Handy AutoCAD-14. Safe Plot
...Again...Lost hidden-center-phantom-dashed lines, all lines are solid on paper! Five (10, 20...) sheets thrown in basket, wasted time and money...Because LTscale was changed in Modelspace (set not equal 1) to make a distinction between hidden and continuous lines, and was not changed to 1 in Paperspace before printing (PSltscale = 1).
The following AutoLISP - new command PLO providing safe plot: first the value of LTscale checked and, if it is not equal 1, set LTscale to this value, then plot command.
(DEFUN C:PLO()(if (> (getvar
"LTSCALE") 1)(setvar "LTSCALE" 1))(initdia)(command ".plot"))
Next time you send the drawing for printing, enter the command PLO. After that Plot window appears on the screen. There is no regeneration of all ViewPorts, the lines on screen still may look solid, not hidden, but don't worry, on the paper you will get the correct representation. The problem solved!.. Not really. There is another possible issue - linetype scale of objects in Modelspace not equal 1.
You know, when hidden line is too short, in order to make it hidden on paper you can change linetype scale of that line to, for instance 0.5 and the other objects to 0.3 or 0.7. Finally before printing you decide to set LTscale for this layout equal 0.5, then after some experiments you are changing it to 0.4. Perfect! After that another CAD person is assigned to finish the drawing you started. He or she is trying to set LTscale to normal value equal 1 and getting unexpectedly bad print. Maybe it is better to follow the rules:
A. NEVER change linetype scale, always use 1
B. Add in acad.lin file custom, more dense linetypes (samples shown below) and use them in drawing.
;; LINES 4 (TWO TIMES MORE DENSE THAN CORRESPONDING
HIDDEN2 OR DASHED2 etc.)
You can globally change linetype scale to 1: select all objects and in Properties window change *VARIES* against Linetype scale to 1.
Last thing for consideration: PSltscale value. Traditionally it should be set to 1: ViewPorts can have varying magnifications, yet display linetypes identically. But if ALL ViewPorts on ALL layouts will have the same scale, you can set PSltscale to 0, once set LTscale equal to ViewPort scale (e.g. 12 for scale 1" = 1'-0") and use standard command PLOT (not PLO).
Note 1. When the drawing will have only one layout and the drawing is simple and all parts of the drawing require the same scale drafting, you may not need PaperSpace. All drafting can be done in ModelSpace. Classical case - shop drawings of piece details in steel detailing.
Note 2. Even if the drawing is assuming using PaperSpace, you may not always need to create ViewPorts for objects. For instance, if layout is only notes and abbreviations, why don't you place all text/Mtext objects directly on PaperSpace - it is easier.
Alex Borodulin 11/17/09