z-axis only moves a few mm on home

[tokdan]

I've been dealing with problems on this 3d printer for 6 months. Now, the z-axis moves only a few mm on home then stops. I have checked the rods, they are straight, I have checked that the z-axis is level. I have loosed the brass nut screws slightly. Both sides of the z-axis start and stop at the same time.

Frankly, I am out of ideas and tech isn't answering my emails any more. Any suggestions or help would be appreciated.

[jonsag]

In what direction does it move?
If it moves only up, then your down limit switch is faulty, or something in it's connections.
Measure it.

/jon

[tokdan]

The z-axis move correctly(down). It just moves a few mm then stops.

[jonsag]

Does it run fine in up direction?
If it sticks, then something is skewed.
Is the gantry at the same height both left and right?

Can you then run it down again?
It should be able to go down to the same position as when you started.
If not that indicates the down limit switch is blocking it.

/jon

[tokdan]

No it doesn't run fine in up direction. It moves a few mm and stops up or down.

Yes, gantry is the same height left and right.

I have limit switches in transit and will install a new one when I receive them.

[jonsag]

Then I'm guessing something is locking up the movement.

/jon