Logic and Solid Edge

One of the current posts at the Siemens BBS for Solid Edge has a topic of interest to me and it is in part about the useage of Synchronous Technology over traditional by current users and the logic employed by ST.  Dan Staples had a reply there and it was as follows.

“Re: OK, so why aren’t you using ST?

We had some good sessions at the Productivity Summits on Live Rules and it gave me an opportunity to summarize that they are nothing more than applying basic human reasoning to CAD. Take any part you see lying around your operation — it doesn’t even have to be in CAD — maybe it’s better if its not. Just look at it and see if you can name some of the design intent that clearly exists in the part (and of course a physical part has no sketches and history tree). What do you see? Stuff lined up? Stuff tangent?

I’d bet some things you are going to see (depending on the part) are;   1. The part is symmetrical.  2. There are tangencies between faces.  3. There are holes that all line up, either sharing the the same axis, or all in a row along X or Y  4. There are faces that are clearly in the same plane.   Do you suppose these things happened by accident? No, someone (maybe you) designed it that way. You don’t need a sketch and a history tree to tell you that — you as a human can look at it and see that design intent in the final part very clearly. Why can’t the CAD system see this?   Answer: It can. That is what Live Rules is –> Applying basic human-level analysis to a part to mine the intent that is inherent in it. Then, its up to you if you want to override that reasoning on a case by case basis, or let it do what is naturally apparent in that part to humans (and now to CAD via Live Rules).

Dan Staples  Director, Solid Edge Product Development”

I had an incident in my shop this past week reflects upon what he said. A friend of mine had a part cut wrong and he brought it over for me to weld the boo-boo so it could be recut. When you do a weld fill-in on a cut part it is always best to rough recut it before you leave the welder’s shop if you can. You can have low spots very easily as you have a fine line to walk between just enough and gobbing way to much on a part just to make sure.

Now for some reason Bobby just could not remember that my lathe was not the one in his shop he was used to using. So he would start it up and then immediately reverse it because it was going the wrong way. I let him do that a couple of times before I stopped him and pointed out that it was hard on my lathe for him to do that. He sheepishly admitted he knew that but my lathe was wired wrong. So I pointed out to him the logic behind the engage lever. I said think of the direction of rotation you want to go in and pull the lever in that direction and you can’t go wrong. My creature of habit friend never did it again once it was explained to him in those terms.

What you say about ST makes perfect sense to me Dan. ST is a different mind-set and while it does not do it all it does so much very well I can’t imagine working without it for the parts my company makes.

There is a learning curve with ST and a logic mind-set and as is true with any tool it can’t be used for everything. But once you use it I dare say that there will be no return to a world of straight history based parts creation. The power of direct editing is to powerful to ignore.

This is a go no go plate for checking filled capsules for defects like split caps. If there is a split the capsule will not fall through.  The holes have two draft angles and a cylinder. Now with ST I can create this plate as I did before meeting with my client without knowing precisely the size of the cylinder. He brought the data with him and I sat down and edited the hole that was the origin of the pattern and had a correct resized part in seconds. Literally. It is always a bit amusing to see a customer sit down for the taking of time for the editing of the part he knows is coming. He is used to traditional  history based editing after all. On a part like this it took perhaps a half-minute from beginning to end. In the future there will be other capsule sizes and each one will take more time to open the original part file and create a new file name and save the new derived part than it will to edit and  create a whole new part size. When you turn to your customer and say “thats it, were done” it is good manners not to tell them to pick their jaw up off of the table 😀


A change of mindset and learning new logic has been tremendously productive for this shop. I look at parts like this and remember how it used to be and I don’t ever want to go back.


18 responses to “Logic and Solid Edge

  1. How is editing the seed of the pattern different than the history approach?

    • In direct editing the difference is that I do not have to go back in the history and redo the original sketch and then go from there. With ST I just click on the pattern anywhere and the steering wheel shows up on the seed. I click on the driving dimension I want to change, fill in the new dimension in the popup, accept and I am done in less than thirty seconds in this particular case. Furthermore if I needed to eliminate a couple of holes for whatever reason on down the road it is a simple matter of select and delete just those holes with the exception of the seed hole of course.

  2. Nice, but you have just described what I do in SolidWorks. Just double-click on the hole, change the dimensions. I can also eliminate any instances of the hole at will.

    • Grig-
      When you double-click your hole, you are actually moving back up the history tree, activating the parameters of the feature, making the needed changes, accepting the changes. In the background the system then needs to REBUILDING/Verifying your model topography from that point to the end of the model. This is where you will see the difference in ST.

      ST sees a grouping of equal diameter faces, you select a face and it displays the “known” diameter. You then just tell ST that I need a different diameter and off your go. There is no moving up or down a tree and no need to rebuild the model from a specific point in the tree.

      It gets better because now I can “design” a part using both methods (history and history-free). I can control the parts of the design that I need to control with parameters and then let the system worry about the rest.

      Here’s, what I think is a good example. We all know that when it comes to history-based designs it is a “best-practice” to save all our tappers and blends so that they are at the bottom of our tree. We do this because we really don’t want these “cosmetic” features messing up the real design of our part. But we all know that blends and tapers can have a significant drag on our modeling process and usually requires many features to create the finished part. Finally, if anything fails when it comes to medium-complex modeled parts it’s the blends or tapers that always fail!

      With ST I create my design using history, switch over to ST and apply all the blends and tapers. Now when it comes time for updates I don’t have to wait for all those blends and tapers- that I really don’t care about- to update in my history tree.

    • Grig,
      I am going to reply to you on this with a video link. I have just been buried with a ton of work though and it will take a few days before I can get back to this. I think judging by what you are saying that you are not familiar with the workflow direct editing has compared to history based and what you may be doing is not the same thing as what I am talking about.

  3. I would have to agree with Grig that the process is very similar. But in reality it’s what is happening in the background that makes the difference and this is where you find the true points of a debate on technology, software performance (timing on ECOs) and the ability to make those unplanned changes you didn’t “design” into your parametrics or the fact that you don’t necessarily need to spend the time to create your “design intent” while you are designing your part.

  4. Grig, sorry about the delay here in getting back. First off here is a link.

    If you will notice on this edit there is no stepping into the history in any way. While SolidWorks can do something similar in this specific instance with the move face command every time you do so another addition happens to the history tree and a regen has to happen every time. A part with a multitude of holes will bog down quickly. If you watch the “history” panel you will see no chages entered for this edit.
    Also on file size. In this instance the file size went from 1.273 meg to 1.282 meg. When I revert back these same numbers are still accurate. With SW there is a new addition to the history of the part each time and I would imagine that this part file size would have grown considerably there.
    The additional power of direct editing and live rules would perhaps be better demonstrated to you with these two videos.


    Science & Technology


    Standard YouTube License

  5. Thanks, that is an interesting video. There are a few things I liked. What I disliked immensely was the interface. It is so AutoCAD-ish, no elegance at all.

    And the whole process is so much slower than SolidWorks. Sorry, but I do not buy the fact that adding history is a bad thing. Looks like SolidEdge automated a “save to Parasolid” macro for removing history (like the SolidWorks defeature command or a simple save as Parasolid).

    BTW, why so many dimensions??? Don’t you have relations in SE?

    • Hi George. It is funny how differing programs appeal to differing mindsets. To me back when I looked at SW twice during the days of SE V20, say five years ago, I found the reverse to be true and the logic and layout of SE was far more intuitive to me. On the dimensions. Of course there are relationships there and however I wish to set them up with live rules. What specifically are you asking about? I am also curious about the speed of the process and would like to know if you could share a video of what you mean here? The other SW users I know who are familiar with SE and have had some actual hands on time are not making this claim. There is a huge difference in how SE saves things and how SW does and this is why. In SW when you do these edits there is an addition in each change in the history tree. There is also a direct increase in the size and the complexity of the file as each edit is retained and they are all cumulative. With the direct editing the using this part I reference in this post the file size hardly changes. I could have changed the profile of the drafts and or cylinders in the SE ST file any number of times and still have almost the same exact file size. If I were to do the same thing in SW each time I did an edit this would be another addition to the history and file. With all of these adding up the files sizes, and regen times for each edit, all grow quickly. It is an entirely different thing than the idea of automated save to parasolid macro you mention. Once you save in SE ST there is no pileup of data. When you save in History everything has to be accounted for and carried forward because your part is dependent on everything done and the order in which it is done. ST does not care what order or how many edits. ST has far fewer problems with feature dependencies breaking and leaving you with a part to be reconstructed before you can go any further unlike history. ST does not care most of the time what you choose to edit and when you edit. History has a structure that often can’t work that way and you better know what you are doing or your part will blow up. History also has another little problem. Imported parts. ST does not care where or how anything was made it can import and work on it immediately.

      I find that in general ST or direct editing requires a different mindset than straight history based modeling does. I came to SE from VX CADCAM which was a straight history based modeler and yes at first it was confusing. I had only been been using a 3d modeler for about four years at that time. I find that the guys that have been using history based stuff for a really long time seem to take longer to learn ST and have more problems getting their minds wrapped around it. Once they do though it becomes a part of their every day tool kit.

      Have you actually tried using a direct modeler for a while yet?

  6. Why do you keep saying that changing the design in SW would mean adding new features to the tree? Most of the times you can just change the exiting ones.

    It is quite interesting that you say there are some SW users who like the SE interface. The funny thing is that former SE users that are now working in SW and, as such, became our suppliers told me exactly the opposite. SW has a much more elegant interface and they find they can create more complex models faster. Also, the transition to SolidWorks was painless.

    At this point i am not debating the fact that direct editing is valuable, especially for small machining shops who create simple parts. For serious stuff, the general opinion is that you need a serious tool like SolidWorks. At least if you look for a job as a designer, most online adds are for SW.

    • OK maybe this is a matter of incorrect terminology here. Perhaps a better way would be to say it adds more data to an existing feature each time? But still in the background even if this is all hidden in one feature you now have multiple layers in there. There is data that is linked/added every time and it never goes away. The files grow in complexity and size with each edit. Perhaps you might wish to look at it this way. This is a set of features hidden in a feature and the end result is the same no matter what name you put on it. Increased file sizes and increased complexity and direct editing does not carry this baggage.

      I went back and reviewed what I had said and it was two fold. One the logic of SE appealed to me personally over the one in SW and two, “I am also curious about the speed of the process and would like to know if you could share a video of what you mean here? The other SW users I know who are familiar with SE and have had some actual hands on time are not making this claim” which was not a comment upon an elegant interface but rather utilitarian value and speed of parts creation and editing.

      I am amused by the simple stuff comments by the way and wonder if you have seen the 400,000 plus component assemblies and complex consumer molded products done in SE. You might want to research online what has been done in SE before you say that. http://www.google.com/search?q=products+designed+with+Solid+Edge&hl=en&biw=1110&bih=813&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=CYhFUIO_EoWc9gSHzoBQ&sqi=2&ved=0CFEQsAQ

      Matt Lombard and Billy Oliver are two of my chief sources on SW information and both are quite competent with complicated things there and are also SE users. Matt has some stuff being posted over on his SE blog, see link above, you may find interesting and no doubt could address your concerns better. I don’t think anyone could really say he does not know SW. I would also point out that even if the complexity thing was true the vast majority of all CAD parts out there are MCAD so the vast majority of CAD users would do quite well here plus have direct editing.

      I will most certainly grant you that the majority of jobs out there right now are for SW users although that gap is beginning to close up some. It will take a few years but I believe SE is going to do to SW what SW did to ProE.

      I am pretty certain at this point in time that yours is not strictly a dialogue to debate about the merits of things so now I have a question for you. Just for curiosities sake how well do you think things are going to be working for SW in the near future with a kernal change, a GUI change to Catia Lite and I figure the introduction of direct editing to? I am not going to bring the cloud possibilities up here because Dassault may relent on this whereas I don’t think there is a chance of them relenting on the other things I bring up. I am of the opinion that you should enjoy what you have now because it probably is all going to turn into software you are going to have to learn all over again and be full of major bugs for years.

      Just curious to know what you do for a living to by the way.

  7. Thank you for your patience, Dave. I really appreciate it!

    I just wanted to make sure you are fully aware that some of your statements regarding SW are not entirely correct. For example the fact that you continue to say that by modifying a feature in SolidWorks you add complexity to the model. You can test that easily. Do a few modifications to existing features or sketches and you will notice that the rebuild times or file sizes can go either up or down based solely on the fact that you simplified or complicated the model.

    I agree with you that Matt is an authority in modelling in general and SolidWorks in particular. I watched the latest videos on the blog you mentioned and, while I liked some of the SE capabilities, I was unimpressed with his SW examples. He was trying so hard to make SW look bad… it was like the video was made by a beginner in SW. That being said, he has a very good excuse for doing so.
    I am sorry, I do not know who Bill is, but I trust you here. I am sure he is as good as Matt.

    I also agree with you that this dialogue should finish for now. You provided an interesting point of view and I hope I gave you a few pointers that will make you a bit more careful in the future when you make statements about software that you do not know too much about. Just research a bit before you post. Maybe ask Matt or Bill.

    As I said in the beginning, I like your style of writing and the CAM topics are really, really good. I hope you would not mind if I will continue reading your articles here.

    Regarding SW, I can tell you that I see it as a tool. I am designing tooling, by the way. At this time we are not concerned as much about new software solutions. When they will be available, we might give them a try. We might even give SE a try in the future, who knows? CAD is just a tool after all. 🙂

    • George, I am interested in continuing this conversation with you off the blog. The email address shown for you bounces though and comes back as not existing. You might want to update your address. “Remote host said: 554 delivery error: dd This user doesn’t have a yahoo.com account” is the error message.

  8. hmmm. that is strange. my email is georgenmichael at yahoo dot com.
    I do not know how to update it as you requested.

  9. Got your email.

  10. I owe George an apology folks. It appears after checking with someone who ran the actual part referenced here that SW does not increase in size and complexity in this particular instance. I am not an actual user of SW so I rely on the information others give me and in this case it was wrong. I will be submitting files to others for testing before I post like this again as it is not my purpose to decieve but rather to inform. Thanks for the egg on the face here George as I deserve it for sloppy research and will do my best to avoid this again.

  11. George, I have had emails bounce three times today at the email address you posted above. You may have a problem of some sort there.

  12. Strange. I got your email and I replied back to you.

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