Nozzle Distance wrong between Homing and Printing

Necro

Hello all together,

i have a little problem an di hope anyone can help me. I have an Anet A8 with the Repetier Firmware 0.92.9. I leveld the Nozzle/Bed only with the screws under the bed. The nozzle is perfectly leveld. When i click Homing, the nozzle also has a perfect distance to the bed. But when i start a print, the nozzle has a distance to the bed, i think 0,3mm. You can see it in the Video. But i don´t know what is the problem. Can anybody help me?

Video

Here is my Start G-Code from Cura Slicer and my Repetier Config

G21 ;metric values G90 ;absolute positioning M82 ;set extruder to absolute mode M107 ;start with the fan off G28 X0 Y0 ;move X/Y to min endstops G28 Z0 ;move Z to min endstops G1 Z15.0 F9000 ;move the platform down 15mm G92 E0 ;zero the extruded length G1 F200 E3 ;extrude 3mm of feed stock G92 E0 ;zero the extruded length again G1 F9000
Configuration.h

Repetier

What is the problem? I guess your first layer height is 0.3mm so where else should the nozzle be. You can not print at z=0 as there would be no space for extrusion.

Necro

Hello,

first i leveled the nozzle with the paper. The paper goes under the nozzle with a little scratching. So i have the right distance, or? Then i start a print. right now the nozzle has a distance from 0,3mm i think. i can´t measure it, because the print is running. So is it possible to lower the distance between nozzle and bed when the print is running?

I click Homing - Distance between nozzle and bed is like with a sheed of paper

I start the print - Distance between nozzle and bed is round about 0,3mm more

Repetier

Sound like it is as supposed to be. As I said printing needs a distance and starts with first layer height. That is as expected.

MartinH

If you enable babystep in firmware then you can fine tune Z while printing 1st layer.

Necro

MartinH,

Thanks a lot. That was it. :)

dtgamer99

Good morning,I have this same exact problem. After I run Manual leveling and start a print, the nozzle is too high for the filament to stick to the bed. This happened after I flashed over to 92.10. Why is this happening? I try to correct this by moving my bed closer (knobs) as I'm printing and when I try Manual leveling again, the nozzle is too close to the bed. If I type G28, G1 x100 y100 z0 and then m84 and level the bed, it will print too high also.I might just go back to starting a print, turning the machine off and moving the nozzle around as I level. Too bad. It really seemed like a great option.I will try the "babysteps". I can pause my print and adjust it that way if needed.

MartinH

what type of Z endstop are you using, if it is mechanical then adjust its position or activating screw so that Z0 is just touching the bed

dtgamer99

I don't know. What if I tell you that when I drop the nozzle down to Z0 I just move the nozzle around and adjust my 3 bed screws? I don't enter any new values in software or anything. But this is what I have been doing when I Manual Level or send commands through Repetier. As soon as I print I have to adjust the bed again as the nozzle is higher than paper thickness. I check to see if I had "bed coat" option but it's not. So I really don't know whats happening. I just turned off my machine prior to printing and adjusted the bed and restarted my print. It's working fine.

Again, no idea why the other options don't work.

Repetier

If you are doing z max homing you can adjust z length in eeprom to get lower. For z min homing make sure

#define ENDSTOP_Z_BACK_ON_HOME 0

Here the endstop defines where Z=0 is (it triggers) so you need to adjust the bed or endstop in that case for better z0.

dtgamer99

I have this set for my machine. Shouldn't my YXZ be 200x200x200 for the bed?

And what should I enter for the Z max back on home? Some thing like Z_MAX_LENGTH 199?

#if DAVINCI==1

#if MODEL==0

#define Y_MAX_LENGTH 217 - ENDSTOP_Y_BACK_ON_HOME

#else

#define Y_MAX_LENGTH 215 - ENDSTOP_Y_BACK_ON_HOME

#endif

#define X_MAX_LENGTH 237 - ENDSTOP_X_BACK_ON_HOME

#define Z_MAX_LENGTH 200 - ENDSTOP_Z_BACK_ON_HOME

#endif

Repetier

Looks like you have 200mm space so z length is 200 - whatever you set z back on home. A bit is required for autoleveling to work correct so 1-2mm should be enough making z length 199-198

Necro

dtgamer99

Sorry for the long delay in responding. Z Length of 198 was the magic number. Everything has fallen into place and I'm very happy.Thanks Support!