Issue Description
You want to create a Fill Pattern to accurately represent aspects of your project, but you also need it to work with the different scales used.
Solution
1. Set the scale to 1:1
2. Draw the fill at true size using the line circle or polyline tool
3. Copy the pattern and go to the Options > Element Attributes > Fills.
4. Select NEW.
5. Select Symbol type > Name the line type.
6. Select > Paste > to copy Pattern over.
Now we need to edit the Stroke values for the horizontal, vertical and offset.
Edit the values until the Pattern you drew starts to take shape.
Select Scale with Plan (Model Size) to make the fill scalable.
Select OK.