Z endstops and Z probe questions

Vince

Having read all I can find on the topic Im still left with many questions.
If I have a Z probe do I need a Z endstop? If not needed is one recommended? I see that a Z MAX endstop is recommended but it would take a long time to go the the Z max and back again so I hope to avoid this.
If I fit a Z MIN endstop should this be set to nozzle-bed touch height.

If I dont have any Z endstops how does the Z zero and what is the safest way to ensure the probe is deployed before any probing action.
For a normal print (without z endstops) what is the startup sequence needed when first powered up to print start.

Sorry for so many questions but the penny still has not dropped for me with this.

Thanks
Vince

juulius

 dont know what for printer you have but with the command G32 and G29 it wil go to the probing action. G32 homing + probing and G29 only probing. i use only G32 because i want to home first before probing.

on my printer i have the following 

z-probe trigger signal >>> z-max endstop pin (5volt and digital pin) (could also be any other digital pin)

servo motor  >>> x-max endstop pin (5volt, digital pin and ground) (could also be any other digital pin)

With the probe start script and finished script u can tell the firmware what to run when going into probing. So even before probing actualy happens it wil run the start script first. in my start script i lower the probe first with M340 P0 S500 and when it has done probing, finsished script, i let the probe go up to its original position M340 P0 S0   

because i have the probe on the z-max i can use m119 it wil show the status of al the endstops and that of the z-probe. dont know when you use a other digital pin than that of the endstops that the m119 gcode still works.

what i did before i even started was trigger the z-probe and use m119 to see if the status of the z-probe changed, if not than i new i configured it wrong. also i used the m340 gcode like m340 P0 S50 to see if the servo would move 

hope this helps a bit 

Vince

Juulius
Thanks for reply. I still dont know if you are using a separate Z endstop of some sort or just the z probe (wherever it may be connected).
so a G32 does homing then probing. How is z homed without a dedicated z endstop. If I try a Z home it just goes crashing through the (working) z probe without stopping.

My printer is my own design, large-ish Cartesian using RAMBo 1.3
 

juulius

so you have configured something like this?

Z homing in negative direction direction (towards min endstop). (Z_HOME_DIR)

i think that it has something to do with configuring the z probe also as z-endstop that it doesnt like 

here is my setup, i have a delta bot 

so i have 3 ensdstops for homing 

X axis on x-min

y axis on y-min 

z axis on z-min 

my probe z pin z-max 

Vince

OK so you do have a normal z min endstop.

My new printer is the first one Iv fitted a z probe to and I thought you could get away without a z endstop .I think I read you can but it seems complex.

I understand I can add 'probe start script' to lower the probe but I don't think the probe will drop for a z homing.

Anyway, I thik to get it running I will just fit a z min endstop in the normal way, then experiment with the probe later.