Surface perpendicularity problems with Extruded Solids

[mjcole]

Hello,

I'm not trying to flame UG but I think we all no there are some dimensional accuracy issues with the software 2.00" becoming 1.999999999986 etc.

My co workers and I have run into problems assembling files due to non perpendicular surfaces from simple extruded solids in UG. Has anyone dealt with this before and if so are there any ways to fix this with Part Cleaning or System accuracy decimal places?

Michael

 

[cowski]

Concerning the non-perpendicular surfaces: is all of the geometry to be extruded planar? (ie all line endpoints, arc endpoints, etc have 0 Z value). Also, are you sure that the extrude direction is perpendicular to the plane of your geometry? I have seen some unexpected issues with the extrude command, but so far it has always been a case of garbage in/garbage out.

Do you see the dimensional problem in conjunction with the non-perpendicular surfaces? It seems like those would go hand in hand. If you see dimensional oddities independent of the other problem, then I would start looking into it.

 

[mjcole]

Yes,

All of the extrusions are directly perpendicular to the sketches or curves, but when doing an angle analysis of face perpendicular direction the values do not equal 90 degrees.


Michael

 

[cowski]

Is there a simple step-by-step example you could post so that other forum readers can try to recreate your problem?

What are you measuring the angle to? eg one of the faces vs WCS Z direction?

How about your modeling tolerances, what are they set at?

 

[feadude]

If the listing window decimal places was set to anything less than 11 (system) digits and you used the copy / paste from the listing window to get some values for modeling construction values and then listing window decimal places was changed to system value then you will see some values like 1.999999999986 . I have seen somethings similar where I used 2 and then listing window decimal places was changed to system or vice versa and it gave me 1.999999999986.
It is best not to mess with "listing window decimal places" setting which is in the preferences-user interface. Our draftsman/system administrator set it to 6 digits and now we have set it back to system (UG recommended 11 digits),
and we have problems like yours. I understand listing window is for display purposes but its values are used for construction values using copy/paste.
I hope this helps.