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Determining area/volume in mechanism

puzzled
7-Bedrock

Determining area/volume in mechanism

i have a crank slider mechanism

crank slides up and down.....now is it possible to know how much area the whole mechanism covers>>????

 

is it possible by motion envelope????if yes then how?


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Yes. Set up a servo motor in Mechanisms for your assembly that creates the motion you want to study, then set up the kinematic analysis to simulate one cycle, and run it. Then you can get back into Standard application to do a motion analysis, and have the analysis save the volume occupied by of all parts or any selected sub-set of parts as a motion envelope/cloud. You can tweak the precision level so that you get a very coarse cloud or a much more precise cloud. Run it with the low level precision first to make sure its doing what you want because the higher you set that precisions level, the slower it runs. That volume can be saved as a feature. Back in Mechanisms mode, you can also Insert a Trace Curve using that same kinematic analysis. This allows you to track the motion of a single point throughout that motion. This is helpful if you want to compare the results of a baseline against a proposed design change in the mechanism.

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9 REPLIES 9

Yes. Set up a servo motor in Mechanisms for your assembly that creates the motion you want to study, then set up the kinematic analysis to simulate one cycle, and run it. Then you can get back into Standard application to do a motion analysis, and have the analysis save the volume occupied by of all parts or any selected sub-set of parts as a motion envelope/cloud. You can tweak the precision level so that you get a very coarse cloud or a much more precise cloud. Run it with the low level precision first to make sure its doing what you want because the higher you set that precisions level, the slower it runs. That volume can be saved as a feature. Back in Mechanisms mode, you can also Insert a Trace Curve using that same kinematic analysis. This allows you to track the motion of a single point throughout that motion. This is helpful if you want to compare the results of a baseline against a proposed design change in the mechanism.

thanks for your reply sir.....but i am stuck after running mechanism.....when i ran motion analysis from standard application it shows the path travelled and after that what step should be taken i dont know....so please can you provide the step???it would be great help....

puzzled
7-Bedrock
(To:puzzled)

ok here is what i did....plese comment if i am wrong...

motion analysis--->created envelope-->motion over then added a feature--->selected the envelope and then in same tab selected "volume" of quilt....is it right?

I don't see the "volume of quilt" tab that you described. I just run the motion analysis, create the feature, then pick Analysis>Measure>Volume>Quilt and select the envelope that I just created. I'm running Wildfire 5 here.

yes means selected envelope........but when i checked it out...the volume came out lesser than area 😮 ??????how is it possible!!!!!!!!

I would have to see your specific example, but I suspect it is possible that the volume is self-intersecting. This could cause some sort of error that may result in an error such as what you are seeing. If it looks like that could be happening, I would try breaking that motion into something less than one cycle. If the mechanism is triggered by an axial rotation, try running the mechanism so that it only completes 25% of the cycle & measure that. I'm just guessing here, but it would be easy to test. I have a simple single cylinder engine assembly mechanism that I believe came as part of the Mechanisms training and I can run that for one cycle and it reports out the correct volume measurement, so my guess is there could be something about the envelope generated by your mechanism that is confusing Pro/E.

http://www.youtube.com/watch?v=mJSQ2mU2N4Y&feature=c4-overview&list=UU4A_lZ2tfDZwkriyGnyhm1Q

check it please if you want i can send you whole assembly?

because i cant solve and you might that help you in getting accurate rather than guessing

OK, the first thing I would suggest is limiting that motion to just one revolution. You aren't getting any additional volumes (in real life) by turning the crank more than 360 degrees, and you could be creating additional surfaces in that quilt that could possibly be confusing the volume calculation. In fact, that piston head only needs to be calculated during 180 degrees motion. It takes up the same volume on the up stroke as it already did on the down stroke. The second thing i would suggest is rather than making one envelope of ALLmoving parts, make one envelope/quilt for each moving component that you are interested in.

wow that was some helpful info i came across really helpful thank you.

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