Dynamic simulation very slow

[Anonymous]

Hi Everyone

I downloaded the file from Youtube channel of thang010146 to practice the dynamic simulation. 

I expected it will be fast because its not so complicated. But I found Its not so smooth to run it.

My computer is Lenovo P53 with i7-9750H/ Quadro T1000/16GB Ram. I think its enough util I run it.

Do you guys have any suggestions  to improve it? Thanks in advance!

PS. the file is attached and all the conditions is all assigned.

Min

[JDMather]

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@Anonymous wrote:

My computer is Lenovo P53 with i7-9750H/ Quadro T1000/16GB Ram.

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What version of Inventor are you using (including Update number)?

2018 SP0?

If you do a Manage>Rebuild All are any issues reported?

The motions are planar - have you tried 2D Contact rather than 3D Contacts?

For the purpose of this analysis - is it really necessary to have  the Gear Rod free to rotate, or could it be simplified to only translate along Z axis (Prismatic Joint)?

[Anonymous]

Hi JDMather

Thanks for your reply!

I used the inventor professional 2018. And I have try your suggestion but found the same result. Very slow..

I don't know which part is wrong or its just normal to when you run the dynamic simulation.

Could we run it with multi processor or we have no choice?

[Anonymous]

As you can see, I want to edit the property of joint in dynamic simulation  and the speed of the CPU has been up to over 4. And then the computer is stuck by this.  Is it normal ?Do I need to download any service packs?

I will be appreciated if any one can help!

[j.palmeL29YX]

The suggestions of @JDMather were exactly my first thoughts too, but before I could finish my test - Jeffrey's response was faster 😉.

Because I have only IV 2020, you can not open my file(s).

But mayby some explanation will help you.

First I did some small modifiacations at your parts: e.g. GearRod centered to the origin (I don't understand why you created an additional workplane),  removed the small inner fillets in GearRod, the Pawl's got an additional Sketch (Project CutEdges at The XY-Plane).

Next I assembled the mechanism completely new (I don't know it this is/was necessary).

In the Dynamic simulation I created the Joints as you can see in the video. (If you have further questions I can describe it more detailed).

Creating the Simulation is shown in >>this video<<. To compute 4 complete cycles of the lever down and up I needed less than 2 minutes. (You can see it in the Simulation Player window at the right).

My Laptop is not a HighEnd-Bolide - CPU i7 @ 2,6 GHz (exact the same CPU as yours).

I hope this will help you a little.

[JDMather]

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@Anonymous wrote:

I have try your suggestion but found the same result. Very slow..

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Can you Attach your new assembly here?

[JDMather]

As I go through this I continue to find issues.

I think there is a sort of detritus that builds up when geometry is not modeled cleanly.

I can't point to something as proof, but in my experience when I see unresolved issues like this sick sketch, Extrusion 39 as the first extrusion in a part, Sketch37 as the first sketch and Dimensions in the 200s as a start, when I start over cleanly from scratch - everything seems to suddenly work as expected.

[JDMather · Accepted solution]

In Ass1.iam I set the DS joints how I would initially test this mechanism and it didn't work.

Over the past 10 years I have done many of these and fought many hours trying to figure out why it didn't work as expected.  Start over from scratch in new assembly (although these parts are suspect too) and everything works fine.

I did a Save As DS Diagnosis.iam (See Attached) and then deleted everything except Base and GearRod.

This should drag with mouse easy in DS Environment - but it doesn't work.

So then I started a new assembly from scratch (See Attached) with just these first two components and it worked fine.  I didn't continue on, but I think you can follow my steps.  (If it were my work, I would also remodel all of the parts as I do not trust them.

Over the years it has been my experience that once a DS assembly is broken - there is no way to fix it. (At least when it is someone else's work and I have no idea what crazy stuff they tried and left over detritis that I cannot locate).

Start over using what was learned from initial attempt to do it right.

[Anonymous]

Hi @JDMather 

Thanks for your reply and your time to solve it!

After reading your explanation I am try to assemble a new one now. But I find that if I give the forced motion to the joint,the computer will crash when I want to edit the joint next time.(like the picture shown) . Do you know how to solve this problem?

I open your files but the problem is it cant run when I click the play like the picture shown

Thanks again for your help and hope you have a good day 🙂

Min

[Anonymous]

Hi  @j.palmeL29YX

Thanks for your help! I have try to use the 2D contact. But there is always a warning(the curve intersect in multi places) when I want to run the DS. Do you know how to solve this?

Thanks again for your help and hope you have a good day 

[j.palmeL29YX · Accepted solution]

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@Anonymous wrote:

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I have try to use the 2D contact. But there is always a warning(the curve intersect in multi places) when I want to run the DS. Do you know how to solve this?

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You should do a close look at the initial position of your parts. I guess at least one of the 2D-contacts is already overlapping.

>>Here<< I have intentionally created such a situation - and get exactly the same warning message.

If this doesn't help, please post your current model as asked @JDMather above (see post #8)

HTH

[j.palmeL29YX]

BTW:

To get a "good" initial position of your mechanism, you can follow >>these<< steps.

[j.palmeL29YX]

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@Anonymous wrote:

... there is always a warning(the curve intersect in multi places) when I want to run the DS. Do you know how to solve this?

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Hi @Anonymous ,

are you still here? Could our (@JDMather and my) tips help you to solve your problem?

If so, click the "accept as solution" button. This can help others find solutions faster.

If not let us know what we can do to help you.