Troubleshooting .DXF is too far from Site

Introduction

Issue description

Sometimes, in the USA, a customer follows the directions to save a .dwg as a .dxf, explode everything in the drawing, etc. Then when they go to upload to the .dxf to IVION, they get the error message saying the .dxf is too far away from the site.  What can be causing this issue is the units / unit settings in the original .dwg and how that can impact the scale of the drawing after saving as a .dxf and exploding.  What is happening is the drawing is scaled by a factor of 12 which is the unit factor between ft and inches.  

Scope

This is related to the Vector Map import and .dxf files.  Users will need to have access to AutoCAD to evaluate if this issue is possibly occurring.  

Pre-requisites

Ability to upload vector maps, knowledge of AutoCAD and units settings, and preferably a license for AutoCAD.

Troubleshooting procedure

1. Ask the customer to send the .dxf and the original .dwg, if possible.  Check the units of the drawing and make sure there isn’t an issue there.  

Below is an example of a .dxf that a customer sent in since they could not get it imported successfully with all layers into IVION.

When typing ‘dwgunits’ in the command line, it shows the units are set to Feet.

After typing dwgunits in the command line, the unit for length is <2> which is Feet.

When viewing the drawing settings from the Toolspace, it shows units are set to Feet, more specifically US Survey Feet for any Imperial to Metric conversion.  Here you can also see which coordinate system is being used for the drawing if they wish to upload the vector map via spatial reference system and encounter an issue.

When typing Units into the command line, it shows the units are set to Feet.

2 Evaluate the difference in coordinates or any known measurements between the original .dwg and the .dxf they created from the .dwg.

The original .dwg had the proper areas and lengths but notice how the .dxf above appears off.  The space ‘9819’ is labeled as 1,810 sqft but if you select the polygon and look at the Properties palette, it shows the area being 260,640 sqft.  

Note that 260,640 / (12 inches per foot)^2 = 260,640 / 144 = 1,810 sqft

Therefore, the space is 260,640 square inches in the drawing which equals 1,810 sqft.  The issue is that the drawing units are set to feet so dimensionally CAD thinks this space in the .dxf is 260,640 sqft.

Somewhere along the way of saving the .dwg as a .dxf and exploding elements, the dimensions in the drawing were changed to inches while the unit settings remained as feet.  This may cause confusion, especially if looking at the drawing settings to see units.  At first glance, it could be that IVION is the source of the issue when in fact it is the .dxf conversion / prep workflow prior to importation into IVION.