how to keep steppers enabled during build

Hi all, I just finished building a custom machine and one of the differences between my machine and the standard machines is that the Z axis is not on screws - it is on a rack and pinion system.

The ReplicatorG software that I'm using disables the stepper driver when the Z axis is not being moved, which unfortunately in my case causes the head to unceremoniously crash into the build platform as soon as either X or Y starts moving.

The simple fix for this would be to find a method of setting the stepper driver control code to never disable any stepper driver once the build has started.

Is this a configurable option or are we talking recompiling the code?

Thanks,

DougM

If you're using the reprap firmware, then you should be able to turn this option off in the firmware code file configuration.h.

// Set these to 1 to disable an axis when it's not being used,
// and for the extruder.  Usually only Z is disabled when not in
// use.  You will probably find that disabling the others (i.e.
// powering down the steppers that drive them) when the ends of
// movements are reached causes poor-quality builds.  (Inertia
// causes overshoot if the motors are not left powered up.)

#define DISABLE_X 0
#define DISABLE_Y 0
#define DISABLE_Z 1
#define DISABLE_E 0

Just change the one for z to 0.

Sorry to have to ask but I'm having a devil of a time finding the right source for the firmware

I have a reprap motherboard V1.2
it is running firmware v2.4
So that's the third generation of electronics

So I go to [reprap.org]
and I see the "stable version v1.1" which points to Sourceforge:Home / PIC Firmware / 20060430 which seems kinda old.
But that points me to the most recent stable version - reprap-mendel-20110207.zip which, unfortunately doesn't tell me the version number.
So I downloaded that and looked in the Firmware folder but it doesn't appear to contain anything that looks like motherboard firmware.

anyway, my story goes on like that for a long time.

Could you please point me to the source for the v2.4 firmware? When I google I get lots of hits for the motherboard v2.4 but that's the hardware v2.4, not the software v2.4.

Thanks,

DougM

Ok, I think I found the code. Having some problems compiling, but thank you for your help.

There are problems with the 20110207 firmware files for gen 3. Someone else has documented how to compile it here on the forum. I did this but it still didn't work for me. Try 20100806 instead. If you're on 64-bit system, try 20100719. It's located in the subdirectory mendel\firmware\FiveD..\FiveD..\configuration.h.

Good luck.