- Delete even stubborn layers.
- AutoCad Do's and Don'ts
- The .BAK, .SV$, and the .DWL files explained.
I've had a couple of people ask me recently how to purge/delete a layer that refuses to remove itself from their lives. You know what I mean...you turn off all of the other layers, you check for any entities on this stubborn layer (can't see anything!) and yet it just won't go away! Chances are this layer is referenced in a block, or an old dimension, or some other obscure way and consequently it doesn't see itself as being totally empty. And we all know that if a layer isn't empty or is referenced some place you don't stand a chance of purging it!
Enter the fabulous LAYDEL command! This former Express Tool grew up and became a real live command a couple of releases ago. This super sonic command will be happy to delete a layer regardless of what is on it! In fact - if you the layer is referenced in a block definition it will open up that block...rip out the layer...and redefine the block right there on the fly - imagine that!
Remember though...where there is power there is danger! (so please keep that in mind).
Training:
This is always a hot topic amongst CAD managers and most experienced users. These can’t always be followed but that is only in very rare circumstances. Feel free to print this out and frame it for your office.
AutoCAD Don’ts
- Never explode a dimension. When you think it’s necessary to explode one, don’t.
- Never explode a hatch.
- Do not place the Titleblock or border in Model Space. (Like legacy GC)
- Do not scale the Titleblock or border, larger or smaller, than 1:1. (Like legacy GC)
- Do not scale or rotate reference files. (Like legacy GC) The only exception to this is when you are dealing with a consultant who uses a different scale of units or a different origin. For example, Architectural units and Civil units are different by a factor of 12.
- Do not “plot to fit” when plotting a drawing. Force the drawing to an accurate scale. Contractors and clients will most likely take scale measurements off your drawing. If the scale is off even a small amount it could be very costly, or dangerous.
- Do not draw on layer “0”. If you do, move it to the appropriate layer after it’s complete. Excpetion are element inside a block. See the How-To Section on Block Creation.
- Do not draw on the “defpoints” layer. This layer is for AutoCAD to use for dimension information. Some users draw viewports on this layer...Don't. Use the VL command to change them to "G-Anno-Nplt" automatically.
- Always check over and Spell check a drawing before you plot it.
- Always Save a drawing before you print. Most often a drawing crashes right around the time you finish it and go to plot it out. Most old school users do this already.
- Always Purge a drawing before you close it. Use the CD command which will do this for you.
- Whenever possible, use a reference when you have the same information that is shown in more than one drawing.
- Limit the number of reference files you create. Don't create several reference files when a layer will do in one reference!
- Zoom Extents before closing a drawing. Use the CD command which will do this for you.
- When drawing dimensions, avoid dog legs (more than three lines in a leader), crossovers, and draw the leaders at a consistent angle whenever possible.
- Make sure the leader actually touches the object it is calling out. Use your object snaps.
- Lock your Model space viewports. Use the LV command to do this quickly.
The .BAK, .SV$, and the .DWL files explained.
The BAK File:
The BAK file is created from the current DWG when you Save the drawing. The BAK file defaults to the folder in which the related DWG file is saved. It is the same size as the drawing file from which it was generated.
The SV$ File:
The Automatic Save file extension is SV$ (not the oft presumed AC$ which is a temporary file). You configure the time interval at which that file is saved by the savetime command. It is currently set to save every 15 minutes. It is also the same size of the drawing file from which it was generated. These files are saved to a Temp folder on your computer. This folder is located at C:\Document and Settings\Your Username\Local Settings\Temp.
The DWL File:
This is a lock file. I frequently refer to it as the little "traffic cop" file that is created when a drawing is opened so if someone else opens that same drawing while it's open, they receive the "Read Only" notice. This is only 1KB. When a drawing is closed this file will delete itself.
Both the BAK and SV$ files are there to "save the day" if you have a system crash.
Beginning with AutoCad 2006, when you launch AutoCAD after having a system crash, the Drawing Recovery manager appears with the names and related files of the drawings open at the time of the crash. As for the little DWL file, it will automatically go away when the drawing it was locking is closed. If there's a system crash (or any other "illegal exit" of a drawing), it sticks around since it never received the official notice the drawing is closed.