ABL - Air Printing Issues...help needed.

[fkirdis]

Hi,

I just finished ABL on my Prusa I3v 10" and everything went really smooth with the setup. I used the latest available Marlin firmware and my printer probes 5 grid points. G28 and G29 command works perfectly except the air printing part .
When i try to incorporate those commands in my start G-Code, it executes them perfectly but does not offset correctly when its time to print my chosen 3D model. Below is my start code.
--------------------------------------------------------------------
G28 ; home all axes
G29 ; Probe Bed
G92 E0 ; zero the extruded length
G1 E10 F300 ; purge nozzle with 10mm of filament
G1 E10 F30 ; purge nozzle with 1mm of filament
G92 E0 ; zero the extruded length again
M190 S40 ; set and wait for bed temp to be reached
--------------------------------------------------------------------


I have below offsets for my probe and I have verified it several times in order to be sure (approx. 5 times ). I've also tried to put the Z-probe offset in my slicer (S3D) with no luck.
Am i missing the obvious (...trivial solution) or what. Because its as long as I have G28/9 in my start code, that should be enough for the compensation?!?

So turn to my fellow reprappers and ask you kindly, WHAT AM I MISSING?

// Offsets to the probe relative to the extruder tip (Hotend - Probe)
// X and Y offsets must be integers
#define X_PROBE_OFFSET_FROM_EXTRUDER -32 // Probe on: -left +right
#define Y_PROBE_OFFSET_FROM_EXTRUDER 0 // Probe on: -front +behind
#define Z_PROBE_OFFSET_FROM_EXTRUDER -2.8 // -below (always!)



/Ferhat

[Roxy]

Marlin is going through a bug fix phase right now. Unfortunately, I think you grabbed the 'development' version from GitHub. This has the air printing bug. This is bad because the problem is severe enough people can't really use the development branch and it is limiting how much it can be used to look for bugs.

My advice is you go get the 'Release' branch from there. The air printing bug will disappear.

[fkirdis]

Ok, thx for the advice! I will try the "Release" branch.

[jasay]

In addition to using release branch, if you have EEPROM turned on, make sure you run a M502 & M500 so that marlin uses offset the values from configuration.h and not from the LCD.

Also, in your start code, the "F" in the G1 commands is feedrate not distance so you will extrude 10mm of filament twice, first fast and then slow.

[Carrot_or_Stick]

Can you provide a link to the "Release" branch, I can only seem to find the "Development" one on git.

Marlin is going through a bug fix phase right now. Unfortunately, I think you grabbed the 'development' version from GitHub. This has the air printing bug. This is bad because the problem is severe enough people can't really use the development branch and it is limiting how much it can be used to look for bugs.

My advice is you go get the 'Release' branch from there. The air printing bug will disappear.

[AbuMaia]

https://github.com/MarlinFirmware/Marlin/releases

[fkirdis]

Thx for all the help, it now works correctly. Roxy I've also incorporated your Enhanced G29 command, much nicer than the original (e.g. no retracting between probing), KUDOS! Now i just need to get my 1st layer to stick on my buildtak (tried changing the offset). When i look at the nozzle, i can clearly see the compensation, its kinda a oscillating alot. Well well i try to level my bed as much as possible with help of the topological map and try again

Thx again!!!!

[fkirdis]

Thx for all the help, it now works correctly. Roxy I've also incorporated your Enhanced G29 command, much nicer than the original (e.g. no retracting between probing), KUDOS! Now i just need to get my 1st layer to stick on my buildtak (tried changing the offset). When i look at the nozzle, i can clearly see the compensation, its kinda a oscillating alot. Well well i try to level my bed as much as possible with help of the topological map and try again

Thx again!!!!

Sure enough it was the buildtak, i guess the usage time was expired... at least in center of the bed (think i will be using PET tape in future). Put some UHU glue on the buildtak, viola amazing results . I think I am in love with the ABL
Thx again for all the help!!!!!

Regards Ferhat!

[Roxy]

Yeah, the Auto Bed Leveling is nice. The first layer almost always goes down nice!

[tugeagon]

Have the bugs been worked out of the firmware with ABL? I had the air-printing issue so I just reverted back to stock. Would really like to get that ABL going.