Auto Bed Levelling Glitches

[Roxy]

I apologize for creating a new thread about auto levelling...I hesitated in posting several different threads about my quarrels, so I thought it would be best if I started a new thread.

Given how long and how chaotic most of the Auto Bed Leveling threads have become... I suspect everybody is on-board for creating new threads for individual support issues.

I've just finished installing and updating my printer with the auto bed leveling set up, and was wondering if this is normal

On a cold startup, entering G28 homes all my axis's like it normally does (goes to 0,0,0 and then the arm comes down on the servo and gets the z-end-stop)
I then run a G29, which then starts it's first probe at 0,0 like G28 and continues in its grid probe from the 0,0 origin.

However, if I run G28, and then a second G28, once it homes the X,Y it goes to the middle of the bed. Running a G29 after this from the middle of the bed, the gird is much more centred on the bed vs only running g28 once.

My question is, is this to be expected, and obviously, it's wise to run the G28 command twice before G29 so that it begins its probe from the center of the bed?

From what you are saying, my guess is you have safe homing turned on. Can you upload you Configuration.h file? And it would be really helpful to upload a short video of it doing what you asking about.

Secondly, I'm noticing a weird glitch in my servo itself. It seems that whenever the printer is powered, no matter which position the servo is in, it will twitch ever so slightly every few seconds. This becomes even more so when one of the axis' moves (for instance, during the leveling procedure( the servo twitches back and forth about 2 degrees. I thought maybe it was interference or maybe my wires were crossed, but everything appears to be working fine. Any ideas on the cause of that one?

Most likely you can stop this by defining:

#define PROBE_SERVO_DEACTIVATION_DELAY 500