Data and Exchange

                                                Inventor uses specific file formats for parts (IPT), assemblies (IAM), and drawing views (IDW or DWG). You can directly import and export files in DWG format. Design Web Format (DWF) is the preferred 2D/3D data interchange and review format in the Autodesk family of products.

                                                Inventor includes an Architecture, Engineering, and Construction (AEC) Exchange tool. This tool is used to create and publish simplified 3D representations, intelligent connection points, and additional information in native file formats for AutoCAD MEP software. You can export 3D geometry to AutoCAD Architecture, Revit-based software, and AutoCAD software.

                                                In Inventor, you can exchange data between applications, including CATIA V5, UGS, SolidWorks, and Pro/ENGINEER. Inventor supports direct import and export of CATIA V5, JT 6, JT 7, Parasolid, and Granite files. It also supports direct import of UG-NX, SolidWorks, Pro/E, and SAT files.

                                                The Inventor Construction Environment provides fault-tolerant import of large STEP and IGES data sets. A quarantine holds entities containing geometric problems, such as surface slivers and mismatched boundary curves. In Inventor, you can:

                                                • Publish drawings as PDF files.
                                                • Publish 3D part and assembly models in SAT or JT formats.
                                                • Create STL files for output to stereo lithography and 3D print machines.