G32 crashing on negative X position

ecl66

Greetings to All,

I am using the latest 0.92.9 release on a RAMPS 1.4 with Xmin Ymin Zmax limit switches and an inductive Z probe.

When I run the G32 command, the head moves in negative X territory (i.e. past the Xmin limit switch) so I need to press the emergency stop!

If I move the head to the middle of the bed, then G32 proceeds normally.

Could you please advise on what could be the issue here?

many thanks 

Repetier

1. Home before probing.

2. Check eeprom for

  a) z probe offset

  b) probe point coordinates to be inside bed

3. If you level with a grid make sure P1 is the origin and P2-P1 +X axis, P3-P1 +Yaxis so it probes a sqaure and not a parallelogram.

ecl66

Thanks for your quick reply.

1- I am homing indeed (G28)

2- probe points are inside the bed

3 - area is a square:

here is my config:

#define FEATURE_AUTOLEVEL 1

#define Z_PROBE_X1 40

#define Z_PROBE_Y1 20

#define Z_PROBE_X2 190

#define Z_PROBE_Y2 20

#define Z_PROBE_X3 40

#define Z_PROBE_Y3 170

#define BED_LEVELING_METHOD 1

I also have set z probe offset (probe is right front of nozzle)

#define Z_PROBE_X_OFFSET 70

#define Z_PROBE_Y_OFFSET -70

BTW, I do have 

define X_MAX_LENGTH 195

#define Y_MAX_LENGTH 195

#define Z_MAX_LENGTH 120

#define X_MIN_POS -46  (x end is on the left, prusa i3 type config)

#define Y_MIN_POS -15  (y end is on the back)

One more question: is it possible to change Z_PROBE_HEIGHT using a gcode command, or do I need to reccompile the firmware every time I need to change this value?

MartinH

you can change Z probe height in eeprom config in repetir host

You say X min pos is -46,  is this -46 from left side of bed,  make sure pobe positions are reachable by probe offsets.

ecl66

Hi Martin,

Thanks for your reply.

- strangely enough, when I open the eeprom config in repetier host, i only get an empty window (only column titles) - is there a specific issue with Mac OS X (El Capitan)?

- yes, the probing area is reachable by the probe, that's why I don't understand the issue.

Cheers

 

MartinH

If you have re-uploaded firmware, you may still have old values stored in the eeprom.

send a M502  to read the firmware values and try probing again.

if it works, store the settings with a M500

ecl66

thanks again Martin. i'm just banging my head as I can't find out the problem (i am aware of M502/M500).

Repetier

Your positions/dimensions do not fit.

xmin+xlength is xmax = 149 so how can you measure 190?

Z_PROBE_HEIGHT  is in eeprom and can be changed there as well. Soon our dev version gets also a command to set it and a menu entry.

First move should go to x = 40-70 (offset z probe) = -30 according to your settings. As you allow x = -46 that should be no problem.

ecl66

Thanks. I was actually trying to write changes in the software to allow  Z_PROBE_HEIGHT modification using Gcode, so that's great news. I am just stuck in trying to understand how to write new data to Com:: parameters. I could send you the code if you wished.

I guess I mixed up xlength and xmax in my config. I know understand those values are in absolute X coordinates, right?

Indeed, I also thought that first move would go to -30, so I am wondering why it is trying to go beyond -46... If I measure a single point using G30, offsets do work well.

Repetier

Com:: is all output related and has nothing to do with storing parameter.

If oyu use eepromeditor you can change all modfyable parameters there. Also your solution may lie there as these values are used for positions and these may differ from config values. For dual x axis we also had strange things that seem to fixed now in dev version in case you have such a printer.