Hi,
The patterns are functional but are intended as metric patterns.
To be installed under
...QCAD/patterns/metric/*.pat
Your drawing must use Metric as measuring system, see Drawing Preferences.
You cannot mix the creation of metric and imperial patterns in the same drawing document.
This type of pattern coding can be seen as tiling an area using tiles, all with the same unique pattern.
HWOD20E1 is defined on a 50 by 50 units tile.
HWOOD5E1 uses a 100 by 100 units tile.
The size of the base tile is not stored in a pat file and can not easily be deducted for all cases.
Typical for
CADhatch patterns is breaking 'demanding' orientations up in cloned definitions making it 21/19 tiles wide in these cases.
Unsure how the pattern preview is handled but it doesn't react on changing the scale.
Suspecting that the size of the preview square is 30 by 30 units plus a border, displaying a pattern at unit scale.
Except with a metric document and pattern names starting with 'AR-', then the preview square is 900 by 900 units plus a border.
Still, both patterns are not empty for the left lower part of 30 by 30 units.
When installed as imperial the pattern must be scaled down by factor 25.4 at least.
Or:
Every value listed in the pat file must be scaled down to inches.
Except the first value of each line because that is an orientation in degrees.
A general advice under QCAD is keeping your hatch origin near the hatched area.
These patterns will start to loose coherency beyond 5-10k tiles.
This also accounts for Hatches in Blocks where the Block definition and/or the insertion point is far from the origin.
Regards,
CVH