Deleting Blocks and Layers

Why won't these stubborn ACAD elements go away? December 9, 2004

I am an old pencil pusher and architectural detailer, recently converted to ACAD. I start all my drawings in our standard template. I have imported some drawings from architects to get floor plans and moulding details. Now my layers are full of over 200 layers that the architects use. When I try to delete them, it will not let me. I get a message that you can not delete layer 0, defpoints, used layers or xref layers. Since my template starts out as a blank page, except for a few layers used for border and text in layout page, I don't know why I can't delete these layers. If I apply layers filter to show all xref layers, it is empty, so that's not it. I think it is linked to blocks, since importing these drawings, I have acquired numerous blocks, some of which are floor plans. How do you delete unwanted blocks? Tried ACAD help, but could not find an answer. Using ACAD 2004. Ah, for the old days, when an eraser could delete anything.

Forum Responses
(CAD Forum)
From contributor V:
Immediately upon opening your template drawing, try using the "purge" command. Also try using the Layer Manager to individually delete unwanted layers. Layer 0 and defpoints are standard. I use Architectural Desktop 2004 and there are also several layers that are created by default for walls, etc. by the program.

From contributor S:
I don't think it is possible to delete defpoints, as AutoCAD uses it for its own definition points, if I'm right. I agree with the previous posting regarding purging the drawing, which you will find under file and then drawing utilities in the drop down menus from the top of the screen.

Good luck with your venture into AutoCAD from paper - it's worth it, despite the frustrations at first. You'll find this site very valuable for problem solving, philosophical debate on the pros and cons of paper verses CAD, plus a good splash of humor along the way.

From contributor R:
The above is correct as far as normal purging goes. Check to see if the layers are "locked" (that little padlock symbol next to the layer). If so, unlock them, and try purging again.

Are you trying to "delete" the layer using the Format > Layer > Delete command? If so, ACAD won't allow some layers to be deleted, which can be frustrating.

Use either the Layer Manager or the Purge command (type purge) and look at the command line to see what layers are being offered for purging. Also, when I'm presented with this problem, I try exploding the entire drawing, though only as a last resort. Before deleting or purging, make sure that you're only purging layers you're not going to need. I use a third party program called Super Purge that has the option of purging any layer. The only drawback is that once it's purged, it's gone forever. As far as the defpoint layer is concerned, it's not a "default layer" technically. It's only created when the dimension command is invoked. It goes back to the DOS years.

Good luck with your ACAD learning. It can be both interesting and frustrating! If you have questions, post them on this site. This forum is full of helpful and knowledgeable people who've gone through the same problems you're going to have.

From contributor J:
When I receive an architect's drawing with one million layers, the first thing I do is make a copy of it to work with. This way, if I make a mistake, I can always start fresh. I then work inside the arch drawings.

Depending on the situation, this is what I do:
1. Using the layer manager, I make sure that all of the layers are unlocked, thawed, turned on, not frozen in current viewport. Now you can see everything.

2. In model space, use zoom extents. If the drawing zooms and you can't see any objects that would cause this to happen, there might be some very little objects like points or extremely small text somewhere. If so, use the erase command and window in the empty areas around the main part of the drawing to see if anything gets highlighted, and erase them.

3. Delete all layout tabs (except model) to get rid of any title blocks or unwanted trash in paper space (if applicable).

4. Do my first purge to get rid of all unused objects (blocks, layers, etc.). With large drawings, this helps to free up memory and speed things up. Depending on your system, if a drawing is real big, it slows down AutoCAD on things like regen, pan, etc. Also, when you purge, make sure your layer is set so that you know there are few or no objects on that layer, like layer 0.

5. Type xref to see if there are any xref’s attached. I detach any xref’s that are not found or unloaded. If there is an xref attached and loaded and I want to keep it, I will select it and use the “Bind” button, then select “insert”. This will permanently insert the xref into that DWG as if you did it with the regular insert command. Now you have total control over its properties. Now there should not be any xref’s in the drawing.

6. Purge again to narrow down the process and help speed things up.

7. I use the express tools “Layer iso” to start isolating layers that I want to delete. Then turn back on all of the layers. It’s not a good idea to select a lot of different layers at one time - this way you can look and make sure there is nothing on that layer you need. After deleting a few layers, purge again and see if they are gone. If not, there is something using that layer, like a block. If you don’t want to retain any blocks, explode the whole drawing. You might have to repeat the explode command several times or even do a section at a time to make sure you get everything. If you don’t have express tools, get them - there are a lot of neat tools in there.

8. When I finally get most of the unwanted stuff out of the way so I can see exactly what I want, I isolate those layers and copy them way off to the side. Then turn back on all layers and delete the original area and purge. Then zoom extents and the copy you made should be center screen.

9. Now you should only have the layers of the copy you made. At this point, depending on what I want, I’ll change whatever is left to one layer and purge.

10. Save the purged drawing for reference. Use cut and paste to bring the object into the drawing you want. This way you don’t run the risk of bringing over any other stuff you could not get rid of.

This process works for me most of the time, and I’m sure as time goes on, you will develop different ways to do this. Just remember to share.

From the original questioner:
Thanks for the info. Using purge, I was able to clean up both blocks and layers on my standard template. Contributor J, I think I will try your system on the next project where I import an architects drawing. Think this will speed up my regen.

From contributor Z:
The purge will work as a global function if you create a wblock from the drawing you are in. The screen will ask for the name, use the same as the drawing, and say okay. Be careful - make a backup of the file you are in. Then reopen the file and all information not needed will be purged.

From contributor S:
There is a utility available called Super Purge. It will delete anything and everything in one swipe. You pick what you want it to do. It even deletes nested entities.