Part sketch changes - new install of SW 2015 on Windows 10

[Spurs]

I did a new install on SW2015 on a windows 10 system

I am having behavior that I never saw before on my old system and I wonder if it is a setting in system options that I am not familiar with.

If I create a new sketch and for example draw a circle without a dimension - say it ends up being 29.5 mm radius just by free hand, and then I draw a 2nd circle freehand and lets say it ends up as 39.555 mm in radius. If I then dimension the 2nd circle to 39.0 mm its size on screen does not change visually but dimensionally it has. Likewise the smaller 1st circle visually has not visually changed in size, however when I check its size its radius has dropped from the 29.5 to something smaller - like 29.22134.

Is there a setting so that when I dimension the 2nd item in the sketch, the first item does not change?

BTW - I just tried the same thing and fixed the first circle - it still changes size even when fixed ????

 

[BiPolarMoment]

This is a feature added in 2014 and I'm typically in favor of it. For example when drawing a revolved feature with multiple changes in diameter prior to inserting the first dimension it has a good tendency to "explode" when the desired dimension is greatly different than the as-drawn size, especially if there are radii.

I'm not sure if you can turn it off. But, it only happens for the first dimension so if you don't want it to happen, throw a dimension on the first circle before the second is drawn.

See here:

http://www.javelin-tech.com/blog/20...auto-scale-first-sketch-model-video-tutorial/

 

[Spurs]

Bipolar
What happens if you have a complex set of curves and geometry and they are not yet fixed with a dimension? Do you simply dimension any individual feature to the size that is already there and then from then on anything you dimension will only affect the one thing you ware dimensioning?

 

[BiPolarMoment]

I'm not sure I understand the way you phrased that. Once you've dimensioned something everything else will be scaled down or up so that the proportions of the sketch is maintained. So if you drew a rectangle that was 4" x 4" (pre dimensioned) and dimension one flat-to-flat to 1" the other flat-to-flat will also be scaled to 1" but it's not actually defined yet so it can also be dimensioned. If you add a dimension to the second flat-to-flat as 2" and it will be a 1" x 2" rectangle.

Essentially the first dimension you put on the drawing dictates the scale of everything that is already drawn, anything further drawn should act the same as you've always known. It is atypical for me to have any clue what size my initial features are being drawn at (they could be 10x the size I will end up at) but I should know the relative scale between them and shape they should be so this is a very handy feature.

This probably explains it better:

http://www.hawkridgesys.com/blog/solidworks-sketch-auto-scale/

 

[Spurs]

Ok
I got it thanks
I am surprised that there is no way to turn this off - to me it is annoying