diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/Config_Reference.md | 14 | ||||
| -rw-r--r-- | docs/Multi_MCU_Homing.md | 42 | ||||
| -rw-r--r-- | docs/Overview.md | 5 | ||||
| -rw-r--r-- | docs/_klipper3d/mkdocs.yml | 5 |
4 files changed, 58 insertions, 8 deletions
diff --git a/docs/Config_Reference.md b/docs/Config_Reference.md index 906cfb8f..a3d9842a 100644 --- a/docs/Config_Reference.md +++ b/docs/Config_Reference.md @@ -119,7 +119,9 @@ different names for the stepper (eg, `stepper_x` vs `stepper_a`). Below are common stepper definitions. See the [rotation distance document](Rotation_Distance.md) for -information on calculating the `rotation_distance` parameter. +information on calculating the `rotation_distance` parameter. See the +[Multi-MCU homing](Multi_MCU_Homing.md) document for information on +homing using multiple micro-controllers. ``` [stepper_x] @@ -152,8 +154,10 @@ microsteps: # distance the axis travels for one full rotation of the final gear. # The default is to not use a gear ratio. endstop_pin: -# Endstop switch detection pin. This parameter must be provided for -# the X, Y, and Z steppers on cartesian style printers. +# Endstop switch detection pin. If this endstop pin is on a +# different mcu than the stepper motor then it enables "multi-mcu +# homing". This parameter must be provided for the X, Y, and Z +# steppers on cartesian style printers. #position_min: 0 # Minimum valid distance (in mm) the user may command the stepper to # move to. The default is 0mm. @@ -1611,7 +1615,9 @@ stepper_z config section. ``` [probe] pin: -# Probe detection pin. This parameter must be provided. +# Probe detection pin. If the pin is on a different microcontroller +# than the Z steppers then it enables "multi-mcu homing". This +# parameter must be provided. #deactivate_on_each_sample: True # This determines if Klipper should execute deactivation gcode # between each probe attempt when performing a multiple probe diff --git a/docs/Multi_MCU_Homing.md b/docs/Multi_MCU_Homing.md new file mode 100644 index 00000000..22d2508e --- /dev/null +++ b/docs/Multi_MCU_Homing.md @@ -0,0 +1,42 @@ +# Multiple Micro-controller Homing and Probing + +Klipper supports a mechanism for homing with an endstop attached to +one micro-controller while its stepper motors are on a different +micro-controller. This support is referred to as "multi-mcu +homing". This feature is also used when a Z probe is on a different +micro-controller than the Z stepper motors. + +This feature can be useful to simplify wiring, as it may be more +convenient to attach an endstop or probe to a closer micro-controller. +However, using this feature may result in "overshoot" of the stepper +motors during homing and probing operations. + +The overshoot occurs due to possible message transmission delays +between the micro-controller monitoring the endstop and the +micro-controllers moving the stepper motors. The Klipper code is +designed to limit this delay to no more than 25ms. (When multi-mcu +homing is activated, the micro-controllers send periodic status +messages and check that corresponding status messages are received +within 25ms.) + +So, for example, if homing at 10mm/s then it is possible for an +overshoot of up to 0.250mm (10mm/s * .025s == 0.250mm). Care should be +taken when configuring multi-mcu homing to account for this type of +overshoot. Using slower homing or probing speeds can reduce the +overshoot. + +Stepper motor overshoot should not adversely impact the precision of +the homing and probing procedure. The Klipper code will detect the +overshoot and account for it in its calculations. However, it is +important that the hardware design is capable of handling overshoot +without causing damage to the machine. + +Should Klipper detect a communication issue between micro-controllers +during multi-mcu homing then it will raise a "Communication timeout +during homing" error. + +Note that an axis with multiple steppers (eg, `stepper_z` and +`stepper_z1`) need to be on the same micro-controller in order to use +multi-mcu homing. For example, if an endstop is on a separate +micro-controller from `stepper_z` then `stepper_z1` must be on the +same micro-controller as `stepper_z`. diff --git a/docs/Overview.md b/docs/Overview.md index 632f584e..a758a991 100644 --- a/docs/Overview.md +++ b/docs/Overview.md @@ -41,18 +41,19 @@ communication with the Klipper developers. using adxl345 accelerometer hardware to measure resonance. - [Pressure advance](Pressure_Advance.md): Calibrate extruder pressure. -- [Slicers](Slicers.md): Configure "slicer" software for Klipper. +- [G-Codes](G-Codes.md): Information on commands supported by Klipper. - [Command Templates](Command_Templates.md): G-Code macros and conditional evaluation. - [Status Reference](Status_Reference.md): Information available to macros (and similar). - [TMC Drivers](TMC_Drivers.md): Using Trinamic stepper motor drivers with Klipper. +- [Multi-MCU Homing](Multi_MCU_Homing.md): Homing and probing using multiple micro-controllers. +- [Slicers](Slicers.md): Configure "slicer" software for Klipper. - [Skew correction](skew_correction.md): Adjustments for axes not perfectly square. - [PWM tools](Using_PWM_Tools.md): Guide on how to use PWM controlled tools such as lasers or spindles. -- [G-Codes](G-Codes.md): Information on commands supported by Klipper. ## Developer Documentation diff --git a/docs/_klipper3d/mkdocs.yml b/docs/_klipper3d/mkdocs.yml index bf8f1908..c7724dc0 100644 --- a/docs/_klipper3d/mkdocs.yml +++ b/docs/_klipper3d/mkdocs.yml @@ -94,14 +94,15 @@ nav: - Resonance_Compensation.md - Measuring_Resonances.md - Pressure_Advance.md - - Slicers.md + - G-Codes.md - Command templates: - Command_Templates.md - Status_Reference.md - TMC_Drivers.md + - Multi_MCU_Homing.md + - Slicers.md - skew_correction.md - Using_PWM_Tools.md - - G-Codes.md - Developer Documentation: - Code_Overview.md - Kinematics.md |