Find us on Google+ Construction Time Again - Inventor Sketches ~ Inventor Tales

Sunday, August 29, 2010

Construction Time Again - Inventor Sketches

“The road to success is always under construction. Under construction. That means you're always working. So that's what he's doing.”
Chad Epperson

There's a busy week ahead of me, so this is a shorter blog today.

But I wanted to talk about something that is often taken for granted.  Construction lines.

When I'm training, I'll even tell students "They're a good practice, but don't wake up in a cold sweat if you forgot a construction line." 

Construction lines.  Can I just forget they exist?
So why do I say they're a good practice? 

Well, it is good book keeping.  But the single biggest reason is that a construction line is ignored for the purposes of creating a sketch boundary.

Okay, so what does that mean when translated from 'geek speak'.
Here's a rectangle, divided by a line.  About as simple as it gets.  All lines are standard lines.

Nothing special here!
But what happens when I extrude the lines?  The line running down the middle splits the profile, meaning you have to make two picks to extrude the entire rectangle

Inventor sees two regions here

But if I make the middle line a construction line, the line is ignored, and the entire sketch can be selected in one click. 

You can make the line a construction line by selecting it, and clicking on the construction line button.

Make the regular line a construction line

Now, with the construction line created, the extrusion only requires a single click to select the entire profile.

Construction line created!

Profile can be selected in one pick

So there's the big difference.  Do I convert lines to construction lines when necessary?  Yes, I do.  I find it particularly useful when I have a complicated sketch with a lot of line geometry.  I find it makes creating the extrusion a lot easier.

That's it for now.  Happy Inventing!


  1. I use Construction Lines quite a bit. Very handy, especially when projecting geometry into sketches. I think that projected geometry should default to Construction lines. Or at least let there be an Application Option which lets you set the default linetype of projected geometry.

  2. Good place to use construction geometry. I have done that myself on a few occasions.

    I used to be a lot lazier using construction geometry in my younger days. I've become a lot more disciplined now.