Can't tune Z height "endstop hit: z"
October 18, 2015 01:46AM
--- <--Probe height
--- <-Hotend height (~1mm below probe)

When I home (G28), Z is sitting at 0.16.
I have a Z offset (using M206) of -0.35.

Problem is once I start a print it immediately shows "endstop hit: z". Z = 0.25.

Bottom line it won't go any lower than 0.25 and that's not low enough. The probe is installed as high as it can go to get the nozzle as close to the bed as it'll go. I'm trying to get it to go that little bit further with the M206 offset.

I understand not being able to go below an endstop but what am I missing? Feels like a catch 22.
Re: Can't tune Z height "endstop hit: z"
October 18, 2015 02:50AM
Invert the endstop logic in the firmware configuration.h file
Re: Can't tune Z height "endstop hit: z"
October 18, 2015 08:36AM
Can you explain a bit further?
I'm familiar with the configuration.h file just not sure what you mean.

Thanks
Re: Can't tune Z height "endstop hit: z"
October 18, 2015 09:48AM
In configuration.h there's a line:

#define min_software_endstops false // If true, axis won't move to coordinates less than HOME_POS.

Make sure that this is false - the result will be that if it goes to the endstop then it will stop, but you can command it to go past that point. It's then your responsibility to make sure it doesn't crash into the bed!
Re: Can't tune Z height "endstop hit: z"
October 18, 2015 09:55AM
It is false already.
I thought that says don't go past the min range defined in the firmware only and that nothing gets it past the hardware endstop.

Am I wrong?
Re: Can't tune Z height "endstop hit: z"
October 18, 2015 01:05PM
No I mean:
const bool Z_MIN_ENDSTOP_INVERTING = false;
Re: Can't tune Z height "endstop hit: z"
October 21, 2015 01:38PM
Quote
eried
No I mean:
const bool Z_MIN_ENDSTOP_INVERTING = false;

Thanks for the idea but that definitely wasn't it! Setting that to true caused it to drive right into the bed during homing.

To clarify, my issue isn't that it's not homing. It does. The issue is that I'm unable to tune it to get close enough to the bed for the first layer once it starts printing.
Re: Can't tune Z height "endstop hit: z"
October 21, 2015 01:55PM
David J and eried. Thanks for the ideas. They sent me looking in the right direction.

The issue was Z_MIN_POS.

It was set to 0. Had to set it to -1 to allow it to go lower.
I already had min_software_endstops false. I thought that's what would allow it to go below Z_MIN_POS but I guess not.

I'm good to go now though!
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