Kinematic Solutions are provided by Issues and Solutions when targeting the Kinematic milestone. This page as a whole provides the background information for it. Individual sections are linked from the corresponding solutions.

The Kinematic Solutions are part of an overall holistic (whole-machine) approach to calibrate both the cameras and various mechanics of the machine by playing the two against each other. On one hand, the known metrics of machine motion are used to calibrate the cameras. On the other hand, the camera is used to make the motion more precise. The inherent chicken and egg situation between the two is circumvented by exploiting various forms of symmetry and by approximation through iteration, things that would be hard or tedious to do by hand.

To get some impressions, watch a video of these and other calibration solutions. The video is not complete, so come back to this page.

For each axis, capture the lower and higher soft limit, i.e., the very extremes the controller axis is allowed to move. Jog to the low or high extreme respectively.

If the axis has limit switches (or if the controller has its own soft limits, which are not to be confused), use a position close to these, but still safe not to accidentally trigger them, taking fast moves and machine vibration/flex into account. Allow for ~0.2mm wiggle room.

When you are happy with the position, press Accept to capture the axis coordinate:

These captures coordinates will set the Soft Limits as described on the Machine Axes page.

In case of a Z axis, do not confused the Soft Limits with the Save Z Zone (which is a different thing, as explained here). To capture Z Soft Limits you need to jog over the area of the machine, where you need to lower the nozzle(s) the most. This can be where the bottom camera is sunken into the machine table, or where the nozzle tips are changed or some other low point the nozzle needs to be able reach in operation. Then jog Z to the lowest allowed position.

In case of a dedicated Z axis per nozzle (e.g. single nozzle machine), set the higher soft limit a bit below the mechanical range or limit switch.

In case of shared Z axes where two nozzles are moved up/down together by the same Z axis motor, the low and high soft limits on the motor axis are determined by one or the other nozzle being lowered as low as admissible, i.e., the high positions of the nozzles should not be taken into consideration. In some designs the up-going nozzle is pulled up by a spring and blocked from moving further up, long before the opposite nozzle has reached the lowest operational position, which further explains why the down-going nozzle gives the only relevant position.

Please also make sure, that you are still in effective articulation range of the mechanics, e.g., if you have a cam setup, make sure the cam/rollers are not blocked or maxed out yet. The following image shows an example of a cam operated shared Z axis at its mechanical limit. Again, best do not go all the way to the limit, allow for some wiggle room. Also note how the opposite up-going nozzle was already blocked well below that point, i.e. that its Z position cannot be taken into consideration for setting the Soft Limit:

Choose whether you want Dynamic Safe Z handling or not:

With Dynamic Safe Z, the nozzle Safe Z motion is optimized to be as minimal and fast as possible, by exploiting the fact that smaller parts need to be lifted up less to be at Safe Z, i.e. to clear all obstacles on the machine table. The Safe Z coordinate is adjusted to the underside of the part.

With Fixed Safe Z, the nozzle Safe Z motion is always the same, i.e. the nozzle is always conservatively lifted so high that even the tallest part will clear all obstacles on the machine table. Use this setting to make the nozzles balanced at Safe Z, if you prefer this style. This is usually a slower but simpler method. Note: For machines with only "binary" nozzle Z positions (e.g. pneumatic) Fixed Safe Z must be selected!

According to the choice of Dynamic Safe Z, these solutions let you capture Safe Z for all the nozzles from the machine position. Note, the instructions are different for Dynamic Safe Z (shown here) and Fixed Safe Z. Follow the instructions carefully.

These captured coordinates will set the Safe Z zone as described on the Machine Axes page.

If Dynamic Safe Z is enabled, the nozzle needs headroom inside the Safe Z Zone in order to dynamically adjust the Z higher, if a taller part is on the nozzle tip. Issues & Solutions can detect if the headroom i.e. the Safe Z Zone is too small. You must then either increase the Safe Z Zone (if possible) or reduce the Max. Part Height on the nozzle tip.

See either the Machine Axes page or this section about maximum part dimensions, configured on the Nozzle Tip.