Z-Axis moving too far

[Kensei]

Hello,

I have a problem with my Prusa I3 Aluminum with the updated lead screw.
The Z-Axis always moves too far in relation to the settings. When I try to print, I home the extruder and calibrate the printer head so that a piece of paper just fits between the head and the bed. Then I start the printing process and suddenly the extruder is about 5 mm away from the bed in z-direction. When I check the z-position, it shows 0.2 mm like it should. The other axis are fine and seem to follow the correct path. After the first layer, the head should move upwards again by 0.2 mm, but instead moves another 5 mm upwards.
I tried this with three different models and always have the same problem.
Therefore, I tried to move the head manually over the prepare menu. I set the interval to 0.1 mm and moved upwards. I got the same result. I lifted the head up by 0.2 mm over the menu and the the motor lifted it up by 5 mm.

So it seems like the printer thinks 0.2 mm is 5 mm. What could be wrong? How can I change this?
One more detail: The main board, which originally came with the printer, did not work (other unrelated problem) and now I am using a replacement unit. Unfortunately, I don't know if the original board functioned correctly.

Thank you very much for your help!

[William]

You have better to replace a new board first, there is a way to calibrate the interval between head and hotbed that means you are able to adjust the endstop position to suit the appropriate interval after you autohome.

[Kensei]

Thank you for your answer! Could you explain a bit more what you mean by calibrating the interval between head and hotbed?
Do you mean changing the turns/mm setting in the firmware. The setting right now is 2540 turns/mm for every axis.
I read somewhere, that the right setting is around 400, is that correct?

[Hodman]

I am having this same issue and have not yet been able to resolve it. Were you able to get it resolved?

[William]

I suggest you upload the firmware of your printer. You can find the firmware for your printer in this web.
http://www.geeetech.com/forum/viewtopic ... 10&t=17046

[Boggy]

I'm also having this problem. I have reflashed the board firmware but no change.

The Z axis is out by a factor of 10. Eg 1 mm of commanded move gives 10mm movement.

Steppers are set at Z=2560
My print starts 3.5 mm away from the bed

[Gingko]

I'm also having this problem. I have reflashed the board firmware but no change.

The Z axis is out by a factor of 10. Eg 1 mm of commanded move gives 10mm movement.

Steppers are set at Z=2560
My print starts 3.5 mm away from the bed

If your screw thread is with trapezoidal thread rather than triangle thread, the step/mm should be changed to 400.
Send G Code "M92 Z400" to set up and then "M500" to save it.

[geodin]

I'm also having this problem. I have reflashed the board firmware but no change.

The Z axis is out by a factor of 10. Eg 1 mm of commanded move gives 10mm movement.

Steppers are set at Z=2560
My print starts 3.5 mm away from the bed

If your screw thread is with trapezoidal thread rather than triangle thread, the step/mm should be changed to 400.
Send G Code "M92 Z400" to set up and then "M500" to save it.

Hi new user with the same problem.
Can you talk me through how to do this step?

If your screw thread is with trapezoidal thread rather than triangle thread, the step/mm should be changed to 400.
Send G Code "M92 Z400" to set up and then "M500" to save it.


Thanks.
geodin

[Gingko]

Hi, Geodin
Firstly, the printer should be connected to slicer software, then in (manual) control box, there is an input box,
you could send GCode through it, first "M92 Z400" then send "M500" to save.

After that you can check through LCD->Control->Stepmm to see if it has been changed successfully.

[Fabian Pucciarelli]

Same problem FIXED:
Check the threaded rod of your printer(Especially I3 PRO X, I3 PRO W, I3 PRO B, I3 PRO C)
If your printer working with T8 threaded rod
You need to send Gcode"M92 Z400" via USB port.(When you upload the firmware finished)
Then you need to send Gcode"M500" to save the setting.