Z axis can't goes up or down+Abnormal movement

[Admin]

If you find Z axis can't move after you assemble your printer, you can refer to this.

I suggest you take off the threaded rods, then move Z axis from LCD.
If one motor jams, you can swap two Z-axis motor cable connector on the main board, check whether the problem will change from one motor to another motor.
If two motors jam, I suggest you swap Z-axis driver with a good-working driver.
If two motors can work well, I have some tips for you.
1. Please remove the smooth rods and the thread rods on a table and check if they are bent].
If the rod is not bent,
You can add lubricating oil for the rod

2. Please tighten the screws of the coupling. The correct mount way:

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3. The left Z-axis height should be same as the right Z axis. And you can refer to this post.
http://www.geeetech.com/forum/viewtopi ... 917(thanks

4. Maybe the A4988 of Z-axis has not enough power to drive the motor. And you should increase the voltage of A4988. you can refer to this post.
http://www.geeetech.com/forum/viewtopic ... 7&t=17038

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5. You should loose the Z brass nut a little.

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6. Check this area(Linear Bearing：LMH8LUU)
Please do not tighten the screws too tightly

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7. Check the thread rod type of Z axis
For T8 rod.You can send Gcode"M92 Z400" and then send"M500" to save the setting

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For M8 rod. You can upload the official firmware directly

8.You can use a file to polish this hole in the i3-08 part

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[wthile]

if you losen the "yellow" nut would that not cause Z axis wobble?

[wthile]

I followed these instructions and this worked well. I used synthetic gun lube on the threaded rods and all works well now. I have another problem but I will create another post for that.

[LenFischer]

I had problems with my z axis not moving right after my build. It seemed to be a combination of the threaded rods not moving smoothly, and the motors and shafts not being properly aligned. I solved the first problem by removing the threaded rods, spraying them down with WD-40, and running them through the threaded z-axis nut repeatedly until they moved smoothly. I solved the second problem by raising the couplings for the threaded rods so there is approximately a 1 cm gap between the top of the stepper motors and the bottom of the coupling. This solved it for me.

[RaySkye]

I am having this issue but it appears that the upper brackets (Part i3-08) is pushing the rods out of alignment. How do I go about getting replacements for this part? I have a feeling that the ones I have are slightly off.

I will try the steps in this thread and let you know the outcome.

[William]

I am having this issue but it appears that the upper brackets (Part i3-08) is pushing the rods out of alignment. How do I go about getting replacements for this part? I have a feeling that the ones I have are slightly off.

I will try the steps in this thread and let you know the outcome.

You can contact the technical@geeetech.com
to send you the stl files for I3-08

[RaySkye]

You can contact the technical@geeetech.com
to send you the stl files for I3-08

This solution would not have helped since I was not able to print.

I was able to partially resolve the issue with lubrication though.

I have to be very careful at the start of my prints since the Z axis has a tendency to un-sync and bind. Once it starts it is pretty decent.

Now I just have to figure out how to get the layers to actually stick instead of flaking off. That is an issue for a different topic though.

[RaySkye]

Resolved the issues. Turns out there was a stripped nut on the left brass nut. It caused the rod to bend to the right and out of alignment. I was able to remove the nut (the hole is wrecked) and adjust the remaining bolts so everything is aligned now.

If someone else runs into this problem it might be a good idea for them to start with the alignment and work out from there.

[N_O_O_D_L_E_S]

I am having a similar issue, which has utterly baffled me. When controlling the Z axis from repetier host, it moves around fine, but the second I click the home button it stops and starts making a horrible grinding noise. I have tried lubricating the rods and aligning them again, but as far as I am aware it can't be the hardware as it works fine until it tries to home. Any advice is greatly appreciated. Thanks :]