topic driven dimension with geometry constraint defect in Fusion Support Forum

driven dimension with geometry constraint defect

Anonymous — Sun, 01 Jul 2018 23:19:20 GMT

Model workspace, Sketch: Removing a geometry constraint does not free* the driven dimension it was locking.

How to reproduce:

1: New Sketch

2: Draw two lines so that the T (perpendicular) constraint applies or add one after.

3: Add an angle dimension so that it's driven from the constraint (90 degrees).

4: Remove the perpendicular constraint. (this should free the driven angle)

5: Drag a line end point to change intersection angle. This shows the freedom (correct) and the driven angle updates.

*Defect, the dimension is shown in parentheses '(angle)' or driven yet it's free.

*Defect, the angle is free yet can not be edited directly (dbl click)

Comment: I tested am Equal constraint, same issue. The driven is freed yet not correctly displayed or editable.

thanks for the time.

steve

Re: driven dimension with geometry constraint defect

jhackney1972 — Mon, 02 Jul 2018 01:07:03 GMT

You do not understand the purpose of a driven dimension (in parentheses). When placing sketch dimensions, any dimension that you place that over-constrains the sketch will be place as "Driven". Fusion 360 will prompt you to see if you desire to place the driven dimension. Driven dimensions cannot be edited, as you found out. You must change them to "Driving". (Read on below graphic)

Once you toggle it to "Driving" you can double click on it to edit the value. This is because, as the name suggests, it can accept a value and "drive" the sketch. When a sketch dimension is "Driven" you can drag the entity controlling the driven dimension to any value you desire, angle or linear. Once you drag it, then change it to "Driving" it will retain the value at that instant. Driven dimensions are only placed for reference and will not change to "Driving" dimension automatically for any reason, they must be toggled manually. So when you remove the perpendicular sketch constraint, the "Driven" dimension will remain and you can freely drag the line. The converse is also true, if the angle dimension is a "Driving" dimension say 89 degrees and you try to add a perpendicular sketch constrain, it will fail. Make it "Driven" and the perpendicular sketch constrain will change it to 90 degrees.

Fusion is functioning correctly in all aspects and there is no Defect or Bug.

Re: driven dimension with geometry constraint defect

Anonymous — Fri, 31 Aug 2018 21:11:37 GMT

Respectfully,

As a software engineer myself, I disagree with the preservation of graphical representation of a constraint that has been removed. If a constraint is removed, it's no longer driving or constraining anything and the parentheses around any driven dimension from it no longer exist and should be freed (and it is physically free ) but also graphically free to show/warn the author that it may be affected by other dimension they did not intend. I understand the function just fine, that's a defect by any standard. To show (1 mm) is to represent its not free, yet it may be, is misleading.

I accept your solution without agreeing with it on the comment that, "Driven dimensions are only placed for reference and will not change to "Driving" dimension automatically for any reason, they must be toggled manually."

So Driven 'reference' labels are not trustworthy in all cases is agreeable and would not be strictly a defect.

Thank you for the time.