Here a little tutorial for print DXF at 1-1 scale when they are bigger then A4 page.

Here a straight cone designed using Cone Designer.

Here the DXF in A9CAD

Go to Print Setup in File menu

Print Setup window

Remove the Scaled to fit option and set 1mm to 1mm

Then hit Refresh button

Now the drawing is at the real size and goes over the page

Hit the Windows radio button then choose the window to be printed

Now the drawing windows is ready to be printed and to the same for the other part. Assemble the printed paper sheets.