Ord Bot "Tweak"

[Turbo442]

I am curious if the linear rails will overwhelm the X and Y stepper drivers at high speed? I agree they should track much more precisely than the V-grove pulleys.

[Grebbo]

I wonder that myself, I'm used to bigger stepper motors and do not have much experience with the smaller ones commonly used with the 3D printers or belt drives for that matter, saying that, just by moving them by hand "they" feel a LOT smoother then the standard v-grove pulleys so fingers crossed, also I read somewhere that if you use fine machine oil rather than grease for the linear rails that will make them even smoother and "lighter"

[Grebbo]

didn't do much over the weekend, the weather is too hot, but managed to cut a Spool holder arms...

[Grebbo]

I am curious if the linear rails will overwhelm the X and Y stepper drivers at high speed? I agree they should track much more precisely than the V-grove pulleys.

Turbo442 made me think a bit more about the stepper drivers peaking out at higher speeds; I guess it’s a real possibility? The only thing that might save me is the fact that I’m running DRV8825’s as my drivers which according to Pololu website handle more current than the standard A4988’s,,,, time will tell?

[Grebbo]

So, not much to report, it’s been hot here in OZ for the last couple of weeks so it hard to convince yourself to sit in front of a computer rather than have a BBQ and drink beer.
I have managed to tidy up a lot of my wiring, set up the Hall Effect end stops, calibrated the axis etc, so not far to go.
I have test run the axis through the LCD controller and can report that early indications are very positive, X & Y are super smooth and seem to move rapidly without any issues, the Z axis is very nice also and the rotation of ball screws is also very smooth as one would expect (Coincidently, moving the ball screws by hand also feels a lot lighter and soother that the original threaded rod) can’t wait to start printing
I have been learning a lot about how to configure Marlin on Rumba but wish they had a “Wizard” like the one just brought out by Repetier, maybe in the near future..
Have anyone had any success in getting their Z axis motors to run on separate drivers rather than to share one?

[TLHarrell]

If you have enough locations for motor drivers (4 axis controller) it should be simple enough to set up two as slaved together. My CNC machine has a double Y axis that is set up this way.

[Grebbo]

If you have enough locations for motor drivers (4 axis controller) it should be simple enough to set up two as slaved together. My CNC machine has a double Y axis that is set up this way.

Well, so far I just tried a couple of suggestions from other forums on how to get the Z steppers to work on individual drives, but I have had no success, I’m sure I’m just missing something?? I have plenty of redundant drivers as I run RUMBA control that comes with 6 drivers, so in theory it should be possible, what board and firmware are you running TLHarrell ??

[cvoinescu]

In Marlin, all you have to do is wire the second Z motor into the E1 driver, find and uncomment a line in Configuration_adv.h, and rebuild and upload the firmware.

The line you need reads

Code: Select all

//#define Z_DUAL_STEPPER_DRIVERS

and you need to remove the slashes:

Code: Select all

#define Z_DUAL_STEPPER_DRIVERS

That's all! If it doesn't work, let me know and I'll try to help. Other firmwares may have a similar setting, but I'm familiar only with Marlin.

[Grebbo]

In Marlin, all you have to do is wire the second Z motor into the E1 driver, find and uncomment a line in Configuration_adv.h, and rebuild and upload the firmware.

The line you need reads

Code: Select all

//#define Z_DUAL_STEPPER_DRIVERS

and you need to remove the slashes:

Code: Select all

#define Z_DUAL_STEPPER_DRIVERS

That's all! If it doesn't work, let me know and I'll try to help. Other firmwares may have a similar setting, but I'm familiar only with Marlin.

Awesome, thanks for that!!

I will give that a try over the weekend and report back!

[Grebbo]

So I tried changing Configuration_adv.h (line 146) and it comes up with the following error??
strange??

below is the error message:


In file included from /Configuration.h:635,
from /Marlin.h:22,
from BlinkM.cpp:5:
/Configuration_adv.h:165:4: error: #error "You cannot have dual drivers for both Y and Z"

This is what my Configuration_adv.h looks like: (without defining line 146)

Code: Select all

//#define Z_LATE_ENABLE // Enable Z the last moment. Needed if your Z driver overheats.

// A single Z stepper driver is usually used to drive 2 stepper motors.
// Uncomment this define to utilize a separate stepper driver for each Z axis motor.
// Only a few motherboards support this, like RAMPS, which have dual extruder support (the 2nd, often unused, extruder driver is used
// to control the 2nd Z axis stepper motor). The pins are currently only defined for a RAMPS motherboards.
// On a RAMPS (or other 5 driver) motherboard, using this feature will limit you to using 1 extruder.
//#define Z_DUAL_STEPPER_DRIVERS

#ifdef Z_DUAL_STEPPER_DRIVERS
  #undef EXTRUDERS
  #define EXTRUDERS 1
#endif

// Same again but for Y Axis.
//#define Y_DUAL_STEPPER_DRIVERS

// Define if the two Y drives need to rotate in opposite directions
#define INVERT_Y2_VS_Y_DIR true

#ifdef Y_DUAL_STEPPER_DRIVERS
  #undef EXTRUDERS
  #define EXTRUDERS 1
#endif

#ifdef Z_DUAL_STEPPER_DRIVERS && Y_DUAL_STEPPER_DRIVERS
  #error "You cannot have dual drivers for both Y and Z"
#endif

// Enable this for dual x-carriage printers.
// A dual x-carriage design has the advantage that the inactive extruder can be parked which
// prevents hot-end ooze contaminating the print. It also reduces the weight of each x-carriage
// allowing faster printing speeds.
//#define DUAL_X_CARRIAGE
#ifdef DUAL_X_CARRIAGE
// Configuration for second X-carriage
// Note: the first x-carriage is defined as the x-carriage which homes to the minimum endstop;
// the second x-carriage always homes to the maximum endstop.
#define X2_MIN_POS 80     // set minimum to ensure second x-carriage doesn't hit the parked first X-carriage
#define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
#define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
#define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
    // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
    // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
    // without modifying the firmware (through the "M218 T1 X???" command).
    // Remember: you should set the second extruder x-offset to 0 in your slicer.