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Motion

Motion

(OP)
O.K., Guys.  I've been working on this one on and off for quite some time now.  I don't believe there is a solution with SolidWorks, but before I give up I wanted to run it by you.

I have designed a machine that is fairly complex, but the drive motion is fairly simple (at least I think it is).  My client wants to see the machine in action with a pretty rendering.  Not an unusual or particularly difficult task.  However, I am unable to get the motion to travel through a full cycle without Animator freaking out.  In fact, I can only get it to travel through 179° of motion before total nonsense occurs.

You can check out the files at : http://www.mediafire.com/?a4zkmgoalnw

I've included a rough drag through motion, so you understand what my end goal should be.

If you use the angle mate to drive the motion in Animator, once you get past half of a cycle the program just arbitrarily decides where to place the components in an obviously inappropriate way.  I've been through this with my VAR and SW to no avail.  I could just be asking too much from the old bird.

Any help would be appreciated, but don't get sucked too far in.  It will drive you mad....

I'm currently using SW2007 SP3.0.

Dan

www.eltronresearch.com

RE: Motion

It looks like I can't download this at work.  However, (stupid question) have you tried splitting the animation into two parts?

RE: Motion

I think that's going to be very tough.  The solution might require creating a helper surface to guide the motion of the components.  In cases like these, I track the motion of the "problem" part, extrude a surface (using the fit spline feature to make a single surface) and making a coincident mate between a point in the problem part to the single-face extruded surface.  This helps keep the sudden flop-over from happening.

Sorry if that sounds a bit vague--I've got to jump on other projects now, so I don't have any time to try it in your instance.

Jeff Mowry
www.industrialdesignhaus.com
Reason trumps all.  And awe transcends reason.

RE: Motion

(OP)
I have tried the animation in two parts, and it just doesn't look right.  There's always a skip where the two halves meet up.  

Just to clarify a little bit, the motion works when I apply a rotarty motor.  It also works if I run it through COSMOS Motion (when I have the joints correct).  The problem is with Animator.  The client is happy with the output from the motion study, but I'm agitated that Animator won't do what the other add-ins seem to be able to figure out.

I've thought about the option of following a spline with the motion.  However, not only do you end up with a sort of torroidal, super-complex spline from following the motion of a point on one of the surfaces, but you can only control distance and angle mates in Animator.

Great suggestions, but I've already been down those roads.  I have a feeling I'm just pushing SW a little too far.  

The ball is still in play, though.  Your mission should you choose to accept it...(Mission Impossible theme plays).

Dan

www.eltronresearch.com

RE: Motion

No way Animator will come close to what those other modules will do--so you have to get into all sorts of ridiculous hacks to get what you need--and you still may not truly obtain it.

The surface hack I mentioned is more than following a spline (which won't work).  You cannot do this with more mates--it needs to be done with very few mates with Animator.  If time allows I'll see if I can make it work.  I do think it's possible, but not without some well thought-out hacks and some creativity.

Jeff Mowry
www.industrialdesignhaus.com
Reason trumps all.  And awe transcends reason.

RE: Motion

(OP)
I'm guessing by the overwhelming silence that hearing from everyone I'm just asking too much from the software.  Thanks for giving it a look, Jeff.

Does anybody else know of other animation software that might be able to pick up where SW drops the ball?

Dan

www.eltronresearch.com

RE: Motion

Mechanisms animation is easily accomplished in programs such as ADAMS and Working Model 3D, basically you create a series of simple bodies and constraints, and define motions for them. Then you attach your stp file to the appropriate ADAMS part, assuming that you want a nice rendered shape for the part.

FAQ404-804 may give you some ideas.

FWIW, the example you have given would probably take me about 2 or 3 hours from scratch to set up as a mechanism, in ADAMS/VIEW, but I am by no means a fast worker in VIEW as I use it rarely. I have modelled an automotive differential with LSD, for example, but that probably took me a couple of days.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

RE: Motion

I've been buried in work lately, so no looks at this since I last posted.

Jeff Mowry
www.industrialdesignhaus.com
Reason trumps all.  And awe transcends reason.

RE: Motion

A long PIA way that I did an animation once was by placing a gazillion configurations in a DT.  Okay, so I exaggerate, only 144, but you get the point.

When that was all set, I turned on the screen capture and clicked through all of the configurations and then turned off the screen capture and wrote the avi.

Yes, I know, brutal!  Looked hack compared to Animator's normally smooth motion, but it got the point across.

Oh yeah, you'll see it right away if you clicked the configurations in the wrong order or skipped on by accident.

Christopher Zona - Product Designer
Concord, Ontario

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