Z MAX HOMING - Auto bed leveling

simptek

I have setup auto bed leveling. Per the instructions it recommends homing to Z MAX. I have installed an endstop on top and have enabled it in firmware. When i manually home z through the repetier host software it does the following.

1. it goes up touched the endstop
2. backs off to the distance that i specified
3. then it goes back touches the endstop again
4. then goes all the way down and crashes into the bed --(of course i am not expecting this behavior)--

I think that i am missing a configuration point in the header file but not sure which. Can someone give me clear instructions on getting Z MAX homing to work correctly? I am using the repetier firmware and the repetier host software on a prusa style cartesian printer nothing special.

Repetier

Are you on dev version?
See what

Z_UP_AFTER_HOMEis set to. This is the target z after z homing and if that is set 0 it would go down. If z length is a bit to big that means crashing into the bed. Should be a bit less then z height.

simptek

No. Im not on the dev version. I think i figured out what is going on.

After I home Z it goes to a specified distance to then heat the hotend. Well I have it set to go to 30.

#define HOMING_ORDER HOME_ORDER_ZXYTZ

#define ZHOME_MIN_TEMPERATURE 180

#define ZHOME_HEAT_ALL 1

#define ZHOME_HEAT_HEIGHT 30

For some reason or another it thinks Z=0 is about 50mm under the bed. So in order for me to keep it from wanting to go through the bed I have to set that number really high. Right now I have it set to 60 and its only about 5mm above the bed. So its not a Z MAX Homing situation at all i guess. The printer doesnt know where Z=0 is. After it heats the hotend it homes to Z again then crashes once more because I have the Z_PROBE_BED_DISTANCE set to 10. So I have to set that number high also.

simptek

Should I try the dev version? Because Im struggling to get everything working consistently and repeatable.

Repetier

Yes, dev version is very short before becoming final 1.0 and has better z probing (less errors).

WalkerKD

Where do I find the dev version for download?

Repetier

https://www.repetier.com/firmware/dev/<br/><br/>is the config tool for it. Or on github selecting dev branch.