The Analysis Tools Sanity Check

July 31st, 2015

Let’s call it a ‘sanity check’.  Sometimes you need to prove to yourself, or possibly your boss, that your analysis tools are calculating results correctly.  Maybe you’re reviewing the results and something doesn’t look quite right.  There are plenty of scenarios where you may be called upon to use hand calculations to back up what your workstation and software can do for you in seconds, minutes or hours.  With our designs becoming increasingly more complex, this can definitely seem like an impossible task.  Fear not!  With Engineering knowledge, understanding how your analysis tools operate, plus a bit of diligence you can do just that.

Here is an example of using hand calculations to verify results from a SOLIDWORKS Motion analysis of a three component linkage.  I’ve simplified the analysis to consider the starting, static position because, well, you have to start somewhere!  The plot for calculated motor torque appears to be incorrect.  The Motion analysis result for motor torque at the starting position is 24 lbf-ft while the expected result should be approximately 10 lbf-ft.

When beginning your hand calculations, be sure to note any assumptions that you need make.  In this example, I am neglecting the mass of the components at the starting position, friction at the mate locations and gravity.

Analysis Tools 2015-0630a Hand Calculations


Now that I have the calculations in as simplified a format as possible (equation D), I can set up an Excel spreadsheet to calculate what Motion should have generated as a result.

Analysis Tools 2015-0630b Excel Calculations

My next steps are to investigate the original Motion study and SOLIDWORKS assembly to determine why the software didn’t calculate motor torque to be 10.8 lbf-ft.  In this example, it has to do with the mate scheme used for building the mechanism.  SOLIDWORKS Motion used the mates directly from the assembly, so how the mechanism was constructed is extremely important.  In the original design, my mate scheme had four redundancies, as indicated on the Mates folder inside the Motion study.  In SOLIDWORKS Motion, a redundant mate occurs when more than one mate constrains a specific degree of freedom for an assembly component.  The redundant mates have to be excluded from the Motion analysis before the mechanism calculation begins.  This is what caused the motor torque output to be incorrect.

Analysis Tools 2015-0630c Motion Incorrect

Now that I have determined it was my faulty mate scheme that led to the incorrect calculation, I can modify my assembly mates to work towards a mechanism with zero redundancies.  A mechanism with zero redundant mates will allow SOLIDWORKS Motion to correctly calculate forces acting on the mechanism.

The changes I made to the assembly were adding hinge components to the assembly, fixed the hinge components in space to provide an established path to ground and changed the mate scheme for the linkages.  The linkages were originally positioned with mates attached to an assembly sketch.  By adding the pins I can replace multiple mates connecting the linkages to sketch entities with a few hinge mates.  Reducing the number of mates in the assembly helps to remove redundancy from the mechanism.

Analysis Tools 2015-0630d Motion Correct

Now that my Motion study is calculating the correct motor torque at a known position, I can increase the complexity of the analysis and have a high level of confidence regarding the results.  My next steps would be to include the mass of the components by unsuppressing gravity from the Motion study.  I would then change the motor definition to move the mechanism through the appropriate range of motion.  Eventually, I would include the effects of friction on the mates.  But I could not take any of these additional steps without first verifying that I was obtaining the correct output utilizing hand calculations.  So the next time you’re not sure if your analysis tool is giving you the correct result, do the smart thing – trust but verify!

Now go make your products better with SOLIDWORKS Simulation. Use the comments section below to share any success stories. I would love to hear how you are using it in your designs!

Bill Reuss

Elite Application Engineer CAE Technical Specialist 3DVision Technologies

Quick Tip: Linear Pattern-Up to Reference

July 29th, 2015

In SOLIDWORKS 2015, Up to reference was added as an option in Linear Patterns.  Typically you set the distance between the instances and the number of instances.  Now you can specify the distance up to some piece of geometry allowing the software to figure out either the distance or instance count.

Up to reference

You still choose an edge for the pattern direction.  You now choose Up to reference and something to reference to.  You are building a much more intelligent model while capturing the design intent.

You can also tell it how far you want the last instance to be offset from the end.  When you do this, you need to tell SOLIDWORKS where to measure from.  The Centroid calculates from the center of the patterned feature.  The Selected reference allows you to choose where it is measured from.

End and offset

Now you can either choose the Spacing or Number of instances for the pattern to follow.  These are just simple toggle buttons.

Spacing or Number

If you go with Spacing then it will determine the number of instances that are needed.  Click on the image below to see the option.

Pattern Spacing


If you tell it the number of instances then it will calculate the spacing needed.  Click on the image below to see the option.

Pattern Instance

It’s a really powerful option.  To do this before, you needed to use equations and variables.  Now it can all be done as an option.  This makes it so much easier and faster for the user to get your design done.  It should also be faster for the software to solve since it doesn’t need to calculate as much information as it would with equations.

Do you remember this from the 2015 What’s New manual?  Have you used it on any designs yet?  Let me know in the comments if this is something you can use.

Josh Spencer

Elite Application Engineer, CSWE 3DVision Technologies

3D Printing – Improving Precision, Productivity and Patient Satisfaction

July 24th, 2015

I once had a co-worker  that told me being an engineer is a life-time of learning.  I have often kept this at the back of my mind throughout my career and it has become very important in my role here at 3DVision Technologies.  I may not know the answer to the problem, but I know where to look and who to ask when I need to.  My role is to try to help potential customers integrate our technology, Additive Manufacturing specifically, into their current manufacturing processes.  I see and hear about so many different applications and processes, it can sometimes be overwhelming.

From MRI data to 3D Printing

Last year I met Dr. Katz at one of our 3D Printing Open Houses hosted at our Cincinnati Headquarters.  He was not an engineer, nor a designer, but wanted to use 3D Printing in his business to help his customers.  Dr. Katz is in the medical field, specifically working with people born with a specific defect in their jaw bone (mandible) which causes the patient severe pain.  They call this specialty Cranio-Maxillofacial (or CMF) Anaplastology (this is where that life of learning comes into play, including new words!).  What Dr. Katz provided me was raw MRI data of a patients mandible.  If we could help him print this bone, this in turn would help him build a prosthetic to alleviate a life of pain for this customer.  GAME ON!

The Results

I have no medical training (aside from First Aide from several years on an emergency response team), so after a bit of research I turned to our friends at Materialise to see if they could help.  Their Mimics Innovation Suite not only helped them with the Prosthetic design, but it also handles the raw MRI/CT Scan data for creating the STL file (a really great looking STL file!) The white skull was printed from Polycarbonate on our Fortus 450mc. In this case, this material was acceptable as we were only using it as a tool.

3D Printing  Skull 2 3D Printing  Skull

We could have also used an ISO certified (ISO 10993) Polycarbonate which is one of only (2) bio-compatible materials currently available in FDM.  This would allow short term contact with skin, but was not a long term option (yet).  The “frosted” skull was from VeroClear printed on our Objet 260 Connex 3.  VeroClear is very similar in appearance to the Biocompatible material, MED610.

3D Printing Clear Skull 3D Printing Clear Skull 2

If you have any questions let me know in the comments section below!

Jeremy Marvin

Application Engineer - 3D Printing 3DVision Technologies

Multi-language in Enterprise PDM Data Cards

July 22nd, 2015

In a recent post I gave you some ideas on supporting multiple languages in Enterprise PDM. There are two ways you can “filter” your data cards so users only see the language they speak.

You can make different data cards per language and save them in different locations within your vault. (i.e. save the English card in a root folder that only English users will work in, save the French card in a root folder where only French users will work…) This works well as long as your folder structure is setup on a per language basis.

If users of any language may be working in any location in the vault, and you do not want to confuse your users by seeing a foreign language…

You can create an Enterprise PDM group per language you support. Add your users into the groups accordingly.

Enterprise PDM Languages

Then create a tab control on your data card. Each tab corresponding to each language. English text on the English tab, French text on the French tab, etc. (Don’t forget you can copy/paste controls and their format from one tab to another – this can be a big time saver.)

Enterprise PDM NameofGroup

Instead of showing all three tabs, have the tabs controlled by the variable: “<Name of group>”

Now, depending on which group the user is in, he will only see the controls in the tab of his own language.

1. If a user is a member of more than one language, Enterprise PDM will only display the first tab it the list (so there is no reason to add people to more than one language group.)

2. Being a member of more than one group type does not affect the tab displayed. i.e. if he is in the “German” group and also is a member of the “Design” group, the “Design” group membership is not used to determine the displayed tab -he would see the “German” tab.


Did this help? Need more questions answered about Enterprise PDM? Let me know in the comments section below!

Jeff Sweeney

CSWE Engineering Data Specialist 3DVision Technologies

Nominal Wall Thickness Inside Plastics Simulation

July 16th, 2015

Wall Thickness – a major concern when designing a plastic part.

During the injection of the mold the melted plastic flow front will always move in the direction of least resistance. You can think of this similar to water flowing through a pipe.  The larger the pipe the easier the volume of water will flow.  If the wall is too thick in comparison to other sections of the part the plastic flow will “Race Track” or move ahead of the rest of the flow front.  This causes issues such as air traps, weld/knit lines, and possible cosmetic problems.  If the walls are too thin this can cause issues such as “Short Shot”. Short shots occur when the flow front becomes to hard to push by the machine (typically reaching the maximum injection pressure), or the flow front cools too fast due to the lack of volume.  Short shots do not fully fill the cavity and create an incomplete plastic part.  Ideally a part will have a uniform wall thickness.  In real life this is hard to accomplish but being able to predict areas that may be a problem before running an injection analysis helps an engineer find a good balance.

SolidWorks has always had the ability to check the thickness of a part through the evaluate tab of the command manager.  The command is “Thickness Analysis” and it has been the go to command to determine different thickness within a part.

Thickness Analysis

Nominal Wall Thickness Command

Now SolidWorks offers a “Nominal Wall Thickness” tool under the Advisor category of the Plastics Tree.  The “Nominal Wall Thickness” command allows a user to compare thickness in the model based on a value or percentage.  This addition gives the user a quick thickness analysis right inside the Plastics Interface.

Nominal Wall Thickness


Property Manager

The results are a quick and easy to understand plot that facilitates the reduction in sink, short shot, and warping.



Nominal Wall



Have you used this command before? want to learn about a different command in SOLIDWORKS? Let me know in the comment section below!

Robert Warren

Elite Application Engineer CAE Technical Specialist 3DVision Technologies

What is the Vary Sketch Option in a Pattern?

July 8th, 2015

I have an option that you might have overlooked or just didn’t know what it does.  It’s the Vary Sketch option.

Vary Sketch

The definition from the Help File says, “Select the Vary Sketch option to let the pattern instances change dimensions as they repeat.”  Let’s take a look at what you have to do and how it might help you.

So what I’m going to do is create a triangular part first.

Base Image

Now we need to have a feature added to it.  It can either be a Boss or Cut.  As we pattern the feature, we want it to follow the top angled edge.  The sketch that is used for the feature is important.  First off you want it be fully defined.  This is important so we know which dimension changes.  Next we want the top of our feature sketch to be dimensioned to the angled edge.  This will allow the feature to follow this angle.  If you would add a height dimension, your pattern would not work.

Feature Sketch

Here comes the unique part.  Start the linear pattern tool.  Choose the feature you want to pattern and set the spacing & instance count.  For the direction, choose the sketch dimension that is in the direction you want to pattern too.  You can always choose a sketch dimension to use it as the direction.  Fun trick isn’t it?

Sketch Dimension Direction

You should have the ability to choose Vary Sketch under the Pattern Options.  If you don’t then it would be a normal pattern that you would expect.

Without Vary

But if you would select Vary Sketch in the options, look at what happens.  It changes the overall height to maintain all the dimension in all the instances.

With Vary

You might wonder when this option was added to SOLIDWORKS.  I think it was added in the 1997 Plus release.

Hopefully this will help you get your desired model created.  Have you ever used this option? Have questions about another feature in SOLIDWORKS?  Let me know in the comments below.

Josh Spencer

Elite Application Engineer, CSWE 3DVision Technologies

Happy Independence Day From 3DVision Technologies

July 4th, 2015

Independence day

We hope everyone enjoys their 4th of July weekend with good weather, cookouts and spending time with family and friends. In the spirit of this holiday we wanted to share a brief history of the holiday and ponder what the founding fathers would think about how far our 3D Printing Technology has come.

The fourth of July also known as Independence day has been a federal holiday since 1941. However this celebrations history goes back to 1776 when the 13 original colonies found themselves fighting for their independence from Great Britain. Although the Declaration of Independence was voted on and passed  July 2nd the  Continental Congress  formally adopted the Declaration of Independence two days later on July 4th. 56 delegates signed the Declaration including two future presidents. Benjamin Franklin at 70 years old was the oldest member to sign the Deceleration. Franklin is one of the most famous inventors in history, if only he and the other delegates could see us now…

History of 3D Printing 

Over 200 years after the signing of the Deceleration of Independence the first 3D printers can be traced back to 1986.  Just 3 years after the first patent was filed Stratasys was Incorporated in 1989. After patenting Fused Deposition Modeling (FDM) technology and releasing the Dimension line of 3D printers Stratasys became the market leader in 2004.  Today Stratasys sells over 30 different types of 3D printers and its portfolio of  3D printing materials is the most comprehensive in the industry.

3DVision Technologies 3D Printing History

3DVision Technologies became a value added reseller for Stratasys starting in 2004. The 3D printing team consisted of 3 people that were licensed to sell only Dimension 3D printers. After 11 years of selling Stratasys 3D printers in Ohio, Indiana, and Kentucky 3DVision Technologies now has 11 employees on the 3D printing team servicing over 260 machines. 

3D Printed Lithophane

3DVision Technologies  would like to wish you a happy 4th of July. In the spirit of America’s birthday  we created a patriotic 3D printed lithophane on the Fortus 250 that we think Benjamin Franklin and the other founding fathers would enjoy. A lithophane is a piece of artwork that is very thin and translucent that can only be seen clearly when back lit with a light source.

Flat View

Independence day

Front View No Light

Independence day

Front View With Light

Independence day

Tell us what you think about our Lithophane in the comments section below!

Cody Markham

Assistant Marketing Manager 3DVision Technologies

Natural Frequency Analysis

July 2nd, 2015

Natural Frequency analysis in SOLIDWORKS Simulation allows us to efficiently investigate the resonant frequencies of a design.  This analysis type helps us ensure that the natural modes of vibration are well away from environmental forcing frequencies that a design might encounter during service.  Like all analysis work, effective post-processing of your Natural Frequency analysis is key to communicating results to others.  The standard output of a Natural Frequency analysis are the resonant frequencies and associated mode shapes of the design, which we can easily plot in SOLIDWORKS Simulation.

Natural Frequency analysis

In SOLIDWORKS Simulation 2015, there were three additional frequency plot options added that are beneficial to conveying your Natural Frequency analysis results.  Those plots, or Frequency Response Graphs, are Mode Number, Effective Mass Participation Factor (EMPF) and Cumulative Effective Mass Participation Factor (CEMPF).  You can create these plots by right-clicking on your Simulation Results folder and choosing the option “Define Frequency Response Graph…”.

Natural Frequency analysis

The Mode Number plot shows a graphical representation of the natural frequencies calculated by the analysis.  This is a step up, in my opinion, from the simple list that is provided by right-clicking on the Simulation Results folder and choosing the option “List Resonant Frequencies”.

Natural Frequency analysis

The second frequency response graph, Effective Mass Participation Factor (EMPF), helps us visualize how the mass is vibrating in X, Y and Z, for each natural frequency.

Natural Frequency analysis

The third frequency response graph, Cumulative Effective Mass Participation Factor (CEMPF), helps us visualize the accumulation of mass participating in vibration as we calculate an increasing number of natural frequencies of our designs.

Natural Frequency analysis

The EMPF and CEMPF plots are especially important when we are calculating Natural Frequencies of a design that will be subject to time dependent loads during normal product use.  I plan on using these plots as I begin working on dynamic studies when investigating product performance subjected to random vibration or harmonic loading conditions.

Be sure to check out the three new Frequency Response Graphs in SOLIDWORKS Simulation 2015 to see how they can improve your Frequency Analysis post-processing.  Now go make your products better with SOLIDWORKS Simulation!

Bill Reuss

Elite Application Engineer CAE Technical Specialist 3DVision Technologies

Do you need a DriveWorks form for mobile?

June 24th, 2015

I don’t have to tell you that more and more of the cool kids are using mobile devices. Mobile web page design is becoming more important -especially now that Google’s search engine favors sites that are “mobile friendly“.

It isn’t hard to design your DriveWorks forms to adapt to the user’s viewing size, but is it worth the effort? Does it matter to you?

It is really pretty easy to find out. DriveWorks 12 has a special variable – Form Container Width (DWFormContainerWidth) that reports the width of the user’s screen while they are browsing your products with DriveWorks Live. When the specifier starts as specification, DWFormContainerWidth automatically updates with a numeric value representing the width. (In fact in test mode you can change the width and watch the value update.) For simple tweaks, you can use this value when defining the widths (and heights) of your pictures, positions of your buttons. If you wanted to give your mobile users a completely different experience, you can even change which form is displayed with logic in your form navigation.

DriveWorks MobileLogic

(This image would have the form navigation go down the green line if the width is more than 450, otherwise the navigation would go down the red.)

It is pretty easy and powerful. Our good friends at Javelin have a very nice blog entry and video that I recommend that you check out! They show you how you can quickly change the size of your images and move your buttons based on the new DWFormContainerWidth variable.

Since you are likely tracking who has been on your DriveWorks Live site anyway, go ahead and add a field to your database output to record the screen width of all users that have been on your site.

DriveWorks Live ScreenWidth

Start recording this information for a few days and look through the data to see what you have collected.

Now you’ll at least know what your current users are using, but don’t forget if your forms did support mobile better, perhaps your web site traffic would increase?

Let me know your results in the comment section below!

Jeff Sweeney

CSWE Engineering Data Specialist 3DVision Technologies

ABS Snap Fit Non-Linear Static Study

June 22nd, 2015

I recently acquired a dehumidifying rod from a family member and it was missing the mounting components.  After looking everywhere in my family members basement we could not locate the missing items.  So what is some one who has access to SOLIDWORKS and a 3D Printer to do?  That’s right lets make our own.

A dehumidifying rod is an electric heater that facilitates natural convection in enclosed areas like safes, vehicles, small rooms etc.  The first place to start is thermal side of things and material selection.  The Uprint Plus uses an ABS like material for the printer with a melting temperature of 600 degrees F.  The rod runs at a constant 100 degrees F with a maximum of 125 degrees F.  The wide temperature factor of safety lead me to proceed with a 3D printed design.

The dehumidifying rod mounts had two requirements.  One that they could be screwed down to secure the rod, and that the rod can be easily removed for maintenance if needed.  This lead to a snap fit design.  The original design was stout and bulky and left me wondering if it was overkill.  This is where SOLIDWORKS Simulation is introduced into the design phase.  I wanted to verify that the rod could be removed and “snapped” back into place easily. Because the material is an ABS and the snap fit is a sliding contact this requires a Non-Linear analysis.


The Simulation  setup was straight forward.  The rod will remain stationary and the the Clip will be moved a prescribed displacement until it “snaps” onto the rod.  To simplify the model and speed up the run time the analysis will be completed using symmetry.  A no penetration contact was specified on the contacting faces of the rod and the clip.  A mesh control was specified in these contact areas as well.

Steel was the material choice for the rod and an modified default ABS was used for the clip.  The ABS was copied to a custom material folder and changed to be a Plasticity- von Mises material model.  The true Stress-Strain curve of the ABS material was unknown so a representation of the curve known as a Bilinear stress-strain curve was used.  This curve uses the Tangent modulus roughly 1/10th of the Elastic modulus, as the second portion of the curve beyond yield.

Material Properties ABS




The results from the first design did indeed show that it was too stout and required a large force to push the clip onto the rod.  The contact plot clearly shows a force requirement of 45 lbs. to spread the clip at the widest point.  This force value lead to a redesign of the clips upper arm.

Design 1 Stress

Contact 1


Design Two narrowed the upper arm and reduced the force required by 30 lbs.  The force however was still too high and required another design change.

Design 2 Stress

Contact 2


The Third and final design change reduced the arm thickness as well as changed the lower fillet size.  The changes reduced the force required to “snap” the rod in place to a reasonable 3.5 lbs.

Design 3 Stress

Contact 3


SOLIDWORKS Simulation Premium Non-Lienar analysis allowed me to design a mounting clip that holds the dehumidifying rod firm and in place without over design.  Quickly and easily I was able to walk through multiple design iterations and Simulations verifying a reasonable “snap” force.  I am happy to report the dehumidifying rod is in place and has been working for a couple of weeks without issue. Have you used a Non-Linear analysis before or have questions? Let me know in the comment section below!

Robert Warren

Elite Application Engineer CAE Technical Specialist 3DVision Technologies

Get every new post delivered to your inbox
Join other followers
Powered By