Z-axis moving problem.

Hi, I had a problem in printing G-code file which is generated from skeinforge, the problems is my mendel z-axis seem dont lift-up after finish laying each layer. (I tried put my hand on a threaded rod, in fact it just lift-up very little, not enough space to lay another layer on top.)

I'm not sure is't may be a wrong setting of configuration.h" at Five_GCode_interpreter.

#ifdef MENDEL

// define the XYZ parameters of Mendel

#define X_STEPS_PER_MM 10.047
#define X_STEPS_PER_INCH (X_STEPS_PER_MM*INCHES_TO_MM) // *RO
#define INVERT_X_DIR 0

#define Y_STEPS_PER_MM 10.047
#define Y_STEPS_PER_INCH (Y_STEPS_PER_MM*INCHES_TO_MM) // *RO
#define INVERT_Y_DIR 0

#define Z_STEPS_PER_MM 833.398
#define Z_STEPS_PER_INCH (Z_STEPS_PER_MM*INCHES_TO_MM) // *RO
#define INVERT_Z_DIR 0

here is some my setting for printing

1.) Using Reprpa-Host software
2.) Skeinforge layer thickness(mm) = 0.4 (no raft)
3.) My z-threadrod is 1.25mm pitch and stepper motor 1.8 deg

I've no idea is't a firmware problem or my skeinforge wrong setting cause.

Just added two pic. which is i've printed "x-bar-clamp-m4_4off" the correct object height should be 10~11mm but i got printed out just only 4.43mm.

Edited 1 time(s). Last edit at 07/22/2010 01:24PM by tv7957ht.

First, have a look at the GCode in use, wether the Z axis is actually commanded to lift 0.4 mm for each layer. GCode is pretty easy to read, just use a text editor and look at the numbers following a "Z".

If the numbers are correct, you want to adjust the Z_STEPS_PER_MM value. In full step mode you have 200 steps / 1.25 mm = 160 Z_STEPS_PER_MM. In half step mode, it's double the value, or 320. This doesn't take gearing into account and assumes one turn of the motor == on turn of the rod.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Those are odd numbers. My belts are 5mm pitch so X & Y are 10 steps per millimetre with 8 tooth pulleys.

Z is geared down by 8/21, so with half stepping you have 400 * 21 / (8 * 1.25) = 840. Looks like the figures are for non-metric belt.

I think the most likely reason you are so far out, assuming you don't have micro stepping drives, is that z is trying to step too fast and is skipping.

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Hi, nophead thank you again of your advise, I just keep ""#define Z_STEPS_PER_MM 833.398 "" in configuration.h and i just simply revise a setting Skeinforge Speed Setting ---- "Maximum Z feed rate (mm/s) = 0.5" than my z-axis stepper motor move correctly.

Thanks a lot !!!!