Measuring arclength between two points on a curve 2

[treddie]

Hi!

Is there a way to measure the arc length between two points on a curve? When you select the curve to measure it, of course it reports back the arclength of the ENTIRE curve...there is no way to specify points along it that you would like to measure between, or am I missing something here?

Right now, it seems the only thing you can do is go the convoluted route and use a calculator to subtract one point's position along the curve form the other point's position, but that requires doing an Edit Definition on the points and getting the data out...not nearly as quick as having the simple ability to click on points with the measure tool.

 

[CorBlimeyLimey]

Use the Split tool to split the curve at the designated points

-or-

Draw a construction curve between the two points

 

[CorBlimeyLimey]

Oops, sorry ... not sure if that applies in Pro/E. I thought I was in the SolidWorks forum.

 

[jvian]

Actually that is the method I would use in ProE. Define two points along the original curve at which you want to measure, then split (or trim) the curve twice using each point as the splitting reference (keeping both sides of the trim each time). The result should be three curves defining the original curve which can easily be referenced together for a trajectory or full length if needed again. Also I should note that this requires the curve to be a feature not an "edge". If you are using an edge then you must first copy and paste an exact curve to do this.

Hope that helps,

-J-

 

[treddie]

Thanks for the responses!

Still, a bit of work to do something really simple, but definitely faster than my convoluted method.

jvian > In response to working with edges, It does not seem possible to select a single edge to copy/paste with, so that it can be brought back in as a curve.

 

[CorBlimeyLimey]

I've just discovered that the dimension tool in SolidWorks will give an arc length by first selecting the arc and then two points along the arc. The two points can be sketch points or end points of other sketch elements.

Maybe Pro/E's dimension tool has something similar?

 

[jvian]

Treddie - It is possible to copy and paste edges as I do this daily for offset curves and for splitting/trimming curves as I described. Not sure what may be the problem but make sure that you are selecting the edge by first selecting the feature the edge belongs to then the edge itself without using the cntrl key to grab additional curves (this destroys the copy functionality). Chains or full length composite curves can be selected using the shift key or by defining the curve as rule based once the copy interface dashboard is open (under details of the references tab). I hope this is not confusing but I don't know how else to describe it. This functionality has been around since WF2.0 and here is a link (not very good) to a site that has a couple of pics.

http://www.imakenews.com/ptcexpress/e_article000650346.cfm?x=b11,0,w

There are also other sites with examples out there I just don't know them off the top of my head. I know that what your trying to do is possible.

Hope that helps,

-J-

 

[jvian]

Also I wanted to add that with respect to CorBlimeyLimey's suggestion the same is possible in ProE. Just pick the arc and the endpoints to specify an arc length dimension. Ive used this with drawing involute profiles that require a circular tooth thickness or space width dimension.

Just a couple more penny's for you,

-J-

 

[treddie]

Am I mistaken in interpreting that you mean you can do these things in ProE Sketcher? That I know about, but I am working outside of Sketcher (please see attached image).

Here, I have a curve and a point set selected. Now, if I go up to Analysis > Measure > Length, the point set will deselect, and there is no option or method I can find (either in standard or rule-based mode), to select two points from the point set to set as limits along the curve.

 

[jvian]

The reason for the point set is to split the large curve into many small ones and is not actually used during the measurement. Yes it is more work but it is the only way I have found that works. In your picture for example if you want to measure the length of the curve between two of the rivet features at the points indicated at their bases then the large curve running along the pattern needs to be trimmed between the points of interest. Two trim features are required and be sure to select the "both sides" option to keep both sides of the trimmed curve. After the second trim feature you should have a small curve between the two points of interest which can then have its length measured.

The above reply with respect to inside sketcher was in regards to CorB's post so you can disregard.

Hope that helps,

-J-

 

[treddie]

OK, that makes sense. Sure wish PTC could speed up productivity, though, with some simple new methods. I think it is the one big thing that has been lacking in Pro.

And I guess the issue of copying a feature's edge and pasting it back in as a curve (outside of Sketcher) can't be done either, correct?

 

[jvian]

Not sure what version of ProE your running but there have been quite a few productivity increases in WF5.0 and now with Creo 1.0. We use Creo here because of the huge improvements on the simulation (mechanica) side. As far as the copy and paste edges as curves I think there is still something you are doing incorrectly because I do this daily. In your picture for example if you select just the outer top edge of the cylinder you should be able to copy and paste as a curve (either exact or approximate for C2 condition) remember though not to use cntrl to select additional curves instead use shift to select valid tangential chains.

Attached is a picture where I selected an edge then copy and paste it as a new "copy" feature. The details button on the reference tab will allow easy selection of additional curves for the copy feature.

Hope it helps,

-J-

 

[treddie]

Just great...no one's attachments are appearing...not even my own. Have to figure out if this is a problem at the site or on my machine. Have to figure out what is going on.

 

[treddie]

Are you guys seeing attachments?