fine-tuning a swept blend

[2ms1]

Below are pics of this swept blend I am working with. U'll notice that it has 9 sections. I would like the portion located within the middle 3 sections to be straight. However, instead it is kind of wavy - I think u can see what I mean in the pics. As shown here, the middle three sections all have identical dimensions.

What would you do to get a truly straight section in there?

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2006-05-24_182924_pinky2.prt.zip
Edited by: 2ms1

 

[KamaleshAruna]

Hi,


I hope this is due to spline trajectory of blend. Though the sections are similar, the flow is spline.


One idea i suggust to fine tune is,


Introduce additional 2 sections in between the existing sections and add them into the blend. Since the section is same, you can save the section and retrive it for all additional sections.


This is just an idea. try it.

 

[2ms1]

I will try that when I get up in the morning (here it is very late at night). In the meantime, could u please explain what a spline trajectory is? I wasnt aware of there being different kinds of trajectories or anything like that. Any additional insight into how these blends work would b much appreciated. Even if simply adding more sections will do the trick, I would like to have some inkling of the theory of things. Ideally, I would like the width and height of the very middle section to be the absolute minimum values. I do not like the idea that the blend produces portions of the part that are unpredictably narrower or thinner than I was able to explicitely dictate through the dimensions of the sections themselves.

 

[2ms1]

I wish there was a way to specify constraints on the blend, for example that the surface be perpendicular to each of the three middle sections -- such a constraint would of course systematically produce the results I want. however, there appears to be no such capability

 

[michaelpaul]

Not sure if this would work but........

since you want to keep the three sections to be straight while the rest would be smooth, maybe you would have to create three seperate sweeps for this. I don't know if you can define which sections should have a smooth transition and which would have a straight transition.

if you had three different sweeps, you would define the ones that you wand to have a smooth transition and then define the middle sweep to have a straight transition.

You're getting the wave because when Pro determines the "smooth" traansition, it's creating a spline to guide the protrusion along as it passes smoothly throough each defined section.

I dunno though, just throwing out an idea. it may not be the best, but it may work for you.

Michael