Eng / Arch units causing a scaling issue

[tim_newsome]

Survey dwg file is in Engineering / feet. Client layout dwg is in Architectural inches.

very little cad in client file so I change the DDUNITS to decimal and feet then scaled the objects by (.0833333333) and manual placed them according to survey file that is X-ref. I have done this many times before and never had an issue.

I just tried to copy and paste and there is still a units scaling issue. Each way I copy and paste there is obviously a .0833333 conversion each way.

Insertion scale are both set to feet. Where else can units be changed or set besides DDUNITS?

[remi678731]

Are you using C3D or AutoCAD

[tim_newsome]

Plain AutoCAD

[tedg]

Not sure if this applies but look into these variables for each of the files, make sure they match:

insunits
insunitsdefsource
insunitsdeftarget

[tim_newsome]

Just did a copy and past in the same file and it did the same thing. Its literally a defined copy and paste scale factor.

tried the last post variables and they did not solve it.

[magnusonzach]

Have you tried a copy > paste as block? I find that sometimes (I go from IMP to Metric often) when I paste as a block, I can adjust the scale manually to "1" with Properties. I'll draw a couple working lines from 0,0 to make sure it gets aligned properly. Wish there was a paste as block to original location option...

[rkmcswain]

What @tedg says. AutoCAD tries to be smart and "figure out the scaling for you".... when it should just let the experts do it....

Make sure INSUNITS = 0 in both drawings.

[Omoth]

You should not have to change units in either drawing... I wouldn't recommend that.

I have had success with copy/paste from the arch drawing into my drawing then scale it 1/12 (easier than 0.83333333) and adjust the position and rotation.

[rllupo422258]

Autocad & C3D are very good at determining scaling, as long as it knows what units it is dealing with in the source and target drawings. They both need to be set correctly. There is NO REASON to ever leave units set as undefined - your drawing has SOME units, correct? Surveys are typically FEET, architectural and structural are usually inches, etc. Why not define them?

Simply open each drawing and set its DWGUNITS correctly. Type DWGUNITS, pick the units (0=Unitless, 1=inches, 2=feet, etc), then pick your appropriate units and precision, then answer YES to "scale other drawings...", and YES to "match INSUNITS to drawing units...", then NO when you are asked whether to scale content (assuming everything was drawing correctly and only the units were set incorrectly). If you do this in all of your drawings, any time you XREF or insert other drawings (defined as SOURCE files) into your file (defined as the TARGET) and they are all correctly defined, Autocad/C3D will work it out.

Just make sure your INSUNITS are set to the same as your DWGUNITS. This way, when you are in a survey (feet), and you XREF or insert a file whether it is feet or inches (or whatever), Autocad will do so with the correct scaling automatically.

One other issue you may come across if you ever use a file (source or target) whose units are set to UNITLESS - in your OPTIONS> User Preferences, YOUR settings for the settings that say what to do if a source file is set to unitless. If you have this set to feet, but the source file is actually inches (but defined as unitless), Autocad does not know any better and will assume the units are feet because your options/setttings say so.

Hope this helps,
Bob Lupo

[cadtag]

Personally, I always force my drawings to be unitless. It's easy enough to scale inserts up or down by a factor of 12 (US ) or shift the decimal point around for metric. Post the 2016 Release, this has become critical to do, as the new setting for US Survey Ft in addition to International Feet was a pointless fubar that really accomplished nothing useful, and resulted in xrefs and images landing in an incorrect location.

I can appreciate what Autodesk was trying to accomplish, and If I had to regularly convert Metric to US or vice-versa, I might find it tolerable. My experience theough is that the INSUNITS concept was very poorly implemented, and is frankly less useful than nothing.