Buzzing Z steppers

Hi All and sorry in advance for what will probably be an idiot noob question.

I'm having an issue with my Z axis steppers buzzing but not moving.

New to the 3d printing game, this was a generic kit from china, got it up and running, a few successful prints before I cracked it at the electronics and replaced them with a RAMPS 1.4 setup running marlin.

Have been tinkering with it on and off for months since, clearing away the various issues, but have simply not been able to figure out how to get the Z axis motors to move.

Some quick troubleshooting:
Tried swapping z axis with x.
The Z steppers worked fine when hooked up as x, both motors rotating normally
The X steppers worked when hooked up as Z, but the movement was much more dramatic, believe this is down to the increased step rate in the firmware.
Checked the wiring of z motors, repeatedly, checked pairing with an led, cannot find an issue there.
Roughly fifty bajillion tweaks to the firmware trying out various bits of advice I've found on the net.

I keep coming back to, if the x stepper works when its plugged into the z axis, and the z steppers both work when plugged into the X axis, why wont the Z steppers work when plugged into the Z axis?

Any advice or even leads on keyword searches I should be performing is much appreciated, I'm still learning terminology and may well just be looking in completely the wrong area for a fix.

Cheers,

And true to form, I'm a massive noob. Issue is solved, apologies to anyone who wasted their time reading above.

For anyone having the same issue, try having a look at your z axis steps per unit. Everywhere I read would have the z axis rate about 5 times higher than the x or y.

After reading what I'd written above about how the x axis would fling itself around when plugged into the Z, I thought I'd try just dropping the steps per unit on the Z down to the same as the X and see if the X axis travel distance was the same when given the same steps per unit, thought maybe something was screwy with the driver. Turned out the travel distance was the same on the x axis. Even more pleasant of a surprise is that when I swapped the two back to normal, the z axis was also now working properly.

I have no idea how this relates to the behaviours I was seeing when swapping axis before... for some reason the x axis can handle the high steps per unit and the z cant, but now I have them all working I can pick up where I'd left off in the calibrations.

Hopefully writing up this mistake might help someone with same issue in the future.

If you have M5 threaded rods for the Z axis drive then your Z steps/mm should be ~4000.

Then what usually causes the problem you describe is the homing speed for Z is set too high in the following line in config.h
#define HOMING_FEEDRATE_Z (4*60)


change that too
#define HOMING_FEEDRATE_Z (2*60)

Thankyou very much obewan. Will give that a go once I get back home.

Wrote up my query late last night after a long tinkering/researching session and I've got a policy with long term projects of always trying to finish on a win, makes coming back to them the next day much easier. When the z motors started rotating that was it for the night.

I don't currently have the motors homing, am just trying to move them using the move axis function, but I think your right. The threaded rods "ratio" (sorry that doesn't sound right to me, but nearest word I can think of is gear ratios) needs the steps per mm to be higher to keep it in line with the travel of the belts. Now its all moving I can start taking calibration measurements, but something like feed rate or max acceleration/travel rather than adjusting the total steps per mm sounds more like the proper fix.