User's Manual Part 2

Glossary 276
PLA
PLA (Poly L a ct i c Acid ) i s a bi odegradable plastic, typically
made from renewable raw materials such as cornstarch or
sugarcane. Besides 3D printing filament, oth er comm on
uses are for plastic cups and plastic water bottles. 1, 42,
210, 212, 214, 219, 220, 232, See also filament
polar coordinates
Polar coordinates describe two-dimensional location via ra-
dius, r , and angle, ✓.ComparewithCartesiancoordinates,
which instead describe two-dimensional location via x and
y coordinates. The Polar3D printer uses polar coordinates
at the hardware level, which has several advantages; see the
Polar 3D video “WWBD - Polar is Better”.
Does this mean that you or your students need to use or
understand po l ar coordinates? No! The Polar3D pri nter
expects i nd u st r y -stan d ar d .stl files, which describe loca-
tion in the more familiar Cartesian x, y,andz coordinates;
the Polar3D printer’s firmware automatically converts from
the Cartesian coordinates describing an object to the polar
coordinates (technically, cylindrical coordinates) that the
printer’s hardware uses.
However, if you have students who are learning about polar
coordinates i n their math class – see Common Core stan-
dard http://www.corestandards.org/Math/Content/HSN/CN/B/4/
– you may wish to draw such students’ attention to the un-
derlying polar operation of the Polar3D printer, both to
help motivate them as to why one might want to l e arn
about polar coordinates, and to hel p them visualize the