Lines, offsets, and breaks

[kmanuele]

Blank drawing, create a sketch on the XY plane, edit sketch.

Draw a line ('A'), then offset that line an arbitrary distance -line 'B'.

Draw a perpendicular line from A to B.

Break line A -- automatically selects intersection of the perpendicular line, as expected.

Problem 1: part of line B is removed (what?)

Problem 2: I can't move either piece of line A that supposedly was broken. Can't even point-point move in the same sketch. I can delete it. I can offset it, then delete the A piece. This would serve my purpose here -- except the mating B piece below is missing ☹️

Repeat above, but just two parallel lines with the perpendicular.  In this case, everything the same except break doesn't remove the 'B' line piece.

What's happening here?

Thx

K

[laughingcreek]

problem 1- it's not deleting part of line b, it's just not transferring the offset constraint to the broken bit from line A.  a peculiarity for sure.   fusion will try to repair applied constraints when you do things like break and trim.  but frequently gets it wrong.  most of us here have a bit of an aversion to the offset constraint anyway, so this probably goes mostly unnoticed.

problem 2 - not seeing that.  you probably have a constraint some where (either purposefully applied, or applied for you during the break) that is probably preventing move.  you could post an example if you want something more definitive.

[kmanuele]

Thanks;

I've attached a simple sample file. Two parallel lines (not offset). Top line broken at the perpendicular.

Can't move either piece of the top line independently. None of the constraints shown in the sketch palette would seem to limit this.

Don't get me going re: offsets in Fusion 360. 😵  Spend a lot of time working them, though I understand (somewhat) why they would be a problem in this environment.

[laughingcreek]

remember the bit about fusion trying to apply appropriate constraints when you use break?  that's what's happening here.  you can tell by looking at it that the lines are constrained with a coincident because there are not dots at the intersection.  hovering over the intersection reveals the constraints, and hovering over a particular constraint will cause the sketch curves it is applied to to change to an ever so slightly darker blue.  you can then delete the one you didn't want.(the mouse pointer doesn't show on my screen shots.  it's over the constrain)

if there hadn't been a constraint there it would look more like this-

[laughingcreek · Accepted solution]

fwiw-when I DO use offset, I generally delete the offset constrain and apply my own dimensions.

[kmanuele]

Seems like a lot of extra steps.

But thanks for your help.