Thursday, 8 May 2014

AutoCAD selection tools

Let me share a couple of words on AutoCAD selection tools. I have been in quite a few engineering offices and for some reason these commands are not used properly or even at all. For example I haven’t heard anyone using temporary tracking “TK” command no matter of the AutoCAD flavor and user background (electrical, mechanical, P&I D)
                Let’s review the standard ones; single click selection or window selection. Single click just adds to selection and holding shift removes from selection. Window selection can be left-right and right-left having different effects.

 Right-left selection (displayed with a green shade inside the selection window) will select everything included in the selection window plus all intersected by the selection window.

Left-right selection (displayed with a blue shade inside the selection window) will select just the things inside the selection window.

A lot of the times though your elements won’t fit a rectangular window so you can do a polygon selection.
This selection can be “WP” window polygon or “CS” crossing polygon or “F” fence. WP will select just the elements inside your polygon.

CS will select elements inside and everything your polygon intersects.

Fence will select jus the elements intersected by your polygon.

When you use WP, CP or F and you picked a wrong point for your polygon (eg. You have osnap on and it snapped to existing geometry) you can type “u” (undo) and it will undo the last segment of the polygon (this can be done multiple times to undo several segments).

If you accepted your selection too early, picked wrong base point or you realized you need to add stuff to your selection then “ESC” your command and start it again. Then when prompted to select objects type “P” previous which will select your elements again.

Fence is especially useful with trim and in the image bellow I have used it to cut the yellow lines in between the circles.

Bellow I have used fence again to extend the yellow lines up to the blue outside circle.

Let me show you track “TK” command now. I want to copy the bottom circle up 200 and left 200 in one operation.  When prompted for location on copy command type “TK” and start tracking from inside the original circle left (or up) 200 and then in the other direction.
In this example I will copy the circle 200 mm from each edge of the square. You can use “TK” for the copy point and paste point.

All these commands are available with any of the modify commands (trim, extend, copy, move, rotate, stretch, etc.)
Watch the video for a better visual understanding of these commands.


And of course the video:

UPDATE 09-Jul2014: Check the new post with a bigger selection list here