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Simulation Mechanical | Adjust Inventor Parameters

Autodesk Simulation Mechanical 2013 Adjust Inventor ParametersDid you want direct access to the CAD model parameters in a more powerful simulation and analysis software? Autodesk Simulation Mechanical 2013 allows you to change the Autodesk Inventor Parameters and update the CAD model on the fly without having to start Inventor.

Inventor Parameters

This awesome addition can be found on the Ribbon’s Mesh tab, in the Cad Additions panel.

Starting this will invoke a dialog containing all the Inventor parameters and their relation to Inventor’s modeled features.

Autodesk Simulation Mechanical 2013 Adjust Inventor Parameters

The adjustments are developed in real time, from inside Simulation Mechanical/s interface. In the image above I adjusted the thickness parameter slightly to close the gap between contact surfaces. You can easily adjust parameters to add or remove mass in different scenarios.

Autodesk Inventor Parameter Change comparison in Simulation Mechanical 2013

In this example, I reduced the thickness from 0.040” to 0.010”.

TIP: after adjusting a parameter, pick the Update button. This applies the changes and rebuilds the model. If you don’t use the Update button, the changes are simply stored in the dialog, but the model does not change.

Changes and Caution

Autodesk Simulation Mechanical 2013 Editor after change     Autodesk inventor file remains unharmed after Simulation Mechanical adjustment

It clearly appears as though Simulation Mechanical is returning to the original CAD model and making changes there, before reimporting the model. In the image above you may notice all the suppressed features. These were not present in the initial CAD import as they were suppressed in the Inventor Level Of Detail. After making the thickness adjustment, the model is rebuilt and suddenly all the other components were imported.

I thought the inventor file was being manipulated permanently, however this does not appear to be the case. The image to the upper right shows the Inventor file which was opened directly after the Simulation Mechanical parameter adjustment. The Shell thickness remains the same inside Inventor. (I was a bit worried to tell you the truth Smile)

Autodesk Simulation Mechanical model changed in all scenaiosI took a look at my Thermal Analysis scenario, and unfortunately the model rebuild also affected that scenario as well. I was hoping that the parameters and subsequent adjustments could be maintained differently in each scenario, but that does not appear to be the case either. The image to the right shows how the previously solved Transient Thermal analysis is now arranged. Uggghh. I can always suppress them in the FEA Editor and rerun if necessary.

Simulation TV

James Herzing, mastermind at the Autodesk Sim Squad, provided a good video at Simulation TV on using this feature. Here’s the video.

James Herzing discusses using Inventor Parameters within Simulation Mechanical 2013

Closing Thoughts

I like the ability to make the adjustments to Inventor Parameters. However, with the benefit comes a cost: Be very aware of your FEA build and results, and be prepared to rerun your analyses after the change.


Direct Modeling VS. Parametric debate continues

Bill Fane moderated a recent discussion titled “Cad Smackdown – Direct vs. Parametric Modeling”, that, as he put it, was not intended as a debate of one’s benefit over the other, but a realistic discussion of the two paradigms as a whole.  There was very little pitting capabilities of platforms against each other, and did prove to be an overall discussion of the two platforms and industry concerns.  Unfortunately, the conversation was not designed to produce a result, and as such did not, however a few interesting points were brought up, and I’ll comment these and offer some perspective on design and the future.

Those that were on the panel were:

Bill Fane, Cadalyst contributing editor    “We’ve gotten so hung up on the design tools rather than some of the design processes …”

• John Buchowski, vice president, Creo product development, PTC
• Ben Eadie, blogger and SolidWorks instructor,    “we’re trying to focus on whether it’s parametric or non-parametric, why not focus on what tools they need to get the job done?”
• John McCullough, vice president, product management, Kubotek    “the direct modeling approach is really about centering a lot of the technology around the geometry”
• Mike Payne, co-founder of SpaceClaim, SolidWorks and PTC      ”we’ve all got short attention spans, and we need systems that work the way we think …”
• Dan Staples, director of Solid Edge product development, Siemens PLM Software
• Carl White, director, digital design product management, Autodesk Continue Reading

Inventor | Multi-Body Concept Sketching without Constraints

imageHere’s a simple and quick idea to consider next time you are beating out an initial concept. Use the awesome capabilities of Multi-body modeling to create separate components in an assembly, but don’t add Dimensional or Geometric constraints…yet.

Look, let’s say you’re having trouble working some details out in your mind. You want to start adding rough components and then refine them later. Perfect. Not adding dimensions and the like make things so much easier to stretch around in sketch. When you have things a little better sorted out, then go back to the sketch and add those constraints as needed.

Better Parameter Conventions

The other benefit to this is that you don’t have to get yourself fixed into Parameter names that you are unhappy with, because you couldn’t see things evolving yet. I am a huge Parameter junky, and my Skeleton files are filled with Descriptive Parameter expressions. Because of this, I often work my way into a corner with Parameter designations that were poorly conceived. This kind of workflow will give you a bit better understanding of how things will work BEFORE you are in neck deep.

Don’t forget to use the Direct Parameter naming when you do go back and add those Dimensions : “SleeveThick = 0.125 in”. You can even use this once a Parameter has been stored and named with the default “d1” convention. Just double click the Dimension and enter the ‘name = value’ convention and the ‘d name’ will be overridden. Fast and easy cleanup. Multi-Body and Direct Parameter Naming are just two of the reasons why the Autodesk 2011 product line is still my favorite.

Inventor – Top Down Design and Manufacturing Limitations

Back to the Discussion TOC

Autodesk Inventor 2011 is capable of designing anything. There are some limitations to the software, and we use our skills and talents to guide Inventor in order to deliver what we need.

There is one things that Inventor can’t do for us. It can’t make up for limitation in the production facilities. It can however prepare for them.

Limitations of Manufacturers and Methods

All Manufacturing methods carry with them some form of limitation. Most manufacturing companies have state of the art equipment, but many are still biased to one form of production or another. Developing a good working relationship with the production company can give you knowledge of what can or cannot be accomplished to bring your design to life.

Another more obvious concern is material limitations. We always have to keep a material’s capabilities in mind, and that brings us back to the manufacturing process. Some materials just can;t be manipulated by certain methods.

Design with the limitations in mind

Design with the end processes in mine. Whether you are a separate design firm, or tied to a manufacturing facility, keeping the design within the bounds of the manufacturer’s capabilities can keep you away from needless and painful design revisions.

If possible, create the base skeleton file with an understanding of these limitation.  I often try to limit my design to the lowest common denominator of a designated manufacturing practice. I know that my local capabilities are a 3 axis CNC vertical mill. With that in mind, I steer away from tight undercuts.


In the image above I am having to limit a ramp in order to mill a critical track in the component. Stress Analysis will help me determine if this change will actually perform properly. Another option will be to invert the ramp, or buy new tooling. If I do invert it, I’ll need to know what tool geometries will be used to create the slot.

Continue Reading

Inventor – Top Down Design and Passing Parameters

Back to the Series Introduction and TOC

The concept of passing Parameters is one of the (if not the most) useful things that Autodesk  Inventor will do to help you develop your Top-Down design. This involves using Parameters in numerous ‘child’ part and assembly files that have been previously defined in a main ‘parent’ reference file. Even if you only make a box and constrain everything to it, Parameters are still at the heart of the process. The result is that when you change a Parameter in the main file, the entire design recognizes the adjustment.

These recommendations are the focus of this discussion:

  • Convey Design Intent with Shared Parameters
  • Parameter Naming conventions
  • Excel Spreadsheet linking


Convey Design Intent with Shared Parameters

A main skeleton part file should be used to store core parameters that shape the overall design.  This skeleton is then passed on to to the other parts and assemblies in the design through a Derived Component. This process permits the overall Parameters to be passed on to the Derived Component, thus inheriting a portion of the design intent.  Like DNA from parent to child. Continue Reading

Inventor – Direct Parameter Naming Tip

We’ve seen this demonstrated, but I wanted it in my collection, so call it a cover if you like. Autodesk added a new function to Inventor 2011, that permits the use of ‘=’ character to instruct the application to RENAME the parameter AND dimension it according  to the input, all in one fast entry.  This… Continue Reading

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