This is a remix of item 1559629.

Changes include:

1. Changed width of pen holder to 2 inches to match width of pivot block. Now edges can be used to set measurement in addition to pointer.
2. Moved/added pointer to top of blocks with a window to see ruler better.
3. Shortened rod lengths and receptacles for better view of ruler in window.
4. Combined large base and rod into one part.
5. Printed rod for pointed tip vertical to eliminate flat along side.
6. Mirrored parts so the threads are standard direction (i.e. righty-tighty or counterclockwise is a loose screw).