Author Topic: Ltscale - Feet vs. Inch Units?  (Read 4224 times)

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dan19936

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Ltscale - Feet vs. Inch Units?
« on: February 02, 2007, 02:13:59 AM »
I'm creating a dimension setup routine and I'd like it to cover setting up units as either inch/foot/millimeter.
I.e.:
1 unit = 1 inch (standard architectural)
1 unit = 1 foot (civil, maybe some structural engineers?)
1 unit = 1 mm (standard metric)

The routine will also set LTSCALE to match the drawing scale, however I'm a little stumped about how a civil setup uses it.
From acad.lin

*HIDDEN,Hidden __ __ __ __ __ __ __ __ __ __ __ __ __ __
A,.25,-.125

This tells me that a line is drawn .25 units then a gap of .125 units. In standard architectural this is 1/4" and 1/8", however for civil isn't this 3" and 1-1/2"? Are civil drawings setup with LTSCALE being 1/12 (0.0833) to get the linetypes to come out right?

acadiso.lin has the values multiplied by 25.4 so that makes sense for metric.
*HIDDEN,Hidden __ __ __ __ __ __ __ __ __ __ __ __ __ __
A, 6.35, -3.175

(Though do metric users resent that standard linetypes are really based on imperial dimensions? Why not even millimeters?)

Thanks,

Dan
« Last Edit: February 02, 2007, 02:18:55 AM by dan19936 »

sinc

  • Guest
Re: Ltscale - Feet vs. Inch Units?
« Reply #1 on: February 02, 2007, 08:21:56 AM »
In standard architectural this is 1/4" and 1/8", however for civil isn't this 3" and 1-1/2"? Are civil drawings setup with LTSCALE being 1/12 (0.0833) to get the linetypes to come out right?


No.

Civil drawings generally do not have scales like 1/8" = 1'.  Instead, they usually have scales like 1" = 50'.  Then there are two different ways of doing things: PSLTSCALE=1 and LTSCALE=1 or PSLTSCALE-0 and LTSCALE=drawing scale.  So for a 1" = 50' drawing, if PSLTSCALE=0, then LTSCALE=50.

The linetypes that come with ACAD.LIN are usually considered to be roughly 2x too large.  So people deal with this in one of two ways: create their own linetype definitions that are half-as-big as the HIDDEN2, CENTER2, etc. linetypes, or set the linetype scale for each individual object to 0.5 (instead of the normal 1).

sinc

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Re: Ltscale - Feet vs. Inch Units?
« Reply #2 on: February 02, 2007, 09:00:57 AM »
Oh, I probably should have also pointed out that the ACAD.LIN definitions use drawing units.  Archies are generally working in 1 foot of model space = 12 drawing units, while Civies usually use 1 foot of model space = 1 drawing unit.  That's probably the factor of 1/12 that you're looking for.