HomeZ with sensor
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Can anyone tell me if during a home z operation with a sensor you should turn off compensation before sensing. Should you use G29 S2 or not?
i.e.
G28 XYU ; Home X
G91 ; relative mode
G1 H2 Z5 F1800 ; raise head 4mm to ensure it is above the Z probe trigger height
G90 ; back to absolute mode
G1 X155 Y160 F10000 ; move to bed centre for probing
;G29 S2
G30 ; probe the bed and set Z height
;G29 S1
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I always have.
I only load the height map at the start of a print.
And I unload it at the end of the print.
Frederick
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no you need to establish z=0 (G30) before loading a heightmap
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@Veti
Hi, that's what the code does,
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homing unloads the height map.
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@Veti said in HomeZ with sensor:
homing unloads the height map.
Hi,
I know that has changed in the past so I checked it just to be safe - this was with firmware 3.1.1 AND 3.2.0
I executed G29 S1 and verified with the DWC that mesh compensation was in use.
Then I executed:
- G90 G1 Z25 F600 ; to be sure the end stop sensors were not triggered
- G91 G1 H1 Z-30 F300 ; one slow speed homing move
I checked via the DWC and mesh compensation was still in use.
Frederick
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try a G28 Z. that has a different meaning
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@Veti said in HomeZ with sensor:
try a G28 Z. that has a different meaning
OK I renamed my existing homeZ.g file and created a new one just with:
G90
G1 H2 Z25 F600
G91
G1 H1 Z-30 F300
G90Same result. The DWC reported mesh compensation was still in use.
Glad to do more tests.
Frederick
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maybe i got it confused with marlin
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@Veti said in HomeZ with sensor:
maybe i got it confused with marlin
I have trouble keeping things straight as the "side effects" of various commands have changed over time.
So I now just do everything explicitly in my code.
Frederick
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but thinking about it.
even if you are rehoming and an offset would be applied. the point where you homed should be 0 anyway
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Hi, just coming back to the original point,
are you saying that I don't need to use G29 S2 and G29 S1 as that is already explicit in the Home functionality?
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@pcsentinel said in HomeZ with sensor:
Hi, just coming back to the original point,
are you saying that I don't need to use G29 S2 and G29 S1 as that is already explicit in the Home functionality?
You may still need to use G29 S1 and G29 S2.
I tested firmware 3.1.1 and homing does not affect the state of mesh compensation. I will test 3.2 if that applies to you.
The "side effects of certain commands have changed over time BUT it is always safe to do things explicitly rather than depend on "side effects".
The worse that happens is you issue a command that is redundant.
Frederick
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I think it would be best practice to clear any bed transformations before trying to reset Z0 with homing or doing a G29, etc.
