How to control sketch length to a nominal?

[Inoram]

I want to draw a sketch that I will use for a sweep that I want to constrain to a nominal number (probably 41 or 42"). The sketch will be a variety of lines and arcs (tangent to the lines). The actual nominal number is not important (can be anything). And the variable pieces mostly are not very important either, just fitting it in the space I have is the only real constraint.

What is a good way to do this?

thanks

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[TomD.inPDX]

I can't picture this, Matt. I suspect you have two answers; relations built from the sketch (perimeter dimension relation?) or a trajpar relation in the swept sketch. Trajpar is a value from 0-1 along the trajectory (open sketch) or 0-360 (closed sketch) in relation to the origin sketch.

[Inoram]

I was thinking relations. I'll have to think about it some more, it may or may not be worth the time to even do it that way though. With Trajpar I will have to dig out my trajpar notes and see if that would apply. I use trajpar so rarely I always have to re-read how to use it.

thanks for the input.

[TomD.inPDX]

You might also look at the graph option. This is also a value driven by relations, but the relation is a graph. You can then be very specific about changes in the variable section sweep.

[Patriot_1776 · Accepted solution]

I'm confused......do you want the overall LENGTH of the trajectory to be 41 or 42", regardless of the make-up (arcs/lines, etc.) of the trajectory? If so, you'll want to use the perimeter option in sketcher.

[Inoram]

YES! that worked perfect, thanks.

[TomD.inPDX]

Sorry Matt; I was assuming you knew about perimeter dimensions. My comments were related to the VSS sketch linking the perimeter value from the trajectory sketch. Glad Frank picked up on what you were really asking.

[Inoram]

Antonius I appreciate the confidence, but there's so many things I don't need to use day to day, I either forget or forget the exact way to use them (like trajpar). And I still more recently went from WF3 to creo2, so if it's a change since then I may have missed completely. But in general, I have no problem asking for help

thanks!

Yeah I was getting ready to draw a sketch of what I was trying to do, but Frank's advice was exactly what I needed. In fact, when I did it I was surprised how well it worked.

[Patriot_1776]

Lucky guess on my part. I've found the hardest thing about helping people here is trying to understand what they REALLY need. It's hard to put complex geometry questions into words, ya know?

I REALLY like when they added the perimiter option, I like using it in spinal bends to make sure the bent shape is the same length as the straight shape. The only drawback is that you can only have one per sketch. They should fix that.

[Inoram]

Well, for the sake of clarity and all, this was the shape....I hid the dimensions as they were really not relevant to the issue.

[Patriot_1776]

Cool!

[TomD.inPDX]

I don't remember Pro/E -not- having perimeter dims for sketches.

Didn't know you could only make one per sketch. That I might have to double check. Maybe a few limitations to multiples?

[BrianMartin]

Like Frank, I was very happy to have the perimeter option added to the sketcher tool. It was probably put in somewhere around 2000i2. And also like Frank, I always use it to insure my spinal bends are the same length as my "unbent" geometry. There have only been a few times I had to resort to relations to overcome the limitation of only being able to use one per sketch. In practice it's not that big of a hurdle.

[Patriot_1776]

Yup, it's REAL handy. It'd be nice to have an "area" option in sketcher too.......

[TomD.inPDX]

Now you've gone too far, Frank.

[Patriot_1776]

[ptc-5008082]

Perimeter dimension was in Release 20

[Patriot_1776]

I KNEW it was a while ago. I find it very handy on the occasions you need it, even despite it's limitation.