Prusa i3 ramps 1.4 , min endstops only - z printing offset magicaly is active

N37

Hello,

I have got problem, my configuration does not include z offset, and in repetier host i do not have any offsets set. everything 0

but when homing printer homes fine, and when i start printing form SD the printer is homing properly, than it is moving printing head up, and waiting for extruder to heat up, and than it starts printing but about 1 cm over the bed level "in air" why, and how to fix that.

Second question when can i expect the "reset eprom memory function to be implemented in firmware ? "

Repetier

Please in host run

G28

and when finished

M114

and see what it reports compared to real position. There are several Z changing options. If it shows 0 and you are higher you might have

#define ENDSTOP_Z_BACK_ON_HOME 0

set on a different value. That is always added before restting z. There are also methods to move z after homing up but then M114 should report correct Z and next Z move would work correctly. Also check bed coating in eeprom.

M502

M500

resets eeprom to Configursation.h values, so that is already possible.

N37

SENDING:G28 ok 0 X:0.00 Y:0.00 Z:0.000 E:0.0000 ok 0 ok 0

>>> M114SENDING:M114ok 0

X:0.00 Y:0.00 Z:0.000 E:0.0000

Bed coating in epprom set to clean bed, and also tested with manual value 0 with the same results.
my config relative to the defines you have pointed is:
#define ENDSTOP_X_BACK_MOVE 5#define ENDSTOP_Y_BACK_MOVE 5#define ENDSTOP_Z_BACK_MOVE 2#define ENDSTOP_X_RETEST_REDUCTION_FACTOR 3#define ENDSTOP_Y_RETEST_REDUCTION_FACTOR 3#define ENDSTOP_Z_RETEST_REDUCTION_FACTOR 3#define ENDSTOP_X_BACK_ON_HOME 10#define ENDSTOP_Y_BACK_ON_HOME 10#define ENDSTOP_Z_BACK_ON_HOME 0#define ALWAYS_CHECK_ENDSTOPS 1
so everything should be fine.
sending M502

M500

Does not change the way it works.

Printer still prints about 5mm over the bed surface.

Video here :

https://drive.google.com/open?id=0B4X4QYpSs7s4OWpwcFZDc3pXd0U </div><div style="box-sizing: border-box; background-color: rgb(255, 255, 255);">

Another problem as you can see on the video is that the fan is not turning on automaticaly when the extruder temp is over 50 (the way i've set it in firmware)

and ones over a few times it starts printing as "cold run" , on video as shown, ones it was printing fine from SD from the same file with proper extrusion, and ones it starts printing without extrusion as kind of test run.

I do not understand why, everything i do is just reset the printer using the stop button on the full graphic smart controller.

MartinH

what is your Z steps/mm set to in eeprom ?

N37

#define DRIVE_SYSTEM 0

#define XAXIS_STEPS_PER_MM 200

#define YAXIS_STEPS_PER_MM 200

#define ZAXIS_STEPS_PER_MM 8000

#define EXTRUDER_FAN_COOL_TEMP 50

#define PDM_FOR_EXTRUDER 0

#define PDM_FOR_COOLER 0

#define DECOUPLING_TEST_MAX_HOLD_VARIANCE 20

#define DECOUPLING_TEST_MIN_TEMP_RISE 1

#define KILL_IF_SENSOR_DEFECT 0

#define RETRACT_ON_PAUSE 2

#define PAUSE_START_COMMANDS ""

#define PAUSE_END_COMMANDS ""

#define SHARED_EXTRUDER_HEATER 0

#define EXT0_X_OFFSET 0

#define EXT0_Y_OFFSET 0

#define EXT0_Z_OFFSET 0

#define EXT0_STEPS_PER_MM 237.037

#define EXT0_TEMPSENSOR_TYPE 1

#define EXT0_TEMPSENSOR_PIN TEMP_0_PIN

#define EXT0_HEATER_PIN HEATER_0_PIN

#define EXT0_STEP_PIN ORIG_E0_STEP_PIN

#define EXT0_DIR_PIN ORIG_E0_DIR_PIN

#define EXT0_INVERSE 1

#define EXT0_ENABLE_PIN ORIG_E0_ENABLE_PIN

#define EXT0_ENABLE_ON 0

#define EXT0_MIRROR_STEPPER 0

#define EXT0_STEP2_PIN ORIG_E0_STEP_PIN

#define EXT0_DIR2_PIN ORIG_E0_DIR_PIN

#define EXT0_INVERSE2 0

#define EXT0_ENABLE2_PIN ORIG_E0_ENABLE_PIN

#define EXT0_MAX_FEEDRATE 10

#define EXT0_MAX_START_FEEDRATE 10

#define EXT0_MAX_ACCELERATION 1000

#define EXT0_HEAT_MANAGER 3

#define EXT0_WATCHPERIOD 1

#define EXT0_PID_INTEGRAL_DRIVE_MAX 230

#define EXT0_PID_INTEGRAL_DRIVE_MIN 40

#define EXT0_PID_PGAIN_OR_DEAD_TIME 7

#define EXT0_PID_I 2

#define EXT0_PID_D 40

#define EXT0_PID_MAX 255

#define EXT0_ADVANCE_K 0

#define EXT0_ADVANCE_L 0

#define EXT0_ADVANCE_BACKLASH_STEPS 0

#define EXT0_WAIT_RETRACT_TEMP 150

#define EXT0_WAIT_RETRACT_UNITS 0

#define EXT0_SELECT_COMMANDS ""

#define EXT0_DESELECT_COMMANDS ""

#define EXT0_EXTRUDER_COOLER_PIN HEATER_2_PIN

#define EXT0_EXTRUDER_COOLER_SPEED 255

#define EXT0_DECOUPLE_TEST_PERIOD 12000

#define EXT0_JAM_PIN -1

#define EXT0_JAM_PULLUP 0

#define FEATURE_RETRACTION 1

#define AUTORETRACT_ENABLED 0

#define RETRACTION_LENGTH 3

#define RETRACTION_LONG_LENGTH 13

#define RETRACTION_SPEED 40

#define RETRACTION_Z_LIFT 0

#define RETRACTION_UNDO_EXTRA_LENGTH 0

#define RETRACTION_UNDO_EXTRA_LONG_LENGTH 0

#define RETRACTION_UNDO_SPEED 20

#define FILAMENTCHANGE_X_POS 0

#define FILAMENTCHANGE_Y_POS 0

#define FILAMENTCHANGE_Z_ADD 2

#define FILAMENTCHANGE_REHOME 0

#define FILAMENTCHANGE_SHORTRETRACT 5

#define FILAMENTCHANGE_LONGRETRACT 50

#define JAM_STEPS 220

#define JAM_SLOWDOWN_STEPS 320

#define JAM_SLOWDOWN_TO 70

#define JAM_ERROR_STEPS 500

#define JAM_MIN_STEPS 10

#define JAM_ACTION 1

#define RETRACT_DURING_HEATUP true

#define PID_CONTROL_RANGE 20

#define SKIP_M109_IF_WITHIN 2

#define SCALE_PID_TO_MAX 1

#define TEMP_HYSTERESIS 0

#define EXTRUDE_MAXLENGTH 160

#define NUM_TEMPS_USERTHERMISTOR0 0

#define USER_THERMISTORTABLE0 {}

#define NUM_TEMPS_USERTHERMISTOR1 0

#define USER_THERMISTORTABLE1 {}

#define NUM_TEMPS_USERTHERMISTOR2 0

#define USER_THERMISTORTABLE2 {}

#define GENERIC_THERM_VREF 5

#define GENERIC_THERM_NUM_ENTRIES 33

#define HEATER_PWM_SPEED 0

N37

I've got all stepper drivers set DRV8255 1/32 microsteps standard nema 17 200steps per rotation stepper mottors.

16 teeth pooley for GT2 belt driven x and y

And rods are 8mm x8mm per rotation for Z

i must admit that my prototype was using M5 standard rods (0,8 mm per rotation) for Z and the value 8000 is fine for M5 rods

N37

#define ZAXIS_STEPS_PER_MM 8000

I think my BUG is here, shouldn't that be 800 for 8mm per rotation pitch with the rods that I have now ... ? :)

It is so simple, that i feel so freaking stupid to bother you guys .....

Free beer in Cracov on Poland, just send me a message.

Or just tel me where to go in Germany next time i'll be on my way to family house in Saarbrucken :)

And Thumbs UP for Martin, you are the best mate !

T

N37

But now it prints about 0,8 mm over the bed surface and proper homing level.

So setting the 800 steps per mm changed height error about 10 times, so it is relevant to the 10 times less steps per mm comparing to the 8000 value it was before.

I have checked the pitch , and it is exactly 8mm per revolution.

So last thing that might be wrong is the microstepping.

In ramps with all 3 jumpers installed for DRV8825 microstepping should be 1/32 but maby it isn't ?

MartinH

Yes 3 jumpers should = 1/32 microstepping on those drivers. so '800' should be correct with 4 start 8mm lead screws.

You may need to fine tune the 800 tho, home the Z axis then send a G1 Z100 and measure the distance it travells,if it moves more or less than 100mm then adjust the '800' to compensate for the error