Z motors dont move up when printing(M8x2mm leadscrews).

[johnz]

I have a geetech Acrylic i3 with the GT2560 board I put the I3X single extruder firmware. Everything works except when i go to print the Z motors don't move up as it is printing they just stay at one layer and don't move UP...pleas any HELP..??? thanks.

[Mark]

is your Z axis homing ok? when you manually control Z axis, will it move as you told?

[johnz]

yes the homing is good everything homes good all motors except the z axis wont move up when printing..??

[johnz]

One of my rods bent so I bought 2 of these will that make a difference??

[Mark]

will it fit the couplers and the holes on the frame? If so, then I think you need to calibrate the steps/mm for the Z axis, check out this guide:
http://reprap.org/wiki/Triffid_Hunter's ... de#Z_steps

[johnz]

Not much of a guide?? Where In the firmware do I find this or how do I adjust it









/
/

[Mark]

You can find the settings in the configuration.h tab of the firmware and adjust it:
#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,2560,93}

Or there is a easy way to do this, you can manually move Z axis up 50mm, and then measure the actual length it moves, compare to these two values and set a proper steps to the Z axis.

[johnz]

ok this is the kind of I have .. M8 x 2 Trapezoidal thread ..im going to do some more search on how to set it up??

[Mark]

The original one for the I3X Z axis is 200*16/1.25=2560, so I think then your new rod would be 200*16/2=1600.

[hexa]

Hello Dudes,
i have these M8x2mm trapezodial leadscrews too!
Like Mark said the calculator says that you have to set your esteps/mm for the z-axis to 1600.
When i enter this value my z axis moves way too far!
I don´t understand why because the math is correct for this when you have a motor with 200 steps and 16 microsteps.

So i figured out that a value of 400 is right for me!
With the esteps set to 400 my z axis moves very accurate !

I also needed to set the current of the stepper driver to a higer value. Before the poti was at 50% now it is at 75%