Z Axis: Home is fine, printing too much distance between layers

[Peadey]

Hi everybody,

me and my kids are sort of frustrated after building the printer on christmas together. All seemed perfectely fine until...

..we started the first print.

The problem: the Z-axis goes exactely where should be, when we send to home position. This should be 0, right? So, while printing, the Z-axis starts about 4 mm higher then 0 over the heat bed. And, even worse: every layer seems to have much too much distance to the previous one. So no printing is possible, only long threads of filament hang around...

Is there an "offset" problem? I played around with firmware (i.E. #define Z_HOME_RETRACT_MM 2 -> 5; sended Gcode"M92 Z400"), tried to adjust the home position, but no success, the behavior becomes even worse.

Has anyone an idea how to solve this?

Thank you so much guys for your help. And have a nice christmas time!

Peter

[_kaktus_]

Hello.


Tell us if you have calibrated all axis drives?
It's a long way to build a printer for correct printing.

[Peadey]

Yes everything is calibrated.

Could it be that the Threaded Rods are an older version and doesn't work with the newest firmware?

[_kaktus_]

Hi.


It is possible that the printer had two types of threaded rods.
With metric thread (e.g. M8), and drawbars (e.g. TR8x2).

Depending on this, the printer parameters must be configured accordingly. You will find details in this forum.

[hqueiroga]

Hi. Have you found the cause of the problem? I have the same here... homing is ok, Z points are calibrated properly but it starts printing too high (about 5mm higher than the Z home position) and height between layers seems to be too distant so layers don't glue each other.

[martinyazz]

It does sound like the firmware is setup for the finer screw thread. You may have the better course thread with 4 starts which requires less stepper motor turning. What z axis resolution is set in the eeprom firmware (I assume you are using Repetier host) ?