topic Re: Complex transitional constraints in Inventor Forum

Complex transitional constraints

Anonymous — Wed, 04 Oct 2017 18:29:40 GMT

Please watch the video. The current pivot point for the bottle CG of the bottle. I'd like to be able to simulate the motion all the way onto the rails.

Re: Complex transitional constraints

johnsonshiue — Wed, 04 Oct 2017 22:13:51 GMT

Hi! You did not attach the video or provide the link. You may also want to share the files. The behavior sounds file specific.

Many thanks!

Re: Complex transitional constraints

Anonymous — Wed, 04 Oct 2017 23:42:21 GMT

Video attached

Re: Complex transitional constraints

johnsonshiue — Thu, 05 Oct 2017 01:11:41 GMT

Hi! I think I know what you are going after. If possible, could you share the files to me (johnson.shiue@autodesk.com)? I would like to play around with it and check some options.

Many thanks!

Re: Complex transitional constraints

Anonymous — Thu, 05 Oct 2017 11:08:24 GMT

Good morning Mr Shiue,

Thank you for taking up my challenge. I sincerely appreciate it. Please feel free to delete the cylindrical extrusion in the bottle (it was the only way I could get a translation), and anything else that makes the task more manageable. Pack-n-go zip attached.

Re: Complex transitional constraints

JDMather — Thu, 05 Oct 2017 12:44:59 GMT

This might be possible with a dummy surface and Transistional constraint, but I would be more interested in solving in the Dynamic Simulation Environment.

Do you have Inventor Professional with Environments>Dynamic Simulation?

Re: Complex transitional constraints

Anonymous — Thu, 05 Oct 2017 14:07:35 GMT

Yes. I have INV 2018 Pro.

Re: Complex transitional constraints

JDMather — Thu, 05 Oct 2017 14:41:58 GMT

It may take some time till I can get to this as we are in the middle of mid-terms exam, but this looks like an interesting problem that I want to pursue.

If someone else doesn't respond with solution and this goes several days - be sure to Bump it back to the top so that it isn't overlooked.

I think the solution is really a quite simple 2D contact and 3D contacts as the respective bottles stay in the same plane, but why is the rod 1931 not long enough to contact all bottles? Isn't that what pushes the bottles?

There are some parts missing from your assembly attachment.

I am not concerned with the missing fasteners, but what is part 1908 and part TEST PIN?

Re: Complex transitional constraints

Anonymous — Thu, 05 Oct 2017 15:16:11 GMT

I left the rod short for clarity. It would go all the way across in the finished model. I made this model quick and dirty in order to address the tough issue (transitional constraint). I made the test pin because I couldn't figure out how to get the bottle to follow the surface I created. It seems that the transitional constraint requires one cylindrical surface. The bottle does not remain in one plane. See position 1 and position 2 photos below. 1908 is the opposite end plate. Thanks!

Re: Complex transitional constraints

JDMather — Thu, 05 Oct 2017 16:15:36 GMT

@Anonymous wrote:

The bottle does not remain in one plane. See position 1 and position 2 photos below.

What is Work Plane 4 in your assembly? What is the purpose of Mate:36?

In both of your images the bottle appears to move on one plane - Workplane 4.

Re: Complex transitional constraints

Anonymous — Thu, 05 Oct 2017 16:18:14 GMT

Work plane 4 is the bottle axis center as it moves, but it rotates along the rails 90 degrees too.

Re: Complex transitional constraints

JDMather — Fri, 06 Oct 2017 14:36:42 GMT

@Anonymous

Is something like this what you are after (turn on your sound).

I have Inventor doing 2500 calculations - so it might appear a little slow.

I could then Publish to Inventor Studio and playback at whatever speed is appropriate.

I didn't take the time to represent the actual chain.

That is something I would do in Inventor Studio rather than in Dynamic Simulation.

Re: Complex transitional constraints

JDMather — Fri, 06 Oct 2017 15:20:33 GMT

The sprockets might appear to be moving haphazardly, but when the animation is Rendered - the motion will be smooth depending on the frame rate chosen.

Re: Complex transitional constraints

Anonymous — Fri, 06 Oct 2017 15:29:08 GMT

JD!

That is beyond marvelous. It's perfect. Thank you. I really must study the DS environment. This model should help enormously.

Thank you,

Re: Complex transitional constraints

JDMather — Fri, 06 Oct 2017 15:34:12 GMT

Here is my "solution" as depicted in the videos. It is a little rough as I didn't spend much time on this first attempt - but might be enough to get you started.