Insert, Xref and US Survey Feet

[jpCADconsulting]

Hi folks,

I have a survey file from our surveyor, drawn in US Survey Feet. INSUINTS is correctly set to 21 in that file.

In our file, drawn in INCHES, INSUNITS set to 1, I'm seeing different results between inserting and xrefing the survey in.

If I INSERT the survey, the unit conversion is listed correctly as US Survey Feet and the scale is 12.0000

If I XREF the survey in, the unit conversion is also listed correctly as US Survey Feet and the scale is also 12.0000, however, the plan is scaled up ever so slightly so that at the distance from 0,0 that the plan is, they are off by about 2'-7". NOTE: This is a scaling issue, not an alignment issue.

This happens in AutoCAD 2018 and in 2022.

Anyone else seeing this behavior?

[pendean]

Can you share DWGs or sample DWGs with the problem?

[RSomppi]

If the scale factor is correct, how can it be  scale issue?

Make sure base is set to (0,0,0).

[jpCADconsulting]

That is my question exactly...

Here is my process (sorry I can't post the files at the moment as this is an active project - I'll see if I can erase most of it so it's indistinguishable - stay tuned)

I make a new file with UNITS and INSUNITS set to inches. We'll call it "File A"

I insert the external file that is in US Survey Feet - we'll call it "File B" - into File A as a block.

I then rename that block so I can also xref the external file in

I then Xref File B (the exact same external file) into File A.

One is slightly larger than the other.

Bug?

[TomBeauford]

US Survey Feet vs. International Feet Warning prompt https://forums.autodesk.com/t5/civil-3d-ideas/us-survey-feet-vs-international-feet-warning-prompt/id...

Sounds like one insert used US Survey Feet and the other used International Feet.

[jpCADconsulting]

How can that be? I'm not inserting two different files.

I'm "inserting" the same exact file twice, once using the INSERT command, Once using the XREF command.

Bonkers. I'm going to do a test and post example files.

[pendean]

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@jpCADconsulting wrote:

How can that be? I'm not inserting two different files.

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If you cannot share files then do this instead 

https://knowledge.autodesk.com/customer-service/account-management/users-software/support-options#:~....

[jpCADconsulting]

Weirder still. (I have included all mentioned files for you to have a gander at).

I made a new file in inches and that file is called "TEST FILE A - Inches.dwg".

I made a test file in US Survey Feet (I just drew a box around the site in the original file and deleted everything else). That file is "TEST FILE B - US Survey Feet.dwg".

I then inserted "TEST FILE B - US Survey Feet" into "TEST FILE A - Inches" at 0,0. As you can see, the units/scaling are correct:

I then xrefed "TEST FILE B - US Survey Feet" into "TEST FILE A - Inches" at 0,0. As you can see, the units/scaling are correct:

Now however, in TEST FILE A - Inches, the block (in red) is 1/12th the size of the xrefs (yellow).

The block's units read as inches:

 

 

The xref's units read correctly as US Survey Feet

 

[pendean]

Your US SURVEY FEET file's distance from 0,0,0 is absolutely crazy far: you hit an AutoCAD limit/issue there.

Fix that file: get with the file originator and you two work together on it.

[jpCADconsulting]

That part is sort of out of my (our) hands.  But good to know.

Nice find!

[jpCADconsulting]

Still, the question... why the different behavior between INSTERT and XREF?

[pendean]

@jpCADconsulting It's the same problem, which appears to be "out of (our) hands" so... .

You can always test inhouse to confirm: what's holding you back?

[RobDraw]

When hitting roadblocks like this, it's sometimes not to fret over the why's. Rebuilding both files from the same template can do wonders.

[ChicagoLooper]

@pendean wrote

<<....Your US SURVEY FEET file's distance from 0,0,0 is absolutely crazy far....>>

In the US, the coordinates for the State Plane Coordinate System, SPCS, are always large. (This post won't cover the reasons why, but easily could.) Most States have more than one zone, e.g. Illinois, Indiana and Ohio have 2 zones each, Wisconsin, Colorado, Florida and Michigan have 3 zone each, Texas has 5, California 6, and Alaska 10.

Many small States have only 1 zone, e.g. Vermont, Connecticut, Rhode Island and Maryland but some large ones do too, they include Montana, South Carolina, North Carolina and Tennessee. The number of zones a State has is determined by each State and their zones typically follow County borders for demarcation. There are over 100 Zones in the US and the US Territories.  

The SPCS is easy to use, provided you know how to lookup and use the correct Zone. When SPCS is used in a digital drawing environment such as AutoCAD they have a high level of accuracy (less than 1:10,000) due to each individual zone having its own PROJECTION. The coordinates may be large, but they're not that crazy.

If a version of AutoCAD hinders a user due to limits placed in the drawing, then the user should switch to another version, one that specifically can handle SPCS, especially the verticals with a Coordinate System Library which a user can select from and assign to modelspace. 

[pendean]

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@ChicagoLooper wrote:

If a version of AutoCAD hinders a user due to limits placed in the drawing, then the user should switch another version, one that specifically can handle SPCS, especially the verticals with a Coordinate System Library which a user can select from and assign to modelspace. 

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Amen!

[ChicagoLooper]

I would never convert a survey originally drawn in feet and create a duplicate drawing that uses feet-and-inches. If I did, the surveyed coordinates, the x/y’s, would get messed up.

In a survey the coordinates are golden (the typical US survey is in feet). Believe it or not, modelspace represents the earth's surface while surveyed coordinates represent real world 'points' on that same surface. You want the points or the x/y’s, in the survey to be honored. If they're not, then you or your boss, just paid a licensed surveyor unnecessarily. And don’t forget, you paid that surveyor to 'get it right' not to 'get it close!'

Your feetinserttoinchesmakeblockxref procedure is whacky. Why? Because you've taken your 1st drawing, a survey feet drawing, scaled it to inches in a 2nd drawing, then inserted the 2nd back into the 1st. Aaahh…..excuse me while I climb back into my chair.....I got so dizzy typing it I accidentally fell on the floor.

You need to expand your drawing repertoire and draw in feet instead of drawing in feet-and-inches. If you feel compelled to use feet-and-inches anyway, be forewarned, your Bing aerial imagery will no longer be consistent with your line work. Yes, you can make Bing aerial imagery appear as a basemap in the original Survey Drawing if know how to assign the same coordinate system used by the surveyor.

<<Sidenote: If you want to know how to turn on Bing Aerial in the survey you uploaded, start a new thread titled How to Turn on Bing Aerial Imagery in a Survey Drawing so it’s Consistent with my Line Work.>>

To make the paste procedure work accurately, abandon your procedure and do this instead:

1. Open the survey drawing. Type UNITS on command line and change the units to UNITLESS.
2. While still in the survey, perform a Save As (You make a COPY w/Save As because you want the original survey to remain as-is). When you save it, keep the same name as the original but add an underscore version 2 as a suffix, like this *_v2.   
3. Next while still in *_v2, SELECTALL=>Right Click=>SCALE=>base point enter 0,0=>scale factor enter 12=>ENTER
4. Pan and Zoom to the newly scaled objects=>Select all the scaled objects=>Right Click=>Clipboard=>Copy to Clipboard=>base point enter 0,0=>ENTER
5. Next, go to your ‘inches’ drawing such as TEST FILE A – Inches.dwg, the drawing you uploaded in a previous post=>Right Click in modelspace=>Clipboard=>Paste to Original Coordinates (or Paste as Block).