What is Your Modeling Style ?

by Phenom ‎02-13-2017 10:34 PM - edited ‎02-14-2017 08:14 AM (1,524 Views)

That the purpose of 3D modeling and drafting is ultimately to convey the design idea for downstream analysis and/or manufacturing is a no-brainer. This is year 2017 and stating that the ability to create digital prototypes of objects before they are manufactured is a boon sounds too retro. With advancements in solid modeling and hundreds of enhancements pouring in with each release of Solid Edge, the big question still is - do we really follow a modeling style, a modeling workflow or a modeling strategy that actually mimics a manufacturing process that the raw material undergoes through the final product? 

Shaft01.png

Look at this shaft which represents the final design. Does it reveal how it was modeled. One way of modeling this shaft would be by revolving a sketch. Does that match your style? Another way which you were perhaps compelled to follow was to extrude smaller cylinders end to end because the information was provided in terms of the various diameters and lengths ? or did you, using the same information chipped off the waste portion from raw cylindrical stock ?

Your design intent would largely govern the method you adopt. In the heydays of ordered modeling, sketching 2D elements was followed by building features on top of them. This workflow essentially locked your design intent. Once the shaft was modeled using a particular method, the design was tied to the sketches and so was your design intent. There was no way you could easily go back and think of modifying the design in an alternative way.Shaft02.png

The model appeared adamant or resistive to edits because the underlying sketch has hijacked your design intent. Modifications to the model were no longer possible outside the limits of what the sketches would allow.

Synchronous Technology bestows designers with enormous design freedom. You still start with 2D objects which actually create 3D regions with zero thickness that can be extruded or revolved or lofted or swept as per the form and function. This still appears traditional and you can proceed with any of the aforementioned techniques to create the 3D model. What follows next is a huge differentiating factor - you can simply forget the sketches - forever! In fact in the Synchronous environment, sketches themselves exhibit gracefulness and line up under the Used Sketches collector so they no longer come in way of editing the model or the design intent. You can delete those with no harm to the model but it is best to leave them in the Pathfinder.

Subsequent to this, faces can be freely pushed or pulled or rotated. Occasionally you can decide to delete some. Sketches will not hinder your ability to manipulate the model geometry. You are in direct charge of your model and your design intent. Plunder the wealth of features that the Solid Edge synchronous environment wholeheartedly offers like the Steering Wheel, using formulas for model dimensions, 3D face relations and so forth.

Yet some designs lend themselves to be modified best at the cross-section level. The shaft in case is a good example. You are not at a loss when the sketches are long gone, because the Synchronous environment provides another gem of a feature called the Live Section that can be placed directly on a model. Sections in 3D models are not new and Solid Edge has had this facility for a long time. What sets apart a Live Section from its previous avatars is that they are live, as the name suggests. Changes made to a Live Section influences the model geometry.

Shaft03.png

A Live Section can be created quickly by simply picking a nearby face or reference plane and then moving it freely to the desired location using its Steering Wheel. Apply just those dimensions to the Live Section elements that matter to your currently intended modification. This is unlike a sketch-driven feature which ideally calls for a fully constrained underlying sketch for guaranteeing a failure-proof future. This comes built-in with synchronous models since the model is not obliged to come equipped with all the know-how for a successfully rebuild of all features.

Unlike sketches, Live Sections can be multiple. You can create several of them even in imported geometry at places where you feel edits are to be made. The number is limited only by imagination and the intended changes in a 3D model.Shaft04.png

Ultimately, Live Sections can be disposed off which means they can be simply deleted. This is because new ones can be created any time and at any location in the model. Unlike underlying sketches which need to be carried along with the 3D model as a burden, Live Sections are lightweight, in fact weightless and this in turn also reduces the model regeneration time.

Since there are no underlying sketches, no 2D relations to solve nor any overhead of fully constraining the sketch, it makes the design process faster and the models robust and lightweight all at the same time. Do you find this anything less than a miracle ?

With all virtues of Live Sections highlighted and underlined, the time to start using one is now. Nothing should stop you from sharing your models or just the images and seek advice upfront on how you could use Live Sections in your design if you are not sure. Experts on the Solid Edge forum would be more than willing to show you the way.

Also, if your company policy permits, share images of models showing how you have already used Live Sections in some of your designs in the comments section below. If not, then a short description about your intelligent use of Live Section too are a welcome.

Comments
by Phenom
on ‎02-14-2017 08:00 AM

Brilliant my Friend!

 

BR,

by Phenom
‎02-19-2017 10:33 PM - edited ‎03-03-2017 04:05 AM

Thank you @Imics

 

by Valued Contributor
on ‎03-01-2017 11:53 AM

I read this a couple of weeks ago trying to get a better grip on the Synchronous mode of drafting and what it's actually good for.  I thought the article was well written with good, collected thought flow and dressed well with images.  Trouble is this feature is of little to no use in the current production environment I work in.  With the freedom to change random faces comes the great task of locking down the model to the nth degree to prevent undesirable and uncontrolled changes. Note that nearly all of the parts in the library are used in multiple assemblies, many have hundreds of WU.   Every change to a production part must be ECR driven and well documented all the way back up the tree.  The ability to change parts in freeform could turn into a quality control and tooling mishap disaster.  In my opinion Siemens has missed the boat on what they are focusing their efforts on.  Maybe this is still a vast lack of training on my part and I just need to learn how to use the features properly, the way they were intended.  Trouble is time for further playing around with tutorial and instructional blogs and videos.  After our SE reseller came in to do training sessions, the department as a whole made the decision to keep Synchronous edits out of our models.  "If you see "the wheel" pop up STOP and get switched back to ordered mode."  With projects on our plates and if the gains of changing the way we model cannot be convinced in a day of training sessions then we must drop it and move on. I continue to look up info here and there in a weak attempt to keep current. I’m guessing the chirruping of crickets in part of the SE community is due to something along these lines. You asked the question, “What is your modeling style?” My, response is, “Not at all like shown here or in the tutorials or in many of the webinars; the nature of our work forbids it.” And the discouraging lack of response might hint that I’m not in the minority.

 

Two things in short:

 1) The article was a great read, informative and confirmed/solidified other bits that I've picked up about Synchronous modeling. I thank you for it.

2) Synchronous modeling has little or no use at the place I work it has just added clutter and a bunch of defaults to change with each release.

 

Not to be completely ungrateful, there are some new features that are quite useful and work smoothly. Listing them here would be OT but I would be glad to chat about them.

 

Ben Nemec

by Honored Contributor
on ‎04-03-2017 01:16 PM

@bnemec, It's not clear to me what the risks of using synchronous are for you. You say "Note that nearly all of the parts in the library are used in multiple assemblies, many have hundreds of WU". I can see having multiple users with access to these inadvertantly or intentionally changing them. I get that. But that can occur with ordered parts as well. The way we prevent that problem (other than vigorous hand slapping) is by using life cycle tools. Our "static" files are released and therefore not easily changed without some administrative event occurring first: A revision or changes performed only by certain permitted personnel.

by Valued Contributor
‎04-03-2017 02:00 PM - edited ‎04-03-2017 02:03 PM

Hello @bshand,

   I agree that ordered parts can be changed as well.  We have had very little problems with people intentionally changing production models (adjustable assembiles excluded, but that is OT for this thread.)   Concerning parts, the problem in most cases we spectulate is inadvertantely making an undesired change to adjacent face(s) when making a documented revision.  There would be prototypes made where hopefully the unexpected change would be noticed, this would waste time and money in an unessesary iteration.  At best we would catch it using the view tracker in draft when dimensions/annotations change that shouldn't be.  Now to go back and without concrete sketches driving the model we would have to try to get back to where we were, or just scrap the revised model, roll back to the static version and start over with the revisions.  So it appears that each face or feature of the model would need to be constrained 100%.  In the practicing I've tried to do I have found that Solid Edge rarely guesses the right solution to make the rest of the features follow along, the handy canned examples excluded.

  I think I admitted in a previous post that this may all well be due to a lack of training in ST to learn how to use all the tools of that method to make it work.  Also mentioned, if the advantages cannot justify the cost and time consumed in training everyone in the department to learn a new style of modeling, ST is a no go here.  We just do not see the gain.  I search now and again for tutorial and blogs, and try some ST modeling following the example hoping maybe it will work.  So far I have just ended up frustrated and in my mind I'm thinking of the sketches I would use to build it.  Perhaps it is because we do very very little top down modeling maybe ST produces a bigger gain in that style?

 

My $0.02

by Honored Contributor
on ‎04-03-2017 02:22 PM

@bnemec

 

Fair enough. There are thousands of users with unique methods and preferences. Our users mostly use synchronous and I can't say we've had inadvertent change problems with our models. I'm not a 100% sold synchronous fan and besides features that sync just doesn't do well there is often just too much going on in some synchronous models to see what's locked down vs. what's changable. And sometimes sync models just do some baffiling things. Whereas with ordered since models are constructed step-wise and features are segregated I think changes are easier to control. With sync "invisible" changes can occur and build up, causing problems later. But I absolutely love it for imported parts. Plus, you can always make ordered features synchronous later if you wish.

by Valued Contributor
on ‎04-03-2017 02:47 PM

@bshand,

  Now you've peaked my curiosity again.  I can see ST working in an imported model where there is no history or driving sketches.  I'll have to give it a go next time I need to clean up and edit an imported model.

 

by Honored Contributor
on ‎04-03-2017 02:56 PM

@bnemec,  It's absolutely the bee's knees for that. Wonderful.

by PLM World Member Pioneer PLM World Member Pioneer
on ‎04-11-2017 10:51 PM

As a 63yo mechanical designer I have seen the design industry evolve from totally manual document preparation through electronically-assisted board drafting to totally workstation-based operation over a period of 40 years. During that time I have also observed the progressive collapse of the 'traditional' heirarchy in many design offices, to the point where both senior and peer review, checking and signoff are now rarely implemented. Although I was an 'early adopter' myself, I am one of a generation of design professionals who largely shied away from engagement with early developments in CAD/CAM/CAE yet went on to become senior managers of CAE-based projects which they were ill-equipped to understand let alone supervise.

My point here is that there has been a massive failure to capture established 'design wisdom' in today's 'clever' CAD suites. A good designer is aware of material and process limitations, actively seeks out peer review, engages with a network of associates as well as keeping up-to-date with developments in his industry and SELECTIVELY applying new techniques and technologies. Software itself, however, FAILS to support much of the information capture necessary to ensure that the designer (or, hopefully, team) is working as efficiently as possible. Is the stock material readily available to make this part? Is the selected bearing a cost-effective heavily-stocked item, or a high-priced exotic variant? Will the welded assembly fit into the galvanizing bath?

Regardless of whether you are a history-based modeller or an advocate of Synchronous Technology OR trying to juggle a balance of the two, take a HARD look at what drives design rework. Parts that can't be manufactured or assembled as designed, unobtainable or overpriced bought-ins, excessive scrap from inefficient machining, delays & high labour costs from excessive/difficult welding, unattainable/uninspectable or poorly-specified tolerances etc. leading to reject parts are ALL avoidable at the initial design stage, yet it requires knowledge & discipline independent of the CAD system to avoid these pitfalls. Ease of change (as heavily promoted during the introduction of Synchronous) is not a panacea UNLESS managed/scrutinized. How quickly I can change a part in-assembly from 48.3 to 53.5mm is a hollow claim if it must be made from 50mm stock!

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