Bed Leveling Issues (X Axis) Help!!

Abraxton

Hello I hope someone can assist me with this issue.. as i've been spending countless hours on trying to figure it out..

(my poor daughter hates the 3d printer now as she see's I'm obsessed with it )

I installed a Hall-o z probe sensor on a Rostock mini in efforts to use the auto leveling feature of Repetier .92

The probe it working as expected.  However when i try to do an auto level via G29 or G32 or G32 S2

the X's Z axis is always lower than the Z axis near Y & Z... in fact the Z access (near Y&Z) seem to be the same height..

its just the X's Z position that is always lower by say 10mm....

so when it goes through its calibration process the the Z height near the X axis starts off at say 5mm and slopes up towards the Y axis to 10mm

then heads towards the Z axis at the same 10mm..

I also already made sure all 3 carriages were at the same height from top to bottom.

Another question i had relates to the Z probe being hooked up to z-min; i noticed that when the z probe triggers it stops the z axis (until it retracts fully) causing the printer head to drag along with the X&Y movements only... is this normal? 

Repetier

Ok, you got me confused with xyz axis and xyz towers. It is really easier to understand if you name the columns abc like in the online configuration tool.

1. Did you calibrate the endstop offsets such that after homing and G131 (only needed when extruder is not in exact center) all colums have the same distance to the bed or what ever lower reference point you can assume perpendicular to columns. Use M99 X0 , M99 Y0, M99 Z0 to position them at a same height (which one is not important) and G132 S2 to compute and store endstop offsets.

2. Run G28 and G32 S2 and you are done. If z-probe height is wrong, your z length might be wrong. So after first tests go slowly down and test if z=0 is where it should be. Important for step 2 is using measurement points as near to columns as possible. This reduces the error.

3. Now you might find that center position is not the same level, which can happen if diagonal length or horizontal radius are wrong. Changing them might require rerunning step 2.

For your last question. Make sure you have in the endstop list no z-min selected. Even if you use it as z probe it has to be set as none in the endstop list. Z-Probe ha sit's own pin setting for it.

Abraxton

Thanks for you help with this..

The last problem i resolved last night (i disabled the z-min under the end stop setting leaving only Z probe enabled) thinking the firmware was trying to use both end stops at the same time and it worked.  and i see your reply indicated that this was correct.

In relation to the 1st problem, i followed your instruction but for some reason the printer still thinks the z height is way off on some areas... If i do a (Adjust Z 0 via printer controls and save) then G28, G131, G132 S1 (see my heat map after this) then a G28, G32 S2 (you can see the printers probing height changes at this point) .. for some reason (even though my bed is level and endstops were properly calibrated ) the leveling seems all off.. 

I also created 2 videos in efforts to further explain the problem which can be downloaded form the below 2 links-

http://gofile.me/2D9EY/kbd1bdl7

http://gofile.me/2D9EY/wWSkX5Rr

X: -80.00 -57.14 -34.29 -11.43 11.43 34.29 57.14 80.00

y:80.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

y:57.14 0.00 0.00 9.92 10.22 10.44 10.71 0.00 0.00

y:34.29 0.00 9.45 9.77 10.06 10.26 10.49 10.64 0.00

y:11.43 0.00 9.36 9.59 10.08 10.17 10.44 10.53 0.00

y:-11.43 0.00 9.32 9.61 9.92 10.13 10.33 10.37 0.00

y:-34.29 0.00 9.34 9.63 9.90 10.15 10.26 10.24 0.00

y:-57.14 0.00 0.00 9.65 9.83 10.10 10.06 0.00 0.00

y:-80.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Abraxton

YES!!!!!!!!!! I finally figured this thing out!

God only known how many days I've been trying to fix this issue.. searching the internet only to come back empty handed!

and all it was...

When you use G29 or G32 you must ensure the carriage (print head, nozzel .. whatever you'd like to call it) is positioned close to the print bed (let say G1 Z5) before you run the leveling commands.  if you run it after a G28 per say (when the carriage is at the top) the bed leveling will be all out of whack.. and you'll be scratching your head for days..

yeah baby!

Repetier

I have to investigate it further. Not sure where I used to start it. I surely start not at the top to speed things up, but that should not make a difference. Since it does for you it must be some error that only occurs for higher starting heights.

I first thought it was your wrong understanding of M131 and M132. For more infos read

http://www.repetier.com/documentation/repetier-firmware/z-probing/

Abraxton

Works great now!

I can finally sleep

as an fyi if you run G29 or G32 from the top, the carriage kicks towards the x axis first (my first probe point) then kicks back..

i think it has something to do with it not being able to reach the edge of the bed (or first probe point) from such a high starting position.  so simply doing a G1 Z5 (first) , then G29 or G32 resolves the problem.

Now if i could just prevent PLA support from  sticking to the damn models id be good.. but something tells me this can't be fixed..

of perhaps its the type of pla filament I'm using.. as on my other 3d printer (Afina) running ABS.. support pops off with almost no effort...  then again,. i just got a new batch of radio shack abs (non afire brand) and the parts get glued to the support with that brand of filament... haven't tried pla on that one yet.

Good thing i have 2 of these printers.. had to reengineer many parts for the rostock mini from scratch.. they even have the fans pointed in the wrong direction , which causes almost back to back clogging.. i repointed them up towards the heat sync ... and run the fan continuously at low speeds and walla! no more cloggs..

Repetier

You can loose support quite easy if you have a vertical gap of around nozzle diameter. Slicers allow setting this gap. Only if objects are curved you can sometimes closer and sometimes farther away so still some parts stick like hell.