Block Creation Guidance

One of the greatest timesavers when drawing with CAD is using blocks. The idea of draw it once use it many times is intended to standardize and centralize our blocks library. For the most part, we have been doing ok in centralizing the blocks in the details area on the network. We have made an effort in the past to update our blocks to a common standard but the task is daunting with approximately 1700 blocks. The blocks were created throughout the “CAD years” for Lanc & Tully from about 1988 to present. Many people have added blocks using various standards and lack of standards. I have set forth a few guidelines to make building and using our block library easier.

There are fundamentally three ways to use blocks. Full size objects to be inserted into modelspace, Symbols that will be inserted into modelspace that represent real life objects and “scaled” or “off-size” details that will be inserted into a layout in paperspace. The procedures we should follow will depend on how we intend to use the block. I am always available to review creating blocks on a one on one basis.

Layers:

Blocks for details that are to be inserted in a layout paperspace will be drawn on layer “DETAILS” only. We will do this because we will never be turning off any layers on a detail. Drawing it on one layer also ensures that parts of the detail are not inadvertently turned off. AutoCAD layers can only have one color and linetype associated with it so we will use color and linetype overrides to have color and linetype variation in our blocks.

Blocks for symbols or true size objects that will be inserted into modelspace will either use the current layer standards or use layer “0” if you intend to use the block across various layers and you want that block to take on the characteristics of the layer it is inserted on.

Text:

Mtext should be used in all text. This will prevent a user from moving “almost all” of a paragraph. Mtext can be formatted and indented numbered notes can now be created.

Paperspace Blocks:

Text shall be created using “Standard” textstyle. The Standard textstyle allows for variable text height. Text height shall be 0.1 for notes and dimensions. Use “Fontchg” from the custom toolbar to make sure your drawing has the standard style definitions loaded. All text in a detail shall be “White” except for the detail title, which shall be “Red” and underlined. The underline shall be an integral part of the text object. To underline text in the mtext editor, just highlight the text to be underlined and click on the “U” for underline in the options above. If it is necessary to use regular text instead of mtext, start the text with “%%U” and the text will be underlined. We will not be drawing lines to underline text anymore. Detail titles shall use a new text style called “detail-title”. This style will set the height of the detail title text to 0.2 automatically and use the same font so that all detail titles are consistent.

Modelspace Blocks:

There are two ways to show text in modelspace blocks. Text can be either regular text or mtext and built into the block as unchangeable text when the block is defined or the block can contain attributes. Attributes offer a way to show text that can be changed without redefining the block each time. Basically, attributes are fields for holding text. Creating attribute laden blocks is an advanced topic and I will be happy to help set up the block if you find a specific need. When using regular or mtext, you must decide how the block is to be used before setting colors/layers. If the text is to take on the colors and layer properties of the layer it is inserted on then you should create the text on layer “0”. If you want the text to be on a specific layer all the time, follow the layer standards for choosing a layer of the correct color for text.

Colors:

Paperspace blocks:

o 1 – (Red) – Heavy

o 6 – (Magenta) – Normal Object line

o 7 – (White) – Lighter Object line and text

o 5 – (Cyan) – Very Light line for fine detail

o 8 – (Grey) – Hatching, Soft-looking lines

Modelspace Blocks:

Standard Layers will determine coloring for these blocks.

Dimensioning Blocks:

Dimensioning is most common in Paperspace Detail Blocks. “Standard” (without any dimstyle overrides) is the dimstyle that should be current before creating dimensions for these blocks. Refer to “Setting Dimstyles to Current Stds” below to make sure your “standard” dimstyle is set to the current standards. Use “Quick Leader” for making leaders with associated mtext. DO NOT EXPLODE associative dimensions. Almost any change you want to make to a dimension or leader can be accomplished by overriding a property setting in the properties dialog box.

Hatching:

All hatching in paperspace detail blocks should be color “8”. Hatching in modelspace blocks will follow the current layer standard. NEVER EXPLODE any hatching.

Insertion Points:

Choosing an insertion point for a block is very important. In order to choose the most useful insertion point, you must understand how the block is to be used. For example, if you create a block of a symbol for a catch basin, the insertion point should be the center of the block. If you are making a detail block to be used in modelspace, the insertion point isn’t as important but we will use a point in the lower left corner of the objects drawn as our standard insertion point for detail blocks.

Setting Dimstyles to Current Stds:

***Warning***

This procedure will overwrite ALL (7) of the standard dimstyles we are currently using. Overwriting your existing dimstyles will affect any dimensions and leaders already in your drawing. You must weight the merit of using this tool on older drawings. If you decide to go ahead with the overwrite, you must review your drawing in entirety as dimensional text will most certainly be formatted differently The text itself will not change. Usually, editing those dimensions should be relatively simple once the affected dimensions are identified.

Under express tools, in dimensions there is a menu item “Dimstyle Import”.

Use the Browse to navigate to “S:\Drafting Standards\” and choose “_Std_Dimstyles.dim” to Open.

Make sure “Overwrite Existing Style” is clicked on then click “OK”.

These guidelines were laid out to help standardize procedures for our block library. There may be times when these conventions are too restrictive and we will address those as they come up. Please see me if you have any questions about making and using blocks or any procedures covered in this document.

Thank You,

Tom Hanley