Why first move of tue bed leveling is going up?

Arisoy

@fcwilt said in Why first move of tue bed leveling is going up?:

Now change the H2 parameter in the G31 command to H5.

I don't find where is this command with H2.

It's here?

;;;;;;;;;; BLTouch ;;;;;;;;;;
M950 S0 C"20.io0.out"                     ; Create a servo pin on io0 (toolboard 1LC)
M558 P9 C"20.io0.in" H5 F240 T10800 A5    ; set Z probe type to unmodulated and the dive height + speeds
G31 P25 X-28.00 Y-13.00 Z3.700          	  ; set Z probe trigger value, offset and trigger height, more Z means closer to the bed

But there is no H2 parameter in the G31 command.

fcwilt

@arisoy said in Why first move of tue bed leveling is going up?:

@fcwilt said in Why first move of tue bed leveling is going up?:

Now change the H2 parameter in the G31 command to H5.

I don't find where is this command with H2.

It's here?
;;;;;;;;;; BLTouch ;;;;;;;;;;
M950 S0 C"20.io0.out"                     ; Create a servo pin on io0 (toolboard 1LC)
M558 P9 C"20.io0.in" H5 F240 T10800 A5    ; set Z probe type to unmodulated and the dive height + speeds
G31 P25 X-28.00 Y-13.00 Z3.700          	  ; set Z probe trigger value, offset and trigger height, more Z means closer to the bed
But there is no H2 parameter in the G31 command.

Sorry my bad. It is in the M558. Trusted to my memory - I shouldn't do that.

Frederick

PCR

@arisoy what's your Z M566?

Arisoy

@fcwilt The paramater was already H5 so I tried H2 But no change. I set it back to H5.

fcwilt

@arisoy said in Why first move of tue bed leveling is going up?:

@fcwilt The paramater was already H5 so I tried H2 But no change. I set it back to H5.

Thanks.

Let's try the suggestion posted previously.

Add G90 G1 X155 Y150 Z10 before the set of three G30 commands in your bed.g file and report the behavior.

Thanks.

Frederick

Arisoy

@fcwilt I already did it. And after this positioning command "G90 G1 X155 Y150 Z10" the bed did a fast move up while the bltouch is going to the first probe point then wait for the probe to be in the good place and finally did the probing work.

infiniteloop

@arisoy said in Why first move of tue bed leveling is going up?:

For one, you can increment the dive height.

I don't know how to do that. Can you tell me please.

Look at my first post in this thread.

fcwilt

@arisoy said in Why first move of tue bed leveling is going up?:

@fcwilt I already did it. And after this positioning command "G90 G1 X155 Y150 Z10" the bed did a fast move up while the bltouch is going to the first probe point then wait for the probe to be in the good place and finally did the probing work.

Thanks.

Please change the Z10 to Z20 and see how that affects the behavior.

It may help to post a video of what you are seeing to be sure we all understand what is happening.

Thanks.

Frederick

Arisoy

@fcwilt Ok so i homed all axis and then i take a video from what happened.

I started the video and just after i send the G32 command.

As you can see at first the bed moves up. I don't want that at all. I want the probe to go at his place first and then the bed can moves up.

link text

infiniteloop

@arisoy Split the G1 movement in two:

Move X/Y to whatever point you want
Lower Z to 10 or 20 mm

Possibly you can omit Z completely - at the moment, I can't verify that …

fcwilt

@arisoy said in Why first move of tue bed leveling is going up?:

@fcwilt Ok so i homed all axis and then i take a video from what happened.

I started the video and just after i send the G32 command.

As you can see at first the bed moves up. I don't want that at all. I want the probe to go at his place first and then the bed can moves up.

link text

Thanks.

I went and watched my printer and it does what yours is doing. That initial Z movement prior to the first probe has never caused me any issues.

You could adjust the initial G1 to move to the first probe XY point.

Frederick

Arisoy

@infiniteloop I did it. I split the G1 in two. The G1 command works fine.

But after that the G30 command moves the bed up again and fast close to the probe. And then the probing starts.

So if the bed is not leveled the bed will crash to the probe during this first fast move.

I don't want to add some mouvement before the bed moves up fast. I want it to not do that. It should probe directly not move up first.

Like it's done when you home your printer. When homing the Z i can start it from the bottom and the bed will slowly search the probe. It wil not move fast and then start to probe.

fcwilt

@arisoy said in Why first move of tue bed leveling is going up?:

@infiniteloop I did it. I split the G1 in two. The G1 command works fine.

But after that the G30 command moves the bed up again and fast close to the probe. And then the probing starts.

So if the bed is not leveled the bed will crash to the probe during this first fast move.

I don't want to add some mouvement before the bed moves up fast. I want it to not do that. It should probe directly not move up first.

Like it's done when you home your printer. When homing the Z i can start it from the bottom and the bed will slowly search the probe. It wil not move fast and then start to probe.

A Z probe can have this issue with a bed setup like yours (and mine).

I dealt with it by having a Z endstop switch for each Z axis.

See this video which starts with the bed way out of level. It homes and "levels" using the Z endstops. At the point it is level enough that the Z probe can always do the final leveling without issue.

Bed Leveling

You might try adjusting the H5 parameter to H10 or H15 to see how that affects the behavior.

Frederick

Arisoy

@fcwilt Ok i think i'll maybe do the Z home like this too.

Thanks you all for your patience and for your help