rkrammes
Posts: 4
Joined: Wed Jul 13, 2016 12:02 am

Help with Z-offset after installing sensor for bed leveling.

Sorry guys I haven't been able to figure this one out on my own. I added a mini IR sensor to do auto bed leveling and I must have messed something up in Marlin because now the global offset for Z doesn't seem to affect the starting height. The only thing that seems to work is changing the z probe offset in firmware. I can post snippits from configuration.h if someone is willing to look it over for me, but I feel like a total newbie again, even though I have been printing for over a year and thought I had a decent grasp of these things by now. :oops:

I am printing on a core-xy reprap I built from thingiverse so there is no factory firmware. Everything was just adjusted as worked through issues so I could be way off with my settings for all I know but I have done a pretty good amount of printing and everything seems to work pretty well other than this new issue.
CompoundCarl
Posts: 2005
Joined: Wed Aug 05, 2015 7:23 am

Re: Help with Z-offset after installing sensor for bed level

What global offset are you talking about? A simple test would be to create a gcode file that only has the following lines

G28 X0 Y0 Z0
G29
G1 Z10 F1800

Run that file and then run the following

G28 X0 Y0 Z0
G29
G1 Z20 F1800

In this case, we move to Z=20mm at the end. You should see it move to a different height. If you don't then something is definitely wrong.
dorsai3d
Posts: 237
Joined: Mon Jan 11, 2016 9:01 am

Re: Help with Z-offset after installing sensor for bed level

Many firmwares won't let you go past Z=0, so if your offset is negative enough, it won't matter what you command, it will only go to what the firmware sees as Z0 (which is defined by your probe offset).
rkrammes
Posts: 4
Joined: Wed Jul 13, 2016 12:02 am

Re: Help with Z-offset after installing sensor for bed level

I'm talking about the Z-Axis offset in the Global G-Code Offsets section of the G-Code tab in the process settings of Simplify 3D. This is what I had been using to fine tune the first layer in my prints.

G1 commands seem to work fine.
rkrammes
Posts: 4
Joined: Wed Jul 13, 2016 12:02 am

Re: Help with Z-offset after installing sensor for bed level

dorsai3d wrote:Many firmwares won't let you go past Z=0, so if your offset is negative enough, it won't matter what you command, it will only go to what the firmware sees as Z0 (which is defined by your probe offset).
In this instance I actually am printing a bit too close to the print bed and am trying to apply a positive offset.

I am guessing the problem is somewhere in here.

//===========================================================================
//=============================Mechanical Settings===========================
//===========================================================================

// Uncomment the following line to enable CoreXY kinematics
#define COREXY

// coarse Endstop Settings
#define ENDSTOPPULLUPS // Comment this out (using // at the start of the line) to disable the endstop pullup resistors

#ifndef ENDSTOPPULLUPS
// fine endstop settings: Individual pullups. will be ignored if ENDSTOPPULLUPS is defined
// #define ENDSTOPPULLUP_XMAX
// #define ENDSTOPPULLUP_YMAX
// #define ENDSTOPPULLUP_ZMAX
// #define ENDSTOPPULLUP_XMIN
// #define ENDSTOPPULLUP_YMIN
// #define ENDSTOPPULLUP_ZMIN
#endif

#ifdef ENDSTOPPULLUPS
#define ENDSTOPPULLUP_XMAX
#define ENDSTOPPULLUP_YMAX
#define ENDSTOPPULLUP_ZMAX
#define ENDSTOPPULLUP_XMIN
#define ENDSTOPPULLUP_YMIN
#define ENDSTOPPULLUP_ZMIN
#endif

// The pullups are needed if you directly connect a mechanical endswitch between the signal and ground pins.
const bool X_MIN_ENDSTOP_INVERTING = false; // set to true to invert the logic of the endstop.
const bool Y_MIN_ENDSTOP_INVERTING = false; // set to true to invert the logic of the endstop.
const bool Z_MIN_ENDSTOP_INVERTING = false; // set to true to invert the logic of the endstop.
const bool X_MAX_ENDSTOP_INVERTING = true; // set to true to invert the logic of the endstop.
const bool Y_MAX_ENDSTOP_INVERTING = true; // set to true to invert the logic of the endstop.
const bool Z_MAX_ENDSTOP_INVERTING = true; // set to true to invert the logic of the endstop.
//#define DISABLE_MAX_ENDSTOPS
//#define DISABLE_MIN_ENDSTOPS

// Disable max endstops for compatibility with endstop checking routine
#if defined(COREXY) && !defined(DISABLE_MAX_ENDSTOPS)
#define DISABLE_MAX_ENDSTOPS
#endif

// For Inverting Stepper Enable Pins (Active Low) use 0, Non Inverting (Active High) use 1
#define X_ENABLE_ON 0
#define Y_ENABLE_ON 0
#define Z_ENABLE_ON 0
#define E_ENABLE_ON 0 // For all extruders

// Disables axis when it's not being used.
#define DISABLE_X false
#define DISABLE_Y false
#define DISABLE_Z false
#define DISABLE_E false // For all extruders
#define DISABLE_INACTIVE_EXTRUDER true //disable only inactive extruders and keep active extruder enabled

#define INVERT_X_DIR false // for Mendel set to false, for Orca set to true
#define INVERT_Y_DIR false // for Mendel set to true, for Orca set to false
#define INVERT_Z_DIR false // for Mendel set to false, for Orca set to true
#define INVERT_E0_DIR false // for direct drive extruder v9 set to true, for geared extruder set to false
#define INVERT_E1_DIR false // for direct drive extruder v9 set to true, for geared extruder set to false
#define INVERT_E2_DIR true // for direct drive extruder v9 set to true, for geared extruder set to false

// ENDSTOP SETTINGS:
// Sets direction of endstops when homing; 1=MAX, -1=MIN
#define X_HOME_DIR -1
#define Y_HOME_DIR -1
#define Z_HOME_DIR -1

#define min_software_endstops false // If true, axis won't move to coordinates less than HOME_POS.
#define max_software_endstops true // If true, axis won't move to coordinates greater than the defined lengths below.

// Travel limits after homing
#define X_MAX_POS 242
#define X_MIN_POS -42
#define Y_MAX_POS 222
#define Y_MIN_POS -22
#define Z_MAX_POS 200
#define Z_MIN_POS 0

#define X_MAX_LENGTH (X_MAX_POS - X_MIN_POS)
#define Y_MAX_LENGTH (Y_MAX_POS - Y_MIN_POS)
#define Z_MAX_LENGTH (Z_MAX_POS - Z_MIN_POS)
//============================= Bed Auto Leveling ===========================

#define ENABLE_AUTO_BED_LEVELING // Delete the comment to enable (remove // at the start of the line)
#define Z_PROBE_REPEATABILITY_TEST // If not commented out, Z-Probe Repeatability test will be included if Auto Bed Leveling is Enabled.

#ifdef ENABLE_AUTO_BED_LEVELING

// There are 2 different ways to pick the X and Y locations to probe:

// - "grid" mode
// Probe every point in a rectangular grid
// You must specify the rectangle, and the density of sample points
// This mode is preferred because there are more measurements.
// It used to be called ACCURATE_BED_LEVELING but "grid" is more descriptive

// - "3-point" mode
// Probe 3 arbitrary points on the bed (that aren't colinear)
// You must specify the X & Y coordinates of all 3 points

#define AUTO_BED_LEVELING_GRID
// with AUTO_BED_LEVELING_GRID, the bed is sampled in a
// AUTO_BED_LEVELING_GRID_POINTSxAUTO_BED_LEVELING_GRID_POINTS grid
// and least squares solution is calculated
// Note: this feature occupies 10'206 byte
#ifdef AUTO_BED_LEVELING_GRID

// set the rectangle in which to probe
#define LEFT_PROBE_BED_POSITION 15
#define RIGHT_PROBE_BED_POSITION 170
#define BACK_PROBE_BED_POSITION 180
#define FRONT_PROBE_BED_POSITION 20

// set the number of grid points per dimension
// I wouldn't see a reason to go above 3 (=9 probing points on the bed)
#define AUTO_BED_LEVELING_GRID_POINTS 3


#else // not AUTO_BED_LEVELING_GRID
// with no grid, just probe 3 arbitrary points. A simple cross-product
// is used to esimate the plane of the print bed

#define ABL_PROBE_PT_1_X 15
#define ABL_PROBE_PT_1_Y 180
#define ABL_PROBE_PT_2_X 15
#define ABL_PROBE_PT_2_Y 20
#define ABL_PROBE_PT_3_X 170
#define ABL_PROBE_PT_3_Y 20

#endif // AUTO_BED_LEVELING_GRID


// these are the offsets to the probe relative to the extruder tip (Hotend - Probe)
// X and Y offsets must be integers
#define X_PROBE_OFFSET_FROM_EXTRUDER 0
#define Y_PROBE_OFFSET_FROM_EXTRUDER -27
#define Z_PROBE_OFFSET_FROM_EXTRUDER -1.3

#define Z_RAISE_BEFORE_HOMING 10 // (in mm) Raise Z before homing (G28) for Probe Clearance.
// Be sure you have this distance over your Z_MAX_POS in case

#define XY_TRAVEL_SPEED 4000 // X and Y axis travel speed between probes, in mm/min

#define Z_RAISE_BEFORE_PROBING 10 //How much the extruder will be raised before traveling to the first probing point.
#define Z_RAISE_BETWEEN_PROBINGS 2 //How much the extruder will be raised when traveling from between next probing points

//#define Z_PROBE_SLED // turn on if you have a z-probe mounted on a sled like those designed by Charles Bell
//#define SLED_DOCKING_OFFSET 5 // the extra distance the X axis must travel to pickup the sled. 0 should be fine but you can push it further if you'd like.

//If defined, the Probe servo will be turned on only during movement and then turned off to avoid jerk
//The value is the delay to turn the servo off after powered on - depends on the servo speed; 300ms is good value, but you can try lower it.
// You MUST HAVE the SERVO_ENDSTOPS defined to use here a value higher than zero otherwise your code will not compile.

// #define PROBE_SERVO_DEACTIVATION_DELAY 300


//If you have enabled the Bed Auto Leveling and are using the same Z Probe for Z Homing,
//it is highly recommended you let this Z_SAFE_HOMING enabled!!!

#define Z_SAFE_HOMING // This feature is meant to avoid Z homing with probe outside the bed area.
// When defined, it will:
// - Allow Z homing only after X and Y homing AND stepper drivers still enabled
// - If stepper drivers timeout, it will need X and Y homing again before Z homing
// - Position the probe in a defined XY point before Z Homing when homing all axis (G28)
// - Block Z homing only when the probe is outside bed area.

#ifdef Z_SAFE_HOMING

#define Z_SAFE_HOMING_X_POINT (100) // X point for Z homing when homing all axis (G28)
#define Z_SAFE_HOMING_Y_POINT (100) // Y point for Z homing when homing all axis (G28)

#endif

#ifdef AUTO_BED_LEVELING_GRID // Check if Probe_Offset * Grid Points is greater than Probing Range
#if X_PROBE_OFFSET_FROM_EXTRUDER < 0
#if (-(X_PROBE_OFFSET_FROM_EXTRUDER * AUTO_BED_LEVELING_GRID_POINTS) >= (RIGHT_PROBE_BED_POSITION - LEFT_PROBE_BED_POSITION))
#error "The X axis probing range is not enough to fit all the points defined in AUTO_BED_LEVELING_GRID_POINTS"
#endif
#else
#if ((X_PROBE_OFFSET_FROM_EXTRUDER * AUTO_BED_LEVELING_GRID_POINTS) >= (RIGHT_PROBE_BED_POSITION - LEFT_PROBE_BED_POSITION))
#error "The X axis probing range is not enough to fit all the points defined in AUTO_BED_LEVELING_GRID_POINTS"
#endif
#endif
#if Y_PROBE_OFFSET_FROM_EXTRUDER < 0
#if (-(Y_PROBE_OFFSET_FROM_EXTRUDER * AUTO_BED_LEVELING_GRID_POINTS) >= (BACK_PROBE_BED_POSITION - FRONT_PROBE_BED_POSITION))
#error "The Y axis probing range is not enough to fit all the points defined in AUTO_BED_LEVELING_GRID_POINTS"
#endif
#else
#if ((Y_PROBE_OFFSET_FROM_EXTRUDER * AUTO_BED_LEVELING_GRID_POINTS) >= (BACK_PROBE_BED_POSITION - FRONT_PROBE_BED_POSITION))
#error "The Y axis probing range is not enough to fit all the points defined in AUTO_BED_LEVELING_GRID_POINTS"
#endif
#endif


#endif

#endif // ENABLE_AUTO_BED_LEVELING


// The position of the homing switches
//#define MANUAL_HOME_POSITIONS // If defined, MANUAL_*_HOME_POS below will be used
//#define BED_CENTER_AT_0_0 // If defined, the center of the bed is at (X=0, Y=0)

//Manual homing switch locations:
// For deltabots this means top and center of the Cartesian print volume.
#define MANUAL_X_HOME_POS 0
#define MANUAL_Y_HOME_POS 0
#define MANUAL_Z_HOME_POS 0
//#define MANUAL_Z_HOME_POS 402 // For delta: Distance between nozzle and print surface after homing.

//// MOVEMENT SETTINGS
#define NUM_AXIS 4 // The axis order in all axis related arrays is X, Y, Z, E
#define HOMING_FEEDRATE {50*60, 50*60, 4*60, 0} // set the homing speeds (mm/min)

// default settings

#define DEFAULT_AXIS_STEPS_PER_UNIT {55.94,55.94,394.35,417} // default steps per unit for Ultimaker
#define DEFAULT_MAX_FEEDRATE {200, 200, 5, 25} // (mm/sec)
#define DEFAULT_MAX_ACCELERATION {3000,3000,100,10000} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION 3000 // X, Y, Z and E max acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 3000 // X, Y, Z and E max acceleration in mm/s^2 for retracts

// Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
// The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
// For the other hotends it is their distance from the extruder 0 hotend.
// #define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
// #define EXTRUDER_OFFSET_Y {0.0, 5.00} // (in mm) for each extruder, offset of the hotend on the Y axis

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK 15.0 // (mm/sec)
#define DEFAULT_ZJERK 0.4 // (mm/sec)
#define DEFAULT_EJERK 5.0 // (mm/sec)

//===========================================================================
//=============================Additional Features===========================
//===========================================================================

// Custom M code points
#define CUSTOM_M_CODES
#ifdef CUSTOM_M_CODES
#define CUSTOM_M_CODE_SET_Z_PROBE_OFFSET 851
#define Z_PROBE_OFFSET_RANGE_MIN -3
#define Z_PROBE_OFFSET_RANGE_MAX 3
#endif
CompoundCarl
Posts: 2005
Joined: Wed Aug 05, 2015 7:23 am

Re: Help with Z-offset after installing sensor for bed level

rkrammes wrote:I'm talking about the Z-Axis offset in the Global G-Code Offsets section of the G-Code tab in the process settings of Simplify 3D. This is what I had been using to fine tune the first layer in my prints.

G1 commands seem to work fine.
If the G1 commands work, then there's no reason why the global gcode offset wouldn't work. It does exactly the same thing. It just shifts the Z-values of your G1 commands. Look at the file yourself after you add a larger gcode offset. So if you're saying that the G1 commands work correctly and move to a higher position, then the z-axis global offset should work as well.
rkrammes
Posts: 4
Joined: Wed Jul 13, 2016 12:02 am

Re: Help with Z-offset after installing sensor for bed level

CompoundCarl wrote:
rkrammes wrote:I'm talking about the Z-Axis offset in the Global G-Code Offsets section of the G-Code tab in the process settings of Simplify 3D. This is what I had been using to fine tune the first layer in my prints.

G1 commands seem to work fine.
If the G1 commands work, then there's no reason why the global gcode offset wouldn't work. It does exactly the same thing. It just shifts the Z-values of your G1 commands. Look at the file yourself after you add a larger gcode offset. So if you're saying that the G1 commands work correctly and move to a higher position, then the z-axis global offset should work as well.
Sure, but on the first layer isn't it a bit different since you are dealing with endstops?
CompoundCarl
Posts: 2005
Joined: Wed Aug 05, 2015 7:23 am

Re: Help with Z-offset after installing sensor for bed level

If you ran the code I posted above, it would be EXACTLY the same as what the z-axis global offset does.

G28 X0 Y0 Z0
G29
G1 Z20 F1800

It homes to the endstops then does auto leveling, then moves to a Z-value that was offset. Exactly the same. Look through the gcode files yourself if you don't believe me. You can see that adjusting the z-axis global offset will just adjust the Z-values in the file.

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