"Z probe already triggered at the start of the homing move."????

SupraGuy

@crchisholm said in "Z probe already triggered at the start of the homing move."????:

I say I don't have a probe, but actually I have a BLTouch (still uninstalled and in the original package). I have not printed anything to mount it too yet, so I was hoping to put that off until everything else was setup and working.

Bad Plan???

I wouldn't say that it's a bad plan, particularly if you have everything that you need to get basic printing started without needing the BLTouch sensor to get started.

Adding the sensor isn't too big a deal, and you can always revert back to a known working configuration if you decide that you need to print something else without getting it working.

Phaedrux

@crchisholm said in "Z probe already triggered at the start of the homing move."????:

; Endstops
M574 X1 Y1 S0 ; Set active low and disabled endstops
; Z-Probe
M574 Z1 S2 ; Set endstops controlled by probe
M558 P5 H5 F0 T6000 ; Set Z probe type to switch and the dive height + speeds
G31 P500 X0 Y0 Z0 ; Set Z probe trigger value, offset and trigger height
M557 X15:13 Y15:195 S20 ; Define mesh grid

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v2 on Fri Feb 01 2019 16:04:24 GMT-0500 (Eastern Standard Time)
G91 ; relative positioning
G1 Z5 F6000 S2 ; lift Z relative to current position
G90 ; absolute positioning
G1 X15 Y15 F6000 ; go to first probe point
G30 ; home Z by probing the bed

You can change your configuration to use a simple endstop for the Z axis for the time being, and setup the BLTouch later once you have the parts printed.

First you'll need to change the quoted config section above to match the following:

; Endstops
M574 X1 Y1 Z1 S0 ; Set active low and disabled endstops

; Z-Probe
; M574 Z1 S2 ; Set endstops controlled by probe
; M558 P5 H5 F0 T6000 ; Set Z probe type to switch and the dive height + speeds
; G31 P500 X0 Y0 Z0 ; Set Z probe trigger value, offset and trigger height
; M557 X15:13 Y15:195 S20 ; Define mesh grid

Basically just added the Z min endstop to the first M574 command, and commented out the whole z probe section.

For the homing files you'll have to change homez and homeall to not use a G30 command and instead use G1 S1 Z move to seek the endstop.

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v2 on Fri Feb 01 2019 16:04:24 GMT-0500 (Eastern Standard Time)
G91 ; relative positioning
G1 Z5 F6000 S2 ; lift Z relative to current position
G1 S1 Z-300 ; seek end stop
G1 Z5 ; back up 
G1 S1 Z-300 F300 ; home Z again slowly
G90 ; absolute positioning
G1 Z5 ; part nozzle 5mm above the bed

SupraGuy

For that matter, you can set upt he printer to use a manual adjustment for the Z probe

M558 P0

This will allow you to use the Z jog buttons in the DWC as the Z probe, adjusting the Z height to 0 manually until you're ready to print the BLTouch parts.

My earlier response was assuming that you had an already complete kit though.

crchisholm

this worked great. Thanks.
One more question, though. Am I right to assume that the Duet supports either am min or max end-stop, but not both?

Phaedrux

@crchisholm you really only need one or the other to home to, afterwards the firmware will enforce travel limits.

You can use one of the other endstops like e0 or e1 and use it as a general trigger endstop to do whatever you want if triggered. They can all be wired together if you use a switch on each axis for max.

crchisholm

@phaedrux question: the code you show above... can it be entered and exicuted directly in the DWC? I have my printer built and all functionality tested except the BlTouch, so I don’t want to do something now that creates a problem (like a crash into the bed). I think I understand the M557 and M558 commands, and a lessor understanding of the G29, G30 and G31 commands but not real confident yet. Ruining this sfuff like console commands would allow me to dip my toes in the process ( I think)

Phaedrux

Yes every command can be run from the console. The config.g is just a list of commands that gets run in order at startup. There's nothing special about it other than that. Any time a new command is run it takes effect.

So you could enter each line one at a time in the console. Or to make for less typing you could enter the commands into a new macro file called BLTouch test and then run that macro. That way if you want to revert just reboot the duet. If it all tests ok you can put the commands into config.g.

The gcode wiki is a good reference to keep on hand for figuring out how the gcodes work.

G29 is for mesh bed leveling.
G30 runs the macro bed.g. and can be used for a number of things like lead screw leveling. It's not required.
G31 defines the XYZ position of the probe in relation to the nozzle tip. So when the probe triggers the system know where the nozzle is.

crchisholm

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crchisholm

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crchisholm

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Scachi

@crchisholm You have your bltouch connected now ?
Check your sensor signal wiring and the value of your probe-z shown in the web frontend.
If it reads 1000 all the time you may have a wiring problem like bad crimp or using the wrong polarity of your probe signal cable or something like that.

Check the documentation and all the test and probe release reset command mentioned there:
https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_BLTouch

crchisholm

I don't know why I am having trouble typing here, but what I actually entered in DWC was...
M557 X0:200 Y0:200 S50
M558 P9 H5 F100 T6000
G32
and I get the Z Probe already triggered before probing move started.

Phaedrux

@crchisholm what do you have in bed.g? That's what gets run when you send g32

crchisholm

@scachi Well, you called that one correctly! I have continuity on four or the five wires all the way from the termination point back to the jack on the BLTouch connector. The white wire does not. I am not sure what I can do about this as my eyes are just not up to working on a connector that small. I may have to return the device back to Amazon and order another. This is frustrating, but then, no body forced me to build this printer. Crap

crchisholm

@phaedrux As you will see from my last, I now have another issue I have to get resolved before I move ahead with this.

To answer your question.....

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v2 on Fri Feb 01 2019 16:04:23 GMT-0500 (Eastern Standard Time)
M561 ; clear any bed transform
G29 ; probe the bed and enable compensation

BTW, how do you mark code as you did in your message. I tried <code></code> and that didn't seem to work.

Phaedrux

All the forum markup can be found here: http://commonmark.org/help/

For the Bltouch wire that's unfortunate. Dupont connectors and crimps are quite fiddly. If you aren't able to recrimp the wire yourself perhaps a local electronics shop could give you a hand?

crchisholm

Crap! the return window is closed, so I will have to try and fix this tomorrow, or order another. Sheesh

crchisholm

Ok, so I ordered another BLTouch. It will be here Monday.

@Phaedrux: In the meantime, I know there no since trying to figure out what was going on now that I know there was a problem with the wires, but does the bed.g look ok?

Phaedrux

The bed.g looks like it wouldn't have any problems, but there's only two commands in it. And G29 will automatically cancel any active bed compensation before running, so it's really only calling G32 to run G29. Might as well just call G29.

Phaedrux

Maybe I should elaborate on how G29 can be used.

G32 used to be used to do a 5 point compensation routine that would generate a plane through 5 points you specified in bed.g. G29 has now taken over that roll, but it can do more than just 5 points. It's far more flexible. With G29 you specify a grid (with M557) and then a detailed network of points gets probed to allow for more fine grained adjustments.

You can still use G29 with a sparse grid of points to get the same effect as the old way if you know your bed is really flat already and want to probe it quickly before every print this is not a bad way to go.

However, if your bed isn't very flat but the platform itself is pretty stable, you can do a high detail G29 with lots of points and save that resulting heightmap and reload it before a print without needing to reprobe. Usually it would be loaded at startup in config.g or after homing, or right before printing.

Does that kind of make sense on your options for using G29?

Now that G29 is the recommended way of doing compensation, G32 and bed.g are usually used for printers with 2 or more independently Z axis lead screws so you can do automatic leveling.