my x axis will not travel the full length of the bed

Hi all,

I recently built a 3d printer out of an old cnc mill that I had.

I'm using an arduino mega with ramps 1.4 to run it. I use repetier for the host.

my bed is over 900mm long and I have set it that way in repetier.

when I try to move in the x direction it will only travel to 450mm and stops.

this occurs both with a manual move and in gcode. with gcode, the program continues to run but only the y and z axis move.

I use marlin for the code running on the arduino.

it seems to me like repetier is fine with the length of the bed, but there is something in marlin stopping movement past 450mm.

Is there somewhere in marlin where table size is specified? can anyone think of any reason why this is happening?

thanks for all responses.

There is a max x value in marling.
There is also the steps per mm.
If steps per mm is incorrect it might do that.
Have you laid a ruler on the bed and jogged it 10mm to see if it moves exactly 10mm?

oh yeah, it's calibrated.

I'll look for the max x setting. any idea where it is?

thanks.

In configuration.h

---

[scara3dprinter.wordpress.com]

I hate to be a bother but, I've been through configuration.h 6 times.

can anyone give me variable name, or the general location in the file where this parameter is set?

thanks.

// Travel limits after homing (units are in mm) // XXX JBK will need to set these

// @section machine

#define X_MIN_POS 0
#define Y_MIN_POS 0
#define Z_MIN_POS 0
#define X_MAX_POS 200
#define Y_MAX_POS 200
#define Z_MAX_POS 200

How many steps per mm are you using for X?

632 steps/mm in the x axis.

can't try a different value right now, but I will later tonight.

thanks

I had a quick look at the source, it looks like Marlin holds the X position in steps in a signed 32 bit long. Can't see you running into a problem with 632 steps/mm as that is still only 568800 for 900mm which is easily within the signed 32 bit range.

JamesK, your assistance did the trick! everyone else too, but thank you for pointing me to the spot in code.

for some dumb reason, I thought max x was the distance it travelled right after homing.

thanks again.

Glad you've got it working. That's a nice bed size you've got there - all sorts of interesting projects open up!