Evaluate Geometry 2

[Bobfromoh]

I am using SW2016. I created a "T" section in Sketch. I selected "Evaluate" to determine the section properties (Ixx, Iyy, centroid, etc). Some of the MOI show a small number but should be "0". One of the results, "Angle between principal axes and sketch axes" shows a none zero number. I guess it's the difference between X and Ix, Y and Iy? How do I get this angle to show 0.00 degrees?

Thanks,

 

[MikeHalloran]

( working from memory )
Add some constraints to the sketch?
I.e., horiz/vert lines parallel to axes?


Mike Halloran
Pembroke Pines, FL, USA

 

[Bobfromoh]

Playing around with various geometries, I discovered that the angle goes to "0" when the geometry is symmetrical. For my purposes, I generally only need to know the section properties about one of the axes. Comparing the computer results to hand calculations, I determined that I don't need all that other output from SW.....or do I?

 

[MikeHalloran]

You never know what you will need tomorrow.


Mike Halloran
Pembroke Pines, FL, USA

 

[Bobfromoh]

OK then, why does someone need to know the angle between the principal axis and the sketch axes? What does that information do for you?

 

[MikeHalloran]

It isn't 'someone' who needs to know, it's SW itself.
Sometimes you can sort of see what's going on, during a redraw operation.
SW starts anew with every object oriented at random, and positions and repositions the objects until they satisfy all of the constraints you have applied.
It can sometimes be interesting to remove a few constraints at random and observe how SW destructs and rebuilds what you have constructed.



Mike Halloran
Pembroke Pines, FL, USA

 

[Bobfromoh]

Thanks for the reply.