PDA

View Full Version : Survey Units

Wilkie
19th Mar 2010, 01:21 pm
I have a drawing submitted by a surveyor that I want to add to. The initial drawing unit setting is decimal, unit-less. When I check between grid points, etc, all is fine, but when I change the units in my dimension settings to architectural, they are off by a factor of 12 (what reads 25.00 now dimensions at 2' 1").

I want to work in architectural, but if I scale the drawing up by a factor of 12, then the coordinates are no longer valid when I execute the list command for a survey point.

I don't want to change my dimension factor by 12 and then have to draw new objects in decimal units. There must be some way to have the coordinates correct and the dimensions in architectural format.
Can the USC be factored up by 12 to maintain the correct coordinates, or the units somehow redefined, or some other work around:??

todouble22
19th Mar 2010, 01:34 pm
I have a drawing submitted by a surveyor that I want to add to. The initial drawing unit setting is decimal, unit-less. When I check between grid points, etc, all is fine, but when I change the units in my dimension settings to architectural, they are off by a factor of 12 (what reads 25.00 now dimensions at 2' 1").

I want to work in architectural, but if I scale the drawing up by a factor of 12, then the coordinates are no longer valid when I execute the list command for a survey point.

I don't want to change my dimension factor by 12 and then have to draw new objects in decimal units. There must be some way to have the coordinates correct and the dimensions in architectural format.
Can the USC be factored up by 12 to maintain the correct coordinates, or the units somehow redefined, or some other work around:??

I think what you have to do is keep the decimal and set the units to feet then you have to scale it down 1/12 or 1:12 dont use 0.083 or you could get rounding errors depending on your precision. try that first and see what results you get. You could also use 1/12 scale factor in the measurement scale of the primary units tab in your dimstyle, this will multiply each dimension by 1/12 (0.0833333), converting inch units to feet.

MikeScott
19th Mar 2010, 01:35 pm
25 inches is 2'-1" so I'm failing to see the issue?
25.5 would be 2'-1 1/2"

If it reads 25, and you think that should be centimeters or meters, instead of inches, and you now want to convert to inches, you need to use the scale command and resize the whole thing by the appropiate multiplier.

Wilkie
19th Mar 2010, 01:54 pm
Thanks for your responses. The 25 should be feet, but since it is unit-less in the original surveyors drawings, it is dimensioning as 25". If I re-scale the drawing (up or down), I lose the original coorindate data. I am seeking a way to keep the correct cordinates and get the units to be feet rather than inches.

Does that make sense?

MikeScott
19th Mar 2010, 02:29 pm
It's no longer unitless if you have already turned feet into inches.

I assume that the coordinates are not in the same units then? Right now, they're also being measured in inches..

I'm still thinking the scale command is what you need here, unless you want to fake it with primary dimension text being x12

Try "scale" with a multiplier of 12, and see what happens. If's it's no good, then hit undo and do the Dimension text work-around.

eldon
19th Mar 2010, 02:36 pm
The initial drawing unit setting is decimal, unit-less.

You are trying to mix units - feet and inches. The unitless factor is used when inserting blocks.

If you want to preserve the coordinates, you will have to work in the same units as the initial drawing. No other way.

This is one occasion where metric is a more convenient unit to work in. The surveyors work in metre units and the architects work in mm units with a scaling of 1000. If the scaling is done about the point (0,0), then coordinates are preserved.

Wilkie
19th Mar 2010, 02:37 pm
Thanks Mike, and I agree that may be the fix.

The problem is the re-scale changes all of the coodinates, so if I want to know the actual coordinates of a survey point, I have to use the original drawing, which means I am jumping back and forth between drawings, big pain here. That is why I was looking for a way to some how "re-enter" the information using feet as the the units

You poiint about unit-less stumps me too. I do not understand why if I change the units to feet it doesn't make the dimensional conversion and maintain the coordinate points. The unit-less doens'nt seem to work here

Wilkie
19th Mar 2010, 02:47 pm
Thanks Eldon, you're saying what I feared to be true. Alas, it dosn't sound like there is a work around to this problem. It does seem that someplace in the world of programmers there is a way to convert the coodinate units, but I fear this is not the case.

MikeScott
19th Mar 2010, 03:32 pm
then the dimension fake will work, just multiply the primary units by 12.. then at least dimensions will look right.. you'll just have to remember while adding entities to it, that you're dealing with decimal feet as your drawing units.

This way it won't affect your coordinate system at all.

Wilkie
19th Mar 2010, 08:26 pm
I think I've found the solution.

I opened the original survey drawing and created a block containing all objects. Next I opened a new drawing (or in my case our template), changed the units to feet, and pasted the block into the drawing.

I deleted the block, re-inserted it within the drawing at a scale factor of 12, and aligned the cordinates. I now have the correct coordinates and can dimension in achitectural. Whew and voila:D!

kmgcmk
22nd Nov 2011, 08:14 pm
I have had the same problem, and was hoping to find a better solution. The work around I have is just scaling up the survey data by a factor of 12. If you use the base point of 0,0,0 when scaling, all the coordinates are unaffected.

ctdlc888
16th Feb 2012, 05:31 pm
or you have to have two drawings for each unit.you can go to either