1. Part 15: Sharing our Discovery
PLOT SPECIFICATIONS
paper size, print area, orientation
plot scale, pen values
Part 15: Sharing our Discovery
Setting Up and Printing
a Drawing

2. Objectives Of This Lesson
To discuss and identify the printing and plotting process.
Described what the plot specifications are ?
Discuss the important consideration in plotting.

3. Overview
Printing is the process of making a paper print by sending drawing data from the computer to a hardcopy device, such as a printer or plotter. Printing your drawing will take place after you have decided exactly what you want to appear on your printed drawing. You can decide to print all or portions of your drawing.

4. Plot or Print a Drawing
Plot specifications (plot spec) are a series of values which determine three things: what part of a drawing is plotted, how it appears on the paper, and to what scale it is plotted.
Plot spec common to most systems include: paper size, print area, orientation, plot scale, and pen values.

5. Plot or Print a Drawing (cont.)
Once a request for the hardcopy has been initiated, the CAD system and /or operating system must then create data that can be used by the specific plotter device.
The Cad system’s proprietary data file (such as a DWG or DGN files) is not usable for the plotter since plotters are sold to companies with many different CAD systems.
Plotters and printers have their own language or data they are able to receive. Therefore, at some point in the process, the CAD data must be converted to the printer’s language.

6. The Printing and Plotting Process
You can specify a number of parameters to control the size and the quality of a plot. You can plot a drawing to any size, use various line thickness and colors for different objects. You can rotate a plot, use specific fonts for text and dimensions.
Important Considerations for Plotting:
Selecting a scale for drawings
Composing a drawing layout
Choosing pens colors and line weights

7. Selecting a Scale for Drawings
It is one thing to suing CAD to produce accurate and neat objects/drawings, but it’s another things to plotting those drawing to scale. Especially if the drawings will be used to manufacture or to build.
All CAD drawings are created on a full scale (1:1). You can draw as big or small on the screen as you like. The magnification of the image has no relevance to the actual scale of the drawing. The actual scale is determined when the drawings are plotted.

8. Composing a Drawing Layout
CAD provides special commands to compose a drawing layout. A common used in many popular programs is as follows:
To compose a drawing layout, you can activate a special mode of working called paper space or plot layout The paper space represents the actual sheet size to be used. You arrange any number of diagrams/objects on this sheet and apply a scale to each [window] individually. In a preview it shows exactly how the images will be plotted and the selected sheet size.

9. Composing a Drawing Layout (cont.)
Title
Sheet No.
8 .5” x 11” sheet
Composing a Drawing Layout (cont.)
See the following illustration:
Choose paper size, e.g. “Letter”
Plot scale (Almost always time 1:1)
Orient to landscape or horizontal.
Create view windows for scaling of objects/diagrams.

10. Composing a Drawing Layout (cont.)
Title
Sheet No.
See the following illustration:
Set the desired scale to print view.
3/16”=1’-0”
NTS
Objects are enlarged or reduced to fit to the desired scale for the view.
1/4”=1’-0”
3/16”=1’-0” Rotated

11. Choosing Pens Colors and Lineweights
CAD allows for working with various colors and lineweights. With most CAD programs, the colors you use on-screen are configured with a specific line weight in the plotter.
For example, the objects drawn with red color on-screen may be printed with 0.007” line weight: the objects drawn with blue may be printed with 0.020” line weight. These are called pen settings/assignments.

12. Choosing Pens Colors and Lineweights (cont.)
Note:
In most CAD programs the line weights are displayed using a toggle switch/icon.
Setting up the plotter:
First configure line weights and colors available in the plotter with the CAD program.
Assign each weight in the plotter with a color or pen number in the drawing.
Make a table showing all the line weights and colors a plotter produce and match them with the pen assignments you want to use.

13. Standard Pen Assignments
Standard Pen Assignments established by US National CADD Standard
On-screen color
AutoCAD Pen #
Microstation Pen #
Lineweight
RED 1 3
0.007"
YELLOW 2 4
0.010"
GREEN
0.014"
CYAN 7
BLUE 5
0.020"
MAGENTA 6
0.039"
WHITE/BLACK
0.055

14. Printers and Plotters
Printers and plotters are used to print CAD drawings, at an accuracy at about dpi or higher as well.
The following are some examples of printers and plotters.
Pen plotters
Ink-jet printers/plotters
Laser printers
Electrostatic printers/plotters

15. Pen Plotters Creates drawings by plotting vectors.
Creates by moving pens on media (paper) or by simultaneously moving the media as well as the pens.
Note:
With advancements in the technology pen plotters are not as popular as they use to be.

16. Ink-Jet Plotters
Ink-jet printers/plotters use ink cartridges, not pens.
Ink flows through very fine channels in the cartridge.
Ink-jet printers/plotters are affordable and are most commonly used.

17. Laser Printers
Lasers work on the principle of electrography, similar to copiers.
Screen image is transferred to the drum with a laser scan. Image from the drum is transferred to a printing medium, leaving an electronic charge on it. The printing medium is then passed through a toner applicator. Carbon particles of the toner stick to the printing media to produce the final drawing.
Laser printers commonly print from 300 dpi to 1200 dpi and usually on 8 ½” by 11” [letter size] or 11” by 17” [tabloid size] paper.

18. Electrostatic Printers/Plotters
Electrostatic printers/plotters uses a number of charging heads to create an electronic image on the plotting medium. The charging heads are positioned along the entire length of the plotter.
They are able to print large sheets at 300 dpi to 1200 pic accuracy. Electrostatic plotters take just about 30 seconds to plot a drawing that could take 30 minutes with a pen plotter.

19. Thermal printers
Thermal printers uses heat-sensitive paper and heated pins, are specialty devices used by cartographers and for applications requiring high-volume, two-color printing.

20. Large-Format Printer
Large format color printers, scanners, copiers and plotters are designed for applications in the Graphic Arts, Architecture, Engineering and Construction (AEC), Geographic Information Systems (GIS) and retail markets for poster printing.

21. This concludes the series of to make one familiar with what's involved in understanding and using
CAD
I hope you found these presentations informative, interesting and entertaining.