DataCAD How-To's

 

HOW TO USE THE MULTIPLE DRAWING FILE TECHNIQUE

Jeff Tagerman describes the Multiple Drawing File technique of CAD drawing (for the purposed of Jeff's demonstation he is not using Multi-Scale Plotting). This involves keeping the entire project in one drawing file, and reusing and copying entities as much as possible to avoid inefficiently wasting time and effort redrawing repetitive information. The key to this technique is proper layer management. Entities which are exactly the same on multiple drawings or details should only be drawn once whenever possible. For instance, even if you have 5 drawing sheets your title block and sheet borders are the same from sheet to sheet, so you should have 1 layer with 1 border/title block on it. You can then make 5 new layers, each with only sheet-specific text information on it. This keeps the drawing file small while eliminating repetitive information -- the very foundation of CAD productivity.

Lets use a two story house project to demonstrate. He showed us a completed First Floor plan with dimensions and text. The plan was set up on multiple layers -- 1-WALLS, 1-DR/WIN, 1-DIMS, 1-TEXT, etc. From here, to create a foundation plan make a new layer called FOUNDATN, then do the following:

  1. Turn on only the First Floor walls layer.
  2. Copy the exterior lines of the walls to the FOUNDATN layer.
  3. Turn off the First Floor walls layer, and turn on only the FOUNDATN layer.
  4. Use 2-line Trim and DataCad's other Cleanup functions on the copied lines to close corners, weld lines, etc. This will give you the exterior lines of the foundation walls.
  5. Make the lines for the width of the concrete walls and for the spread footings by using the Geometry/Offset/PerpDist command to copy the foundation lines. If your walls are 10" thick then offset all of the first lines by that distance to form the foundation walls. Then use the Cleanup commands. If the spread footings are 12" thick then offset all of the first lines by that distance to form the spread footings. Use the Cleanup commands.
  6. Use Change/LineType/Entity to change the spread footing lines to dashed lines.
  7. If you used Associative Dimensions on your first floor plan you can to to that layer and copy the relevant ones to the FOUNDATN layer.
  8. Go to the FOUNDATN layer and Stretch the associative dimensions as required to dimension the foundation plan.
  9. To make your second floor plan you would follow the same general steps as above, placing copied entities in new layers such as -- 2-WALLS, 2-DR/WIN, 2-DIMS, 2-TEXT, etc. The (unsupported)"crossing" feature of DataCad v. 7.06 is a big help in picking only the double wall lines that you want.

Notice that by copying like-entities to other layers all of your plans are overlapping one another, but are contained on other layers. You should LEAVE them overlapped. Why? For several reasons:

  1. Let's say you want to Stretch the length of your building. If you turn on all the Wall layers for the First and Second floors, and the Foundation layer, plus all your associative dimensions for those floors, you can stretch them all at once, and you will be assured of changing ALL the floors by EXACTLY the same angle and dimension.
  2. Let's say you add some bearing walls to the second floor, and need to place the same walls directly below on the first floor, and on down to the foundation plan. All you have to do is draw the walls once, then copy and clean them to the other floors just as you did in steps 1-8, above.
  3. If you want to copy, or even just align some doors and windows between floors, you can turn on the appropriate layers and see right away if they are aligned or where they have to move to.
  4. You only have to draw common elements like the outline of a chimney once, on only one layer, which can then be left turned on whether you are viewing one floor at a time or all of them at once.

If you draw ductwork or plumbing fixtures on one floor, you can immediately see where and how they impact the other floors.

The idea of the Multiple Drawing file technique is to make your drawings more accurate and better coordinated, and to save time. Better drawings and less time = fewer headaches and, hopefully, more $$$$.

 

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