From 599649e45d997099cc19a10e53a31bd044e977a1 Mon Sep 17 00:00:00 2001
From: Sebastianv650 <sebastian_v650@kabelmail.de>
Date: Sat, 15 Oct 2016 13:38:47 +0200
Subject: [PATCH 1/3] Add formula for LIN_ADVANCE_K
With this formula, a start value for K for further fine-calibration can be calculated.
---
Marlin/Configuration_adv.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 97bd9803f9..07d9711694 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -503,7 +503,12 @@
// Implementation of a linear pressure control
// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+// K=0 means advance disabled.
+// To get a rough start value for calibration, measure your "free filament length" between the hobbed bolt and the nozzle in cm.
+// Then use the formula that fits your system, where L is the "free filament length":
+// Filament diameter | 1,75mm | 3mm |
+// Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+// Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
From 9818d975878c9db14e3c0338fdab11fbeafb9513 Mon Sep 17 00:00:00 2001
From: Sebastianv650 <sebastian_v650@kabelmail.de>
Date: Sat, 15 Oct 2016 13:46:47 +0200
Subject: [PATCH 2/3] Fix Z-hops during retract/prime lead to blobs
We don't want to have retract/prime movements done with LIN_ADVANCE, that's also true with simultaneously executed Z-hops.
---
Marlin/planner.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Marlin/planner.cpp b/Marlin/planner.cpp
index ffacf76db9..cfc23dfd36 100644
--- a/Marlin/planner.cpp
+++ b/Marlin/planner.cpp
@@ -1206,7 +1206,7 @@ void Planner::_buffer_line(const float &a, const float &b, const float &c, const
// This leads to an enormous number of advance steps due to a huge e_acceleration.
// The math is correct, but you don't want a retract move done with advance!
// So this situation is filtered out here.
- if (!block->steps[E_AXIS] || (!block->steps[X_AXIS] && !block->steps[Y_AXIS] && !block->steps[Z_AXIS]) || stepper.get_advance_k() == 0 || (uint32_t) block->steps[E_AXIS] == block->step_event_count) {
+ if (!block->steps[E_AXIS] || (!block->steps[X_AXIS] && !block->steps[Y_AXIS]) || stepper.get_advance_k() == 0 || (uint32_t) block->steps[E_AXIS] == block->step_event_count) {
block->use_advance_lead = false;
}
else {
From b9109b2875402f3583fb93c4b259bb976e055e8c Mon Sep 17 00:00:00 2001
From: Scott Lahteine <sourcetree@thinkyhead.com>
Date: Sat, 22 Oct 2016 05:03:09 -0500
Subject: [PATCH 3/3] Improve LIN_ADVANCE commentary (all configs)
---
Marlin/Configuration_adv.h | 22 ++++++++++++-------
.../Cartesio/Configuration_adv.h | 17 +++++++++++---
.../Felix/Configuration_adv.h | 17 +++++++++++---
.../Hephestos/Configuration_adv.h | 17 +++++++++++---
.../Hephestos_2/Configuration_adv.h | 17 +++++++++++---
.../K8200/Configuration_adv.h | 17 +++++++++++---
.../K8400/Configuration_adv.h | 17 +++++++++++---
.../RigidBot/Configuration_adv.h | 17 +++++++++++---
.../SCARA/Configuration_adv.h | 17 +++++++++++---
.../TAZ4/Configuration_adv.h | 17 +++++++++++---
.../WITBOX/Configuration_adv.h | 17 +++++++++++---
.../delta/biv2.5/Configuration_adv.h | 17 +++++++++++---
.../delta/generic/Configuration_adv.h | 17 +++++++++++---
.../delta/kossel_mini/Configuration_adv.h | 17 +++++++++++---
.../delta/kossel_pro/Configuration_adv.h | 17 +++++++++++---
.../delta/kossel_xl/Configuration_adv.h | 17 +++++++++++---
.../makibox/Configuration_adv.h | 17 +++++++++++---
.../tvrrug/Round2/Configuration_adv.h | 17 +++++++++++---
18 files changed, 252 insertions(+), 59 deletions(-)
diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 07d9711694..a0a65f9c28 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -501,14 +501,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled.
-// To get a rough start value for calibration, measure your "free filament length" between the hobbed bolt and the nozzle in cm.
-// Then use the formula that fits your system, where L is the "free filament length":
-// Filament diameter | 1,75mm | 3mm |
-// Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
-// Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/Cartesio/Configuration_adv.h b/Marlin/example_configurations/Cartesio/Configuration_adv.h
index 951d5df8b3..98e4912213 100644
--- a/Marlin/example_configurations/Cartesio/Configuration_adv.h
+++ b/Marlin/example_configurations/Cartesio/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/Felix/Configuration_adv.h b/Marlin/example_configurations/Felix/Configuration_adv.h
index dfcabe6b1a..4138656e2e 100644
--- a/Marlin/example_configurations/Felix/Configuration_adv.h
+++ b/Marlin/example_configurations/Felix/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/Hephestos/Configuration_adv.h b/Marlin/example_configurations/Hephestos/Configuration_adv.h
index 6e8d66f8db..fb337fc778 100644
--- a/Marlin/example_configurations/Hephestos/Configuration_adv.h
+++ b/Marlin/example_configurations/Hephestos/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 1.75
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/Hephestos_2/Configuration_adv.h b/Marlin/example_configurations/Hephestos_2/Configuration_adv.h
index e15be7234e..e5c46ae262 100644
--- a/Marlin/example_configurations/Hephestos_2/Configuration_adv.h
+++ b/Marlin/example_configurations/Hephestos_2/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/K8200/Configuration_adv.h b/Marlin/example_configurations/K8200/Configuration_adv.h
index b2c6fd4832..0985448e12 100644
--- a/Marlin/example_configurations/K8200/Configuration_adv.h
+++ b/Marlin/example_configurations/K8200/Configuration_adv.h
@@ -507,9 +507,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/K8400/Configuration_adv.h b/Marlin/example_configurations/K8400/Configuration_adv.h
index 50fd0e0c73..ebb9e83715 100644
--- a/Marlin/example_configurations/K8400/Configuration_adv.h
+++ b/Marlin/example_configurations/K8400/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/RigidBot/Configuration_adv.h b/Marlin/example_configurations/RigidBot/Configuration_adv.h
index 8dbc685dd6..ad70111aa2 100644
--- a/Marlin/example_configurations/RigidBot/Configuration_adv.h
+++ b/Marlin/example_configurations/RigidBot/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 1.75
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/SCARA/Configuration_adv.h b/Marlin/example_configurations/SCARA/Configuration_adv.h
index 51f6cb512a..3312340187 100644
--- a/Marlin/example_configurations/SCARA/Configuration_adv.h
+++ b/Marlin/example_configurations/SCARA/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 1.75
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/TAZ4/Configuration_adv.h b/Marlin/example_configurations/TAZ4/Configuration_adv.h
index 096d97edc8..28eab90c7a 100644
--- a/Marlin/example_configurations/TAZ4/Configuration_adv.h
+++ b/Marlin/example_configurations/TAZ4/Configuration_adv.h
@@ -509,9 +509,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/WITBOX/Configuration_adv.h b/Marlin/example_configurations/WITBOX/Configuration_adv.h
index 6e8d66f8db..fb337fc778 100644
--- a/Marlin/example_configurations/WITBOX/Configuration_adv.h
+++ b/Marlin/example_configurations/WITBOX/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 1.75
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h b/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h
index c5b8101a54..e22c36ce71 100644
--- a/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h
@@ -503,9 +503,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/delta/generic/Configuration_adv.h b/Marlin/example_configurations/delta/generic/Configuration_adv.h
index 870c67c7e4..d8da99e486 100644
--- a/Marlin/example_configurations/delta/generic/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/generic/Configuration_adv.h
@@ -503,9 +503,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h b/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h
index 870c67c7e4..d8da99e486 100644
--- a/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h
@@ -503,9 +503,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h b/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h
index 5c68f33de7..8f80d130cd 100644
--- a/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h
@@ -508,9 +508,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h b/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h
index 0a12114ff6..698f9270b5 100644
--- a/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h
@@ -503,9 +503,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/makibox/Configuration_adv.h b/Marlin/example_configurations/makibox/Configuration_adv.h
index dc08d5b1e8..d1a0f66fa0 100644
--- a/Marlin/example_configurations/makibox/Configuration_adv.h
+++ b/Marlin/example_configurations/makibox/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)
diff --git a/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h b/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h
index dc57f5212d..f68070341b 100644
--- a/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h
+++ b/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h
@@ -501,9 +501,20 @@
#define D_FILAMENT 2.85
#endif
-// Implementation of a linear pressure control
-// Assumption: advance = k * (delta velocity)
-// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+/**
+ * Implementation of linear pressure control
+ *
+ * Assumption: advance = k * (delta velocity)
+ * K=0 means advance disabled.
+ * To get a rough start value for calibration, measure your "free filament length"
+ * between the hobbed bolt and the nozzle (in cm). Use the formula below that fits
+ * your setup, where L is the "free filament length":
+ *
+ * Filament diameter | 1.75mm | 3.0mm |
+ * ----------------------------|-----------|------------|
+ * Stiff filament (PLA) | K=47*L/10 | K=139*L/10 |
+ * Softer filament (ABS, nGen) | K=88*L/10 | K=260*L/10 |
+ */
//#define LIN_ADVANCE
#if ENABLED(LIN_ADVANCE)