Lasersaur focus/alignment tools

These are focus/alignment tools for the Lasersaur, hardware version v14.04b, using a 3" lens with a focal distance of 73.3mm. You can use this with other focal distances by changing the location of the lens in the focusing tube.

To use these with a 73.3mm focal distance, set the bottom of your focusing lens exactly 40mm from the bottom of the tube. Note this is the bottom of the lens, not the bottom of the retaining ring.

These tools have a base offset of 17.3mm (the height of the "plane"
tool) + the thickness of the material or half the thickness of the
material.

We're starting with four tools and will add more as needed.

plane: for paper or other media under .5mm thick. Also good for
verifying that the grid of your media base is level at arbitrary
points. The focus distance should be the same from the grid to the lens at any point on the grid.

wood
1/8" mid: focused to the middle of 1/8" media
1/4" mid: focused to the middle of 1/4" media

acrylic
3mm top: f