Manage Your Data Already!!! the second installment

Previously I discussed there were 2 common data management myths.  The first was Windows Explorer is a data management system.

Before I start my second rant let’s come to an agreement that Part Number = File Name.  Pure and simple.  No more “Bracket” file names.  Descriptions for file names is absolutely absurd.  How many Brackets does your company make?

The second, and I know some of you out there are going to kick and scream and even possibly wait for me after my presentation at SolidWorks World to beat me down, is that Smart Part Numbers are indeed smart.  Are you kidding me??????

2 Scenarios

Scenario 1:  One of my green horn students starts at a company:  This is followed by the severely under-defined orientation about the company, maybe even an even further degraded CAD standards orientation.  This is if they are lucky.  Now they are ready to begin modifying documents for you or even begin a new design for you.  But wait, first they must read a 4000 page document on how to create part numbers.  If this part is aluminum it starts with an “A” unless the forecast is partly cloudy, then it is “Alum”, so on and so forth.  So not only does my scared little green horn have to overcome the company culture but now learn basically a new language for part numbers.

Scenario 2:  One of my green horn students starts at a company:  This is followed by the severely under-defined orientation about the company, maybe even an even further degraded CAD standards orientation.  This is if they are lucky.  Now they are ready to begin modifying documents for you or even begin a new design for you.  You instruct them to hit a certain button (usually the Save or Ctrl+S) and viola a part number is magically created for them and a window pops up that tells them exactly what information about the file is required; i.e. Description, Material, Hardness Spec, Material Treatment like paint or anodize (otherwise known as finish), project, etc…

In the first scenario most companies will give a new employee about 60 days to comply with company policies.  But they will need to anticipate part number screw ups for the next 40 years.

In the second scenario if the employee manages through the 60  – 90 day evaluation period there should be no problem with part number issues.

Let us discuss the idea of the “Smart Part Number”.  As I said in my previous rant, every single designer and now I will add, the rest of the organization, has the best way to name files, organize files and for some reason they believe everyone else understands what is happening in their polka dotted world they call a brain.  Smart Numbers were probably developed by marketing geniuses.  they call it the “Model Mask”.   Here is the problem I see.  Model Masks will inevitably be require to evolve if a company is truly out to make money.  Companies looking to make money will continually strive to define the next innovative product, and if we work on the concept that innovation is the implementation on a new product that enters the market adding new market value then we need to agree that more than likely that parameter has not been defined so we run into 2 situations, innovation is halt because it does not fit the model mask or it is slowed until a new model mask is generated, tested and implemented.

I am throwing out some serious terminology here like Implementation (which assumes that companies are continually refreshing employees on the standards and are continually assessing their performance with measurable matrices), innovation (defined above, but many companies are willing to run the old if it ain’t broke do not fix).

Falling back to the first installment where I discussed increasing productivity to make more money, look at the 2 scenarios discussed earlier and you tell me which one can offer instant productivity out of a green horn, learning/memorizing a 4000 page How to Create a Part Number  book or just hit save, the system will tell you what other info is required.

Now how does this tie into PDM systems you ask?  Well thank you for asking, I have implemented and maintained about 10 PDM systems for companies and part of my implementation is setting up the system with part number schemes that when you do a Save or Ctrl+S the data management system takes control an doles out the next available serial number.  Notice I said serial number.  000000001 -9999999999 are very useful part numbers.  With data management one does not have to worry about descriptive part numbers, there are other more powerful ways of finding the file you need without some complicated matrix to sort through.

The power of data management systems are that they inject steroids into your custom properties.  Most of these systems resemble the Dewy Decimal System at your local library.  As I said before in Scenario 2, during the save a part number is established then a pop up box indicates additional information that your company requires when creating a part number.  Custom Properties are the meta data that is included in the file.  It is the same exact concept behind Windows Media Player or I-tunes, when you load a CD or download a song the extra data that shows up in the player is the meta data, Song Name, Artist, Genre, etc…  Notice that this is search-able in those tools.  PDM should be viewed sort of like these tools.  The difference is now you will have the ability to log revisions, describe the changes, and have a viewable history without the need for a designer to rename, pack and go and all the other workarounds we modelers have come up with.

Now instead of a model mask matrix you can use search tools similar to Google searching Advanced Search Features.  The model mask may be a good tool to develop required fields needed before a save can be completed.  Make sure the fields are descriptions of the information that will be inputted into them.  Then you can create drop down lists, or fields that are linked to outside databases to ensure the information is entered correctly.

Anyhow, the purpose of this rant was to dethrone the concept of Smart Part Numbers.  Much easier to instruct a person to hit the save button than to try to teach them a numbering scheme that will inevitably change or become way to confusing and cumbersome to use.

There will be more to come.

Manage Your Data Already!!!

Ladies and Gentlemen,

As an instructor at a vocational career college with internships at local design firms, I am constantly amazed at the number of companies using a really good Automated Design package like SolidWorks to make sure their designs work, are manufacturable, and meet the requirements of their customers.  (Meeting the requirements is no longer a viable business plan in this global economy, but that is a different topic all together.)

What scares me is that there are still companies out there who believe in 2 data management myths.  I will discuss the first one in this post and the second in a soon to follow rant.

The first data management myth: “Windows Explorer is a data management tool.”

Windows Explorer is a rudimentary viewer into a windows file/folder directories.  That is it. 

People, the models & drawings created in any CAD package at a manufacturing or design firm are the digital records & digital currency that make that company money.  Without those documents, how will you manufacture your product that sales and marketing have oversold in too little time?  Hmmmm? 

3D, History Based, Parametric modelers by nature have a complex set of file relations that no one should every have to figure out. 

If you improperly move this file to another directory or Lords of CAD  forbid “Rename the file to show the next revision in the part number, the drawing looses connectivity, content and functionality, the assembly opens with errors you have never even heard of.  The Yellow and red thing in the feature manager tree are really SolidWorks yelling at you telling you that you royally screwed up! 

Then there is the project of updated drawings to new revisions (you know, the I did not thoroughly review my design so now I have to modify the original design so it can actually work.)  What do you do now?  Make changes to the original document so you have no idea what the previous revision looked like?  Copy the document set and make the changes there renaming those files with the new revision in the file name(just the thought of renaming strikes the fear nerve in me).  Are you sure that you have triple checked all of the other files that your changed document effects?  This process using Windows Explorer is achievable at a costly price.  You design time.  I thought we were moving into an era of design productivity.  This arduous task seems to be light years from being productive.

 As soon as your company adopts a CAD package like SolidWorks it is time to implement Product/Project Data Management.  I know, there are some folk out there who are saying things like: “We only have one designer so we do not need it”  or “We have a procedure that ensures that file names are correct, blah blah, blah…”. 

For the first comment I ask, “Do you want to end up like the Big 3 always asking for bailouts for the people who by your vehicles”.  To be successful you need to be in business to make a profit now and into the future.  Get these systems up and running immediately so that if (when) your business does grow you do not need to scramble to figure something out now.  Every designer has the Greatest directory structure and file naming scheme that everyone will understand.  And monkeys fly out of my butt every day.  By the way, I have beautiful ocean front property to sell you in the Everglades.  What happens when that designer quits? 

Many PDM systems are very scalable to accommodate 1 – 100’s of users.  These data management systems also allow you to either use an existing directory structure or define an even easier one that will take no time for newbies to learn.  Earlier, Matt Lorono wrote a fantastic post about CAD standards, PDM can compliment your CAD standards with naming standards, filing standards, change standards, the list is endless.  It will really complete a Great CAD standard.  PDM can usually hook into ERP/MRP systems to reduce the number of times a cad jockey has to enter the same information over and over again.  Make drawing searches available to everyone company wide.  No CAD needed.

The comment about procedures… When is the last time you read your company procedures?  A procedure about file naming, directory structure, etc… is about 5 years wasted productivity because as we all know it is so incredibly productive to read those things.  We also know that every individual has different ways of bending the procedure to make it work for them.  Think about it, there are easily 50 ways to model the part you are in the process of modeling.  You are telling me you are going to restrict that to 1 way.  What happens when your 1 way inhibits productivity?  In the CAD system you set up templates that everyone starts from.  You require certain things to be done in the model like no under defined sketches, you can use the Design Checker to check these requirements.  With a proper PDM implementation you can set templates that replace the custom properties of a model, then transfer them to a drawing so you only have to enter title block info once.  You can set up a behind the scene directory structure that none of your people have to be aware of because once the info is in the PDM system, all of that info can be used to search for things using a Google style search.  Setup a fill naming structure that will automatically manage file names for your designers.  One less thing for them to worry about screwing up.

Get one of these systems in place now.  Most of them cost less then a one year subscription for your 1495 seat of SolidWorks.  Complete your CAD standards and become more productive now.  Remember, Windows Explorer is not Data management.  Is is a portal into the directory structure of your computer which often leads to chaos.

Back in my day

The longest day of my life is when I was like 18 or so.  It was the day I had my wisdom teeth removed.  I did all of them at once.  This is the one day of my life I was forced to do nothing but lay back and watch TV in dull but powerful pain.   This was still in the early days of the Information Age, before serious portable games, smartphones and the Internet.  I’ve had no days longer since that day.  I’ve had many days that have left me wondering where the day has gone.

It’s weird now to discuss a time before the Internet.  Sure, it kinda existed before 1994, but not in any way that is meaningful to us today.  What makes this kinda ironic is that my generation is one of those generations that is going to be able to talk about how things used to be.  Not in some silly way like “candy used to cost 5 cents”, but in a real paradigm shift sort, like those old-timers that used to talk about the horse and buggy in times before cars.   From those old-timers we get the stereotypical story of having to “walk 10 miles in the snow to school up hill both ways.”  What will my tale be for my grandkids?   I imagine it would be something like like “Back in my day, we didn’t have the Internet.  I used to have to drive in a car in bump to bump traffic to get to a building called a library in order to use my library card just to read something.”

BTW, an article or two about SolidWorks Technical Summit – LA will be forthcoming in the next day or two.

Threading Options (Methods to make threads in SolidWorks)

Reposted with permission of Dan J. Riffell

This topic comes up over and over again, so I thought that I’d put together some of the more popular ways to create a thread in a part environment along with some statistics and reasoning as to why one method would be preferred over another. It should be noted that this may not be a complete list of threading methods, since in this case there is more than one way to thread a cat.

Before you decide to cut threads into your part, a design decision must be made which determines the relative value of modeling the threads. Thread features are often very resource intensive at the part level, and that issue only magnifies when multiple parts are inserted into an assembly. The best policy, depending upon design intent, is to avoid modeling threads in SolidWorks if at all possible. Having said that, below is a list of six ways to model threads (same process for both internal and external threads) in order of increasing complexity of operations:

I. No threads. This is the baseline from which the other numbers have been extracted. Imagine a simple socket-head cap screw shape without threads. # of features = 4. Rebuild time = 0.00-0.02 sec.

II. Cosmetic Threads. Go to Insert/Annotations/ Cosmetic Threads. This paints a visual representation of threads onto your feature. It also imports a thread callout into your drawing. This method does not add any features to your model, and it does not increase rebuild time. It is somewhat parametric as it will partially update with design changes. The disadvantages are that it doesn’t look very realistic, behaves quirky sometimes, and doesn’t show up in model rendering. # of features = 4. Rebuild time = 0.00-0.02 sec.

III. Simple Swept Profile. Draw a line following the temporary axis of your feature. Draw your thread profile. Do a Swept Cut, and choose Twist Along Path. Input the number of turns required. This is a very quick and easy way to cut threads into your feature. It is partially dynamic depending upon your sketch relations. # of features = 7. Rebuild time = 0.06-0.09 sec.

IV. Circular Threads. Draw your thread profile. Do a Revolved Cut around your temporary axis. Do a linear pattern of your cuts. Again, this is a quick and easy way to model threads. The disadvantage is that it is not an actual thread since the cut is revolved and not swept. This method serves to get the point across without being too resource intensive. # of features = 7. Rebuild time = 0.09 sec.

V. Helix Method. Draw a helix that wraps around your feature. Draw your thread profile. Do a Swept Cut of your profile following your helix. This is a very realistic method for creating threads, as you can control the pitch, height, starting angle, etc. of your helix in a simple property manager. The major disadvantage is that helixes are notoriously resource intensive, and it is not dynamic. The amount of resource that swept cuts following a helix command depends upon many factors including the pitch and how/where the cut starts. # of features = 8. As far as rebuild time goes, I got significantly variable results in the range of 0.20 to 45.34 sec depending on how I constructed the cut. With the cut starting 180° from the helix start point, I was able to reproducibly get 0.20 sec rebuilds.

VI. Swept Surface. Draw a line following your temporary axis. Draw a line perpendicular with that line (in a separate sketch) that is collinear with the top or bottom of your feature (or wherever you want your cut to start). Pick Swept Surface and sweep the second line around the first with a Twist Along Path option. Match the parameters to your thread pitch. Convert the edge of this surface into a 3D sketch. This should essentially be the same as a helix. Draw your thread profile. Do a Swept Cut that follows the 3D sketch. Although this method seems like it is overly complicated at first, it has the benefit of being completely parametrically driven depending upon your sketch relations. It will update your cuts to your model changes. The major disadvantage is that it is a resource hog. # of features = 10. Rebuild time = 18.33-19.86 sec.

If threading is something that you have to do very often then I would suggest creating Design Features and reusing them. If you use standard threads you can even create “Taps” and “Dies” that you can position in your parts and use the Combine Feature to remove the material where your threads should go. All of these design methods depend on the environment that you work in and what the intent of the project is.

If this is something that you run into often I would suggest that you submit an enhancement request to SolidWorks and talk to your VAR about the necessity of a thread-creation utility that works similar to the Hole-Wizard. Then wait…patiently…

Hopefully this helps. ————————-
Dan Riffell, CSWP
Projects Coordinator
Eltron Research & Development Originally posted on the SolidWorks Forums in this post thread.

Assembly mates and rebuild times

A recent discussion I had with Chris MacCormack was about how mates within an assembly affect rebuilt times.  He posed a question to me.  Do I fully contrain screws after I insert them?  My answer was basically “yes, as time allows.”  He then stated that he actually promotes the notion of not fully contraining screws.  He went so far as to suggest it would be better to suppress the mates altogether and fixing all components. 

His reason for this policy is that a higher number of mates will slow down rebuild times because SolidWorks has to caculate each mate on every rebuild.  My primary thought is that I prefer my model assemblies to be stable and predictable, which full mate constraint methodology delivers.  Secondarily, on instinct, I was working under the idea that having everything fully constrained helps SolidWorks work out all the details so it doesn’t have to spend so much time figuring everything during a rebuild.  (I was aware that particular kinds of mates do slow down rebuild times.) 

So, I decided to put this to a test.  I created the model assembly shown here.  Though these are not real world parts, they are created and assemblied using real world techniques, with details I would normally use, even to the degree of adding material to each component.

Test subject

I created a series of configurations of this assembly in various states of mating, both with patterned components and with all instances of hardware individually inserted.  I then used handleman’s latest macro, Rebuildtimes.swp (which he recently provided on eng-tipsc.om as a response to a request by another user).  This macro was used several times on each configuration.  Here are the best times for each.

Condition:  First rebuild time (s)
Patterned Fully Constrained:  0.3438
Patterned Partially Constrained:  0.3125
Patterned Not Constrained:  0.2812
Patterned Fixed:  0.2656
All Instances Inserted Fully Constrained:  1.125
All Instances Inserted Partially Constrained:  0.5938
All Instances Inserted Not Constrained:  0.2656
All Instances Inserted Fixed:  0.2656

The test results show a clear pattern.  Chris’ assessment is correct.  With each additional mate, SolidWorks takes more time to rebuilt the assembly.  Even in this small example, there is a significant difference between fully constrained hardware and hardware that was just inserted via smart mates (partially constrained); 1.12 seconds verses .59.  The rebuild time was literally doubled just by adding parallel mates to fully constrain the smart mated hardware.

Even in light of this realization, I do not advocate suppressing all mates and fixing components.  In my experience, this isn’t practical for the real world.  However, this is going to make me reconsider just how I will be handling mating schemes.  There needs to be a balance between the speed of the software and the functionality of the model assembly.  Where is that balancing point?

Foreshortened Linear Dimensions (Clipped Dimensions)

As mentioned in another article in this series, SolidWorks does not support the foreshortening of linear dimensions, except in views where both ends are visible in the view, such as break views.  Also mentioned was that foreshortening of linear dimensions doesn’t make much sense in most circumstances because both ends of dimension must be in view for a drawing’s reader to understand the callout.  As such, they are not supported by the ASME standard.  Even still, there may be some cases where it is necessary or desired to clip a dimension within detail or partial section views.

There is one potential workaround to allow this in SolidWorks, using a series of double arrow symbols created by Jeff Hamilton.  Jeff’s creation requires a modification to your gtol.sym file.  Unfortunately, to implement this change, you’ll either need to be a one man show or a CAD Administrator who has time to update everyone’s computers with the edited gtol.sym file.  This is because any symbols within a drawing reside in the gtol.sym file, and that file is specific to each and every install of SolidWorks.  Another drawback is that the user must visually and manually align the double arrows into the appropriate position.

Selection of double arrows

Barring these drawbacks, this is a pretty good solution for those who really need this function.  The file can be downloaded at this location:  Geometric Tolerancing Symbols Library Foreshorten Arrows Add-on.  Instructions on how to edit the gtol.sym file and use the new symbols are included in the download.  Have fun!