How to Re-size a Pipe Cross-section on an Exaggerated Scale Without Thinking

The Scale Command's Tool Tip

I had a profile view with an 18” diameter pipe drawn in cross-section that actually needed to be 24” in diameter.  I know you are thinking, just draw a new circle with a 24” diameter.  Sure, that’s what I would usually do.  In this case though our cross-section was a roadway profile and we draw those with an exaggerated Y-axis scale.  In this case the x-axis scale was at 1:40 and the y-axis was drawn at 1:4.  We do this to help visualize the changes in elevations along the y-axis.  It’s a common practice in civil engineering plan and profile roadway designs.  These types of cross-sectioned pipes are typically drawn with an ellipse.  I could have taken the time to do the math and determine who wide and tall to draw my ellipse.  I also had a pipe drawn in at 18” that was properly scaled in across both axis.  I copied it and used the scale command.  What scale did I use?  24/18.   That’s not a scale.  Sure it is and it enabled me to get this job done in seconds.  Let me explain.

I had a pipe drawn at 18” in diameter.  It was already an ellipse so it was scaled properly in both the x and y axis.  I just needed it to be a 24” diameter pipe.  In order to show an 18” diameter pipe in a 40 scale drawing at a scale factor of 4 we have to draw a 15’ diameter pipe about the y-axis that is also 18” wide across the x-axis.  This makes for a tall and skinny ellipse.  A 24” pipe would be drawn at 20’ tall.  That is because we scale the y-axis “up” to put it at a different scale in the drawing view.  This math can make your head hurt so do the easy thing.

Access the Last Point Used in AutoCAD With One Keystroke

There are many instances when we draw in AutoCAD where we might want to draw to the last coordinate point we used.  This is how it works.  Draw a line from point A to point B and end the command.  Start the circle command.  For the center point type @ on the command line.  This will draw the circle’s center point at the last point we drew at which is point B on our line.  See the video clip below.

You can use the “@” symbol in any case that requires a coordinate input.  If you want to draw concentric circles draw the first circle.  Draw the second but use the “@” symbol for the center point.  It will select the center of the first circle drawn.

In my post, “How to Break a Line Like a Pro” I showed you how to use the “F” or first option in the break command to break an object at a specific point.  In Tip Number 2, I have you select the exact same point to break an object in one place.   Alexandre Serdakowski, a reader of this site and a Head Draftsman, reminded me of the last point feature of the “@” symbol and that the break command would be a great use case.  Start the break command, select the object, type F, pick your point, then for the second point type in @.  It’s much easier than selecting the same point again.
Also keep in mind that if there is no last point in a drawing yet then using the @ symbol will draw your object point at the origin (0,0).

AutoCAD – How to Break a Line Like a Pro

AutoCAD’s Break command allows you to “break” a line, splitting it into two segments. The Break command “normal” steps are as follows:

1. Start the Break command (type break or br on the command line)
2. Select the object to break which also selects the start of the break area (the area that will be removed from the selected line.)
3. Pick the Second Break point.  This will break the line (arc, circle, polyline, etc.) and remove the segment from the object.

Now for the Tip.  It’s an extra step but it gives you control of where the line is being broken.

1. Start the Break command.  
2. Type F on the command line.  Select exactly where you want the first break point to located.
3. Pick your second break location.

This method makes it easier to control exactly where your line is going to be “broken”.

Tip Number Two.

1. Start the break command and select your object to break.  
2. Type F on the command line and pick the exact place you want to break your line.  
3. For your second point pick the exact same place.  

This tip allows you to break an object in one place leaving the entire object visually intact, but split into two segments.  It will look as if it is still one object until you select it.

You’re welcome.

If you are using AutoCAD and do not create 3D content then why are you using AutoCAD?

Is this a fair question to ask?  AutoCAD LT® can do almost everything "regular" AutoCAD® can except for 3D modeling/rendering features and LISP routines, essentially.  Are you waisting your company's resources by not purchasing AutoCAD LT®?  I don't know, ok I do, but, still.  What do you think?  If you aren't creating 3D content, why?  If you aren't using LISP routines then I ask the same question, why?

Why do you limit yourself?  Why do you pay for tools that you refuse to use?  If you are creating items that only have two dimensions why are you using a three dimensional creation tool?  Many sheet metal fabricators use AutoCAD LT®.  They get it.

I'm not trying to be mean here I am honestly curious.  If you purchased a house with three floors would you only use two of them?  At least store stuff in the third floor right?  Have you ever said to yourself or others, "I've never seen a real need to walk up the stairs to the third floor so I don't use it."  You're paying to heat/cool it and to protect it from the elements.

Make an argument for purchasing full on AutoCAD® but for using it like it's AutoCAD LT®.