DXF file oversize or undersize problem and a workaround solution
No time? I will go right to the point -> The problem is, the usual output file formats (e.g., PDF, SVG, DXF, and the physical print) are either oversized or undersized. I don't know why, but I guess it has something to do with automatically added page margins. So the scale whether fixed or not (through checkbox in the print preview section), is changed to some floating point number (e.g., 1:1.4608 or 1.0246:1) every time the file is opened, and it depends on the size of the page that is selected through preference settings. So how to go about this problem.
Here is my solution for anyone who is shocked to see how difficult it is to get the data out.
Do as follows:
1. Draw a known size rectangle around the whole design, maybe 300mmX300mm.
2. Go to Options -> Current Drawing Preferences -> change Paper to Custom and type in 300 for Paper Width and 300 for Paper Height.
4. Use a vector graphics editing software to re-scale the design to 300mmX300mm., I used Inkscape; I have to mention that I do not literally scale the design(no multiplication), I simply type in the width and height on the top toolbar in Inkscape.
5. Save the file as SVG or PDF format. If this is what you want then that's it. if you want a DXF file, then:
6. Convert the file back to DXF using a file converter.
If you are wondering why I didn't and don't use the export feature, I have to say that aside from the size issue, the SVG and the PDF output formats were not acceptable for my design and is not acceptable when the design has arcs in it (at least in my case). the arc shape became jiggly in the output. So I prefer to have the usual DXF output and use a file converter instead.
Hope you don't pull out your hair like I did at the time ;)
Re: DXF file oversize or undersize problem and a workaround solution
Why so complicated?
Yes, at first start Print Preview sets a page margin to ensure all the content will be on the page, with some space around it. If you want an exact scale, you have to set this manually, by choice from the drop down list or by typing in. "Fixed" indeed is not always persistent. If you draw a frame around the design, do it in the size of the set paper, if the drawing is other than 1:1, scale that frame accordingly. You then can do "Center to Page" in Print Preview instead of shifting around manually.
Important: stay in Print Preview mode when hitting the "Print" icon.
Yes, the inbuilt pdf/svg export can produce jiggly output of curved elements. I experienced this especially with text. If you are on windows you might use an external pdf/svg printer. Or on linux the Cups pdf printer.
When using an external dxf to pdf/svg converting service, or program, you loose control over the final layout of the drawing, linetypes, lineweights, fonts, dimensioning looks, hatches etc. Only in LibreCAD itself it will appear as intended.