I have a problem that occurs on very tall prints. I’m not sure if it’s my setup or a general issue, but my coding skills are lame and I can’t work it out, so I’m hoping for some suggestions.
When a print finishes, the Z axis moves about 10 mm away from the part and to a set XY position and motors de-power and all is well.
On startup, the Z moves the bed about 10 mm away from the hotend, presumeably as a safety measure, then it homes XY and Z…
The above is fine if the height of the part is less than Z limit -20 mm but any more than that means the startup routine will crash into the Z limits (I don’t have limit switches on Z so it just crashes).
Does this happen generally or is it my setup that needs a coding tweak? My thought is that the start macro does not need to have any Z safety offset, since safety is built into the end and cancel macros.
Or maybe reduce the safety to a small amount, like 2 mm.
Where and how can I make changes to the startup offset (homing?).
Any other suggestions that will work as a general solution regardless of print height?
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If you don’t want to lift the tool head during your homing routine, then simply change your homing_override. This is entirely up to you to decide.
I personally wouldn’t eliminate it because in the event of an e-stop during the first layer of a print, you could do a lot of damage to the bed on a subsequent home if the nozzle drags. I limit my Z height to 10mm below the physical limit, and lift Z 5mm during homing so I never crash the top of the printer.
That’s largely what I’m trying to do, but I can’t find out how to do it. I can add an override in the config file, but what parameter controls the amount of tool head lift? How would I set the value, like yours, to 5mm. Is there any documentation on the topic?