Improve Performance by Grounding?

[cvbt-thailand]

I read that, if a part in an assembly is not going to move it is better to use grip snap and ground it than to constrain it.  It sounds like the model will be simpler improve performance.  I have some assemblies which have some parts that are constrained but will not be moved.  Is it good practice to ground them and remove the constraints?

[M.Peppel]

Hello Geoffrey,

I doubt that there will be a big difference in performance. But when I look at your hardware information I would suggest to upgrade to 4 GB of RAM and use the 3GB-Switch to improve performance.

Regards

Matthias 

[JDMather]

---

@cvbt-thailand wrote:

I read that, ....

---

Can you post the source of this information?

[blair]

I am quite amazed that you can do anything in Inventor with this hardware. Integrated on-board video card is not the way to go.

[FProcp]

You could have part x constrained to y, y constrained to z and z constrained to something else, etc, etc. Everytime you change anything Inventor has do a scan through all those mathematical relationships (constraints) to check all still ok. Surely if you ground it and delete constraints, it'll be less work for Inventor.

[cvbt-thailand]

Inventor Tutorials: Constrain Cylindrical Components in AutoDesk WikiHelp, the same tutorials that come with IV.

“Tip: Consider using Grip Snaps to position components and then ground them if you work with large assemblies and the components do not need to move.”

It does seem that grounding ipo constraints could make a model more simple and therefore more stable.  Do you think that this is a good practice?  Does anyone use IV this way?

[SBix26 · Accepted solution]

I always do this with imported assemblies, except for parts that need to move. It's much easier than constraining everything together properly.  I think it would have to save processing time, since constraints need to be calculated.  But I normally used constraints while designing, so I know that my designs will work.

[mcgyvr]

I wouldn't do it.

The day after I ground a part is the day that the design will change and require that part to be ungrounded.

Like others have said, you performance sucks because of the computer/hardware/OS you have. Grounding will make no noticable improvement if any. A new computer with a 64 bit OS, good graphics card and more RAM will easily pay for itself.

[karl]

in short, yes grounding will speed up your performance. As someone else has said, IV would not have to compute all those constraints. I would also turn off adaptivity when it's not needed. Have you considered Skeletal Modeling?

[blair]

IV's highest system load is in generating the IPT for your assembly. The gain on  all grounded parts would be marginal.

1.) Turn off all bling on your system: Start>Control Panel>System>Advanced System Setting>Advanced>Performance>Adjust for Best Performance.

2.) Then unload and turn off any un-needed programs running in the background. 

3.) Dump any nice screen picture you have and switch to a Black Screen.

4.) Change Inventor's visual setting to Performance in the Application Options>Hardware.

5.) Buy a new faster machine if the improvements not enough.

[cwhetten]

This would be easy enough to test, I think.  Just open a large assembly, suppress all the constraints, ground all of the parts, and continue working to judge any difference in performance.  You could even delete all of the constraints just to be 100% sure it's an apples-to-apples comparison (just don't save it that way).

-cwhetten

[FProcp]

I really believe skeletal modelling is the answer. That's my preferred way of working.

Normally you bring in parts or create parts right there in the assembly.

.

Next time try this:

.

1 - Create an assembly save it and then create a part within that assembly. Call that first part skeleton or something similar.

.

2 - Save that assembly. That will save that new part you created (called skeleton) as well to your hard-drive.

.

3 - Now create some sketch planes and then some sketches to create parts from in that skeleton part.

.

4 - Now create your next part in the assembly which will be your first real part in your model.

.

5 - When in that part the first thing you must do is go to the derive command and derive in that first part you called skeleton. This needs to be done for every part you create from now on. Derive in that first part.

.

6 - Use the project command in sketches to project edges from that first skeleton part.

.

7 - Use those projected edges to create your parts.

.

8 - ALWAYS place sketches for new parts in that first skeleton part (you can even uses surfaces in there).

.

9 - ALWAYS move parts by changing the position of the sketches in that first skeleton part.

NO NEED TO USE ASSEMBLY CONSTRAINTS EVER AGAIN

[cvbt-thailand]

I'm impressed by the quantity and variety of responses to my humble post.  Thank you all.

I think I'll stick with modeling mostly with constraints.  I now know I can safely use grounding on parts that will not move.  And, as I suspected, it will make my model simpler, more stable and a tiny bit faster.

Thanks for your concern about my humble computer spec's.  IV actually runs well for part modeling and assembly functions.  It is only when we use dynamic simulation on large models that it begins to hiccup.  Hopefully we'll budget for a new computer next year.