Default startup code for Printrbot needs upgrading

[Barafu]

Default startup Gcode for Printrbot Simple Metal runs as this:

Code: Select all

G28 X0 Y0;
G29;

However, it must be as this:

Code: Select all

G28 X0 Y0;
G28 Z0;
G29;

This is because G29 calibration routine does not work if the nozzle is higher than 1 inch, and fails silently and sets current height as Z0. Then, second print will start in the air and, if unchecked, can even run over the top. This quirk existed for years and Printrbot are not going to fix it.