How can this line be constrained?

[tbenkerE2YG2]

As poor hobbyist i bought myself a Logitech MX Ergo trackball mouse as a CAD mouse. Today i was practicing with it  by randomly doodling with every geometry and function in the sketch. I draw a house like shape on the right. The sides of the rectangle are equal but not dimensioned. As well as the two lines forming a triangle on top. I applied no dimensions or constraint to them. The centerline between them constrained perpendicular but no dimension as well.

As soon as i dimensioned the distance between the central rectangle and the origin that line became constrained while rest of the shape was still unconstrained. If i double click and select the line, all shape scales up and down when i move the line.

As that line has no defined length or starting point i would expect it to be unconstrained as well i am confused.

I am attaching a screenshot pointing the line I am referring to and the sketch file if anyone would like to check.

[Drewpan]

Hi,

I was not suggesting at all that you had broken any rules. I was suggesting that if you really want to learn how

fusion works then that is where to start. You may also want to take a look at the three RULES pinned to the top of the

forum which give good advice for learning and using fusion.

Constraining sketches is a vital skill to have in fusion as the sketch is the basic structure that most of fusion

modelling is built on top of. It is true that fusion will automagically constrain certain things, and it is not always

obvious when or why it does so. A strong knowledge of what constraints are and the different types of constraint

will not only help you constrain your own sketches properly, but will also allow you to work out when fusion has

placed a constraint that is not actually useful to you and needs to be deleted.

This forum is an excellent place to learn and get advice. There are also many YouTube and other tutorials out there

to help you learn. The problem with these external tutorials is that you don't always know if what they are teaching

you is correct. Sometimes they create more problems than they solve on this forum because often a self appointed

"Expert" is self-taught and may be very good at their niche area but their basics are terrible. A Beginner will follow

these tutorials thinking they are learning good material but what they are actually learning will mostly have to be

un-learned and the correct technique taught to them.

Do not despair. You are doing the right thing by practicing and modelling often in areas that you like. As you come

across problems, continue to reach out to the forum for help. We are all here to learn and to help others.

Cheers

Andrew