How to recalibrate a Taz Pro

Hi,

I’m still having mayor issues with my Taz Pro.
The last time I tried to print a benchy, I ended up with a fat grey snake and fully PLA encased tool 0.
I had to rebuild the whole tool:
-thermistor and heating element both stuck in heaps of PLA.
-bearing of hobbed axle busted.

After replacing the whole hotend I now have a printer that consitently buries it’s toolhead in the glass surface.
Things like tool offset calibration go perfect, but it keeps attempting to print the first layer somewhere in the glass surface.

Now did find a calibration procedure on OHAI but I can’t get my head around it.
On Prusa it is a very simple procedure where you let the printer do a calibration print and adjust Z according to results.
But TAZ seems to be quite more difficult.

Can someone help me?

I would like to do a full calibration using 0.4mm nozzles if possible. Otherwise I’ll stick to the
standard 0.5mm.

I’m running latest drunken octopus for taz pro with dual extruder

Sounds like you need to adjust your Z offset on the touchscreen. - moves the nozzle closer to the bed and + moves the nozzle away from the bed. So when you start your print or even before you can go to nudge nozzle, and adjust your offset in the + direction. Make sense?

Well, I’ve just updated to the Drunkenoctopus firmware 42.
-Taz Pro
-Dual extruder
everything else is standard.

Menu > Autohome
All axes home correctly.

Menu > Advanced settings > Tool offsets > Measure automatically
Toolhead does touchoff with T0 and T1 on the cube at bed front,
Another touchoff with T0, then T1 is lowered but immediately raised.
Then a third touchoff and now T0 and T1 are all tested.

Then I do
Menu > Autohome
Menu > Advanced settings > Probe Z offset

I place a sheet of 80grams A4 paper on the bed.
T0 crashes into bed, I can see toolhead bending up.

After some adjustment. I get a -0.27mm Z offset.
Anything lower and the paper is stuck to the bed.
-0.27mm is the lowest that I can move the sheet of paper with some friction around,
and I can retract and re-insert the sheet between tool and bed.

Is this correct procedure?
Do I need thicker paper?
Isn’t -0.27mm a very low value if values of -1.10 to -1.25 are quoted ?

How do I create a test print to see is my settings are correct?


After the above, I turned of the printer for several hours.
Then I loaded yellow and black PLA.
I tried printing the vernier from the usb stick that came with the printer.
This failed becaude the nozzles were rubbing the bed…
Z offset was at -0.27 mm… what am I doing wrong?

Also: when doing the M29 V4 calibration, the toolhead touches off left front,
then races to the right, crashes hard several times into the right side end.
then toches off on washers 2 3 and 4.
Is this a bug in the firmware?
(I did home all axes before starting to print

Bump?!

Help?

What am I doing wrong?

When printing even -0.27 z-offset does not render usable results.
I think I even need to go to positive z-offset?! THis can’t be right, can it?