General CADD Drafting Guidelines:


  1. Drawings must always be created and edited on the network file server (your H:\ drive at Triton College).

  2. While drawing in AutoCAD, you must use the "save" command approximately every ten minutes to be sure that you have your file continuously updated to the network drive.

  3. At end of editing session or end of each day, save the drawing to the file server one last time and exit AutoCAD. Copy the drawing file from the file server to your own USB memory stick.  If the network drive fails, or the drawing file is corrupt for some reason, copy the duplicate copy you made on your memory stick back to your folder on the H: drive. Do not save your files on the C": drive, because it is erased whenever the computer is rebooted and automatically every day after the studio is closed.

  4. AutoCAD can be set to automatically save your work periodically. It will save the current drawing to a special file called$ (or something like that name, but it will always have a filename extension of sv$). This is another failsafe device, in addition to the *.bak file described above. To use this file, open the folder, find the sv$ file, rename it to a .dwg filename extension, and double click to open it. Note that sv$ files are saved by defalt to the folder: C:\Documents and Settings\AT150\Local Settings\Temp\. Therefore, if you reboot the computer for any reason, all contents of the C: drive are reverted to the state if was before you started working, therefore it will not be there.

    To save your drawing automatically in the form of an sv$ file to C:\Documents and Settings\AT150\Local Settings\Temp\ every 10 minutes, at the Command: prompt, type: savetime <ret> 10 <ret>

  5. Never assume that either the network drive or any fixed or removable drives are error-free.
  6. You can never have too many backups.
  7. In general, do not set a current color or linetype to anything other than "BYLAYER". Also do not CHANGE the color or linetype of an entity to anything other than "BYLAYER". There might be some exceptions to this in certain pieces of equipment, millwork, or furniture, but they should be rare.

  8. Use standard layer names, which are found at

  9. Always plot your drawing in a Layout (Paper Space).

  10. Show at least five lineweights in your drawing for visual clarity. Walls in plan have the thickest lineweight, then windows and doors, then notes, then objects on the floor in plan or wall in elevation, then far-away objects, then dimensions, then hatch patterns, which are the thinnest lines.

  11. Make use of the pre-drawn 3d-objects such as cube, cylinder, cone, etc. that exist in the AutoCAD pull-down menus. This will save time in drawing. These objects are pre-made polymeshes with 3dfaces attached to make them appear solid. They can be exploded to edit the vertices of the polymeshes and the 3dfaces. Their vertices can be easily moved by selecting them to put grips on them and stretching the grips to the desired locations.

  12. Extruded CIRCLES, POLYLINES, RECTANGLES, ELLIPSES, and closed LINES always have closed tops (and bottoms) when hidden or shaded in 3d. If you want to create a 3d object with an open top, give the object a "Thickness" rather than use the "Extrude" command.

  13. A POLYLINE object with any width other than zero, a DONUT, or a SOLID object, will not appear filled when viewed in a 3D view other than a plan view. There is no way to change this.

  14. When snapping an insertion point to an object, it will snap to that object's own actual elevation, not the "current" elevation. To prevent snapping objects to elevations other than the 0 elevation, use the .xy filters to set z to 0. Normally when you insert an object, it always should be inserted with its "base" at 0.

  15. When selecting objects to edit, if those objects do not show on the screen they will not get picked, even if their layers were just thawed: Thaw the layers, then "regen" to get those objects to appear on the screen so they can be picked.

  16. Always thaw all layers prior to WBlocking to another file -- frozen layers will be purged during the WBlock. Also, layers with no entities on them, blocks which are not inserted, and unused dimension and text styles will also be purged.

  17. Always turn ON and THAW all layers that you want to plot prior to plotting -- OFF or frozen layers will not be plotted. To quickly turn On and Thaw all layers, type: -LA<RET>ON<RET>*<RET>T<RET>*<RET>REGENALL<RET>.

  18. Always turn FILL ON prior to plotting, if you want the polylines, donuts, and solid to be plotted with "fill."

  19. Always zoom to extents prior to plotting, to make sure there are no "stray" lines outside of the area you think is the extents of the drawing. This will also REGEN the drawing to allow the fill and text to be shown.

  20. The "Undo Back" command will only undo back to the last time drawing was plotted while in drawing editor.

  21. To avoid plotting a Viewport entity (the rectangular box around a viewport), change its layer to DEFPOINTS. If the DEFPOINTS layer does not exist on your drawing, you may make it and Change the Viewport entity to be on it. AutoCAD automatically creates a layer called DEFPOINTS when you draw your first dimension line. AutoCAD places points on this layer which are the Origin points for the dimension line. The DEFPOINTS layer has the peculiar characteristic that you will be able to see it (if ON and Thawed) but it never plots.

  22. A hatch pattern is a "pseudo-block" and has some block-like characteristics. For instance, a hatch pattern is made up of many lines but is considered one entity by AutoCAD. An exploded hatch pattern will "float" down to the "0" layer. Do not explode hatch patterns. You will get too many individual lines in the drawing as a result, and it will be difficult to edit them later.

  23. Dimensions are also "pseudo-blocks" and they have some block-like characteristics. For instance, a dimension is made up of 3 lines, 2 solids, 2 points, and a text entity, but is considered one entity by AutoCAD. An exploded dimension will "float" down to the "0" layer. Do not explode dimensions. An exploded dimension will no longer be associative, so if the geometry of your drawing changes, the dimensions will not record the true measured sizes. You will no longer be able to use the "Dim" "Update" command to change sizes of dimensions, either, if you decide to change your plot scale.

  24. To find the distance between 2 parallel lines, select from the "Tools" Pull-down menu, "Inquiry," then "Distance." (or type DI <RET>). Then OSNAP NEArest to one line, then OSNAP PERpendicular to the other.

  25. To draw a line through the center point of an arc or circle but stop it at the edge of the arc or circle, draw a line from a point and when prompted for a To Point: OSNAP PERpendicular and pick the arc or circle.

  26. Place dimensions in Paper space on the A-ANNO-DIMM layer. Be sure to set the variable DIMASSOC to 2, to make them associative and reach into the Model Space drawing to find the origins of the dimensions.

  27. Place notes and drawing titles in Paper Space on the A-ANNO-NOTE layer.

  28. Place "Keys" or "Targets" (like door numbers and section or elevation marks) in Paper Space (in the Layout). Most targets are 3/16" radius circles. Make sure that you move them if you move the drawing.

  29. When lines are "hidden" polyline, Donut and Solid fill will not be shown, even in plan. It will appear as if fill is turned off. Also, viewports in which "Shade Plot" has been turned to "Hidden" will not plot fill for polylines or donuts or solids. To allow solid fills to be seen in a viewport, shade the viewport in model space and set "Shade Plot" to "As Displayed." You could also create two overlapping viewports, one containing the hidden line model and the other containing only the solid fills, dimensions and notes. Turn on "hideplot" in the viewport containing the hidden line model and leave it off in the viewport that contains the other entities. To prevent double plotting of entities, you may want to freeze layers containing the hidden line model in the second viewport.

  30. Set the variable "FACETRES" to 10 and the variable "VIEWRES" to 20000 to get smooth shaded cylinders and spheres. To see shaded curved forms in their smoothest appearance, use the "Gourad shaded" method.


Frequently Asked Questions

1. What is the difference between OFF and FROZEN layers.

A. Not much. Using "Off" rather than "Freeze" is now recommended for a variety of reasons.