Any possibility to measure arc length? Not only the edge, but maybe also the center-line of bent pipe...

Code: import math # get current part P = CurrentPart() # get a specific 2D sketch Sk = P.GetSketch("Sketch<1>") # look for all arcs in sketch for Fig in Sk.Figures: # found an arc if isinstance(Fig, CircularArc): StartPt = Fig.StartPoint EndPt = Fig.EndPoint CenterPt = Fig.Center Radius = Fig.Radius # calculate straight-line distance between start and end points D = math.sqrt(pow(StartPt[0] - EndPt[0], 2) + pow(StartPt[1] - EndPt[1], 2)) # calculate distance along arc between start and end points Theta = math.acos(1 - ((D * D) / (2 * Radius * Radius))) Length = Radius * Theta print Length I haven't tested it if the arc covers more than 180 degrees. In that case you will probably have to subtract the result from the circle circumference or swap the start and end points around. https://math.stackexchange.com/questions/830413/calculating-the-arc-length-of-a-circle-segment Andy

Andy, I am not questioning your formula, but responding to Mika's question. This is something I asked for a long time ago. Alibre is a computer. For most things it functions as a very smart computer. When I create a straight line, Alibre knows the start point, the end point and the length of the line. And yet when I create an arc, Alibre knows the start point, the end point and the radius. So IT KNOWS the arc length. Yet for arcs Alibre acts as a very dumb computer. If it knows the arc length, it should let me dimension the arc length, not keep it an internal secret.

Sounds like there's two separate issues in this thread: 1. Measuring the length of an arc 2. Drawing an arc to a desired length #1 can be accomplished with the MEASURE TOOL. #2 can be accomplished by using KNOWN angles I would think there would be an appreciable amount of coding to be able to specify all of the known variables and then use them in a formula to generate the arc. That would probably be a 'back burner' item at this point in time. As for #1, I submit the following: Launch and run the "Find Arc Length Test" script.

Arc length can be measured in design with the Measurement Tool. Since Alibre is based on ACIS, 2D-DCM, and 3D-DCM it should be trivial to add dimension tools for this for both design and drawing. They won't be the first ones to dimension arc lengths. https://www.plm.automation.siemens.com/en/products/open/d-cubed/2ddcm/ Siemens PLM Software Releases 2D DCM, Version 57.0 and PGM, Version 57.0 Posted by: DE Editors in Design, New Products, News June 23, 2010 http://www.digitaleng.news/de/sieme...ses-2d-dcm-version-57-0-and-pgm-version-57-0/

Yeah, dimension in the drawing and sketch...I'm not so intrested what is happening in the equations in the heart of the computer processor.

OK, as someone who has been Drafting for 49 years, I have only used an Arc Length Dimension (maybe) three dozen times -- mostly defining Conveyor systems. To that degree I recognize that it does fall into the "rarely used" category. However the Arc Length Dimension has been part of Drafting Standards since (at least) 1928 (the oldest copy of Meir's & French's Engineerimng Drawing) I own. It is still recognized by ASME Y14.100-2013 Engineering Drawing Praciices (and, I believe, still defined under the 2015 update). Hence, it is a Dimension Form that should be included in Alibre Design. !!!

Lew and Mika make a good point. One can measure the arc length but not dimension them in drawings. Why not?

My "argument" is that we need a means to create a Sketch ("tied" to a Surface in most instances) that allows us to Constrain an entity to be (say) Tangent to the path of the Sketch as the mating Surface is moved. Something such as a Conveyor Chain only needs its Length when determining how much to buy (and the Measured Length is (typically) fine for that (though it would be nice could we assign a Measured Length to an Equation Editor Variable value)). If I am using a Roller Chain, then that Sub-Assembly will contain the Number of Rollers that using (Quanty of Rollers-1) X Length of Link gets you the Length of the Chain quite easily.

Add the following line to the end of the script I posted and now the arc length is a parameter that can be used in equations. Code: P.AddParameter('ArcLength', ParameterTypes.Distance, Length) Andy

I agree with this. As much as I appreciate Andy's work and the fact that Alibre have implemented Wizoscript I am also not in a place where I intend to learn code. I like buttons that make it an easy job. If, say, gears could be created by clicking a gear button that opens a window to allow for data input and this process was editable/parametric that would be great

There is a gear generator script included. Steps are: 1. Click on AlibreScript tab 2. Click on Launch 3. Click on Gear Generator 4. Click on Run and you will see: No learning code required... Andy