3diy
/
klipper
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

docs: Add info on delta acceleration limits 

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2017-04-19 19:46:41 -04:00
parent db5b5f121c
commit 563ab5caa5
1 changed files with 17 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
docs/Kinematics.md
View File

@ -170,7 +170,7 @@ the actual tower.
It is then possible to calculate where the head will be along the line It is then possible to calculate where the head will be along the line
of movement after each step is taken on the virtual tower. The key of movement after each step is taken on the virtual tower. The key
formula is Pythagorean's formula: formula is Pythagoras's theorem:
``` ```
distance_to_tower^2 = arm_length^2 - tower_height^2 distance_to_tower^2 = arm_length^2 - tower_height^2
@ -198,6 +198,22 @@ Should the move contain only Z movement (ie, no XY movement at all)
then the same math is used - just in this case the tower is parallel then the same math is used - just in this case the tower is parallel
to the line of movement (its slope is 1.0). to the line of movement (its slope is 1.0).
### Stepper motor acceleration limits ###
With delta kinematics it is possible for a move that is accelerating
in cartesian space to require an acceleration on a particular stepper
motor greater than the move's acceleration. This can occur when a
stepper arm is more horizontal than vertical and the line of movement
is near that stepper's tower.
Klipper does enforce a maximum ceiling on stepper acceleration that is
three times the maximum acceleration of a move in cartesian
space. (Similarly, the maximum velocity of the stepper is limited to
three times the maximum move velocity.) In order to enforce this
limit, moves at the extreme edge of the build envelope (where a
stepper arm may be nearly horizontal) will have a lower maximum
acceleration and velocity.
Extruder kinematics Extruder kinematics
------------------- -------------------