Z axis not homing correctly - PLEASE HELP -- [SOLVED]

Quote
gforce1
I have watched your video and i think the speed for non printing moves is to high.
What are your settings in your slicer? Set them at app. 30 mm/ sec if it works you can try raising them step by step.

That is set to 130 mm/sec!!!

Edited 1 time(s). Last edit at 06/14/2016 04:35PM by VDX.

I lowered the setting to 30mm/sec and it helped just a bit. Instead of staircase, I get a cube in 2-3 pieces shifted. Should I lower it further? I tried other slicer (CuraEngine) but it does the same thing.
I have spotted though, that before the printer shifts to new erroneous coordinates during print, it pauses and thinks for a split of a second and THEN shifts over to the wrong coordinates. Could it be tied to communication problem?

Are you printing from sd?
Turn the poti on the stepper (x-axis) a little bit clockwise.
Have you still got the problem with homing the z-axis? If So set the retract while homing to 5 mm instead of 2 mm

in CONFIGURATION_ADV_H

//homing hits the endstop, then retracts by this distance, before it tries to slowly bump again:
#define X_HOME_RETRACT_MM 5
#define Y_HOME_RETRACT_MM 5
#define Z_HOME_RETRACT_MM 2 --> 5

It will hit the endstop fast then goes up for 5 mm en then hits the endstop slow.
2 mm could be to less for resetting (switch it open again) the endstop.

Quote
gforce1
Are you printing from sd?
Turn the poti on the stepper (x-axis) a little bit clockwise.
Have you still got the problem with homing the z-axis? If So set the retract while homing to 5 mm instead of 2 mm

in CONFIGURATION_ADV_H

//homing hits the endstop, then retracts by this distance, before it tries to slowly bump again:
#define X_HOME_RETRACT_MM 5
#define Y_HOME_RETRACT_MM 5
#define Z_HOME_RETRACT_MM 2 --> 5

It will hit the endstop fast then goes up for 5 mm en then hits the endstop slow.
2 mm could be to less for resetting (switch it open again) the endstop.

I am printing with USB cable. Will try with SD card.
Yes, the z homing is still not consistent. I also will set the retract to 5. What I do when trying to print is I tell the printer to home all axes before print and I watch it as it starts the print process. If z home goes crazy, I stop printing and re-home z. If again it starts and homes z wrong, I repeat until z homes right. Its annoying

As far as turning potentiometer, I would love to measure it before doing anything there. I do have a multimeter but I am unsure what and where to measure and what the value should be.

Edited 1 time(s). Last edit at 05/19/2016 08:34AM by 79dusan.

Adjusting stepper current on a Pololu: [reprap.org]

I wanted to get the thing running today, adjusting things from suggestions. Upon turning the printer on - silence. Power supply is busted and its got white goo leaked all over the insides its definitely dead. I wrote to vendor asking for replacement, although I do not expect much support from their side (Or they will indeed send it but at a full price)
Any ideas where to get a replacement power supply in EU?
It was 250W, 12V 20A

Edited 1 time(s). Last edit at 05/20/2016 02:58PM by 79dusan.

Hey guys,

I got some time to go back to the 3d printer and I totally solved all my problems!!! TL;DR Never underestimate endstop-motor wires cross talk!!!!!! Do not bundle them together.

Thanks for everybodys´ help.

First, I thought I could try to unbundle the z endstop wire from z motors wires wrap to see IF AND ONLY the cross talk couldn´t be an issue. All of the sudden, my z axis homes perfectly. Every time.
So I put it to print a test cube and it started off great, but then begun to shift layers again. So I thought and assumed it could have something to do with cross talk at x motor to the x endstop, so during printing, I tried to close the x endstop for a second with my finger. The printer did exactly what it was doing on its own, it thought for a second and shifted layer!!!

Soooooooooooo, I have unbundled all endstop wires from plastic wraps and YES!!! I have my first test cube!!! Looks great. Its only off by a few splits of a millimeter. Happy days...

Edited 3 time(s). Last edit at 06/12/2016 07:09PM by 79dusan.