47 Replies Latest reply on Jan 31, 2012 12:46 PM by John Biddleston

    Really need help to improve this model, its surfaces and I think I need to redraw from scratch?

    John Biddleston





      I have having trouble modifying the attached part to the new required specification http://thebigconsultant.com/downloads/Multi%20Part%20Mould%20Iss2.1E.zip


      The problems are:-

      - I need to resize it

      - Rebuild errors, and very slow rebuilds

      - Complexity of model




      I am now strongly thinking that I need to redraw the product from scratch. This may be quicker, and also make the model more elegant and easier to use, and adjust.


      I think that the main problems that I have come from the very way the model was built, using the surface lofts right in the early stages. There has always been a problem with the surfacing at the front and rear curves where they join at the extreme front and rear.


      This has had knock on effects, and it taking up too much time. Also, the rebuilds are now horrendous. And I am running quad core at 3.8Ghz with 8GB ram!


      I think that I need to look at a radical new redraw. Maybe using features differently from the off, that will provide more consistent and reliable results. However, I do wish to keep the exact same shape and profile.


      I think that this will be important for the production issue, also. As this is a prototype. I will need to easily make changes to draft and other details. So I think a new model, looking the same, but drawn differently is mandatory.


      I am especially thinking that the "surface lofts" right at the beginning are causing problems. With surface lots the geometry seems very 'ragged' at the extreme front and rear. This requied patching, and in fact I think "surface lofts" might often experience this problem.


      I am looking for a method to completely redraw quickly, and neatly, and maybe suggestion of a new way to draw this exact same shape, but without using surface lofts maybe? It has led to many rebuild problems when I edit, and I think I need an elegant new basis, to achieve the same effect. But in less steps, and more reliably!


      Please could anyone advise?


      Kind regards,

      John Biddleston

        • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
          John Biddleston

          Please note, that I have put a copy of the model here, if anyone wants to take a look!




          Any and all comments are welcome! ... I think that when you 1st draw things, you make them over complex. And so it needs doing neater and in less steps. Also, I think I may be best to make a radical departure from using loft-surfaces, as this method leads to excruciating rebuild errors, and problems at points where the loft-surfaces terminate at a point at the end of the front and rear curves.


          Must be a simpler way. And I'll admit, I'm very stuck!

          • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
            Michael O'Donnell

            Hi John,

            I had a look at your file and thought I'd take a shot at it.

            I've only done the very basics, but it should give you an insight.

            I would suggest:

            • surfacing the entire part first
            • turning it into a solid
            • splitting the part
            • adding further features


            This means if you do need to go back to the start, all the groundwork is in the one area and is linked together.

            I only started surfacing last year and it's taken me a while to get comfortable with it. In the early days I found it best to work up to a point and then (time permitting) build it again from scratch to see how I could reduce the design tree. I'm not as quick as most of the other users, but I am getting stuck lesss and less these days, so it must be working!




              • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                John Biddleston

                Hi Michael,


                Thanks for the feedback on the part I am struggling with.


                Yeah, my SolidWorks VAR has been helping me with this. And I wrote into SolidWorks in the USA, as I know someone who works there, and neither could provide a suitable solution.


                I think that the surface-loft function is very dodgy indeed!


                I did make the ends of the loft tangent, and even went back and put in ruled surfaces to make sure.


                Still getting the terrible wrinkles at the tip and at the rear end of the model.


                Im not sure how to build the same shape without using the lofts, so I am going to try to cut the ends off, and use maybe a fill-surface at the ends?? If this fails I might have to go back and see if I can get the whole thing made with boundry surfaces. But I am not quite sure how to achieve this yet.


                I'll try the "check features" tool also. Still very worried, as I am hugely over-running on time now on this model!!


                Many thanks, Bid

              • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                Jerry Steiger



                I don't have time to look at your model now, but Boundary Surfaces are often a better choice than Lofts.


                When you say front and rear, do you mean the pointy end on the left and the not-so-pointy end on the right? Or is front the part facing toward us and rear the part we see through the holes in the front?


                What do you mean by ragged and what kind of patches were required? Two methods that can often help when things get a little crazy at the ends of a part are to use a helper surface so that you can make your surface tangent or even curvature continuous to the helper or to make the surface larger than needed and then trim it back to the edge you want. The helper surface is especially useful when your part has to have a specified draft all along an edge.


                Jerry Steiger

                • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                  Matt Lombard

                  This part is about 12 hours worth of work, with all the interior detail. 650 features is incredible. It should be about 1/3 - 1/4 of that, max.


                  1. Figure out what "degenerate surfaces" are, and avoid them using the Fill surface with "optimize" turned off (at the capped ends). This will improve shelling and basically everything that touches the ends of the part. The remote control example from the SolidWorks surfacing class should give you some pointers on this shape.
                  2. When you split the part into bodies, push the bodies out to separate files to add the details to the parts. Then bring it all back together in an assembly. Doing it all in one file as you have done just piles features on top of features. This is one of the huge traps of multi-body modeling that enthusiasts get caught in.
                  3. Don't combine incontext (combine feature) with a part like this that should be modeled using master model techniques. The Cavity feature seems to be responsible for only a couple of very small faces, which could be made some other, less "expensive" way.
                  4. Posting customer data to a public forum is a really bad idea, especially if your customer sees it.
                  5. Unfortunately, I think this is a re-do if you want to significantly improve things, especially if you have to make different versions. The part looks nice, but the errors in how you've planned it are the real killer. You could possibly use the Freeze Bar, but I see that you aren't using 2012.
                  6. The error for tangency that you are showing usually appears when your Dir1 and Dir2 curves are not compatible in a corner where the curves touch, so that the software can't satisfy the edge conditions for both directions. Maybe your boundary surface is tangent to the ruled surface, but the dir2 curve is not tangent to the ruled surface, so it's impossible for the software to satisfy all of your requirements in the corner where the dir1 edge (ruled surface) and dir2 intersect. If your input curves/faces don't satisfy the conditions you specify, the software doesn't have a chance. At a degenerate end, the software is very likely to do the wrong thing. So make the end, then chop it off, and replace it with a Fill surface using a sketch point (as a control curve) or reference surfaces (like the ruled surfaces) to control it.
                  7. Very interesting use of the Thicken5 feature and the curve driven patterns. Are the pattern instances toward the end of the part going to work out from a molding point of view for you? Looks like some undercuts. Love the Move Face cheats. I do stuff like that sometimes, but I try not to let anyone know I do stuff like that.
                  8. Fix your toolbars, they might be making you dizzy. This isn't Autocad, you know.


                  I'm sorry to hear about your troubles with this part. SolidWorks is not very well suited to detailed product design using standard techniques. You have to plan out how you're going to get around the limitations of the software before you know exactly what problems you're going to run into. It looks like you're 98% of the way there, and the part does look nice. You've done a great job despite the handicaps you've given yourself. I'd be willing to bet you've learned a lot from this.


                  Best of luck.

                    • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                      John Biddleston



                      You comments are both insightful, and very well considered.... There is so much there for me to understand, that in each sentence, I have had to do quite some research. (in fact I have cut and paste your post into MS Word, and I have been working through today the terminology, and pasting into the document. Also further researching the individual tools, and their capabilities and theory etc). I am still working on this, but hope to begin tomorrow the new build, if I am capable.


                      1. Great info. I had not heard the term "degenerate surfaces", but indeed this is what I kind of suspected, when above I noted that the computer was generating "guestimations" of the profile at certain convergences of the surfaces. ... Seems computers dont like very small figures, and zero is a no no! ... Shame SolidWorks dont advertise their limitations. But thats partly understandable. I do think that they should be more "up-front" though, as I am sure I am not the first that has spent 3 weeks wasted on errors, that I do not understand the reasons for failure. This is not good for workflow, or my health and nerves! Plus, I am put into a tough situation where I am in risk of letting my customer down in timescales, which is of course very very undesirable for obvious reasons.


                      The Fill-Surface tool, does indeed seem to have restorative and 'magic' properties, those being a propensity it seems to not use degenerative meshes by default. But when and where to use, particularly on this model, I still need to decide.

                      - I am considering that maybe, I use one Fill-Surface at each end, and then maybe one or two Boundary-Surface on the top, and again one to two Boundary-Suface on the underside.

                      - Again, I see that Loft-Surface could be used here, and maybe others too. I need to consider carefully. ... I was unable to create the entire top profile with one Boundary-Surface, which was dissapointing. Problems I think were with setting and achieveing correct tangency or curvature. The error report of  "The guide or profile curve's tangent at the constrained point(s) does not match the tangent of the constraint. The discrepancy will be propagated" certainly did not help me, and no amount of clicking and trying various methods to create of constrain blindly, did any bit of good for me. But of course, I am new to this world. The answer may be infuriatingly simple!?


                      I am trying to understand the "Optimize" option in the Fill-Surface dialog box. Certainly the SW explaination of this seems inadiquate to this user. And perhaps applications of each option (on/off) should be further demonstrated in the literature?


                      I have checked the Remote-Control example from the tutorials. I see that they used Surface-Sweeps, but I am confused that it does end at two profiles at 90degrees, which should create a 'degenerate surface' should it not? There is no mesh prevew option in Surface-Sweep, so I am hesistant to use it in this example. I note that they use a Fill-Surface at the other end. I may have to experiment with sweep, but I am unsure if this is the way to progres?

                      - Futher, on the top of the example Remote-Control, a Surface-Loft is used. However, it goes around an oval shaped depression, which splits the profile into an easily defined loft of two sketches, that at on the centre-line. I do not know How I can achieve this, unless I add such a feature to break continuity along and across the mid-point of the centre-line to break up the profile for lofting. This would lose my original design intent, and this work is for a Blue Chip. So I really dont want to upset them, as they were pleased with the previous design renderings and layout.


                      2. Hmmm. Yes, building the Multi-Body Part with all the features was a big pain, due to the size of the design-tree, the rebuild time, and the difficulty in isolating each multibody part for editing hidden areas.

                      - You are suggesting a point in which to 'break away' from the multi-body, and edit the derived components individually. This would have the advantage of making it once again possible to edit 'in-context' in the assembly. Drawbacks, well maybe I need to make sure that my original multi-body is certainly operating parametricly. And thus I do need to plan carefully. I will certainly need to make small alterations to the ergonomics, and certain features based on optimising injection mould tooling, cooling and flow. Wall thicknesses etc, later on. This is a high-volume product. And when I come to edit, I will certainly need to 'move quickly'. Days will be expensive here, and adjusting in hours would be much better!


                      3. Combine 'in-context' and 'maste model techniques'. I am not familiar with some of these terms. Although I will be further researching tomorrow. I will try to avoid cavity, although I do not yet know why? I am assuming by 'expensive' you mean in CPU time, or in slowing down rebuild? ... I need to yet fully understand this, and I did not manage to get on top of these items of knowledge fully today?


                      4. Posting customer data. Yes, I know! ... I am desperate, and it was 2 weeks after my requests for my VAR to help me. They send some information, but were maybe unaware of the degenerate surface issue? I also tried a contact I have who works at SolidWorks in the US, and he had no luck in getting me an answer. So they are either busy over there, dont care, or dont like to mention problems. - I was surprised. I would expect an answer, especially as I pay quite a lot for subscriptions.


                      If I dont solve this, I will really let my customer down. Plus there is no information of what this part is for, or its function. Just the plastic molding itself. And thats where this must be solved. I did not anticipate this lead time, and in fact quoted 3 days to make the changes. This is costing me time and money that I dont have! And more importantly, my customer needs this, and finds it hard to understand, why, when I created the product 95% complete, that I cant complete the lasr 5%. ...


                      ... But that last 5% breaks the current model. And 3 weeks of my tinkering, have not yealded anything but pain. ... So far I have learned 'what not to do'. Great, but not its not the right answer .. to quote CatchPhrase (a UK gameshow).


                      5. Agreed on the re-do. I have been thinking this for a week and a half. Its the process on paper, I need to work out now. The steps, tools used and the order of the build.


                      6. I am still reading this point, and working on trying to get the all-in-one boundary to work. I tried a ruled-surface on the top, and a sketch. Also making the sketch one continuous sketch. Setting direction vector, and also I tried it with the Fill-Surface today also. No score just yet!


                      I think I need to read this again. You have certainly simplified the language, but its going to take me several reads, and I am going to try the chop. I wonder if I should or can, do a Fill-Surface 1st for the ends, and then add perhaps a Boundary between them, and to the sides, with a tangent there in the edges of the product. I'll try this tomorrow.


                      7. Yup. Sometimes you have to get dirty. But, Matt, these features seems ot heavily impact on rebuild time. I want to avoid them. Of course, I have an undercut there also, as its a prototype. I need to fix this on the new model with a better ribbing effect somehow (least of my concerns!).


                      8. Yeah. I like buttons since I started using SolidWorks in '98. Ribbon toolbars did not exist then, and I still dont't like 'em. They be the devils work for sure. And SolidWorks 2009 was something that I would never like to repeat.


                      Thanks for compliment on the design. Yes I am pleased with it. And its mad that I have so little to do, but such a frustrating and long round-about journey to get there. Theres the problem with history-based maybe?


                      Hopefully, the next thing that I learn will be "how to do this" before my customer fires me!! ... Going to be going like the clappers again this weekend!!


                      Many thanks, Bid

                    • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?

                      Hi John,


                      What version of SW are you on?(should update your SW Forum profile with that.)   I'll try to have a look at your file today and get back to you.



                        • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                          John Biddleston

                          Hi Mark,


                          You are very kind. I am using SolidWorks 2012 and the two files I have posted on this forum are here

                          1st edit  - http://thebigconsultant.com/downloads/Multi%20Part%20Mould%20Iss2.1E.zip

                          2nd edit - http://thebigconsultant.com/downloads/Multi%20Part%20Mould%20Iss2.1D%20NEW%20EDIT%204.SLDPRT


                          I am going to order a copy of Matts book, but I am afraid that I wont get it in time to solve this. I am of course going to be looking at this over the weekend, and I am currently trying to glean all I can about the perils of surfacing.


                          It seems that I need to develop a route-map, that is maybe not in the training manuals that will provide a clean model, and in fewer steps. The outcome of course will be similar, but without the surface wrinkles that prevent full rebuild and cause the model to fail at 95% completion!


                          This route map is what I need to get worked out, so that I can complete the work quickly, and then get onto my new tasks.


                          I am also posting a reply to Matts previous post, with my comments and questions / findings today. I have done some reading and research, but thus far have been unable to create a 'clean' model, without the 'degenerate surfaces'. I may well have to start from scratch, but with a good basis, and my previous model as reference, I hope that I can complete this over 2 days or so. I am crossing my fingers!


                          Thank you in advance, and do also please read my reply above to Matts helpful post.


                          Kind regards, Bid

                            • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?

                              Hi John,


                              I've had quick look at this and I think I understand the issue and would like to do a video later today or tomorrow and post it for everyone here. In the meantime, do you have a dropbox or other site that I can place a file for you (12M) so you can verify whether the initial shape based on my alternative method, will be satisfactory? Otherwise, I can give you a download link to our DS FTP site but I need your email. You can respond to me with it at mark.biasotti@3ds.com.





                                • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                  John Biddleston

                                  Hi Mark, thank you for your kind assistance. I have emailed you with my details. Thanks once again. I eagerly await your professional opinion. Kind regards, John

                                    • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                      John Biddleston

                                      Mark has provided a solution, that I am going to investigate. Its really impressive, and also has draught as well as the tangents that I require. As its now 2am here, and I am starting to wane, I am going to have to leave off, and try restoring features onto this model tomorrow. Im hoping that this is the solution to my nightmare, and of course Mark had correctly guessed that my main job is now to productionise the part ready for tooling. I have a good feeling about this, and I'll post very soon on the results and a summary of what I found in this process.


                                      I really appreciate the excellent support and comment that I have found here on this forum. Its worrying though, that out of 540 views, possibly only 6 people or so could see the solution. This is definately not a mainsteam topic, and I think that we could all benefit from more discussion and debate of these features, and this kind of modelling. I'll post an update tomorrow morning!


                                      Kind regards,


                                        • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                          John Biddleston

                                          Mark has provided a great solution. Respect for the skills. I have to work on it right now, as I have lots to do. He also produced a video, which I wish to share with you all here. The video is excellent, and I really learned a great deal. Some very useful techniques here, and in particular highlights are:-


                                          - Draft on a surface derived part

                                          - Best practice with splines

                                          - Spline control, order to use options to optimise, handles, magnitutde etc + essential tips like using alt key to symetrically pull spline handles and more

                                          - The Fit-Spline tool (something I never heard of!), which looks great for use in other applications too, especially if like me, you are a fan of geometry and things being parametric. I'll be using a lot of Fit-Spline from now on, although for different purposes!

                                          - Creating a perfect model surface build



                                          Really great vid. And thanks also to Matt and Charles whose information was also very instructive and useful. I suggest visiting their websites and blogs http://www.swtuts.com and http://www.dezignstuff.com/blog/

                                            • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                              John Biddleston

                                              However, I have to say, that that was stage 1 of my 2 stage problem.


                                              After this next bit, I am over the hill, and ready to complete the model. However, I am sad to say, that this is proving to be more difficult than I imagined.


                                              Here it is.



                                              Take this cap for example. I want the top to be prominent, as shown, and in the next screenshot below, I will place a "grooved surface" feature,  which is a technique that I have used before, that allows me to have a straight internal wall, but with a curved surface on the top of the profile for aesthetic reasons


                                              In the example above I have shown a simple shell, to highlight the fact that this is not a mouldable part. It should from the outside look like this below:-



                                              What I want to do, is to cut into the cap with a 1% draft in a straight cut - offset 1.5mm from the surface at the end of the cap.


                                              i.e. a shape that can be made by tooling that goes into the cap horizontally.


                                              - Also, I want to create a tolerance fit onto the mail body, although this will be a push fit with 0.1mm clearance all round. The fit will be stepped, as in this earlier version shown here:-






                                              I do have some additional issues, that I am trying to find the best practice solution, particularly to create the fit for the cap and main body components. In the cap, I am creating a grooved surface on the top, where the cap buldges slightly. And inside the cap, I ideally need to create a linear cut with draft, offset from the end of the cap by 1.5mm.


                                              I have tried this several ways. The 1st way, here I created a 3D Sketch on the curved plane at the rear of the cap. I then created an offset-surface 1.5mm inwards, which you can see here in light pink. I then created a sketch on the flat plane (where the origin, and cut-drag arrow in grey is located), and set about cutting into here both with draft and without. My plan to offset the end point from the offset-surface. No joy, with or without draft. Only pain.


                                              So I tried a 2nd way. This was to start the sketch directly on the surface, and set the start condition from the main Right-Plane, which is flat. And again cut up to the offset-surface.


                                              I tried this also with offset from a knitted-surface instead. No joy....



                                              ... But with the "Translate surface" set, it does work.



                                              However, "Translate surface" does not provide the desired result. You can see here that the wall thickness is reignificantly reduced below the 1.5mm constant average that it should be. This is due to the fact that "Translate" fixes the offset to a horizonal vector here only. This provides an unacceptable wall thickness here.


                                              The "grooved surface" is a technique that I have used before, that allows me to have a straight internal wall, but with a curved surface on the top of the profile for aesthetic reasons. The inside must be a straight draw, and ideally with a 1-2% draft

                                                • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                  John Biddleston

                                                  In addition, I took to attempt several ways to solve this.


                                                  One is here. I thought, perhaps that I should try to constrict this shell manually, and then remove the offending section.


                                                  So I thought, Ill take the offset here, and use a Ruled-Surface, with the "Tapered-To-Vector" setting enabled.




                                                  But whats wrong here? The draft is the wrong way. I want to cut or trim these surfaces, so that I can make a facimily of the mould tooling shape. However, there is no selection option to reverse the draft angle?!?


                                                  So, just like when you have this problem with the Draft tool sometimes... The solution is of course to select a plane at the other side of the feature. i.e. the one shown in the picture here, below the part.


                                                  But when I select this as the 'reference plane' instead, then I have the exact same problem!!!! .... There is no option that I can see to control the direction of the taper!? Madness. And this is certainly not a mathamatical impossibility.


                                                  All I need to do, is to cut in to the cap, with a draft, and linear sides, with an off-set 1.5mm in the end condition to the outside of the cap. Is there a neat way to do this correctly?

                                                    • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                      John Biddleston

                                                      I have tried to create the draft shape manually, using a loft-surface. From the end of a offset-surface 1.5mm inwards, to a sketch on a plane in front of the tip of the cap, where the sketch is again offset, so that I can create the 1degree draft.


                                                      I then indented to trim-surfaces using the loft-surface as the trim tool. Thus remove the buldge at the top. Shown here


                                                      Then I would simply cut the solid and have a reliable 1degree of draft inside. But it just fails on the trim without telling me why. I am going to take a break, and try another method in 5 mins. I dont know what that method would be. And I am worried that I am going to run out of options. Kind regards, John


                                                      This is the fit I am trying to achieve, but with a draft (forget the cage bit, that for drawing later, and is quite simple). Its the smooth interface between the two fits, and I need to achieve this on the inside of the cap!



                                                        • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                          JOHN GEORGE


                                                          I am not very clear about the intention of this part file.

                                                          Are you trying to remodel the whole part file, or trying to make it solid or tring to add draft to boss and ribs?


                                                          I assume that you are trying to design or make a mold for this part. (Please correct me if I am wrong)

                                                            • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                              John Biddleston

                                                              Hi John,


                                                              Thank you for your enquiry.


                                                              My plan is thus.

                                                              a. I had completed the prototype model last year, and it has been approved by a blue chip company.

                                                              b. I need to update and edit the model, and due to degenerate surfaces, I could not do this. Features were failing etc, and I had to patch, which I did with moderate success, but not enough to make the part work well enough.

                                                              c. Also I need to simplify key areas, how the part is built. But this is secondary to the problem that I have described above. I simply cannot find a way to create the draft feature described above in the "Cap" end. This is really why I had to start with cleaning up the original surfaces, which Mark Biasotti seems to have now done. And quite neatly.


                                                              Adding the ribs, and other features, is no problem for me. In fact they are all  supressed in the latest model which I am posting here (with Mark Biasotti's improvements).

                                                              http://thebigconsultant.com/downloads/Multi%20Part%20Mould%20Iss2.1%20F.SLDPRT (SolidWorks 2012 file)


                                                              However, before I can create these simple and obvious features, (which will be created with the simple solid modelling tools), I have one final cut to make... and that it the inside of the cap, and the interface surface (offset by 0.1mm) which will be on the body. Here, a simple Shell command is no good. I need to create a drafted feature, that is offset by only 1.5mm towards the face at the tip of the "Cap". This will leave a slightly thicker wall thickness on the upper profile of the Cap, but I have a Sketch-Cut ready to deal with that (called Cut-Extrude9) that will deal with this. This Cut-Extrude9 works very well, of course, and just skims the buldge in the top of the Cap to create aesthetic grooves, that also have a purpose of maintaining average wall thickness of 1.5mm


                                                              So in summary, I want to make the part mouldable. Although I expect a 2 part tool with a moving core for the Lid.

                                                              - The rest I hope to make for straight up/down tooling.


                                                              I am not designing the tool, no. I am the designer of this product, but I need to make it work well, so that it can undertake these next processes.

                                                              1. Vacuum Casting for 10-20 off prototypes using soft-tooling

                                                              2. Ready for production issue


                                                              Without a suitable model, and making this thing work and perform in a reasonably simple and parametric way. I am going to have no chance of meeting production timetables.


                                                              Worse though, I for the 1st time, am finding/suspecting that SolidWorks is inadiquate for this kind of design purpose. I have just tried another 6 methods today, to undertake this detailing on the cap. And I am sure that I have discovered that an option is missing in SolidWorks... I'll decribe it below. And further, in my recent post above, I was dissapointed that there was no option on the Ruled-Surface feature, under "Tapered to Vector" to change the direction of the draft that I set. Even by using a plane as reference that was on the other side of the feature (which usually corrects this on the Draft function in Mould Tools)... So here is my latest attempt:-


                                                              a. First I completed a cut into the model, below. Here I cut from an offset-sketch into the Cap. I selected a 1degree draft, and set the end-condition to 'offset-from-surface'. I found that it only worked when I selected the 'translate-surface' option, which does not create the end condition I required (it creates very thin wall thicknesses), but it was the best that I could achieve!


                                                              The resultant cut produces the profile below, when sectioned in the Top-Plane through the centre.


                                                              As you can see here, this is no good on its own. But I stuck upon the workaround (the only one I can now think of), that I could in fact duplicate the same Cap body, from a stage earlier in the design tree, shell it to 1.5mm and then COMBINE both bodies!


                                                              This would certainly result in the exact shape and form that I require for the Cap! (here is the above part sectioned horizontally, shown below showing wall thickness).


                                                              Ok, the end of the cut is a huge problem. But now I am so behind with work, that I need to get past this and start completing the rest of the update work. I was hoping maybe, by the time I did this, I might have a suitable answer, and be able to correct, or maybe manually delete and edit the surface later (I am talking about the thickened bit right at the tip).


                                                              Anyway, so I am thinking. Right. I'll make a duplicate body of the cap, but this time Shelled to 1.5mm... Then I will combine both cap bodies to make my final shape. Its long winded, but I have no other options apparent to me right now.


                                                              So I go to the Move/Copy-Body command. And there is no option to "Copy" the body? I thought that I could simply select the 'no' of bodies, so that I could duplicate. Its not there? So why is this command called Move/Copy when there is NO copy command there at all? Has it been forgotten to be included in this release of SolidWorks? See below:


                                                              I cant make a duplicate copy of the body, and then shell it, to try and combine to make my part. Maybe there are some better ways to create what I require? I dont know.


                                                              I do know, that if I can create this feature, then all the rest are easy. And I will no longer be letting my customer down. For the 1st time, I am now 3 weeks late on this project, and it has consumed all of my time over this period with virtually no movement. I am reluctant to use surfacing again, in SolidWorks, but in this case I must now complete this. There is no other option, and I am having to turn down other work so that I can try to complete this. It is terribly frustrating and costly.


                                                              Kind regards, John B

                                                                • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                  JOHN GEORGE

                                                                  I tried to convert the E version into solid model and this is what I get.

                                                                  The F version gives a lot of rebuild error when I unsuppress the features.


                                                                  multipart mould exp-1.png


                                                                  multipart mould exp-2.png

                                                                    • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                      John Biddleston

                                                                      Hi John,


                                                                      Yep, Version F will give a lot of errors if you unsupress things. I have not even tried this. I am planning on redrawing all the features again more neatly. Or alternatively unsupressing one-by-one and recreating them. The reason? The initial method that the surfaces has been created with, has been changed. - From Surface-Lofts to Surface-Sweeps.


                                                                      I am working on Version F right now, to add back and repair the features or rebuild them.


                                                                      However, I cant create the feature that I described on the inside of the cap above. In the version that you opened and illustrated above, there were problems with the model due to "degenerate surfaces" that prevented me from completing the model past 95% completion.


                                                                      Now, my only challenege is to complete the shape inside the Cap that I require, and I will then just redraw the rest into it, ensuring that everything is parametric.

                                                                        • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                          Jerry Steiger



                                                                          I don't have SW2012 loaded on my computer yet, so I can't open your files to make sure that your part can be done to your satisfaction, but I'm pretty sure that it can. (I don't have the time either, but considering the hours you have put in on this model, you probably don't want to hear about that!) You might, in fact, be better off to move to Pro/E, but once you get over some of the hurdles, surfacing in SW is not an impossible task.Painful at times, but usually not as painful as it seems to have been for you on this project.


                                                                          I would hate to lose your insights in this forum.


                                                                          Jerry Steiger

                                                                            • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                              John Biddleston

                                                                              Jerry, thanks. Yeah. I used to work for SolidWorks about 7 years ago. I even flew to Concorde MA, from the UK to train there at the HQ. I cant lie to you and say that its not occoured to me over the last 2 weeks to consider changing or at least looking at Pro-E. I am hoping to see proof that SolidWorks can do this, and besides now my entire job is on the line over it. 


                                                                              I work as a sole-trader, and I can say that I have never had this kind of problem, which is impacting on me for very important customers. This is for a Blue Chip client, and I just cant afford this loss in productivity. I was supposed to start a new job for a client last week on Monday! And they have been very kind, as I have a good reputation. But this can only stretch so much, and someting has got to give!


                                                                              I have been working again on this full time over the weekend, and I cant even get the cap to cut internall with a draft up to the surface. This is the area, where I needed the fixes so that I could make this cut. ... And in my last model, I had to patch up both ends. But my ability to complete it stopped at about 95% completion. That was at Christmas.


                                                                              If someone can prove that its possible to do this last step, I would be delighted. I really hope that I am wrong, or am doing something stupid. Maybe someone will find this simple. I hope to God that I can finish this tomorrow!

                                                                        • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                          Jerry Steiger



                                                                          It is the user interface that seems to giving you fits. I'm not quite sure why it is this way, but the check box for copy is only visible in the Move/Copy Body feature when you are in the Translate/Rotate mode, not in the Constraints mode. If you click on the box below the Mates that says "Translate/Rotate" you will get the choice to check "Copy" and a box to select the number of copies.


                                                                          Jerry Steiger

                                                                      • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                        Jerry Steiger



                                                                        On your failure to trim, it's a bit hard to tell from the picture, but trims will often fail if edges are just coincident with a surface. It's best to make sure that the two surfaces intersect completely. In fact, I have had trims fail where the I had to extend the surfaces to get "enough" overlap. (This may have been a graphics issue, or it could have to do with the tolerances that SW allows/needs.)


                                                                        Jerry Steiger

                                                                          • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                            John Biddleston

                                                                            Yep. I am guessing that its the open edge of the offset-surface here. But actually if that surface was larger when I first tried it. The one shown is after that one failed, and so I trimmed it up to the surface of the Cap, and then I used the edge of the trimmed Offset-Knit of the Cap to form the start of the ruled and then lofted surface. Non worked.


                                                                            Hence I tried to Move/Compy body, and the Copy feature was missing! Its killing me! ... I cant afford to let customers down like this. I work for myself, and generally am known for the speed that I can produce CAD designs. I would like to be proved wrong, and that I am doing something wrong?

                                                                        • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                          Jerry Steiger



                                                                          I'm glad you got some good help from Matt and Mark. It's agonizing to read through your posts. I'm really pushed for time to spend on the forum, so I can't be much help. I can help on some of the little things. When you tried to make the ruled surface and couldn't get it to draft the right direction, the solution is simple, but apparently not very obvious. See the button with two arrows to the left of the Plane 10 box? Just click it to switch the direction of the taper. This is a really good way to generate the helper surfaces that let you hold the draft on the edges of Boundary or Loft or Sweep surfaces.


                                                                          Jerry Steiger

                                                                            • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                              John Biddleston

                                                                              Jerry, Agonising is not the world! lol. It has been making me feel quite sick with worry!


                                                                              Appreciate your thoughts and help. I am not sure that you are right about the "Ruled-Surface" though. I'll have ot put an example up to be proved right or wrong. The button to the left of the Plane-10 box, does indeed flip the direction of the Ruled-Surface, but there is no equivalent switch to change the diection of Draft from divergent (shown) to convergent. I even tried moving the plane to the other side, and the draft is always convergent! Its ridiculous! ... But I hope that someone can prove me wrong!!

                                                                                • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                                  John Biddleston

                                                                                  Ok. I am really getting mad now.


                                                                                  I am working again of the Cap shape as of 29th Jan (post above). Its the one with the Cut that has the 1.5mm offeset and 'translated' end condition. Yes, its no good. But I had hoped that at least I could manage for a day, until I can get some more help, and maybe get some help once people in the US are back on line.


                                                                                  I did try the Move/Copy function, and as Jerry superbly spotted, the actual "Copy" command is hidden. So I selected Translate/Rotate. And managed to make a duplicate. Which I then shelled. However, when I tried to combine the shelled version and the cut with draft version, the software reported that there was a geometry problem and it did'nt work. It would have been a convoluted method anyway, so its annoying. But I would have wanted to change or clean up the method later anyway. I am now desperate.


                                                                                  So I thought today. Ok. I'll take that model with the incorrect internal surfacing (Jan 29th), and manually create the correct internal shell, so below is a screen-shot of what I am trying to achieve this morning in another effort to complete this.


                                                                                  Above, I am thinking of triming out the incorrect surfaces inside the Cap, from the inside front right to the curved offset surface that bisects the Cap which I have placed just after the shoulder that you can see I have built. The shoulder is for the fit of Cap to Body, and here my intention was to manually trim and rebuild a step just after the shoulder, and then using the Offset-Surface that is 1.5mm inwards of the surface of the Cap, create a new wall internally. Thus I have the fit at the shoulder, which has a 1degree draft, and also the 1.5mm wall thickness which I would trim and ensure has suitable draft manually.


                                                                                  Now it has been mentioned that in using Surface-Trim, that both surfaces must fully bisect each other. However, in the example below, as I try to start trimming, I cant even remove the open end of the 1.5mm Offset-Surface, using the Trim tool (shown in purple below):



                                                                                  Can anyone explain?

                                                                                    • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                                      John Biddleston

                                                                                      On the model created by Mark with using the Surface-Sweep method, I cannot split the handle either.




                                                                                      I desperately need to create a model, that I can

                                                                                      a. Adjust the splines by lets say +/- 1mm in order to get updated components to fit

                                                                                      b. Shell out the Cap with a 1mm draft to make it mouldable

                                                                                      c. Shell the other parts, e.g. handle etc, so that I can add detailing


                                                                                      I have just had a meeting with the client, and I am going to work on some electronics issues for the next 2 hours. Then I am going to come back to this. I have also asked my VAR again to take a look.


                                                                                      Kind regards,


                                                                                      • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                                        Charles Culp

                                                                                        I can't explain. Your method is the way I would typically do it, but seeing that it didn't work, I have attached another method that seemed to work.


                                                                                          • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                                            John Biddleston

                                                                                            Hi Charles, thanks so much.


                                                                                            I am going to take a look at this right now. ... Things are getting really bad here, as I have just found out that my client is now phoning my other customers, asking why I am so late with this work, and concerned that I am not doing the job properly.


                                                                                            I have not been able to take on any work for now 4 weeks due to this. And I dont feel any closer.


                                                                                            I have never failed to deliver on time for customers, or at work. And I have been doing this for now over 10 years!


                                                                                            This is ruining my business, and I really am at my wits end right now.

                                                                                          • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                                            Jerry Steiger



                                                                                            It's hard to tell for sure from looking at the screen shot, not knowing the names of the various surfaces, what is happening. From the error message it looks to me like you've got a surface that just touches the one you want to trim and, as mentioned before, SW isn't too happy about that situation. On the other hand, it looks like SW has previewed the cut correctly, showing the part that should be removed.


                                                                                            I assume you are trying to cut the left end off of the cap that extends out to the right and that the trim surface is the one running more or less vertically in the screen shot. Is that trim surface a complete sheet, with no hole in the middle? If it is, then it is hard to understand why SW isn't trimming it.


                                                                                            Sometimes weird stuff like this happens when I have been working on a part or assembly for a long time without rebooting, or if my memory usage is running too high. Since you've been burning the midnight oil, these are likely possibilities. Save your work, if it is worth saving, shut down SolidWorks, and reboot your machine. You're English; go make a cup of tea!


                                                                                            Jerry Steiger

                                                                                              • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                                                John Biddleston

                                                                                                Jerry. Yep, this is where I am trying to repair the inside of the cap. Its one of several methods that I tried, that failed. ... As you can see, the surfaces fully bisect each other. And the preview on the trim, does indeed show that the trim is previewed. But sady fails, with an error, shown in the screenshot.


                                                                                                Charles Culp's Move-Face workaround is a clever trick, which although we know this is sometimes viewed as 'dirty' way to do this. We dont use these techniques often. It might allow me to rescue the part, with me able to then cut away and trim the inside to manually build up a new interior of the Cap. ... I would in this case, delete internal faces (which makes the cap instantly a set of surfaces) and then manually build the internal shell with draft, and then return the Cap to a solid. I might try this, but it is indeed and never was, my 1st choice of method. As this is a but of a dirty method, and I have to admit, its not easy and is time consuming to build the primatives manually. But what can I do?


                                                                                                Jerry, without stating the obvious. Its is odd that SolidWorks cant do this. After working for some time as an Industrial Designer, I worked for SolidWorks for 3 years, and for the fastest growing VAR at the time in the UK. I achieved sales targets of 30k a month, and I sold a lot of software, and trained/worked with a large number of customers. One would think that the design I have here, which resembles a TV remote control, would be easy for a mid-range 3D CAD like SolidWorks to surface, shell, split of offset shells/surfaces, and then trim those shells/surfaces with a surface cut right through. I can imagine 100's of applications for similar shapes and drawing methods, very similar to the one I have just undertaken! ... ?!


                                                                                                I am having a cup of tea Jerry. And im afraid that I have now burned myself out again. Its 11.30pm here in the UK. And I am going to try again at 8am tomorrow morning. What else can I do.

                                                                                            • Re: Really need help to improve this model, its surfaces and I think I need to redraw from scratch?
                                                                                              Jerry Steiger



                                                                                              Aargh! You're right, I'm wrong. Going off of memory there.


                                                                                              As best as I can tell, the only way to get what you want is to build the ruled surface with no draft by using the Sweep option, picking the plane along whose normal you want the edge to sweep. Then add a draft to the surface. Note that you may have to hide the surface whose edge you used to get the ruled surface, as SW seems to pick the edge of one surface or the other and the "Other face" switch doesn't seem to work.


                                                                                              Jerry Steiger