Switching from Marlin to Repetier - auto leveling

MartinsZB

Hi! I know there is a lot of discussion about the Z and bed leveling. I tried to read them all, but not find the straight instructions on how to configure the FW.

So, my HW configuration is Prusa I3 with Induction sensor attached to print head. It is connected to Zmin and here is how it was configured in Marlin:

1. With G28 the X home 0 (or in my case -20) Y home 0, then move to center of my bed and Z home.

2. With G29 it did the auto bed leveling in a grid (By the way, I really like the Grid leveling)

As I understand in Repetier it is not suggested to use same sensor for Z home and bed leveling?

But If i do, can I do the following:

The both X_MIN_PIN and Z_PROBE_PIN = "Z min endstop"

In startup code:

G28 XY ; Home X and Y

G0 X100 Y90 ; Move to the center of the bed

G28 Z ; Home Z

G32 S0

To find the Z_PROBE_HEIGHT I will move to X100 and Y90, Home Z and measure the distance from nozzle to bed.

Or can I do the following:

Set Homing order: "Z up, X, Y preheat Z"

set ZHOME_X_POS/ZHOME_Y_POS X100 Y90

In startup code:

G28 ; home X,Y then preheat and home Z at X100 Y90

G32 S0 ; Bed auto leveling

Will it work? Is there some better suggestion?

BR, Martins 

Repetier

I have just uploaded a small improvement that allows using z probe for zmin as well. It now corrects Z_PROBE_HEIGHT after signal switch. I think in your case you need 

ALWAYS_CHECK_ENDSTOPS 0

or it will make problems moving at sometimes, especially if moving down.

Please write gcodes correctly. SPaces between parameter and with values. G28 X0 Y0 is how it should be.

If you z home at x=0, y=0 you can autolevel into eeprom and do not need to repeat it. Otherwise your code should work with the update if you add a G1 Z10 after homing to get on probing height.

MartinsZB

Hi, Repetier!

Thanks for your answer! And sorry for wrong syntax in Gcodes.

I am just thinking - If I use this config, can I use following to autolevel in eeprom?:

Or can I do the following:

Set Homing order: "Z up, X, Y preheat Z"

set ZHOME_X_POS/ZHOME_Y_POS X100 Y90

In startup code:

G28 ; home X,Y then preheat and home Z at X100 Y90

G1 Z10

G32 S2 ; Bed auto leveling to eeprom

Thanks for your great job!

Martins

MartinsZB

OK. My first try to switch to Repetier failed. I need to rethink all concept of auto leveling. And read some more - is it possible at all to use sensor, what I use:

LJ12A3-4-Z/BY Inductive Proximity Sensor Detection Switch

Nandox7

@MartinsZB, i also changed to Repetier from Marlin this week and after a few bumps all is working perfectly.

I have a capacitance sensor but a inductive works the same in terms of FW.

What I did was in part what @Repetier mentioned to use G28 X0 Y0 to home first X and Y and then I use G32 to run the 

probing program.

Because it uses the specified points in the Firmware it wents fine.

So basically before with Marlin I had

---

G28

G29

---

Now with Repetier I have:

---

G28 X0 Y0

G32

---

MartinsZB

Now looks a bit better. I manage to get the probe in to the bed. Using ENDSTOP_(X|Y|Z)_BACK_MOVE parameter. Now I can home all axes with G28.

But, can I get transformation matrix with more points, not just 3 points?

Repetier

No, we only have the statically stable solution of 3 points. 

fvonfr

I am trying to do exactly the same thing as MartinsZB and Nandox7 but I must be missing something. 

I have the LJ12A3-4-Z/BY Inductive Proximity Sensor Detection Switch

I connected it to the Z_MIN endstop pin and disconnected the original endstop switch. (there's nowhere convenient to mount it at the Z_MAX position and I'm not interested anyway, I just want to use the inductive prox sensor as an endstop as well as Z Probe. 

My z-homing now behaves strangely. I used the firmware configuration tool to set everything up. Homing direction is towards Z-Min, same as it was working with the limit switch. However now when I home Z using the manual control gui button, the Z axis moves downwards until the proximity switch is triggered, then it reverses and descends again just like homing behaved before. Except the second time descending it continues to move down forever and does not stop when the prox sensor is triggered again. 

I haven't even gotten to the point of actually testing the Z-Probe or auto-level yet

fvonfr

Why does Z have to home at all? Just move up 10mm and begin z-probing. You will measure where the bed is, then afterwards it is known. Wastes time having to move all the way up to the top

Repetier

Does the sensor have an led showing if it is triggering? The second move down on homing is only 2 * move backwards so it should not be for ever. But it will only stop once the hit is signaled so the question is, did the sensor trigger or not on the second way down?

If you always go 10mm up you assume you never start at z max or you crash there. You can do that since on enabling printer that z is z = 0, which is of course normally wrong. If you start > 1/3 z max homing would even be faster then releveling.

Homing with z probe must have z min pin = z probe pin and you must z home only at x=y=0 or your bed rotation adds an error.

fvonfr

Yes, the sensor has an LED showing triggering and it does light up. So the sensor does trigger. 2* the move backwards might be an explanation, and I did do a test later on after posting here which showed that it only moved down something like 40mm, not forever. 

I will try homing using the Z probe some more, (at x,y=0). Once I figure out why Z homing behaves strangely and moves downwards so far after the initial trigger of the sensor.