Z probe error when homing to zmin but still runs through the routine.
I'm using the latest dev revision and am trying to get homing to zmin working with my blthouch. The G28 seems to work just fine if your looking @ the machine, but in the console I get this error right before the nozzle/head starts moving down towards the bed:
18:30:28.312: N2 G28
18:30:32.496: RequestStop:
18:30:34.700: fatal:Could not activate z-probe offset due to coordinate constraints - result is inprecise! Printer stopped and heaters disabled due to this error. Fix error and restart with M999.
18:30:45.619: X:185.00 Y:-0.00 Z:-0.000 E:0.0000
18:30:57.207: N3 M999
18:30:57.207: M110 N1
18:30:57.239: DebugLevel:6
18:30:57.239: info:Continue from fatal state
G32 & G33 work just fine
Any idea if I'm doing something wrong, or is this a bug?
Comments
My homing order is set to HOME_ORDER_XYZ
Should I be using the homing order xy preheat z?
I don't mind setting it to that, but I don't need the nozzle to be hot to probe since my probe is a bltouch.
You are right regarding the negative position. I have seen the hotend be maybe 20mm above the bed but z value on the LCD or via m114 is less than that. So yes it moves into the negative value.
Also if I move to x185 up z160 and confirm that location with m114, then send g28 I right away get the request stop. The nozzle/head then runs through the expected homing sequence which takes about 35 seconds then returns the error below.
7:01:56.092: N7 M999
7:01:56.092: M110 N1
7:01:56.162: DebugLevel:6
7:01:56.162: info:Continue from fatal state
7:02:00.079: N2 M114
7:02:00.142: X:185.00 Y:-0.00 Z:-0.000 E:4.4999
7:02:23.516: N3 G1 Z160.76 F720
7:02:48.903: N4 M114
7:02:49.766: X:185.00 Y:-0.00 Z:160.760 E:4.4999
7:03:04.369: N5 G28 Y0
7:03:05.405: X:185.00 Y:0.00 Z:160.760 E:4.4999
7:03:13.792: N6 M119
7:03:13.823: endstops hit: x_max:L y_min:L z_min:L z_max:H Z-probe state:L
7:03:27.298: N7 M119
7:03:27.336: endstops hit: x_max:L y_min:L z_min:L z_max:H Z-probe state:L
7:03:37.321: N8 M114
7:03:37.355: X:185.00 Y:0.00 Z:160.760 E:4.4999
7:03:54.739: N9 G28 X0
7:03:55.759: X:185.00 Y:0.00 Z:160.760 E:4.4999
7:04:03.971: N10 G28
7:04:05.993: RequestStop:
7:04:40.236: fatal:Could not activate z-probe offset due to coordinate constraints - result is inprecise! Printer stopped and heaters disabled due to this error. Fix error and restart with M999.
7:04:50.339: X:185.00 Y:-0.00 Z:-0.000 E:4.4999
My eeprom @ https://drive.google.com/file/d/0B1drD8vmGXPxTTIyWnd3MjJwcmM/view?usp=drivesdk
Could the FW provide more specific errors in the future?
Regarding the error it says it's coordinate and z probe offset. I was thinking it could say the result of the math. Ie "would result in y coordinate equals -5". That way I would at least know it's the y coordinate is off.
Understanding the math you use in firmware would help us calculate these values. Similar to how you have the probe and dual nozzle graphic in the configurator with the table next to that.
1. Print finished. Print head is left at random XYZ coordinate
2. I turn off the printer
3. I power on the printer.
4. I home z up, xy, z preheat. Z=10, x and y = 100
At step 4 is where the logic fails. Since the FW has no idea where the print head is on the xy plane, moving +100 in xy will smash my printed against the max x and y positions grinding my stepper motors. It might also move past z Max causing other issues.
I think this homing sequence would be more logical.
1. Z up
2. X, Y
3. Preheat.
The existing sequence would work if the 999999 wasn't causing this issue. This is why I think this is either a bug or a feature request. Hopefully that makes sense.