docs: Improve description of delta stepper acceleration limits

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2017-07-19 12:27:32 -04:00
parent c4b8d3ea8b
commit 17a3e25036
2 changed files with 13 additions and 14 deletions

View File

@ -81,16 +81,10 @@ kinematics: delta
# This option must be "delta" for linear delta printers.
max_velocity: 300
# Maximum velocity (in mm/s) of the toolhead relative to the
# print. This limits the velocity of the toolhead relative to the
# print - at the extreme end of the print envelope the delta axis
# steppers themselves may briefly exceed this speed by up to 3
# times. This parameter must be specified.
# print. This parameter must be specified.
max_accel: 3000
# Maximum acceleration (in mm/s^2) of the toolhead relative to the
# print. This limits the acceleration of the toolhead relative to
# the print - at the extreme end of the print envelope the delta
# axis steppers may briefly exceed this acceleration by up to 3
# times. This parameter must be specified.
# print. This parameter must be specified.
max_z_velocity: 200
# For delta printers this limits the maximum velocity (in mm/s) of
# moves with z axis movement. This setting can be used to reduce the

View File

@ -211,13 +211,18 @@ 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.
passes near that stepper's tower. Although these moves could require a
stepper motor acceleration greater than the printer's maximum
configured move acceleration, this would only occur when the stepper
is moving a small amount of mass. (The stepper would essentially only
be moving the mass of the tower carriage.) Therefore, these brief
periods of high acceleration are considered harmless.
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
However, to avoid extreme cases, Klipper enforces a maximum ceiling on
stepper acceleration of three times the printer's configured maximum
move acceleration. (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.