Confusion over Z axis

Hi, I'm building a Prusa and have a question regarding the Z axis sense.

The instructions (on the Wiki/Prusa_build_Manual) say :-

" place the endstops at the 0 coordinate for each axis ...... Z axis moves downwards until the extruder nozzle is just barely above the bed"

& for sensing the stepper motor :-

" Tell the Z axis to move forward (positive) by 10mm. If it moves UP, write "OK" under Z "

Yet when I run PRONTERFACE and click on 'Home' the Z axis moves up .... I expected it to move down to the limit switch?.

Kevin.

which firmware are you using? I think in marlin you need to invert a 2 of the axis by default. check that

lazzymonk Wrote:
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> which firmware are you using? I think in marlin
> you need to invert a 2 of the axis by default.
> check that

Thanks,
I'm not 100% sure which firmware I have (it came pre-loaded on the board) but it did come with a CD with Marlin on it, so I guess that's what's loaded.

It may be easier to just reverse the Z motors wiring rather than play about with firmware.

It's one of the many options in the config. It's almost impossible to avoid tinkering with the config if you want to setup a machine correctly. And a much better option than messing with wiring if you ask me.

Mystery solved ...... I didn't have the Z axis end stop switch (normally closed) connected, so the 'Home' routine thought the switch was actuated, so it was driving the Z axis up to try and release the (non-existent) switch.

Kevin