Angle measure feature not going negative

[M Woodhams]

Hi All


I have created an angle measure and have saved it as a feature. This angle measurement measures the angle between two datum planes. One of the datum planes is fixed; the other is part of an arm which rotates around an axis. I have run a sensitivity analysis of the arm as it travels through its motion and outputted the angle dimension as the arm moves. I was expecting the arm to go from a +40 degrees to a negative 20 degrees but unfortunatly, the angle dimension does not go negative. It does indeed start at +40 degrees, then reduces to zero, then returns back to +20, when I know the dim should read -20.


Does any one know how to use the measure feature to calculate an angle which can be a positive and a negative??<?:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" />


Thanks for reading my question.





M Woodhams

 

[Mloew]

For this type of measurement I usually set up a "dummy" measurement that has a reference 90 or 180 degrees away from the "real" datum. I then use a equation to subtract this offset and get back to the measurement on interest. This way I geta sined value for the angle.


I hope this helps.

 

[Kaz Z06]

Matthew's solution will certainly provide the answer in the form you are looking for. One other option would be to create a "relation" analysis feature and set the angle parameter you wish to measure/report (angle_output) as:



angle_output = $d1


"d1" would be the dimension that sets the angle between the planes. Plot this parameter for your sensitivity study output plot and you should get what you need. The "$" character will force Pro/E to evaluate the angle WRT a "zero" and provide the sign. The "$" character can be very useful for other measures you need tocapture as "+/-" values.


Another optionis to set the "Plot" range to "+/- 180" inside the dialog box for the angular measurement definition. This should report angles back considering the sign. If this works, it may be the easiest to implement as it would be a simple modification to your existing measure.


Cheers,


Chris
Edited by: Kaz Z06

 

[M Woodhams]

Hello all.


Thank you all for your feed back.





Max