topic Re: Constraint two wheel to cross a random Path in Inventor Forum

Constraint two wheel to cross a random Path

Anonymous — Tue, 05 Jan 2021 11:35:19 GMT

Good Morning to everyone! I've a problem with a guide who have to cross a random path. I've used the transitional constrant but it doesn't worked. Sorry for my bad english, i'll post below my system in a .zip file so it will be easier to understand what is the problem.

I'll post even a screen of my system

Re: Constraint two wheel to cross a random Path

Cris-Ideas — Tue, 05 Jan 2021 19:35:29 GMT

Hi,

So solution to your problem actually does NOT exist in inventor.

Sorry to pass this news. ☹️

for much more detail over how constrain solving DOES NOT work in Inventor please visit this threads:

Flexibility not working properly in inventor - BUG that has been there for ever

Constrain solving - as complicated as that

Cris.

Re: Constraint two wheel to cross a random Path

Anonymous — Tue, 05 Jan 2021 20:11:28 GMT

Thank you very much for the answer and for the video 🙏🏻. I’ve understood which is the problem and it’s so incredible that a software like Inventor has this problem

Re: Constraint two wheel to cross a random Path

JDMather — Tue, 05 Jan 2021 20:19:56 GMT

@Anonymous wrote:

... it’s so incredible that a software like Inventor has this problem

@Anonymous

Works fine on my computer.

Environments>Dynamic Simulation.

Re: Constraint two wheel to cross a random Path

Anonymous — Tue, 05 Jan 2021 20:36:26 GMT

Ok, @JDMather thank you very much for the answer, but now i've another question and problem. If i put another set of wheels, as the first one in the figure, and I try to move them, as a "car", they don't work again. The system is this below:

I've attached also the CAD file if you want to try, please. In this case, what can I do? I need of this for my thesis

Re: Constraint two wheel to cross a random Path

JDMather — Tue, 05 Jan 2021 20:56:33 GMT

@Anonymous wrote:
I need of this for my thesis...

I noticed that many of your sketches are not fully defined.

I make sure that my students can fully define a sketch before proceeding into an advanced topic like Dynamic Simulation.

Are you ready to start over from the beginning?

Re: Constraint two wheel to cross a random Path

Anonymous — Tue, 05 Jan 2021 21:04:35 GMT

@JDMather My sketches are not fully defined because this is just “trial” of what I want to do. But before to do it, I need to understand how to make it. I’m sorry if my sketches are not fully defined, but I’ve made this quickly because I need to understand if I can realize that motion or not

Re: Constraint two wheel to cross a random Path

JDMather — Tue, 05 Jan 2021 21:34:57 GMT

That didn't answer my question.

Are you ready to start over?

Re: Constraint two wheel to cross a random Path

Anonymous — Tue, 05 Jan 2021 21:39:06 GMT

Sorry i haven’t read. Yes, I’m ready. I need it.

Re: Constraint two wheel to cross a random Path

johnsonshiue — Tue, 05 Jan 2021 23:06:01 GMT

Hi! I believe this is a limitation and a bug in Inventor. Transitional constraint does seem to like multiple transitioning faces at the same time. It can fail easily. I tried a slightly different solution and it seems to work better. Instead of using cylindrical faces, I used spheres. The spheres seem to work better. Please take a look at attached file.

Many thanks!

Re: Constraint two wheel to cross a random Path

Anonymous — Wed, 06 Jan 2021 08:10:02 GMT

@johnsonshiue Thank you very much for the advice. Now, I'm trying to solve the problem with 2 axes and 4 wheels

Re: Constraint two wheel to cross a random Path

Cris-Ideas — Wed, 06 Jan 2021 08:11:23 GMT

@johnsonshiue

Hi Johnson,

So I took a look. Problem is exactly the same with spheres, cylinders or any other shape you can think of.

It is the same thing that causes problems with FLEX and POS REPS and even in flat assemblies.

Cris

Re: Constraint two wheel to cross a random Path

JDMather — Wed, 06 Jan 2021 13:29:57 GMT

We will go through each step, one-by-one and diagnose as needed.

Open the file Binario.ipt

Edit Sketch1 and add missing dimension(s)/constraints to fully define the sketch.

Re: Constraint two wheel to cross a random Path

JDMather — Wed, 06 Jan 2021 13:33:52 GMT

Right click on Sketch2 and select Redefine and then select the YZ Plane.

Delete WorkPlane1.

Edit Sketch2 and add missing dimension(s)/constraints to fully define the sketch.

Re: Constraint two wheel to cross a random Path

Anonymous — Thu, 07 Jan 2021 09:33:47 GMT

@JDMather Ok, i've made it. Maybe i've understood the "key" of this. The parameters, right?

Re: Constraint two wheel to cross a random Path

JDMather — Thu, 07 Jan 2021 11:31:46 GMT

Attach the corrected part file here.

Once I have verified that you are following my instructions we can move at a faster pace towards a solution in Dynamic Simulation.

Re: Constraint two wheel to cross a random Path

Anonymous — Thu, 07 Jan 2021 12:59:00 GMT

Ok, i've a question. Are only these two the parts that i have to correct ? Or have I to define fully each sketch made by myself?

Re: Constraint two wheel to cross a random Path

JDMather — Thu, 07 Jan 2021 13:08:02 GMT

Before I proceed to Dynamic Simulation - I will have to examine each and every component.

So all parts will have to be correctly modeled.

Re: Constraint two wheel to cross a random Path

Anonymous — Thu, 07 Jan 2021 14:56:20 GMT

The fixed files are below

Re: Constraint two wheel to cross a random Path

JDMather — Thu, 07 Jan 2021 16:29:50 GMT

@Anonymous wrote:

The fixed files are below

I opened the first file in the folder - Edit Sketch1 and do not see any dimensions?