Prusa i3 Z axis doesn't turn

[Leosora]

Hello, I have a problem with my geeetech prisa i3 x, I have connected it to the current and it works, except that the z-axis. I tried to disassemble, lubricate it, reassemble it, loosen screws etc .. Nothing to do. The two motors of the z axis can not turn and make a strange rumor, as if something prevented them from turning. If there is the threaded bar I tried run perfectly, and manually with the threaded bar idem. I do not understand what it has. Please help me.
Thanks

[Mark]

have you checked the driver voltage? usually the Z axis needs more power for it has two motors. you can check this link:
http://www.geeetech.com/forum/viewtopic ... 13&t=17038

[Leosora]

Thanks, i will try tu do it. But i have another problem. I Don't Know how the endstop works

[Mark]

when homing, all the axis will go towards the endstop, trigger it and then stop, if your axis goes in the wrong direction, you need to change it in the firmware:
http://www.geeetech.com/forum/viewtopic ... 13&t=17037

[Leosora]

I Don't understand how i can adjust the power of z axis, and how much power i have to Give at z axis.

[Mark]

there's a trimpot on the A4988, use a screwdriver to turn it clockwise or counter clockwise then you can increase or decrease it, I think 1.0V would be enough.

[Leosora]

How can the smooth rods move easily on the z axis? because in my case the smooth rods moves jerkily when i move them uo and down

[Mark]

how about the diameter of the rods? did somewhere too thick? I think maybe the rods are defective even you lubricate them and didn't work.

[clint3501]

had a similar problem which I fixed. This may or may not help you but here goes.

The issue was the z axis was binding, the side with the X axis stop.

Some of these things you may have checked already so take it for what it is

a) Check that the X axis is level
b) See if you overtighted the X axis belt, if you cranked on it then that may be part of it

If neither of these are this issue, which the above did not help here is what I did

1) Remove Z axis support bracket
2) Removed Z axis rod and checked for it being true (ie no bends)
3) Check Z axis rod for bad threads
4) Check Z axis nut is not burred (check by visual and put it on shaft and run it whole length is you want)
5) Reinstall the Z axis coupling (not hard) just make sure the the flat part of the shaft from the motor and the pin are aligned
6) Reinstall the Z axis nut
7) With the Z axis support bracket off install the Z axis rod and align it so it is plumb when in the Z axis coupling ( I found do it this way fixed the alignment issues)
8) If you want also ream out the Z axis support bracket where the treaded Z axis rod goes through it, I went one size up in a drill size from what the hole as already.
9) Reinstall Z axis support bracket
10) Level the X axis and with a caliper or some other measuring device make sure that the distance between the bottom of the Z axis coupler and the acrylic base the Z motor is on are both the same distance for both sides.
11) using manual control from Repeiter move Z axis up and down
12) Lube the Z axis with breakfree (CLP) or WD40 (small amount at the Z axis nut) - if you choose to.

For me this fixed it. I did not have to fiddle with anything else. There are a lot of interesting solutions to this issue the net however the above is what I did.

[Leosora]

Thanks very much. I have another problem with the y axis. The power of it 1 V, if i put the power at 1.2 V, what does it happen?