Home Z-Axis Twice
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@robinfaurecia said in Home Z-Axis Twice:
@dc42 we will change M574 command!
Our bed is moving and the gantry is fixed in z (only moving x/y).
So you trying to home to maximum Z, i.e. bed at the bottom - correct?
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@dc42 exactly, that´s right!
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@robinfaurecia said in Home Z-Axis Twice:
@dc42 exactly, that´s right!
So remove the G92 command from your Z homing sequence, and the M208 Z limit will define the position when the homing switch is triggered.
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@robinfaurecia said in Home Z-Axis Twice:
@dc42 exactly, that´s right!
Hi,
Why are you wishing to home at Z max (bed at bottom)?
Frederick
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@fcwilt
Because we thought that it is not possible to print the first layer while the endstop is triggered.
Now we try to home Z at Z max. If this makes to much problems we want to change the endstop position to Z min. -
@robinfaurecia said in Home Z-Axis Twice:
@fcwilt
Because we thought that it is not possible to print the first layer while the endstop is triggered.
Now we try to home Z at Z max. If this makes to much problems we want to change the endstop position to Z min.Thanks.
Go ahead and home to Z min - it will work fine and save time.
Frederick
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Now we can home the Z Axis twice thats good!
But everytime we home Z Axis (doesn´t matter if at Z max oder Z min) we have a difference of 0,2 to 0,5 mm between nozzle and bed. Maybe the difference is caused by hitting the endstop a little bit different every time we home the Z-Axis. Do you have any idea how we can fix this problem?
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@robinfaurecia said in Home Z-Axis Twice:
Now we can home the Z Axis twice thats good!
But everytime we home Z Axis (doesn´t matter if at Z max oder Z min) we have a difference of 0,2 to 0,5 mm between nozzle and bed. Maybe the difference is caused by hitting the endstop a little bit different every time we home the Z-Axis. Do you have any idea how we can fix this problem?
Have you tried reducing the speed of the second homing move, to see if that gives you a more reproducible result?
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@dc42 yes we had already ...second hit is really slowmo but it doesn't help.
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@robinfaurecia said in Home Z-Axis Twice:
But everytime we home Z Axis (doesn´t matter if at Z max oder Z min) we have a difference of 0,2 to 0,5 mm between nozzle and bed. Maybe the difference is caused by hitting the endstop a little bit different every time we home the Z-Axis. Do you have any idea how we can fix this problem?
I've never encountered that. I use micro switches with no arm on them and they work fine.
What sort of endstop are you using? Micro switch? Beam Break? Hall Effect Device?
Frederick
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We are using mechanic switches with a push bar.
I've ordered a bem break now to try if its working better.
@fcwilt -
If you have multiple Z motors, and you are measuring nozzle height at bed centre but the Z microswitch is at the side of the bed, perhaps your Z motors are getting out of sync and the bed is tilting?
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@robinfaurecia said in Home Z-Axis Twice:
We are using mechanic switches with a push bar.
I've ordered a bem break now to try if its working better."Push bar" - you mean the arm attached to the micro switch that presses on the actuator button?
Micro switches usually have more than enough accuracy and repeatability for use as end stops.
I suppose it might be possible that some brands of micro switches are not suitable but I have never encountered any.
"Beam Break" devices can work but they may not yield the crisp on/off action desired.
Frederick
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