lineardeltakins - Kinematics for a linear delta robot
The kinematics model is appropriate for a rostock/kossel-style design
with three joints arranged in an equilateral triangle. (0,0) is always
the center of the working volume.
Joint 0 is at (0,R) and subsequent joints are 120 degrees clockwise (note that joint 0 is not at zero radians). The length of the arm is L.
Joints 0-2 are the linear carriages. Axes ABC and UVW are passed through unchanged in joints 3-8, so that e.g., A can still be used to control an extruder.
Three pins have been provided for joints 0-2, to allow for offset trimming
It is suggested that these pins are only used during calibration to determine the proper distance between the work surface and the limit switches for each joint.
Once the proper distance has been determined the pins should be set to zero and update each joints home parameters in the INI file.
lineardeltakins.R float in
Effective diameter of the platform.
R is different than the distance from the center of the table to the center of the belt/smooth rod/extrusion that the joints ride on.
InRepRap delta parlance, R is DELTA_RADIUS which is computed as DELTA_SMOOTH_ROD_OFFSET-DELTA_EFFECTOR_OFFSET-DELTA_CARRIAGE_OFFSET.
lineardeltakins.L float in
Length of the rod connecting the carriage to the effector.
In RepRap delta parlance, L is DELTA_DIAGONAL_ROD
lineardeltakins.J0offs float in
Offset distance applied to Joint 0
lineardeltakins.J1offs float in
Offset distance applied to Joint 1
lineardeltakins.J2offs float in
Offset distance applied to Joint 2
The R and L and joint offset values can be adjusted while Machinekit is running.
However, doing so while in coordinated mode will lead to a step change in joint position, which generally will trigger a following error if in joint mode with machine on.