How to move beyond the end stop, without disabling boundaries?

venkel

I have made a printer:

core-XY

* requires the X-homing to be done after Y-homing

* end stops on X-min (left) and Y-max (rear)

* requires the Y to move 10mm beyond the Y-homing sensor

I have managed to configure the printer to work, by setting "max_software_endstop_y false". This poses the risk of the user going beyond normal printing boundaries with the controller, or some externally connected software.

Do I overlook a configuration possibility with the standard configuration.h?

// ##########################################################################################

// ## Endstop configuration ##

// ##########################################################################################

/* By default all endstops are pulled up to HIGH. You need a pull-up if you

use a mechanical endstop connected with GND. Set value to false for no pull-up

on this endstop.

/

#define ENDSTOP_PULLUP false // ?????

#define ENDSTOP_INVERTING false

#define ENDSTOP_PULLUP_X_MIN ENDSTOP_PULLUP

#define ENDSTOP_PULLUP_Y_MIN ENDSTOP_PULLUP

#define ENDSTOP_PULLUP_Z_MIN ENDSTOP_PULLUP

#define ENDSTOP_PULLUP_X_MAX ENDSTOP_PULLUP

#define ENDSTOP_PULLUP_Y_MAX ENDSTOP_PULLUP

#define ENDSTOP_PULLUP_Z_MAX ENDSTOP_PULLUP

// Set to true to invert the logic of the endstops

#define ENDSTOP_X_MIN_INVERTING ENDSTOP_INVERTING

#define ENDSTOP_Y_MIN_INVERTING ENDSTOP_INVERTING

#define ENDSTOP_Z_MIN_INVERTING ENDSTOP_INVERTING

#define ENDSTOP_X_MAX_INVERTING ENDSTOP_INVERTING

#define ENDSTOP_Y_MAX_INVERTING ENDSTOP_INVERTING

#define ENDSTOP_Z_MAX_INVERTING ENDSTOP_INVERTING

// Set the values true where you have a hardware endstop. The Pin number is taken from pins.h.

#define MIN_HARDWARE_ENDSTOP_X true

#define MIN_HARDWARE_ENDSTOP_Y false

#define MIN_HARDWARE_ENDSTOP_Z true

#define MAX_HARDWARE_ENDSTOP_X false

#define MAX_HARDWARE_ENDSTOP_Y true

#define MAX_HARDWARE_ENDSTOP_Z false

//If your axes are only moving in one direction, make sure the endstops are connected properly.

//If your axes move in one direction ONLY when the endstops are triggered, set ENDSTOPS_INVERTING to true here

//// ADVANCED SETTINGS - to tweak parameters

// For Inverting Stepper Enable Pins (Active Low) use 0, Non Inverting (Active High) use 1

#define X_ENABLE_ON 1

#define Y_ENABLE_ON 1

#define Z_ENABLE_ON 1

// Disables axis when it's not being used.

#define DISABLE_X false

#define DISABLE_Y false

#define DISABLE_Z false

#define DISABLE_E false

/* If you want to keep z motor running on stepper timeout, remove comments below.

 This may be useful if your z bed moves when motors are disabled. Will still

 turn z off when heaters get also disabled.

*/

//#define PREVENT_Z_DISABLE_ON_STEPPER_TIMEOUT

// Inverting axis direction

#define INVERT_X_DIR false

#define INVERT_Y_DIR false

#define INVERT_Z_DIR 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

// Delta robot radius endstop

#define max_software_endstop_r true

//If true, axis won't move to coordinates less than zero.

#define min_software_endstop_x true

#define min_software_endstop_y true

#define min_software_endstop_z true

//If true, axis won't move to coordinates greater than the defined lengths below.

#define max_software_endstop_x true

#define max_software_endstop_y false

#define max_software_endstop_z true

// If during homing the endstop is reached, how many mm should the printer move back for the second try

#define ENDSTOP_X_BACK_MOVE 5

#define ENDSTOP_Y_BACK_MOVE 5

#define ENDSTOP_Z_BACK_MOVE 3

// For higher precision you can reduce the speed for the second test on the endstop

// during homing operation. The homing speed is divided by the value. 1 = same speed, 2 = half speed

#define ENDSTOP_X_RETEST_REDUCTION_FACTOR 4

#define ENDSTOP_Y_RETEST_REDUCTION_FACTOR 4

#define ENDSTOP_Z_RETEST_REDUCTION_FACTOR 4

// When you have several endstops in one circuit you need to disable it after homing by moving a

// small amount back. This is also the case with H-belt systems.

// doesn't work with negative values

#define ENDSTOP_X_BACK_ON_HOME 0.0

#define ENDSTOP_Y_BACK_ON_HOME 0.0

#define ENDSTOP_Z_BACK_ON_HOME 0.0

// You can disable endstop checking for print moves. This is needed, if you get sometimes

// false signals from your endstops. If your endstops don't give false signals, you

// can set it on for safety.

#define ALWAYS_CHECK_ENDSTOPS false

// maximum positions in mm - only fixed numbers!

// For delta robot Z_MAX_LENGTH is the maximum travel of the towers and should be set to the distance between the hotend

// and the platform when the printer is at its home position.

// If EEPROM is enabled these values will be overridden with the values in the EEPROM

#define X_MAX_LENGTH 574

#define Y_MAX_LENGTH 496

#define Z_MAX_LENGTH 500

// Coordinates for the minimum axis. Can also be negative if you want to have the bed start at 0 and the printer can go to the left side

// of the bed. Maximum coordinate is given by adding the above X_MAX_LENGTH values.

#define X_MIN_POS 0

#define Y_MIN_POS 0

#define Z_MIN_POS 0

Repetier

" requires the Y to move 10mm beyond the Y-homing sensor"

so you want to trigger y max and then move another 10mm in max direction? No homing will not do that resp. endstop check will make problems. Eventually you might get away with a negative move after homing if endstop check is disabled for that move, but in normal moves that might cause problems Sounds somewhat wrong to do this so not sure I understood it correctly.

venkel

Let me try to be more precise. During normal printing there's no need to go beyond Y-max. But for an extruder change, the position must be 10mm beyond Y-max, to park one of the extruders.

I cannot change the Y homing position, otherwise there is mechanical interference risk. And X homing can only be done at Y-max (to be clear: Y-max = Y-home).

I'm sure there is a solution, but I'm not confident enough to re-program the printer.ccp code.

Repetier

Normally I would say disable endstop check with ALWAYS_CHECK_ENDSTOPS 0, but in newer firmware we have also improved boundary checks so it would not move just because target is outside boundaries.

But since a y max homing is first and you can not home x first, that is a problem you can only solve by editing firmware, which is no problem since it is open source. Or you switch to y min homing instead, so you move to high y values for switching.

Anyhow if using software solution, disable endstop as described and modify the check target coordinates check to allow y max + 10 as limit. The function responsible for this should be in printer.cpp

bool Printer::isPositionAllowed(float x,float y,float z)

Alternatively add a new M code using our custom even system and set

<div> static INLINE uint8_t isNoDestinationCheck()

{

return flag1 & PRINTER_FLAG1_NO_DESTINATION_CHECK;

}

static INLINE void setNoDestinationCheck(uint8_t b)

{

flag1 = (b ? flag1 | PRINTER_FLAG1_NO_DESTINATION_CHECK : flag1 & _PRINTER_FLAG1_NO_DESTINATION_CHECK);

}

if that flag is enabled, no destination check occurs. So you could use the new M command to disable the safety check and switch extruder. A good place are the extruder select commands.

</div>

Also make sure y endstop triggers at Y max +10 and goes back more then 10mm for retesting so you cover the case enabling printer at y max + 10.

venkel

Ai ai, difficult communication.

1. Y-homing at min is mechanically impossible.

2. It is impossible to home Y at +10mm, as of the potential collision.

3. The Y-probe is setup to trigger 11mm before collision. And it stays high in this area. Works fine.

I will look into the software solution, but I cannot understand at this moment how the boundaries would be set correctly this way.

Repetier

As said I would prefer disabling boundary check for extruder switch and then enable it again. That should allow you to move past endstop if endstop test is disabled.

SuperRembo

It turns out to be possible with standard Repetier G-codes: The S1 option for the G0/G1 command disables the boundary check.

Problem solved.

venkel

One detail is left to be answered. The S1 option of the G0/G1 command disables the boundary check, that is clear. But is this a toggle, or only valid for one command line?
And if it is a toggle, how to enable the boundary check again?

Repetier

G1 S0
enables the boundary check. It is valid until changed.