ABL Servo probe bumps into bed before raising to next location

[adamfilip]

Yes probe is retracted normall

When I run a job, probe is up
Starts to home.. X, Y are done and the carriage moves up Z, and then prob lowers and then Z lowers down until Z endstop is hit,
once Z enstop is engaged the 2nd time, Probe retracts immediately, bumping into the bed, and moving the entire gantry up a few mm,
then ABL sequence starts, goes to first positon, probe lowers again and starts taking measurements.. after the 9 readings.. during the last reading it retract up bumping endstop into the bed, shaking the carriage again vertically
and then it starts printing.

I will take a video to help explain the issue

[adamfilip]

this is my current ABL sequence

https://www.youtube.com/watch?v=V6QG_-9rOzc

[Roxy]

That is some very thick glass on your bed! What firmware are you running? Are you running Bdac's fork of the Marlin tree?

What values do you have for these lines in your Configuration.h file:

#define Z_RAISE_BEFORE_HOMING 9 // (in mm) Raise Z before homing (G28) for Probe Clearance.
#define Z_RAISE_BEFORE_PROBING 9 //How much the extruder will be raised before traveling to the first probing point.
#define Z_RAISE_BETWEEN_PROBINGS 5 //How much the extruder will be raised when traveling from between next probing points

[adamfilip]

yes its 1/4" its nice and flat

#define Z_RAISE_BEFORE_HOMING 10 // (in mm) Raise Z before homing (G28) for Probe Clearance.
// Be sure you have this distance over your Z_MAX_POS in case


#define XY_TRAVEL_SPEED 4000 // X and Y axis travel speed between probes, in mm/min


#define Z_RAISE_BEFORE_PROBING 10 //How much the extruder will be raised before traveling to the first probing point.
#define Z_RAISE_BETWEEN_PROBINGS 10

[Roxy]

What version of the firmware are you running?

[adamfilip]

I dont recall, but i started from a fresh copy. thats about 2 weeks old

[Roxy]

My suggestion would be to grab the Dacb fork of Marlin and use that. You will get the enhanced G29 and that takes care of this issue with the probe hitting the bed during retraction. You should be able to get it here: https://github.com/beckdac/Marlin

His fork is being used by a number of MakerFarm people here. I suspect you will just compile it and it will go. But if it doesn't there are going to be lots of people here that can help you with any issues.

[adamfilip]

this works for the Rambo?
looking at the dates, this seems older

[sniffle]

this works for the Rambo?
looking at the dates, this seems older

It's not 100% up to date, but when it comes to abl things, and is actually further ahead, I used it for a while but i am currerntly using the most recent firmware version

[adamfilip]

Do you know whats "further ahead" about the ABL compared to the regular marlin?