Hi Martin, thanks for posting the DXF file.

> It looks like MoI isn't recognising the units setting in some imported dxf's from other programs,
> and so is switching to the No unit system - could that be adjusted at some time? Sample
> attached.

This is unfortunately a problem with DXF format in general - Autodesk in their wisdom did not see fit to make an official mechanism in DXF to label what units all the coordinates in the file are using.

There is a "kind of" way to label them, which is a particular AutoCAD variable called "$INSUNITS", which controls what unit system to convert into when inserting blocks from other files. That's the closest thing to any unit system setting in the file, and MoI will look for that variable if it's declared in the header section of the DXF file and use it as the unit system if it's present.

But that's somewhat obscure and many programs just don't write any header section at all in the DXF file, the file you posted is one of those with no header section and so no $INSUNITS variable set, and so nothing in it marking any kind of units at all.

I tested your same file with both Rhino and ViaCAD and ran into the same problem in each of those as well - in each of those other programs if I say set units to inches and then import the file you posted, each of those programs just interprets the coordinates in the file as in inches.

What program are you using to generate this DXF file in the first place, is there possibly any option to enable setting $INSUNITS to be output into the file? If so then that would help make units come across into MoI and also Rhino too.

What happens in the same program that you're using if you set units to inches and then try to import or merge the contents of your file back in again, does it know the units of its own generated DXF file in that case? I would think that you'd see the same problem there.

As far as I know the only real option that I would have for a file with no $INSUNITS set like the one you posted is to pop up a dialog box that asks you what units the file are in, right now it just uses "No unit system" when there are no $INSUNITS present.

- Michael