Dezignstuff SolidWorks Blog

It looks like a product I have worked with an inventor on is going places. The “Stethecozy” is an attractive, patented device that houses and sanitizes the stethescope while not in use. It fits a wide range of scopes, and helps prevent against the spread of germs between patients.

The Stethecozy was the winner of the Best Invention for the Common Good award from the Yankee Invention Exposition. Certainly a proud moment for Dr. Stickley. I’m glad to have been involved in this project. It is now moving to production tooling.

Congratulations to Dr. Stickley!

This is kind of in response to all of the great comments I got on the last post about independent contractors.

First of all, if you have a PE license, I recognize that the rules are different. I don’t have a PE because nothing I’ve ever been asked to do has ever even come close to requiring it. I did the EIT thing years ago, but never moved forward with it. Most of my work is in consumer and medical plastics.

I get people asking me, I guess especially more so in the past few months, how they can become an independent contractor. It’s really simple: just get people to hire you to do mechanical design type of work for short amounts of time. That’s it.

Seriously, there is a little more to it than that.

1. Have a great network in place
2. Have the correct tools and skills in place
3. Have a way to communicate with your network

I developed my network over several years in a few different ways. The biggest way was to be an employee of a reseller. Doing tech support, training and demos for resellers you get to know a lot of people, and if you do a good job, the fact that they remember you is a good thing, not a bad thing. Not everyone gets this opportunity, but it is an easy way to get a lot of low level experience and meet a lot of people from a wide range of industries.

The second thing that I did was to be very active on web forums. Working with the reseller made me well known in a small geographical area, say western NY or the Mid-Atlantic, but getting well known on the web gave me more of a general notoriety. I spent a lot of time on the newsgroup comp.cad.solidworks, and then on the SolidWorks forums when they became available. I answered a lot of questions, which was the helpful part, but then I branched into a lot of opinion based stuff, which probably was less helpful for my career than answering technical questions, although a lot of people learned my name. Some people say any press is good press, but I believe content and context count.

Someone asked how much business comes from the web. I’ll be the first to admit that direct web business, or money that falls out of the sky just because I have a web site with the right words and pictures is very low. I have had a couple of jobs from that source, and it just happens that my book deals were one of them, but very little else of consequence. Usually it is word of mouth, even if the original person learned about me through the web.

The other thing I’ve done is to do a lot with user groups, and present on various topics here and there.

My blog is not really intended to be any sort of business driving effort. If it were, I would clean it up a bit, have more modeling content and less opinion. I have maintained a website since 1995. The blog format just makes maintaining it and adding new content much easier.

I get business from around the country, with a couple of steady customers, a few habitual repeat customers, and a lot of one-time affairs. Most of the one-time jobs are for inventors who don’t have any CAD system, and often very little idea of how the whole product development thing goes.

It doesn’t really take that much business to keep one person going, but the hardest thing about it is getting work when you can get it. A steady stream without too much at any one time is the trick. I wind up trying to manage what I consider to be a big project, like a book that takes 3 months with smaller projects that bill maybe 10 hours. It’s hard to do. Another tough thing is a long term customer who has a couple of hours a couple times a week, and then maybe I don’t hear from them for a month, and then I have to work them back into the schedule.

Sometimes people come to me with a job that will only last a couple of hours, say an import repair job or something. You have to have a minimum. I don’t usually charge for communication time, phone calls, emails, etc. but when you spend a few hours communicating for a 1 hour paid job, I tend to have a minimum charge instead of doing that hourly. It doesn’t really pay to try to do very small jobs like that on an hourly basis. So yes, I’ve charged people over $300 for 45 minutes of work. Is it wrong? I tell people up front if that is going to happen, and most often they go through with it. For them the fuss of finding someone else is just too much, and keeping their other projects going is important.

And someone else said that they take whatever work they can get and learn on the job when necessary. I guess I would do that if I charged a bit less. At the rate I charge, I think people expect me to know a few things. I might take a sheet metal design/modeling job, but I wouldn’t sign up to design a conveyor system. My expertise is plastics and complex shapes. I do a fair bit of small mechanism design, and I could certainly do castings, but not machine design.

Here’s the one that some people don’t believe. I don’t do drawings. I mean I have done them, and I can do them, but most customers aren’t interested in drawings. They want 3D data to drive CNC.

I also do some stuff like CAD administration services. Some SolidWorks and Workgroup PDM administration. I do training and on-site troubleshooting.

If you’re going to get into consulting/contracting, I think you need a niche. Who is going to hire someone who is just a general SolidWorks user? There might be a need for that kind of stuff, but I usually get hired when the local talent can’t handle the job. I rarely get that fluff work 2D to 3D that everybody advertises for. I get the kind of jobs where they give me an awful 3D model from Alias or something and ask for a parametric SolidWorks model +/- .005″, and then ask for changes. With 90 day terms. Sometimes you have to take work like that because it is what’s available.

All of the easy CAD modeling work goes to India and China and some places in Africa (like Rwanda) now. So if you want to charge a rate high enough to make it worth your while, you have to know some things that they don’t know in India.

I have a couple of people that I will sometimes off-load jobs to if I don’t have the time. And sometimes they send work my way for different reasons. If I were going to refer work to someone, I wouldn’t just refer any work to anyone, I would want the needs to match the specialty.

Someone else pointed out the differences between modeling work and design work. Sometimes the modeling is extremely simple, but the design work requires you to understand several manufacturing processes, as well as materials, mechanisms, and so on.

Sometimes you don’t get paid on time or at all. Over the past 5 years I’ve been stiffed by 3 different customers for a total of about $10k. It’s a casualty of business, although there are ways to prevent things.

1. don’t let some one who made you sign an overly wordy contract owe you any money – they don’t intend to pay you anyway
2. if there is something irregular about a job, like an overseas client, or clueless inventor, get money up front, say 50%
3. never accept “stock in the company” as payment
4. let people know that you are unhappy with 60 or 90 day terms, and if you can do it, turn down the work altogether or counter with a 100% up front payment requirement, which is equally ridiculous and disrespectful
5. when you get people who just like to continue to tweak things and never come to the end of a project, let them know that you have other things to do, unless they pay well and you don’t mind milking a project
6. make sure people know how far you are willing to go down the prototype and manufacturing route. inventors may assume that you can run a production facility for them and do all of their prototyping
7. inventors often do not understand the differences between buying things as a retail consumer and buying things as a business

Generally, people looking to get into contract work are looking for contacts. I try to discourage people from doing that if they don’t already have a list of people who could hire them for work. You almost have to avoid doing contract work until you can’t afford to avoid it any more. I don’t think you can get into it as a last resort or after you’ve already been laid off. I made the jump when my last employer and I were sick of one another. I asked him to give me a month’s worth of work as an independent, and then go our ways. They did it, and that was all I needed to get rolling.

Anyway, what would I want from a “thing” like this? I’d like a list of people and specialties. If I get some work I can’t do, I’d refer the customer to someone on that list. I think this would be a “we’re gonna help each other out a little” rather than “Matt Lombard is gonna make me rich” kind of list. I wouldn’t want any formal agreement, just a list to refer work to. Maybe a site that people who need work done could look at and pick someone.  Anyone else have any ideas?

How soon? Real soon. I dunno, nobody knows, and if they did they wouldn’t say.

You are either self-punishing, uncurably curious, serious fanboy material or simply have too much time on your hands. It’s that time again. SolidWorks 2010 beta will shortly be available for download. I won’t be able to say anything else about it outside of the SW 2010 beta forums because of the non-disclosure you have to agree to when you sign up. You can remember back to SolidWorks World 2009, with all of the what’s new info that they put out there… Brian McElyea had some of the 2010 enhancements.

One thing you can do that is easy is to download the Whats New PDF and read it over to see what is going to affect you. So for whatever reason you do it, early learning, curiosity, testing, development, or self punishment, come and get it.

Click here to learn more about SW10beta.

Here are some tips for testing:

• Bring lots of patience and an open mind
• Don’t just accept that because a button is in the place where it is supposed to be that it works correctly
• Don’t just accept that because something produces a result that it is the correct result
• make a copy of your data that you want to use, and make sure when you open an assembly that it is not looking to the original data for references
• do not beta test while doing production work
• download the What’s New first, and read it while the rest of the software is downloading (if it’s not bundled in the main download…)
• Don’t expect the What’s New to be comprehensive – look for those easter eggs! and discuss them on the beta forum!
• Do a parallell install – yes, you can have 2010 and 2009 on the same computer and even both running at the same time.
• Don’t overwrite your TOOLBOX!!!
• identify areas that are of interest to you
• methodically go through each area of interest to you, test all the options, try out every button to see what it does.
• keep a log of how each feature measured up to what you expected it to do
• report bugs when you find them, even report old bugs, even though the SW guys will yell at you for doing it – they need to fix the new and the old bugs.
• participate in the beta forum
• don’t discuss beta issues publicly outside of the beta forum
• don’t get your heart set on prizes – Lin ShaoDun wins every year by a LARGE margin, you can only dream of second place

I’m kind of lazy when it comes to tying my shoes. I usually buy shoes that I don’t have to tie at all. But I was coming to Boston and planning to do a lot of walking, so I went out and bought nice new shoes. Of course coming to Boston I had to get New Balance.

The shoelace design on these shoes actually makes me want to tie my shoes. I thought this was a cool thing that they did to revive a struggling institution.  The shoelace is a dying breed. If you look at these laces, you see they look like string beans in the pod. They have little bulges every inch or so.

This design helps to prevent the laces from coming untied. The knot kind of locks into the trough next to the bulge. Simple and effective. Very cool idea. And now I tie my shoes and they never come untied unless I want them to.

Great design idea. An example of “form is function”, and “function is king”.

Splines make some people squeamishly uncomfortable. You can’t put dimensions on them, so how do you manufacture it? How do you make parts fit together if you use splines? How do you run QC to check your parts?

There are a lot of misconceptions about splines. The first is that you can’t put dimensions on them. And the second is that if you put dimensions on them that they become fully defined. The Third turns out to be that if you fully define all the points on a spline, that you can’t drag the points around anymore. Each busted misconception in its own time…

I have good answers for each of these misgivings and misconceptions, but I’ll get to those later. I want to start by addressing why splines are so important, infact indispensible.

Great curvature, baby!

Ok, this is going to sound sexist. That’s because it is. So sue me. If you’re male, there is no way to pretend you don’t notice this kind of stuff. Some types of curvature just draw your eye. That’s all there is to it. Just to keep it kind of cartoony and not too explicit, let’s use Jessica Rabbit from the movie Who Framed Roger Rabbit as an example, because she’s a great example.

Splines are sexy. Jessica just wouldn’t be the same if she were just straight and round, drawn with lines and arcs. Jessica, and just about everything else that we think of as “products”, needs curvature, and in particular, changes in curvature.

The reason why splines are so necessary is that they are the one way we have to make shapes that look organic. Organic shapes are never perfectly straight or perfectly round, they are constantly changing curvature. We as humans are programmed to react to organic shape. Jessica Rabbit’s organic shape provokes a reaction, and product design tries to evoke the same kind of reaction. It’s not a coincidence that they both cry out “empty your wallet”, and we dutifully obey.

If Jessica has an equivalent in the automobile world, it is probably something like a 1960 Corvette. Yow. They both look great in red. Nice headlights! Love those rear fenders. How does it look with the top down? It’s no coincidence that product design is so sexual. It’s no coincidence either that they are both beautifully curvaceous.

Splines or lines and arcs?

Cool shapes in product design is all about curvature that changes smoothly from one radius to another rather than simply a series of tangent arcs that change from one discreet radius immediately to another

discreet radius. Look at these two surfaces below. Which one looks better to you? The one on the right is less lumpy. I think most people would say the one on the right looks better. Of course the one on the right is made with splines. You can almost see the lines and arcs in the one on the left.

Of course it is possible to make splines look very bad if you are trying to do that or are very inexperienced. I think a lot of people make the mistake of thinking that a spline with more spline points is more controllable, and thus a better spline. The truth is that you DON’T want to try to force a spline. The thing about organic curvature that makes it so appealing is that it looks natural. The natural materials are bending or being formed in a natural way. Splines have a very natural way of bending. I’ve been told that the math governing how splines interpolate shapes between points is very much like the natural bending equations for elastic materials.

Interpolated shapes

I classifify shapes into two camps: analytical and interpolated. Analytical shapes have a specific equation that can be written, for example a line or circle each has a familiar equation that you may have learned in high school geometry. A spline I believe is a series of 2nd or 3rd order polynomials. With an analytical shape, you know exactly where every point along that shape is going to be even before you draw the line or the arc. With a spline, you just put down the control points, and SolidWorks interpolates the curve between the points. This concept follows through to features such as the boundary, loft, fill and sweep. You put down the profile curves, and SolidWorks uses the Boundary feature to interpolate the surface between the curves. The difference between analytical and interpolated curves and surfaces is very important. They are not interchangeable.

Arguments against splines

People who don’t trust splines typically talk about dimensions or repeatability. When I create splines in SolidWorks, I never fully dimension them. Its useless to dimension splines. Different CAD packages evaluate splines differently, even if the spline points are all in the same place. Even SolidWorks between releases evaluates splines differently. Even if you were to use a spline on a drawing and fully dimension all of the spline points, the spline could never be exactly recreated based on those dimensions.

The only way to transfer spline based manufacturing data is to send a completed 3D model, and for the manufacturer to use a computer controlled method. Paper drawings may be useful for notes, and reference dimensions but typically not as a way to specify a complex surface or curve. This is most of my business. I don’t remember the last real drawing I gave to a molder, I just hand off 3D data.

Practice with splines

See the spline here with a lot of points looks lumpy. When I first started working with splines, I thought this was the best way to get great control on a shape, but it turns out that the more you try to control the shape, the lumpier it gets. Notice that the second spline is much smoother. This is because you just let the spline math do the work for you. My general rule of thumb is that you add a spline point for every change in convexity (convex up changes to convex down). So you have the two endpoints, which would make a straight spline, a middle spline point, which would make a convex or concave spline, and then a third point which gives the undulating S shape.

In the second set of images, I have applied a curvature comb to the splines. This is a way to visually evaluate the spline. The curvature comb represents the instantaneous curvature at that point along the spline. If the curvature comb changes sides of the spline, that means the spline has changed convexity. Notice that the comb on the top spline confirms that it is lumpy and the changes in curvature are too abrupt. The changes in curvature in the lower spline are much more gradual. Changes in curvature are represented by the change in the height of the comb.

Just for reference, curvature is the inverse of radius, or c=1/r. If you have a large radius, it means small curvature. Small radius (tight corner) has large curvature. Notice that the curvature comb is taller in kinks of the top spline. Notice that in flat areas of the spline (almost linear) the curvature comb is almost zero height.

More to come…

We’ll talk more about this topic later. There is a lot to know about splines.

Sometimes you just need a different tool. No judgment calls about why, you just might for whatever reason need a different tool. I’ve looked at a few CAD tools, and found things that were important improvements over my current tools, and also things that were impossible compromises. After having used mainly one CAD tool for the last 11 years, it can be difficult to be objective about it or alternatives, but I’ll try.

Purpose

What do you need your CAD tool for? You know, not all CAD tools try to be what SolidWorks tries to be. SolidWorks seems to try to be a one-stop-shop. To some extent it succeeds, but sometimes you might just need specialist tools. For example, I’d say that SW is pretty good for stuff like machine design and sheet metal. It’s great for machined parts. SW certainly has capabilities in complex shapes and plastics, but it is far from ideal for these functions. SolidWorks isn’t great at piping or wiring, either, but it does it. I wouldn’t use it for architecture, but you might make it work.

Anyway, here is a little list of things I put together about a few CAD products. I’m not directly familiar with most of these, and I’m not shilling any products or trying to promote any ultimate solution, just talking about alternatives for various purposes. I encourage people with specific experience with some of these products to share what you like or don’t like about the tool, and what kind of work you think it is best suited for. The categories aren’t meant to be definitive, just to give an indication of where I see the tool fitting or not fitting into what I do. The categories certainly oversimplify things. Don’t get worked up about the categories. (Geez, why am I getting defensive about this already? Premonition?) I’m sure I’ve left something out or miscategorized something, and this is the kind of junk that some people get really upset about, so please, no flame war here. I’m looking for considered opinions, not dogma.

General purpose modeling

Complex surfaces (nurbs)

Digital sculpting (mesh)

Simple concept models

 (Moment of Inspiration – MoI)

Architectrure

Reverse Engineering

Rapidform
Geomagic Raindrop
Revworks

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Of these, there are a couple of products that I want to have a closer look at. I’ve used Rhino off and on, but in the next weeks I will try to write about how Rhino can fit into the workflow for a product designer, plastic part designer or complex shape modeling scenario that is somehow tied to SolidWorks.

I obtained a trial license for SolidThinking, a seemingly overlooked piece of software from the Altair company that is involved in some pretty high end software. This looks interesting to me, and could possibly have my type of modeling more squarely in its sights than does SW. Complex surface modeling is at best a niche sideline for SW. For SolidThinking, it appears to be dead center.

Maybe its just the similarity in the names, but Think3 is another product that I get confused with SolidThinking. A recent interview on Novedge rekindled my interest in this product.

Other tools interest me as concept modelers, such as MOI, Shark, and modo. If I had multiple lives to live, I’d love to be a digital sculptor. It’s one of those things that looks like fun, but I’m not sure I could make a living at it.

In conjunction with the digital sculpting is the reverse engineer sofware. Rapidform is one I’ve played with and threatened to do a review of, but have never done it. The connection between digital sculpting and reverse engineering is the point mesh data that both work with. Reverse engineering software enables you to take mesh models from CG/digital sculpting applications and make them into NURBS models compatible with SolidWorks.

modo is hot news these days too because they come from the Luxology company, who is responsible for the PhotoView360 software. I think it is a bit overkill that SolidWorks has sunk so much development resources into rendering, and they have a half complete simple renderer, along with a too-complex, halfway renderer – both about half finished after all of this time of delivering half finished product. It;s like going to my brother’s house. He has 4 construction projects half done. What a mess. Anyway, modo is a newish CG/digital sculpt/mesh modeler, and it looks pretty good.

So you can see I have no end of curiosity, but not near enough time to play with all of this stuff enough to say something useful about it. Any suggestions or favorites from the list for different applications?

In software where the end product (CAD data) is highly process-based, and where there are almost innumerable possible ways of doing any particular task, it is a given that the accuracy of the final product is of utmost importance, but it also becomes important how you arrived at that final product. When you are working with data that may be revisited later or working in an environment where multiple people are contributing, consistency in the process of making SolidWorks data is key.

A lot of people seem to be looking for best practice rules to implement at their company or to support their point of view in an argument about 3D CAD standards. Some of them act as if they think Moses came down from the Mount with CAD best practices carved into silicon.

Part of the reason people are looking for this is that SolidWorks has played fast and loose with best practice from the beginning. Many users were sent down the road with a pat on the back, a smile and a “look how easy this is”. Like unprotected sex, that’s gonna come back at you one of these days.

Fast and loose is all fine when the software is relatively unsophisticated, but times have changed. When selling SolidWorks, no one says any longer “look how easy this is compared to Pro/E”, now they say “look how powerful this is compared to Inventor”.

As the software has become more sophisticated, the only thing that has kept pace with that sophistication is the reseller implementation services. Resellers realized by answering (or not answering) a lot of tech support questions that customers were coming up with questions that weren’t covered by training, and they weren’t really in the scope of tech support. The new field of questions had to do with process. 3D CAD really is a different beast from 2D, and it really does offer us new ways of re-using data.  And it really does change our engineering process.

Anyway, SolidWorks made the software so easy to use in part by shortcutting a lot of general CAD best practice ideas. Now that a lot of users are entrenched in bad habits, some of them are looking for better ways of dealing with this more sophisticated tool. “Best Practice” has this air of panacea about it – a cure-all developed by the collective wisdom of top users from all disciplines. It’s partially true and partially untrue. Sometimes you have to separate the wisdom from the wives tales.

First of all, best practice suggestions are just that – suggestions. There is no single set of hard and fast rules that can be applied to any two different companies. Every company has a different way of doing business, and there are different individuals involved in every situation. Each of those factors will change what works best in that situation.

Second, best practice suggestions are often self-contradictory. When I suggest practices for a company, some times I will suggest one thing, and then I may turn around and suggest exactly the opposite. Some situations call for one tactic and a different situation may call for something entirely different.

Several factors can influence the best practices or standards that you use at your company, and let’s not be shy about saying it like it is. One of the factors is training or overall skill level. If all of your CAD users are wizards, and they are all ultimately flexible, then you should be able to make absolutely anything work.

The other situation is more common and more of the condition that best practice rules are meant to deal with. Users who are not experts can sometimes get themselves in deeper than they can dig themselves out. Best Practice suggestions help guide users like this to help keep them productive, even if they are venturing into a new area of the software where things are unfamiliar.

Finally, best practice suggestions can never be implemented blindly. You and your CAD operators will still have to think about things before they do them regardless of how many CAD standards you write down. There is no substitute for the human mind, even in engineering processes.

The difference between CAD data and engineering design data is that CAD only communicates shape and dimensions. To make your CAD data into engineering data takes a lot of extra thought, planning, research, inventiveness and communication.

As an example of some “best practices”, several years back, I wrote some of these “Rules of Thumb” lists, some of which are still valid.

Mike Sabocheck is the MidAtlantic Territory Technical Manager for SolidWorks. TTMs are the technical side of corporate sales, and get involved in some of the tricky requirements that potential customers sometimes throw into a sales situation. I was offered a TTM position in California, and reluctantly declined. The job seems like a lot of challenge, but also a lot of fun. If there is any job at SW I would want, it would be the TTM job. I’m sure that sounds ridiculous coming from me, but the part of being a reseller engineer that I really liked was dealing with the customer requirement challenges. Of course TTMs have other duties like dealing with resellers, and interacting with user groups which I would also enjoy.

Anyway, I’ve known Mike since he took over as TTM for the Upstate NY region in the 90s. Mike’s a great guy. He’s the one who wrote the famous quote on the back of my first book, which reads in part “…plus his snappy wit and wisdom make SolidWorks accessible to users at all levels.” It was a very carefully worded statement, but I think it came off with just exactly the right tone. Mike knows I’m sometimes a little over the top, but that I’m also enthusiastic about SolidWorks.

Mike is one of those guys that I go to every few months with a question, hoping he can help me out. He also comes to me sometimes, and his recent phone call is what sparked the idea for this blog entry.

Mike asked me about a part I have up on my (very neglected) website. It’s an image of an artificial knee joint implant. This was my initiation at Trimech. They handed me the part and the drawing for it, and said the guy before me couldn’t do it, so here you are, hotshot.

It took me a couple of weeks of thinking about it, and I started several models before I settled on an approach that worked, but I eventually got something that looked reasonably like the part.

I mentioned that they gave me a drawing. This was the crux of Mike’s question. If you have a part like this, how do you make a drawing of the part? The insides of the part are all straight lines and arcs, but the outside is splines and swoops. What can you do? The drawing that I got was awful. It was done in AutoCAD, and it was all lines and arcs, with a lot of cross sections. It didn’t come close to representing the part. It was obvious that the 2D in no way represented the actual 3D.

I don’t know how they made the part, but I would guess it was cast and then ground. It’s possible that the first model was carved by hand, and then a pattern was made from that for the casting. But this was a highly polished surface. I know they couldn’t have manufactured from the drawing because A) the drawing was awful and B) the drawing was 2D, and didn’t give enough information for any manufacturing process to make the part.

This question about drawings and complex shapes is one I’ve had to confront from time to time. I can’t claim to have any definitive answers, because I think the answer depends on the situation every time. Still, there are some things you can say unequivocally.

First, it is unrealistic to expect to make a fully dimensioned print for a part like this. In the same way that I couldn’t model the part from the drawing, even if you start with a correct model, you couldn’t make a meaningful, fully dimensioned 2D drawing of the part.

Second, you have to answer what you need a drawing for in the first place. No one is going to take a sheet of paper over to a manual mill and start spinning wheels and come back with this part. Not gonna happen. The part (or tooling to create the part) is going to be made by some form of computer controlled process. It’s not going to be someone standing at the controller fat-fingering toolpaths, either, this will require software to create toolpaths directly from the CAD data.

Ok, so you’re not going to use a print to manufacture. Maybe the part has some areas that do not need to have a highly polished surface. Well, that’s something to put on a print. Tolerance on a part like this doesn’t mean much. Even though the outer surface is mirror polished, real dimensions could be +/- 0.030″ without any functional problems.

There are actually some location pins, and the inside shape is all straight lines that have to match a cut in the end of the femur. You can dimension stuff like that, if for nothing else so that the matching geometry cut into the bone by the surgeon has some sort of a reference.

The part has to be inspected some how. How will you tell if a part passes QA? Is a guy actually gonna sit there with a set of calipers and measure this thing? Probably not. A comparator? Nah. How about a CMM? Well, possibly. If you’ve got parts like this to inspect, and they have to be quantifiably measured, you’re going to have to use some sort of a CMM, laser or contact. A set of go-no-go gages and a good procedure might do just as well for something like this where there is a complex shape that doesn’t have to meet a really close tolerance.

So, what do you tell somebody who asks how to make drawings of complex shapes?

1. Make sure your drawing has a purpose
2. Make sure your drawing can fulfill the purpose you assign
3. Manufacturing and inspection are two areas that might require drawings: give those people the data they need in the format they can use. Just “because we always have to make a fully dimensioned print” isn’t a good enough reason to make one. It might turn out to be an immense waste of time, and what you get from it may not be useful in any way.

I’ve been guessing a lot about what functionality the term Synchronous Technology was meant to obfuscate. I’ve been both wrong and right about some of my guesses. I’m not the only one. Even Evan Almighty has been wrong and right, but mainly irrelevant. Very few people have any real “facts” about this stuff. We hear what some people want to be true, and some people just blindly repost press releases without any idea at all what it means. We’ve heard some strange emotional rants about why the world needs something like this as opposed to something or anything else, and some equally strange posts seemingly defending SolidWorks from the need to keep up with the Joneses.

I’ve been lucky enough to have Dan Staples of the Solid Edge development team and Chris Kelley, a Siemens marketing guy both stop by the blog here and leave some comments. Dan in particular has been very helpful with the only hard facts I’ve heard anywhere about Synchronous Technology. Even the ST white paper is very heavy in vague declaratives. The truth is that most of those videos posted about ST, well, I’ve been tempted to post equivalent videos of SolidWorks doing exactly the same thing. Not because I have an axe to grind, but just to show that the examples we have seen of ST have been unconvincing because the capabilities already exist in SW and other places. This is why some folks have said ST is nothing new. I think Siemens has done a wonderful job of creating hype, and a less than wonderful job of backing it up. But of course that may be the main attraction of hype – not backing it up is what makes it hype in the first place.

So what have we learned?

- Synchronous Technology means that all of the relations in a part are solved simultaneously instead of linearly.

In SolidWorks, mates in an assembly are all solved simultaneously. So are sketch relations. These are driven by D-Cubed, also owned by Siemens. What are two of the least reliable areas of the SolidWorks software? You got it, sketch relations and mates. Go back and count how many times I’ve singled those two areas out as things I would like to have fixed. I think this is a bad omen for ST. D-Cubed proves that simultaneous solutions are not an incredibly reliable source. Of course SW’s problems could be an implementation issue, and it still remains to be seen how Solid Edge’s implementation of simultaneous solutions for relations within a solid model is going to work in real every day modeling.

There is no doubt, history can be a cumbersome way to create geometry, but it is also just as often a great asset when making changes. Getting away from history is a great theory, but based on what I’ve seen of simultaneous solutions, there may be a reason why other CAD companies are not flocking to it.

- Synchronous Technology really is something new – a new way of putting together a lot of old stuff.

“Synchronous” can mean “solving relations simultaneously”. Or it can mean integrating several modeling technologies or techniques. I think the “synchronous technology” term benefits from some intentional double entendre, but at the same time is sufficiently vague that it doesn’t mean anything in specific as a stand alone phrase. All of this probably makes sloganeering marketing people wet their pants in glee. Still, clever new names or not, this is all familiar territory.

Simultaneous solutions? Check. D-Cubed. Shaky foundation. Been there, done that.

Driving dimensions and geometrical relationships on “dumb” geometry? Check. Spaceclaim.

Feature recognition? Another shaky foundation. Check. Several CAM products use this, as well as FeatureWorks.

Live Rules? Behind the marketing name, this is indistinguishable from parametric relations. In fact, it looks much like parametric relations applied directly on the solid model. Dan sort of confirmed this, I think. Parametric relations on a solid model to me is the one thing to really get excited about with ST. The screen grab below was taken from a youtube video.

- Siemens is totally changing directions in the high end and midrange markets, and is throwing this Hail Mary in the hopes that all the commotion may attract more attention than all of the Spaceclaim and CoCreate non-news.

With Synchronous Technology, Solid Edge has removed itself from the SolidWorks – Inventor fray. They have been removed for some time, they just never admitted it until now. Personally, I think the hype has been brilliant, but the failure to follow up the hype with some sort of intelligible scheme that real users can understand leaves the whole thing looking like the vacuum cleaner salesman saying “trust me!!” It’s kind of telling that I had to dig this info out of people, and that Siemens clearly does not have a clear and intelligible message for users.

Chris Kelley appears to be a one-man Solid Edge blog machine, but he is marketing, not technical. Really, are there any technical Solid Edge blogs out there? Why are they not giving us the low-down from a users point of view (or are they and I’m just not seeing it?) I’m not bashing Solid Edge as a product, I don’t know enough about it to bash it. It seems so much like SolidWorks as to be practically the same, historically, anyway. But the product hasn’t seen the broad industry acceptance that SolidWorks has seen, so Siemens had nothing to lose by changing the rules and aiming low.

What I mean by “aiming low” is that the whole direct editing movement seems to be enthralled with the ease of use idea. I think this is meant to expand the definition of a “CAD user” to mean someone lower on the specialization totem. The message here is “ease of use” rather than “power” or “control”. These ideas always seem to be diametrically opposed.

- What remains in Solid Edge is no longer a history based modeler.

Some people who don’t know (including me) have said that ST is Spaceclaim bolted on to SolidWorks. I don’t believe this to be the case. I’m now under the impression that ST is Spaceclaim bolted on to CoCreate, or there abouts. There is no history left. Siemens has abandoned history based modelers. This seems to be one of the things that Dan was saying.

Many UG users I have known have said that UG never was much for history based modeling, and with Solid Edge showing as an “also ran” in the parametric history based market space, it is no surprise that they decided to changed direction, possibly if for no other reason than to distinguish themselves from SW and IV. So now they have a chance of being on the top of the heap of non-history based modelers, and trying to capitalize on the wave of direct editing modelers really rejuvenated by the popularity and simplicity of Sketchup, and given a shot in the arm by Spaceclaim.

Summary

Solid Edge and Unigraphics/NX are both strong products, but they aren’t market leaders. Solid Edge was acquired from Intergraph, and part of NX is SDRC. How is Siemens going to grow this set of products? A bold move like completely rearchitecting the software might not have been inevitable, but it really isn’t a huge surprise.

I’m very interested to see what rank and file Solid Edge users think of these changes. For those that are happy with the history-based view of the world, Solid Edge may have just handed SolidWorks a small infusion of new customers. There are several people who are not paid by Siemens who are going around claiming that this stuff is the answer to all their prayers, even though they have never laid hands on the software or fully understand how it really works.

I’m going to guess that the new Solid Edge will have a little burst of sales just due to curiosity, but in the end, interest will wane. There is a reason why products like IronCAD, CoCreate, KeyCreator and Spaceclaim have not become overwhelmingly poplular while products like Pro/ENGINEER, SolidWorks and Inventor have. I don’t think a massive hype campaign is going to be enough to change this decades old momentum.

It may be a great idea, and it may have required some revolutionary thinking to bring it to fruition, but I think Synchronous Technology is going to become another forgettable buzzword that marked a sharp turn in the road for an “also ran” history based modeler.

Most of the real straight talk you (or I anyway) get from SW employees is under non-disclosure or personal conversations that really can’t be made public. Bummer. I wear multiple hats in my relationships with SW Corporate. Personal friend, Customer, Partner, Alpha/Beta tester, User Group leader, and big-mouth blogger. The blogger side of the equation is at odds with the other aspects, except maybe as a customer advocate. So I have to pick which battles I’m allowed to fight, and what tools I can use while doing that. Sometimes its an uncomfortable relationship because while the right hand is ranting and bashing the interface and documentation, the left hand is being calm and rational while alpha testing new functionality that I can’t mention or I’d never get the opportunity again.

So if I want to post criticism of SW and use facts based on a SW employee’s words to do it, I have to be very careful to get those words from a legitimate source, probably not one involved in any of my NDA type endeavors. That’s what I did this time.

I started by asking if I could interview a behind the scenes person who was not a direct SW employee, and was not executive level, but who had a lot of direct hands on knowledge of how things got done. Of course that got nixed. It was a little too raw maybe for SW Corp, but exactly what I was looking for.

Instead, the official channels supplied an executive, albeit one I didn’t know. I sent a bevy of questions looking for some sort of an indication of how SolidWorks learns as an organization. I wanted to know how they determined when they had made a mistake and how they changed directions.

In the end, out of maybe a dozen questions, I got one answer that was usable for my purpose. The rest of it is the same sort of guarded and carefully measured language we are used to hearing from executive level, and the folks who get promoted. I think in the end what I got with this one answer was inadvertent straight talk. It is an admission of sorts that it seems like this fellow did not think was a very important matter, but to me seems to explain a lot of what we see going on in the software today.

The victim offered up by the PR folks was Paul Chastell, and in his own words “I’m the director of SolidWorks software development, responsible for development of SW Office, both new releases and maintenance of old. ”

My question to Mr. Chastell was: Does SW employ anyone who plays devil’s advocate when negotiating new functionality? What sorts of tools or techniques do you have to look at ideas critically?

What I was looking for here was just an indication of how SW looks at issues critically. How they might take into account multiple points of view. I wanted a statement other than “we do extensive customer testing”, which is simply a blind assertion which explains nothing at all. Here was Paul’s response.
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We do not employ any devil’s advocates but nor do we work in a vacuum either. Our project cycle is not one where Product Definition throw a spec at development, who throw the result at QA who throw the bugs back. The entire project team (Product Definition, QA, development, usability) are involved from the very birth of a project. In addition certain projects will have other “sponsors” from other groups such as Technical Support who have an interest in the outcome and involvement in the process and with some projects we will include customers in early discussions and early testing.

So while we don’t have a devil’s advocate we do have a number of people, with different concerns, who are able to change the direction of a project even before any code is written.
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Most of this is something you have heard before. The only parts of this that I have not heard before are “We do not employ any devil’s advocates ” and “we don’t have a devil’s advocate”. It sounds to me that he didn’t have the same take on the question that I did. He completely ignored the “looking at ideas critically part”.

One phrase I heard from a SW employee many years ago was “you never think your baby is ugly”. The people evaluating the ideas all have a vested interest in the idea. They don’t have anyone to ocassionally stand up and say the obvious: “Hey, what an ugly baby!” While it is often an uncomfortable function, all product development groups do need someone willing to be a critical voice. Not to say “negative”, but someone who is not afraid to look at the downside honestly as well as the upside. SW owes their customers that much. It is irresponsible to only look at ideas they send us from the sun-shiney side of the street.

I agree that you do need blind optimists in an organization. They will sometimes see things that aren’t there, and while delusional, that point of view can be a valuable source of unconventional ideas. Still, when it comes to shipping actual software to paying customers, you really do at some point need to connect with the ground and fess up to reality. Hope is a good thing, but it is not enough when it comes to engineering products.

When you look at the changes to the 2008 software in some depth, I think the lack of a devil’s advocate in the process becomes obvious. To me the biggest giveaway is the irresponsible change of defaults to the most radical options possible. It is as if they are expecting that no one is going to read the what’s new, and that the only way people are going to know what’s new is if everything new is right up in your face like a raw Boston cabbie trying to get your attention on Boylston St. That point of view is actually valid for an Alpha or Beta release, but not for SP0.

It looks to me that there was no advocate for the user. The changes served the needs of the company. You can save a lot on documentation if change is right up in your face.

Further, there was no advocate for the CAD administrator. Large installations where training and settings are controlled are the ones most affected by the changes in 2008. If someone had taken a critical look at the default settings from a CAD administration point of view before cutting the disks, I firmly believe that 2008 would have been received much differently. I know my reaction to it would have been different if it installed looking familiar, and added options, rather than installed looking quite foreign and removed options. If that were the case, 2008 would have looked like a benefit rather than an impediment, without having changed the actual content of the new software.

In the end, I think SW2008 is a slap in the face for long time users. SW employees have suggested that 2008 is a transitional release, and that we can look for future releases to complete the changes started in 2008. Is that supposed to make me feel better or is it aimed at making me think I should skip 2008 and wait for 2009? Why would you release something as “released software” which is in fact only half done? This is another argument for lengthening the development cycle.

[As an aside, SolidWorks Corporation seems to be operating under the crazy assumption that the Beta cycle is for users, and shortening it is a favor to us so we don't get bored with a long Beta. From my point of view, Beta is partially for finding bugs, but it is even more for fixing bugs. Cutting the length of beta essentially cuts the amount of time SW has to fix bugs, which is exactly backwards from the rest of the positive signals we've had from Concord since SWWorld.]

I don’t think there is any room left for the optimist/cynic to question the assertion that SW08 is a slow adopter. My 2007 book is still selling better than any of the 2008 books on the Amazon SolidWorks category. SW needs to take a critical look at the software that ships out the door, and look at it from the perspective of a customer rather than a QA “good enough” manager or a Marketing “on schedule” manager or a Development “too many resources” manager. The Devil’s Advocate role is one that we now know for certain is missing from the SolidWorks process.

Beta or VHS?

Blueray or HD DVD?

Direct3D or OpenGL?

For years now, Direct3D and OpenGL have coexisted, but things are changing, and it’s not clear where they are going to land.

Why do you need to be aware of the rivalry between Direct3D and OpenGL? Mainly so you can keep on top of hardware choices for your SolidWorks workstations.

What are Direct3D and OpenGL?

Direct3D (a subset of DirectX) is a graphics API (programming language) written by Microsoft, which drives 3D display. Direct3D is widely used by games.

OpenGL (GL = graphics language) is an open source graphics API which has traditionally been used for high-end graphics used in academia and engineering applications.

Most graphics cards support both to some extent, but graphics drivers that support the more advanced functions in OpenGL tend to be much more expensive, ostensibly due to lower volumes.

Most 3D CAD software uses OpenGL, however some softwares have changed sides of the aisle. Spaceclaim and Alibre are driven by Direct3D. Inventor’s hardware requirements specify DirectX or OpenGL. Spaceclaim only cites DirectX. The Alibre site does not specify directly. MoI (Moment Of Inspiration) claims “MoI displays gorgeous anti-aliased curves even on low-end “gaming” video cards.” Rhino still requires OpenGL.

Apple can’t bust in to CAD in a big way

Here’s a little contradiction for you. One of the main arguments against using Mac hardware for SolidWorks is their lack of support for the higher end OpenGL graphics, but Macs ONLY use OpenGL, and can’t use Direct3D (something about a little animosity between Microsoft and Apple upper management). So while SolidWorks is so married to Windows, they are also currently keeping Windows at arms length by using a decidedly non-Windows graphics engine. Still, Apple is unable to capitalize on this, and CAD companies are one by one bailing out of OpenGL and signing on with Direct3D.

Rhino is one of the exceptions. Rhino has recently ported to Mac, and has remained with OpenGL.

If SolidWorks makes the change to Direct3D, allowing users to use $200 video cards instead of $700+++ cards, while still enduring video related crashes, the hopes of porting SW to Mac are dead.

Vista and Direct3D team up to exclude Apple

Microsoft plays a shrewd game. The flashy Vista graphics, the Aero interface, is driven primarily by Direct3D. You might remember in the early days of Vista release, there was a huge flap about OpenGL compatibility and speed in Vista. It’s almost as if Microsoft is actively taunting Apple to capitalize on MS’s screw ups/weaknesses. Apple has gained market share since the release of Vista to be sure, but continues to be unable to seriously penetrate the technical computing field, at least the CAD side of it. Those SW users who have been willing to move to Mac for CAD have had to be willing to live with reduced OpenGL function sets and other sub-optimal arrangements. Apple has had a huge opportunity here, yet they have been unwilling or unable to capitalize.

HOOPS

I don’t fully understand this, but Hoops is a graphics system that runs on top of either Direct3D and/or OpenGL. From what I gather here, Hoops allows software developers to implement the Hoops API instead of exclusively or inclusively Direct3D and OpenGL, and then Hoops makes use of whatever hardware/driver capabilities are available. Hoops is developed by TechSoft, who have written a nice white paper explaining some of the issues around this topic. Obviously, they are trying to sell their Hoops software, but their tests show that DirectX is faster on Vista than OpenGL, which you would expect, since Microsoft is master of both.

SolidWorks uses Hoops, but to me it is unclear exactly how, unless it is as a buffer between SolidWorks and OpenGL or if Hoops has developed some additional capabilities not available in OpenGL. The SolidWorks System Requirements site does not list DirectX.

Dialectic

I just want to address this here because it does not deserve a post of its own. When people get argumentative, there are several paths they might take. I’m talking about life in general, but this applies to a couple topics in particular. First of all the PC vs Mac argument, and secondly lately is the Synchronous Technology argument. People get very passionate about these arguments and seem to leave their senses behind. They lose the ability to let reason guide their arguments. It seems to be with folks making these arguments that anyone who does not 100% agree with them is 100% opposed to them.

If you clear your mind before reading most of what I write on Mac vs PC, you see that I step back and forth, sometimes supporting one, and sometimes the other. This is not because I can’t make up my mind, or because I keep changing my mind, it is because when you look at the issue from different points of view, the issues look different. Think Picasso and Cubism. William Faulkner and The Sound And The Fury. Einstein and relativity. Stuff looks different from different points of view. In some posts I’m way in favor of a SW port to Mac or indeed any other OS just to get away from Microsoft. Yet I’m still labeled as a mac hater, which is not true at all, but people convince themselves of this for some reason.

Still, some facts surround the question. The first is that video is a problem with Mac because of a lack of complete OpenGL support. Another fact is that when configuring a Mac, you have limited options when compared to configuring say a Dell or an HP. Another fact is that you jeopardize your SolidWorks technical support by running on an unsupported system. Rabid Mac users seem blind to the facts, or willing to explain them away in some bizzare fashion. So by opposing strained logic, I become a mac hater.

The other example is the Synchronous Technology nonsense. At this time, almost everything that the public knows about ST has been given to us by marketing or by demo jocks. I was a demo jock for long enough to know that you can’t always believe what you see, and you certainly can’t believe what you hear. The only way to really know what is happening here is to hear from some real users at some future date when the software becomes available to real users. Everyone who posts about this stuff right now is speculating, unless they are copying and pasting press releases, in which case they aren’t offering anything new at all.

So am I against or for ST? It’s not a black and white issue. This is what gets me in trouble with people. I’m opinionated, but I’m opinionated about both sides of issues. It is important to me to at least try to see things from multiple points of view. For example, after reading a couple of short stories by Tolstoy, I decided I didn’t like Tolstoy. But in order to really explain why you don’t like something, you have to study it. So I read Anna Karenina, and War and Peace, and decided that short stories were just not Tolstoy’s thing, but that he was a wonderful writer.

So, I get annoyed when people label me black or white. I’m clearly neither and both. People are rarely so simple, but when some people argue about some topics, they want to make it a battle between right and wrong.

Again, am I for or against ST? I think the direct editing stuff is good and is going to be something positive that the industry will see more of, but I don’t think that direct editing and history based modeling are the next PB&J. I don’t know what to think of all of the automagic sounding feature recognition functions, but I’m instinctively skeptical of software thinking for me. Frankly, what I’m most optimistic about is the ability to add parametric relations to final geometry. THAT excites me, but it sounds like Spaceclaim was at least headed in this direction anyway with the dimensions that could be added to parts.

If you feel the desire to pidgeon-hole me, or indeed anyone at all, sit back and think if I expressed ideas on both sides of the issue, and try to see if there is any merit at all in the ideas. I welcome discussion, disagreement and argument, but I don’t have much patience for semi-religious zealotry. Blind dogmatism is almost always mistaken.

I understand confusion when I see it. Different segments of the CAD industry are moving in different directions, and it is by no means a given which direction is the correct one. In the end, I believe we are going to see more direct editing (non-history) based tools, but I don’t think FrankenCAD is the obvious choice.

In one corner we have the noisy, but still rather stuffy Siemens/UGS with its Synchronous Technology pom-poms and cheerleaders, claiming that history based modelers are going to give way to non-history based direct modeling, or at least mixed modelers which employ non-history based modeling within a history-based framework. This is an ugly FrankenCAD mix, and as details leak out, I don’t think it gets any prettier.

And then in the other corner we are seeing the budding romance of a non-history based modeler (Spaceclaim) with another non-history based modeler (Rhino), but then one of them goes and adds some history based functionality. Rhino with implicit and explicit history shows that the direct editing crowd understands parametrics has value that they can’t deliver. This is FrankenCAD from the other direction. How does adding random parametric history dependent features to a non-history based model work? This sounds rather like CoCreate software, which is another also-ran in the direct editing miasma. This story of Spaceclaim and Rhino teaming up and Rhino adding history isn’t getting as much press as the other Synchronous story, but I think it is the more important of the two.

Here’s why. Oreos. Yes, oreo cookies.

Spaceclaim on its own is limited. It has cool editing capabilities, but they are limited to analytical geometry – prismatic stuff with lines and arcs, single curvature, developable surfaces. It has some limited capability with general case NURBS shapes, but it is really limited. You can make simple machined parts and sheet metal parts, but more complex castings and plastic parts aren’t really part of the Spaceclaim equation. What Spaceclaim is missing is exactly what Rhino is best at – swoops. And frankly, Rhino, in all of its complex shape surfacing glory, is no match for a solid modeler when it comes to prismatic work. Plastic part engineering in Rhino would be tedious. What Rhino is most missing in its software is exactly what Spaceclaim does. Oh, and they are both direct modelers.

Everybody has been waiting for Dassault or Autodesk or PTC or UGS to swoop down and snag Spaceclaim, but it keeps not happening. What is happening is that these two small, rogue, direct editing CAD companies are starting to work together. It’s like an Oreo cookie. The wafer is good, but I wouldn’t eat it by itself. The filling is also yummy, but by itself isn’t satisfying. Put them together and you’ve got something that stands the test of time. I would like to see these two companies do more than just share files.

We’ve heard a lot of explanations about what is going on with Synchronous Technology, but the message is getting more rather than less confusing. At first it was just direct editing tacked on to parametrics, Spaceclaim bolted onto SolidWorks. Then it became something far more than that that mere mortals could not possibly understand, and self-proclaimed brilliant people could not explain. Now it appears to have many aspects to it, including everything previously mentioned, procedural features, form features, and feature recognition. That’s an awful lot of “features” for a direct editing (non-feature-based) modeling scheme.

Secretly, I’m hoping that it might be condensed to a statement something like “parametric relationships brought down to the final model faces, rather than intermediate features”. So you make geometry somehow, anyhow, and then put parametric relationships directly to the faces. You get the benefits of paremetrics without the overhead of history. This is something I wondered about in an earlier post. I’ve been writing a lot about the direct editing conundrum for about a year, mainly due to the appearance of Spaceclaim on the scene.

The alternative to a simple statement of the software seems to be something that is too complex to trust or use. Siemens is using the term “feature recognition”. Feature recognition is something I’m familiar with from two sources – FeatureWorks, which is one of those 40% solutions, and FeatureCAM, which also recognizes features for machining. In both cases, a lot of manual intervention is required to do real work, and in both cases, it works best on very simple geometry.

Another warning flag on the Synchronous stuff is that when I have mixed modes in SolidWorks (history based parts with direct editing features), you get a lot of confusion about how to change things at the end of the tree. Geometry gets “double jeopardy” because you could change it using either history based or direct editing features. Especially if multiple people do the work, this will add to the confusion. The mixed modeling that Synchronous Technology represents is an ugly frankenCAD, in my opinion. Cool idea, yes, but I think in practice this is going to be a bad idea. People will prefer a clean break.

In all of the times I have heard top SolidWorks users talk about the direct editing tools in SolidWorks, they have done it from the point of view that these tools are cool, and can make some tasks easier or simply possible, but they are also a best practice nightmare in terms of maintaining editability, and that its a sloppy way to work.

To me this suggests that if you’re going to move from history to non-history, it is best done either sparingly within a single CAD file or by moving from one CAD file to another, even moving to a different application. Once you start doing direct modeling on a part, switching back and forth causes a lot of confusion.

History based modeling is not going to disappear, let’s be clear about that. There are too many proven benefits. I’m sorry if sometimes history based modeling is intellectually difficult. I’m sorry about that. How else are you going to get the history based benefits of things like the shell feature, or fillets? History is not history.

What’s happening here is that the CAD industry is again appealing to the CAD bottom feeders, a trend that seems to be gaining momentum in an effort to expand the CAD market into new areas it hasn’t previously occupied. People who can’t hang with the intellectual/training demands of history based modeling are going to go for direct modeling. But I don’t think it’s a given that they are going to flock to the unnatural FrankenCAD combination of history and non-history modeling.

It boils down to this: Machinists and people doing simple concepting work will use direct editing because its a no-brainer (think Sketchup) and less expensive. Engineers responsible for production models will still use history based modeling because it represents more complete control. To the extent that you have both types of people in the same organization, it may make sense for that organization to get one tool that does both, but honestly, direct editing comes at the end and the beginning of the project. At the beginning, their models are used as reference, but the production model is made from scratch. At the end of the project, it doesn’t matter because edits are for mfg, for example adding stock, and won’t be pushed back up to the engineering model.

As an aside, all the references to Synchronous Technology so far have been with respect to solid modeling, not necessarily to surface modeling. Add to that the seeming lack of capabilities around complex shapes, and I for one will not be able to make use of this concept at all. I will be much more likely to be able to use whatever comes of the marriage of Spaceclaim and Rhino.

Spaceclaim + Rhino = solids, surfaces, prismatics and general NURBS, mainly direct editing with some history

Synchronous Technology = solids, prismatics, mainly history with some feature recognition and a lot of unknown details

To me, the Spaceclaim/Rhino FrankenCAD – SpaceRhino – seems like the more attractive combination. A big part of the reason for that is that you can see what that combination is, and what it does. This Siemens thing is still too much of a pig in a poke.

Let’s be clear about this. Direct Model Editing is generally an old concept, CAD-wise, which is being applied in some new ways in the last year or so in the CAD world. To some extent it is a technological development, but it is in my opinion more evolutionary than revolutionary. It’s not a big change, just a step forward. The real development here is a marketing development. CAD companies are getting scrappy trying to out-do one another, but they are fighting over the same jaded customers over whom they have fought for the last 30 years.

The real point of the resurgence of Direct Model Editing is that it removes specialized knowledge from the equation. Now you can have your office manager update the cast transmission housing instead of an engineer or CAD specialist. Imagine the money management can save now! We can get rid of engineers, and just have untrained people make models for us!

I think that’s the level that the CAD vendors are pushing. By making CAD available to current non-CAD users, they are opening up a whole new class of customers. The new Siemens offering as well as Spaceclaim are clearly aimed at this non-CAD user. Even SolidWorks is pushing to increase overall seat sales and revenue so much that they can’t do it selling to the relatively entrenched current CAD user base. In SolidWorks, the Instant 3D gimmick is one step in this direction. The Siemens stuff is a leap-frog/copy cat feature, copying Spaceclaim and Instant3D and out-doing each to some extent. Outdoing Spaceclaim because Solid Edge and UG/NX also have parametrics and Spaceclaim does not, and outdoing SolidWorks because the Siemens direct model editing deals with fillets better and the interface for the direct changes is less cumbersome.

For existing CAD users, this means one of two things:

1) If you make your living editing simple models, one of these tools may be used by you (or someone with less skill than you) to do the same work more easily

2) For people who work in more complex parts or design from the ground up, I think the whole direct modeling concept is going to mean very little until it progresses to the next level with the ability to directly manipulate a full range of general NURBS curvature.

I’ve said this before, but I’ll repeat it here because I think it’s at the heart of the argument. Pushing direct modeling tools too far down the ladder to enable non-engineer/designer workers (such as machinists, graphics artists, marketing people or general office personell) to make engineering/design changes will have a backlash.

I personally don’t think the the direct model editing market is going to be significantly larger than the existing CAD market unless the price is in the sub $2000 range. At that price, it will start to cannibalize the low end of the existing CAD market rather than add to it.

Is the functionality valid? Yes. Is the market approach valid? Maybe. I think this is what everyone is waiting to see right now. Who is going to buy into this? Direct model editing is not going to replace parametrics completely. There are too many real benefits in parametrics for models which change predictably.

They are trying to sell this to non-specialists, but ironically, some things about direct model editing require the user to understand more about the underlying construction of CAD models (b-rep, NURBS, and limitations of representing surfaces) than parametric modeling does.

Design Happens in Your Head

Different kinds of design happen differently. Mechanisms can be difficult. But so can flexible parts, and complex shapes. The ideas for these things have to come from somewhere. Rarely does a design just pop up on the screen without having existed somewhere else previously. I’ve written previously about the differences between engineering, design and modeling. Sometimes we treat all of these as if they are one and the same, but they aren’t.

We’ve already established that “modeling” is what happens on the computer. It takes an idea from another source, a sketch or 2D rendering, a physical model, anywhere, and creates the exact shape and adds all the functional details using computer software. In modeling, you make a digital prototype, or a mathematical model which can be used for analysis, post processing, or manufacturing. Modeling is not design.

Engineering is using calculation to predict how a part will work, and then changing the part to perform in a particular way. The process of engineering always forces you through a design phase. I usually think of it as a cycle of analytical problem solving followed by creative problem solving. So in this way, I believe that engineering is both analytical and creative. It has to be. Still, engineering includes design but it is not synonymous with design.

Design happens in your head. CAD vendors talk like they invented design, they want you to believe that their tool does the design for you to some extent. But none of this is true. Design happens in your head, not on the computer screen. What you are doing on the screen is documenting what’s in your head. I know it seems quaint and old-fashioned to use something so dirty and organic as your own head. I mean, a plastic and microelectronic device is so much more sterile than to even metaphorically get your hands dirty by using your head. Still, Design happens in your Head.

Change Happens in Your Head

Once you have conceived of how to do something in your head, only then can you get it down on paper, or into the computer. Let’s think about sketching on paper for a second. Sketching a mechanism or shape or series of shapes on paper is just an imperfect translation from the chimerical mental image in your head which is so easy to change, just by thinking it. The scrawled image on paper is less easy to change – either scrawl new darker lines or erase them and make new ones. Still, the change is relatively easy.

Now think about making that kind of change that you just made on paper in SolidWorks. Yeah, sure, it works like the demos if you design things that you can practice like the demo jocks practice. But things in the real world aren’t like that, even in machine design applications. Parametric modeling is tough, it really is. We talk a lot about “design intent”, which I prefer to call “design for change”. Not even talking about making specific changes to a particular model, but just talking changes in general, “design for change” means that right up front you have to determine how the model will react to change. For example, design for change means saying something like “This row of holes always remains in line and is referenced from that edge.” Later if you want to pull a hole out of the row, not only do you have to make a change to the model, but you also have to make a change to the “Design for Change” scheme.

Some of the parts I have been working on lately are shaped in such a way that identifying individual features is not always easy. This makes “design for change” almost impossible. Combine that kind of challenge with short comings of the software such as losing references or worse yet confusing references when even the simplest change is made, along with all the other unpredictabilities that you run into on the fringes, and you can be cursing parametrics with little provocation. So, making changes is maybe not so easy as it is in the practiced scripted demos.

Documentation Happens on the Screen

So. Design happens in your head. Documentation and the excruciating technical detail of modeling happens on the screen. It sounds so mundane, but whether we make 2D prints or finish at the assembly level, SolidWorks work is all about documenting the design that’s in your head, and then getting it to change predictably.

That said, what would you do to make the computer a better design tool – meaning that you can get the idea out of your head and into a form that other folks can see quickly? Would you draw with a stylus on the screen? Maybe draw with your fingers? Using a 3D stylus with tactile feedback? Do it like Tom Cruise in Minority Report? Is parametric design really all it’s cracked up to be?