Unexpected output of M114 with ABL ON

lmcbmai

I just discovered that right after homing with G28,  M114 reports X position that is off by 0.19 mm. Y and Z coordinates are correct.
My "Park Position X" in EEPROM is -53.5 while M114 shows -53.69. 

SENDING:M114
ok 0
X:-53.69 Y:343.00 Z:149.301 E:0.0000
ok 0

I tried multiple times and the result was always the same. Then I disabled ABL in EEPROM and the value changed to -53.5, which was what I expected.

SENDING:M114
ok 0
X:-53.50 Y:343.00 Z:149.301 E:0.0000
ok 0

I am running the latest 1.x Dev version of firmware on IDEX printer.

Not sure if this a bug. 

I'd appreciate if somebody runs G28 M114 with and without ABL and shares the results.

Thanks

Repetier

First IDEX and ABL ist not so good. It at least removes the capability to use ditto printing which is only working with physically leveled beds.

In your beginning you mix homing and park position which are 2 different things and positions. Homing happens per motor so it does not move using rotation. Therefore the position reached is then transformed after homing into real coordinates which can differ depending on the bed rotation from what you wanted. So in your case you have minimal x rotation which multiplied with z=149.3 gets 0.19 in addition. With z=0 you would not have noticed a difference.

lmcbmai

I've used ditto printing with ABL on and it worked OK. My 40cm x 40cm bed is not perfectly flat, but not too bad either. 

As for you explanation, it sounds like irregularities of bed along Z coordinate defines X. I thought it is other way around. But that's fine, I decided to finally switch to version 2 and won't be further investigating/testing this issue. 

Thanks.

Repetier

Your bed is very planar so ditto might in deed work. In general you can only adjust Z for one extruder so the second gets what rotation gives. If it is small enough to be nearly planar it works, with bigger rotation it fails.