Servo retraction at last point of Auto Bed Level

[Ursus63]

How can i set to move up Z BEFORE retract servo at last point of ABL Grid when i use G29 E? I have an optical endstop on servo and when servo retracts after last point of grid it scratches bed.

[brainscan]

Are you using the latest version of marlin? I think it should do this as standard now but I haven't checked.

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On 10 Mar 2015, at 13:28, Ursus63 notifications@github.com wrote:

How can i set to move up Z BEFORE retract servo at last point of ABL Grid when i use G29 E? I have an optical endstop on servo and when servo retracts after last point of grid it scratches bed.

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[Ursus63]

Downloaded Marlin today. And it don't do this. Now i just disable retraction in firmware at all and add to g-code G1 Z15 and M402 after G29 E and its work. But i think its better to do it in firmware.

[brainscan]

Sorry I thought this was added with the recent update to the bed levelling. It should be the same as the one I've been using which does raise z before retracting. The code can be found at http://3dprintboard.com/showthread.php?3105-Auto_Bed_Leveling-Enhanced-G29-command
Hope this helps.

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On 10 Mar 2015, at 18:31, Ursus63 notifications@github.com wrote:

Downloaded Marlin today. And it don't do this. Now i just disable retraction in firmware at all and add to g-code G1 Z15 and M402 after G29 E and its work. But i think its better to do it in firmware.

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[boelle]

i have at least now added both potential bug label and needs more feedback... if 1-2 more can verify this i will upgrade it to verified bug and include it in a milestone so it can be fixed...

to me its seems pretty important that you raise Z just a bit before you swing up probe arm

of course depends much on what kind of probe... some can raise the probe without raising Z...

[Ursus63]

It will be good to rize probe before retract in G28 and G30 too. G28 i'm modified as described at the link above, but i think it must be in firmware by default. And G30 i think too.

[SkyFlyer2]

The best way is to add the code lifting the Z-axis before any retract servo

Please add the code to function - static void retract_z_probe()
I think it might look something like this:

do_blocking_move_to(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS);

I damaged already one servo without lifting Z-axis before servo retraction.

[SkyFlyer2]

I tried add code to function static void retract_z_probe() - this is not correct, because it always lift Z-axis before retract, even if not required. Need to find another place in code.

[alexborro]

I have added a new feature yesterday. Check this out in configuration.h:

#define Z_PROBE_END_SCRIPT "G1 Z10 F12000\nG1 X15 Y330\nG1 Z0.5\nG1 Z10"
//These commands will be executed in the end of G29 routine. Useful to
retract a deployable probe.

Cheers.

Alex.

2015-03-11 8:46 GMT-03:00 SkyFlyer2 notifications@github.com:

I tried add code to function static void retract_z_probe() - this is not
correct, because it always lift Z-axis before retract, even if not
required. Need to find another place in code.

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#1589 (comment)
.

"Não é o mais forte da espécie que sobrevive, nem o mais inteligente. É
aquele que se adapta melhor as mudanças" ( Charles Darwin )

Alex Borro

[SkyFlyer2]

A nice solution. I will check it.

But this is not solve same problem for commands G28, G30 and M48. No any changes in their code, but the same issue also present there.

[SkyFlyer2]

Hmm. I've checked this changes. No useful changes. The servo retracting BEFORE lift Z-axis, as result it scratches the bed and make damage to servo.

[thinkyhead]

This could be done as an enhancement to G29 or as a compile-time option, or both. I'll see where new code may help.

[avluis]

@thinkyhead Can you think of implementing something similar at the end of a G28 as well - a lift of even 1mm will save many micro switches ;)

[maverikou]

This is a duplicate of #1507

[thinkyhead]

Let's move the discussion over to #1507 then....

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