QCAD.org Forum

Changing the main drawing unit in the Drawing Preferences dialogue does not consistently change the coordinate display in the status bar.

I started a drawing with the application default set to centimetre and the drawing inherited this. All was well until I decided that I would prefer to work in millimeters. Ouch! Now there is no rhyme or reason as to what exactly is displayed in the status bar or (even worse) as to what scale a library object inserted into the drawing will appear.

Please note that QCad does not scale your drawing for you when changing the drawing unit.

For example if a line was 10cm long and you changed the drawing unit to Millimeter, the line is now 10mm long. In fact, the drawing unit does not have any influence on the drawing geometry. It is only used when printing to scale.

If you want to convert your drawing from cm to mm, please use the scale function in addition to changing the unit in the drawing preferences.

OK, now I think I get it. But surely in addition to printing to scale, there is at least one other instance in which it is used: when inserting a library object. In this case, the current scales of both the current drawing and the object must be compared to determine the scale of the object being inserted relative to the drawing. Yes?

John,

My investigation reveals that Andrew is correct. If you look at your QCad.ini - file, which stores all variables that are saved during program exit, you will find:

[LibraryInsert]
LibraryInsertAngle=0.0
LibraryInsertFactor=1.0

This suggests that the librarys inserted use a scale factor of 1.0 until you change it to something else. It appears that no calculations are conducted as you suggested.

Your file for winXP would be at c:\Documents & Settings\"username"\Application Data\RibbonSoft\QCad.ini.

I find the lack of unit conversion support quite inconvenient because I want to measure distances onscreen. It would be nice if RibbonSoft implemented rescaling when changing the drawing unit and inserting a part.