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CAD Basics 101 – Drawing Cleanup

Drawing Cleanup is another important aspect of being a good CAD Drafter. Your drawing can start from scratch or from existing drawings. Most of the time it is the latter and we inherit someone else’s mess. This post we will talk about some of the things that can be done to clean your drawing up, before it gets copied across and entire project. How do you clean a drawing? What exactly are we cleaning in our drawing? Our drawing file is essentially a self-contained database. As with any database, it will perform better if it is optimized or free of clutter. Here are just some things that can clutter your drawing.

Empty Text – Text with nothing but spaces.
Empty block references – a hidden block (empty attributes of points)
Nested Block References
Proxy entities or records – Third party custom objects.
Linetypes
Text Styles
Annotation Scales
Wipeouts
Layers
Dimension Styles
Table Styles
Points (Nodes) – use PDMODE and PDSIZE to find these
The List goes on and on…

Here are a few things to consider to help clean up or keep your drawing cleaner.

PURGE COMMAND

PURGE can be used to remove things like Empty text strings from the drawing, Unused layers, block, linetypes, text styles and more. PURGE is pretty much the easiest step to take towards a clean drawing. Keep in mind that you may need to purge a few times because of nesting of objects. If block A has 5 layers defined in it, and you purge block A from the drawing , then it leaves behind the 5 layers. There is an option for purging nested objects, but just know PURGE is a multi-depth process. When PURGE no longer offers anything to purge, then you are done with PURGE.

Tip: If you ever get an older drawing that you think might have empty text strings and want to see just how bad it is, use the QTEXT command and turn QTEXT on. Then REGEN the drawing, zoom extents and see what kind of trash is in the drawing. QTEXT places a box around the contents of text without displaying any fonts. It was used on early releases of AutoCAD to provide faster Regen and redraw times.

SCALELISTEDIT

ANNOTATIVE Scale Factors can be removed from a drawing using SCALELISTEDIT. Why remove scales from the list? SCALELISTS can grow to a massive number of entries, causing more processing on AutoCAD’s part. Every time you reference a drawing or insert a block you have the potential to add more and more entries. There are automated routines out there to help facilitate cleaning these from your drawings. There are a number of tools on the internet to help assist in automatically purging extra scales from your drawings.

 TFRAMES

WIPEOUTS are invisible and often end up driving someone crazy. A less experienced user may open a drawing and plot it. Then notice there is a hole or a portion of something not plotting. They look in the drawing to see and all looks good. They plot again and again. A Wipeout is covering something and can’t be found. The TFRAMES command will allow you to make your WIPEOUTS visible. Review the WIPEOUTS and remove the ones that are not desired. TFRAMES is a Toggle to Toggle a frame to show the wipeout. Sometimes it takes a REGEN to see them, sometimes TFRAMES just doesn’t work. If you find there is no difference, exit AutoCAD and get back in and try again.

How to Find Invisible Blocks

What happens when you have that one block that just won’t go away? This is where you have to do a little detective work. Sometimes it is easy and it is just a hidden block that is nothing more than a block that contains hidden attributes, but nothing you can actually see on the screen. You can use the ATTDISP setting and set Attribute display to ON. ATTDISP set to ON will force hidden attributes to show on the screen, but if the attributes themselves have nothing in them, you still won’t see them. If you set QTEXT to ON and REGEN, then the blank attributes inside the block will show up. Often Third Party software systems will create these for tracking or initializing the drawing. If it is just one and you know it is part of your Software system then leave it, but if you find multiples, you may want to get rid of the extras and let the Third Party software reset itself.

Tip: Another quick way to find out how many times a block is in a drawing, is to use AutoLISP to find them. Start the SELECT command (or any command that you select objects with) and type the following:

(SSGET “X” ‘((0 . “INSERT”)(2 . “BLKNAME”)))[Enter]

Replace BLKNAME with your block name you are looking for. This will add all occurrences of that block to you selection set, note that different space selections will show they were excluded from the selection set. Visit my AutoLISP Teaser Post if you want to play with some more AutoLISP.

Extra blocks

Some other issues that can cause problems is when a user uses the Clipboard copy methods and paste as block. This creates an auto generated blockname that typically looks like A$7EDF1341A. You can easily end up with lots of these blocks that may just be nested blocks. Often times the user may just wish to copy a block from one drawing to another, so they think, copy as block. Unfortunately that is not exactly what happens when selecting copy as block. What happens with that approach is AutoCAD creates a nested block that contains the block you selected and creates a new auto generated block name for your new block. To do this operation properly, simply select a block in Drawing A (it is already a block) simply Ctl-Shift+C (Copy with basepoint); select the insertion point of the block. If INS osnap does not show, then it is probably not a block. Then select the block and press enter. Open up the destination drawing (Drawing B) and simply use Ctl+V (Paste) pick your insertion point and you are done. The only block definition is the one you wanted. If you find lots of Auto generated Block Names in your drawing you will want to check their block definition and if they are just nested blocks, explode them to un-nest them. Then you can purge the Auto generated block. If the block is comprised of entities and such that are desired to be a block, then use the RENAME command to rename the block to an appropriate name.

PROXY Entities – Hate em’

Proxy objects are essentially custom objects (graphical and non-graphical) that were defined and created by a Third party application that is not currently loaded into AutoCAD. Keep in mind that could be an AutoDesk AutoCAD-addon application too. Custom Objects come from Applications like CADWorx or AutoCAD Civil or… To get rid of the proxy you will want to load the correct object enabler for the object. When you see the dialog box stating proxies, you will also see what application it is looking for in the list, so don’t just dismiss it. Review it and find the correct enabler. If you do not want the proxies in your drawing but you want the graphics they represent, you will need to use the enabler’s exporttocad ability. Each enabler does not necessarily provide this functionality. You will need to research it and find out the correct command name to do so. I’ll probably write a post on this later. Once you rid your drawing of them, then you should be in pretty good shape for that drawing. Proxy objects prevent things like Wblock, or Binding Xrefs and can easily propagate into other drawings if you don’t take care of them.

What else?

There are a number of other things, Microstation linetype issues, Annonomous groups, and more that can get in to your drawing and make it a nightmare to just pass on and inherit to multitudes of other drawings, so always start with a fresh drawing and copy just what you want from existing drawings. Save it and check the drawing size. If it gets large quick, you may have copied in something corrupt. Work through what you copied and try and isolate what or where the corruption is. Since things like Drawing Templates or Title Blocks are used throughout projects it is VERY IMPORTANT to make sure these drawings are CLEAN.

AutoCAD Drawing files have become very complex with all the new features that AutoDesk keeps adding into AutoCAD. I did not cover everything here, but I tried to cover some of the most common things. Do your best to avoid passing on corruption or trash in your drawings. This will improve quality and keep your system operating more efficiently.

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CAD Basics 101 – TEXT

 

I won’t bore you with rants about some of the, let’s say, subpar drafting efforts I have seen over the years. CAD has become more and more advanced and feature rich over the years, and I feel drafting quality has declined. Let’s try and help turn that around. Starting with Text. Text is used to communicate to the person reading the drawing. It is important that we communicate effectively and consistently. Text is basic so here are some basics checks for text.

  • Is text spelled correctly?
  • Is the text clear in meaning?
  • Is the text uncluttered and not overlapped by other line work in the drawing?
  • Is text positioned correctly?
  • Justified and aligned correctly?
  • Is text the right height for the subject matter (Body, Heading or Title)?
  • Text Width?
  • Layer?

Is your text spelled correctly? It is easy enough to verify your spelling. Yes we all make typos and get rushed, but get in the habit of verifying your spelling. Is the text clear? Does the text present the message you are delivering. Abbreviations are used quite frequently in drawings, but you should avoid them if possible, remember the goal is to deliver a clear message.

Is the text uncluttered and not overlapped by other line work in the drawing? Your text should not overlap or be overlapped by other elements in your drawing. Your text should be located in a spot that allows for text to be uncluttered. If your location does not allow for clean placement, you may need to break some of the background out or consider using a wipeout or text mask. I you choose wipeout or text mask methods, make sure you have good standards in place and have communicated the proper process for using them. Remember the printed result is what is used. If your system requires special settings for printing some of the issues that arise from wipeouts and text masks, then it is highly likely someone will print it incorrectly.

Is text positioned correctly? Your text should be relative in position to what you are identifying. A leader that stretches across 3” of printed material could easily lose its association. We will cover Leaders in another post. Is it justified and aligned properly. If you are like many CAD users, you simply copy other text in the drawing, change it and move on. This practice works great, but make sure the text you are copying is right to begin with. One of my personal favorites (read sarcasm) is when I copy a few lines of text, I then update that text, and then suddenly instead of it shifting as it should. The text actually changed position from where it should have been justified. For instance. It looked like it was centered, then when I changed the text to be longer or shorter, I discover it is Left justified. This is easily fixed, but, shows poor quality work on someone’s part. Make sure your alignment is correct. If you are placing an equipment tag inside an equipment outline and it fits centered and looks clean, great. If it is on the left or right of the equipment, Should it be left or right justified, these are things to look at. It may sometimes work, but it may also get confused with another piece of equipment. Check the presentation and make sure it is clear.

Is the text the right height, weight, width for the subject matter? Standards are what dictate these things. You should have some. If you are unaware of them, then ask. Text heights, weight, and width are often controlled by the text style. Text styles are a great way to maintain a consistent look in your drawings. Get to understand them. Note that text height and width are controlled at the text entity level and not the style level. The style simply sets the default for those. Text weight can be controlled in a few ways, Layer, color and by font selection. Again consult your standards on these. If the text is on the correct layer, you probably have the weight right. If the Font is set by the style correctly, you probably have the weight right. Color based plotting can control the weight as well, so keep in mind the best practice is to always draw bylayer for your color setting and not use the color setting at the entity level. Yes there are occasions when you should deviate. We will save bylayer topic for another post as well.

Some of you will relate to this topic, and think yes I wish more people understood this. If this is the case, forward this post on to them. Share the knowledge. I have found that typically most CAD users want learn and improve their skills. I’m sure all of us have opened a drawing and thought, “WHAT WERE THEY THINKING?” Some CAD Users are learning, CAD Systems like AutoCAD, have become so feature rich and full of functionality, often times new users are overwhelmed and not sure what the correct approach or setting should be. I am hoping to post more on CAD Basics on a regular basis. If you find these useful please share, comment or like. Thank you for reading.

Have an amazing day!