General CADD Drafting Guidelines:
- Drawings
must always be created and edited on the network file server
(your H:\ drive at Triton College).
- 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.
- 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.
- AutoCAD can be set to automatically
save your work periodically. It will save the current drawing to a special
file called Drawing1_1_1_7044.sv$ (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>
- Never assume that either the
network drive or any fixed or removable drives are error-free.
You can never have too many backups.
- 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.
- Use standard layer names, which are found
at http://academics.triton.edu/faculty/fheitzman/layname.html
- Always plot your drawing in a Layout (Paper
Space).
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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>.
- Always turn FILL ON prior to plotting,
if you want the polylines, donuts, and solid to be plotted with "fill."
- 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.
- The "Undo Back" command will only undo
back to the last time drawing was plotted while in drawing editor.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Place notes and drawing titles in Paper
Space on the A-ANNO-NOTE layer.
- 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.
- 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.
- 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.