Prusa i3 Z axis not moving up on some prints?

So I have a prusa i3 rework. I have recently purchased many upgrades such as a new upgraded e3d hotend and support brackets. I also recently replaced the ramps board because of a wire trap issue. Recently I have noticed that on most prints the z axis does not move up. I will print an object and come back later and its just smushing the previous layers. Sometimes not moving up at all. I used the same stepsticks with the same voltage settings. I even re-calibrated the step sticks just to be sure there working. All axis's work perfectly in repetier host. What strange is with some prints the z axis works fine. For example, a test cube will print perfectly. But When I print some-other object like my new bowden extruder it will either not move up at all, or sometimes move up and sometimes not. The only thing I could think of as the problem is the new Ramps board. Also I noticed that every once in a while while manually homing the z axis, it will stall for a second. Also I forgot to mention that a few times the x axis layers slip over to the right. This is very rare but it does happen. Is there a fix for this or a way to tell if it is indeed the Ramps?

Bump

Bump!

I'm having the same issue: Z moves fine for homing, and manually in Pronterface. But some prints it won't move...

It could be a feedrate issue,

When homing or making movements in pronterface, the feedrate used is the one displayed one screen, should be two, one for x,y and one for z in mm/s
When printing the firmware controls the feedrate, if this is set too high, the the motors will buzz / grind and not move.

Open up you firmware file and change the max feedrate, in marlin its #define DEFAULT_MAX_FEEDRATE
Just double check what units are being used, sometimes it can be in mm/min

Here's my config:

//=============================================================================
//============================== Movement Settings ============================
//=============================================================================

#define DEFAULT_AXIS_STEPS_PER_UNIT   { 80, 80, 4000, 100 }

#define DEFAULT_MAX_FEEDRATE          { 200, 200, 1, 25 }

#define DEFAULT_MAX_ACCELERATION      { 1500, 1500, 15, 1000 }

#define DEFAULT_ACCELERATION          500    // X, Y, Z and E acceleration for printing moves
#define DEFAULT_RETRACT_ACCELERATION  3000    // E acceleration for retracts
#define DEFAULT_TRAVEL_ACCELERATION   500    // X, Y, Z acceleration for travel (non printing) moves


#define DEFAULT_XJERK                 20.0
#define DEFAULT_YJERK                 20.0
#define DEFAULT_ZJERK                  0.3
#define DEFAULT_EJERK                  5.0

How low does feedrate need to be? Anything higher than 2 and I get problems.

I turned off the EEPROM because I never plan on using it, and that helped out TREMENDOUSLY!
Turns out, the part I was printing didn't want to be printed. I tried printing another part, and it went smoothly. Now I know I ALSO have a stepper current problem for the Z-axis (unrelated to the above).

The numbers look ok, there is no real ideal for the movement settings, it depend on the setup, how ridged the frame is and how well the machine is put together. Once you find numbers that work keep them, or slowly push them up to find your machine max.

As for the EEPROM, there could have been a setting in there that was overriding what you had set in marlin.

What is your steeper current problem?

The numbers seem to be good for now. My prusa used to nearly shake itself apart before I found out about acceleration.

Yeah, as soon as I disabled EEPROM everything got a little better.

Right now, I have both Z steppers wired in parallel, for ease of troubleshooting. But they aren't getting enough current. I need to find my multimeter and adjust the stepper driver. It could also be the driver itself; I have 2 spares that I'll try if adjustment doesn't work.

Ah, looks like you are all over it

Yep. Printing a part now, looks good so far.

To recap:
Issue- z-axis not moving up for printing. Moves fine manually.
Steps taken:
-disabled EEPROM stuff (Comment out the EEPROM line in Marlin config.h)
-set z-axis feedrate and acceleration slow to begin with
-wire stepper motors in series
-adjust driver to 0.9-1.1 volts. Mine is at 0.99 and making a bit of noise, but working!

Hello I have also a problem with my Prusa I3 Reworked edition printer. Recently I have changed the stepper driver for Z axis( i had the Chineze green one, and now I have changed it to pololulu purple). From the start I had to calibrate all over the axis, The initial value was 4000 (leader-screw calculator value) and after testing and measuring I have determined that 8000 is the good value form me. After I have changed in the firmware, the manual test from Repetier-Host went well, besides homing, The Z axis Homing doesn't work: the motors will buzz / grind and not move.
Is there a fix for this? I have changed homing feedrate, increased by 10, but no effect at all.


Thanks in advice!

Post up your numbers, like I did above (in yellow).

Try lowering your feedrate to 3 or so. Also, lower the acceleration.

Also, dissable the EEPROM stuff (Comment out the EEPROM line in Marlin config.h)

You are the best ! I have lowerd homing feedrate / z axis and works fine !!!!! " #define HOMING_FEEDRATE {50*60, 50*60, 2*60, 0} // set the homing speeds (mm/min) "


Thank You!!

Hello I am again. I have a noter problem also, and you might give me a good idea where to search the problem. I calibrate the bead level by thickness of paper. When I start to print a test cube my nozzle stays in air. I have changed my Z ax home sensor. Until now it was a simple end stop. Recently I have changed it to an opto end-stop, in idea of malfunctioning end-stop switch, but now is the same problem. The opto trigger is a peace of 0.5 mm thin printed wall, that is still no moving or dislocating and miss triggering. The problem might come from the start of the print, first the printer sets home positions, after that z axis is rised by 5 mm. When the print starts Z axis go back to first layer hight. In my case is shown on the display that is 0.4 mm but the nozzle is in mid air.
In your opinion what should I test change to resolve my problem.


Thank You!

I don't know. I don't have opto sensors on my machine, so I can't help you there.

My machine is actually out of order at the moment... one of the Z-axis screws is stripped out.

@ Tornado99.

Are you just using Z max endstop ? if yes then you will need to set the Z length so at Z0 the nozzle just touches the bed.

Hello,

I have endstop at Z min, after the picture shown below.
What do you mean by Z length, I need to tell to the printer that Z axis goes from 0 - 150 mm . That is done? Should I make other changes ?

Thank You! Sorry if I misunderstood you, and talking about something else.